Dual Cabernet for Bi-amped Electrostatic speakers.

Matt owns a pair of big ER Audio electrostatic speakers which are bi-amped - the bass section is driven by one amp and the mid/treble is driven by another.
Also has a pair of very nice sounding Ripole subs.

I have a similar system with a bi-amped Acoustat 2+2 stat speaker , so I was eager to build Matt a Dual Cabernet preamp with his stats in mind.

The Dual Cabernet has two seperate and independent linestages.

Preamp 1 uses the two back 6SN7 tubes - its a transformer coupled linestage very similar to what I use in the Gen3 preamps.

Preamp 2 uses the front two 6SN7 tubes and the 6N6/6H30 tubes in the middle .

This is different circuit and has extremely low output impedance, in the order of 30 ohms .
It also has very good bandwidth with response from 5hz to 100Khz +- 0.5dB

Both circuits have the Supratek sonic signature , but preamp 2 is a bit more of a beast in its drive capabilities - you could use it to drive 6 power amps and a set of subs.

The two large knobs on front of pre are the master volume and input selector.

The top front right hand is balance.

The top front middle is level control for preamp 2 .

The back middle knob is level control for preamp 1 and is switchable in and out.

So the master volume is used for volume control and the two level controls are used to set the levels for bass (+sub) and the mid/treble amps.

Admittedly , this is a system for a real enthusiast- you need this specialised preamp and multiple sets of amps, but the result is real control of the tonality of the speakers.

The passive crossover used in most speakers sets the level of bass to mid/treble balance , but its set to the designers ideal, not necessarily what will work best in your room, or to your taste.

It's amazing how the smallest adjustment to this balance can really bring a set of speakers alive. It's more than just frequency response, hit that sweet spot and the two seperate drivers seem to merge and really sing.

And of course, we all have different tastes and its nice to be able to get a tad more bass if you like , or even reduce it if necessary.

There is also the advantage that bi-amping brings- more power and control to each driver as it has its own seperate power amp.

Some customers have used the Dual Cabernet to run a solid state amp on the bass and a sweet tube amp on the mid/treble.

The Dual Cabernet is a real enthusiast's preamp, that can bring stunning results. I voiced this one with stats in mind, and was very pleasantly surprised when I hooked it up to my stats- I was using a Dual Cabernet with 10Y DHT tubes and similar Preamp 2 , but the Gen3 linestage is very exciting.

Supratek Power Amp

I haven't built a power amp for some time, the demand for custom preamps remains high and I really think a good preamp provides the most bang for buck.

Of all the power amps I have built over the years, the compact and lovely sounding Malbec EL34 monobloc was one of my favorites.

With same size chassis as the preamp you could have a reasonably compact 4 box system (preamp and power supply and the two monobloc power amps) that looks and sounds a million dollars.

I have a horn system that has a >100dB bass horn and I wanted an amp that was dead quiet without using DC heaters (they radiate a lot of heat with power tubes)

As my preamps all have true balanced outputs I decided to utilise the perfect balance these provide and build a XLR input power amp with balanced inputs.  Balanced inputs means the power amp doesn't need an internal phase splitter and you could say, that despite the driver stage being a little more complex, it is a "purer" system.

Its certainly quite with no noise detected with ears in bass horn.  Measured noise is less than 1mV.

The driver stage is very powerful and consists of a 6SL7 input driver with 6SN7 White Cathode Follower driver stage( for each phase) for the 6N3C, 6L6GC, EL34 or KT66 power tubes.

Bias is automatic, and no adjustment is ever needed.

I wanted this amp to be super reliable and last for ever, and of course to sound very good.

It puts out a very clean 40 watt at very low distortion, and because of its formidable driver stage continues to put out good sounding power with a clean wave form well beyond 40 watts.

It has very big Hammond transformers that have high bandwidth , so good in fact that I decided to use zero feedback in this amp.

A very nice amp , beautiful sounding, powerful enough for just about any situation , very reliable and easy to live with, just plug it in and it will play for years.

Someone heard it and it was sold immediately, but I was so pleased with the way it came out I'm putting it into production.

$US4000 per pair.

BUYING A TUBE PREAMP

So you want to buy a tube preamp? Good move- a tube preamp can be one of the most rewarding upgrades you can make to a stereo system.
Apart from a new set of speakers , a good tube preamp will give you the most audible change to your system.
But like speakers, there are good and not so good preamps , so what should you look for when previewing preamps?

1. TYPE OF TUBE PREAMP

There are many ways to build a tube preamp. It can be very simple with one tube per channel , and even simpler with one double-triode tube for both channels.
And it can be very complex with lots of tubes and balanced operation.

The main advantage of tubes over solid state transistors is that zero feedback can be utilised in a tube preamp, whereas its very difficult , and usually unsuccessful, to build a transistor pre with zero feedback.
Now feedback isn't necessarily a bad thing , but the amount of feedback needed to linearise a transistor preamp is.
The beauty of a tube preamp is it can be kept as simple as possible , and with this simplicity comes a purity of tone , and a more immediate access to the heart and soul of the music.

But you don't want to get too simple. There were (and still are) some really nice simple and elegant tube preamp designs done back in the middle of the last century.
Maybe a pair of triode tubes with a tube rectifier in the power supply and not much more.
Driving a pair of tube power amps with a nice easy 100Kohm  load they can sound quite nice , albeit usually with a "warm, romantic" tone.

Which can be initially beguiling , but any soft flavour can become annoying after the initial amusement wears off.

And there is no way these simple preamps will drive a solid state amplifier accurately .

And you don't want to get too complex. Mega tubed preamplifiers , some with a dozen tubes in them were common at the turn of the century.
They were capable of extra-ordinary technical specifications - response from 0- 500KHz  +,-  0.5dB and output impedance below 100ohm, so they could drive any load.
They were often fully balanced (hence all the tubes  - to do a true balanced tube preamp you must have double the circuit, double the tubes, double the components.)

These super complex preamps were just plain horrible to listen to, not much better than a mediocre solid state preamp.

A good modern tube design will be single ended Class A design with enough tubes and components to do the job and achieve that tube purity we all love.

With a fully balanced preamp, doubling the tube count and doubling the circuitry leads to a kind of double tracking of the sound, there is a smearing and veiling of the sound that robs the tube preamp of its inherent purity of tone.

Yes balanced operation is everywhere now , but there is absolutely no need for it in a home stereo environment . Its sole purpose is to eliminate noise in very long (>100 feet) cable runs.
It comes from the stage world and that is where it belongs.

If you want to hear the best that tube pre-amplification can deliver than preferably no balanced inputs.
You want a pure single ended source into a single ended tube preamp that is designed to do absolutely zero degradation to the signal.

(Balanced outputs is a different story .  Here we can use a centre tapped transformer to elegantly and simply generate a positive and negative phase for each channel, at the output of the single ended circuit.  And a simple switch will convert it harmlessly  to unbalanced or balanced operation.  Its one of the few win-win situations in audio, although my ears still always prefer unbalanced operation. But its handy if you have balanced power amps. )


So our ideal tube preamp will have a single ended circuit, designed to achieve an appropriate amplification of the signal with zero degradation, perhaps a touch of "good" harmonic distortion (or euphonics) with suitable specifications.


2. SPECIFICATIONS

There's four main specifications you need to worry about with a tube preamp.

The first is frequency response.  The limits of human hearing  are 20Hz to 20Khz , at best.
But even though I can only hear sine tones to 12Khz I can "hear" if a preamp rolls off under 20Khz, so obviously we can hear the harmonic overtones , and so a preamp should be able to extend out to beyond 20Khz at least.
If you are going to connect a subwoofer than you want to get down to 10Hz for infrasonic sound that you feel rather than hear.

The second spec and closely related to the first is output impedance.  The lower the output impedance of a preamp the lower input of a power amp it can drive, linearly .
Linearly, means flat frequency response with no deviation from 20Hz to 20Khz .
The ideal ratio is at least 1:10.  So if a preamp has an output impedance of 300 Ohms it will easily drive a power amp with an input impedance of 3000 ohms (3Kohms)

Going back to our example above of a simple triode preamp - it will have an output impedance (Z) of around 6K, so you wouldn't want to use it with a power amp with input Z of less than 50K .

Most solid state power amps are around 10K so the ideal output Z of a tube preamp is <1K.

How to derive that impedance with maximum fidelity is continued below.

The third spec to consider is gain. In theory a preamp is required to supply enough gain for the following power amp to reach maximum output or power.  How much  depends on the sensitivity of the power amp, ie how much voltage it needs to reach its maximum power .
That can vary, but these days power amp sensitivity is usually quite low , sometimes as low as, or less than 1 volt. Really, these are not power amps, but integrated amps.

However, a high gain preamp always sounds better than a low gain preamp, they have a sense of greater dynamic range , and have a bigger soundstage and imaging properties. They are more capable of "magnifying" the sound, with more realism and texture.

But if the following power amp has very high sensitivity there may be a problem with the volume control being used at low levels and there is a possibility of noise issues.

The ideal solution is for the preamp to have adjustable gain , so as to adjust for the ideal synergy between the two units.

(Well actually the ideal solution is to have a high gain preamp and a low gain power amp- the preamp provides voltage and the power amp turns that voltage into current to drive the speakers. )

Lastly, the noise (and hum) of the pre should be inaudible . Tubes are noisier devices than transistors, but good engineering of the power supply will ensure the pre is quieter than any noise you can hear.

Its particularly critical with the phono section,  as the gain will be as high as 10,000 for a moving coil cartridge.  Most manufacturers cant get this much gain with tubes without a lot of noise, so they drop the gain and use a step up transformer for MC cartridges.
It can be done without the step up , but it requires a lot of experience to get the earthing right , and ensure quiet operation. Its difficult but worth it to get the  more dynamic sound of an all active phono stage.


There are other specs to consider, but these are the 4 main important ones, get them right in the context of your system and you cant go wrong.




3. OUTPUT IMPEDANCE

We said that we want an output Z of <1K ohms.  Most preamp tubes have to have some sort of conversion to get a Z under 1K.

There's a number of ways to do that.

The easiest , and most common way is to use a double triode and use one half of the tube as a cathode follower circuit. Technically, it works very well - it needs very few components and gives a low impedance that will drive just about anything.
Trouble is , it uses 100% generative feedback , and it sounds like it.  Its quite veiled sounding and tends to shrink the soundstage.
Very common in Chinese preamps, and low cost preamps , and manufacturers with little tube design experience.

Another way is to use negative feedback, either local or global.  But to get a typical preamp tube's output Z low with feedback, you need a lot of it.  Again the same problems as with cathode follower.

Low plate resistance tubes give low output Z  , and while not many can get much below 1K ohm they can do a good job , with a little or no feedback .

Tubes like E810F ,  D3a,  6E6P,  4P1L  etc in triode mode , or even power tubes like the 2A3, 300B etc can be used as preamp tubes with the appropriate design.

But these tubes can be rare and need some serious engineering to get the best out of them.

The optimal solution to getting low Z with a suitable preamp tube is to use a step down output transformer.

With a tube like the 6SN7 coupled to a suitable output transformer its possible to get a Z of around 600 ohms- perfect for just about any power amp.

And as discussed above we can easily put a centre tap in the transformer and get a true balanced output , which can be switched in and out.  Its elegant , and if its a high quality transformer will give excellent response and phase performance.
Its my preferred method of design, it can use a little feedback or none at all , and has a harmonic overtone that is very accurate, transparent and musical.

4. TUBES

Common preamps tubes are the 12AU7,12AX7, 12AT7, 12AY7, ECC88 ,6922, 6H30, 6SN7 and some rarer NOS tubes.

The most used are the 12AX7,12AU7, 12AT7 tubes. These are cheap, made in a variety of factories are are just about standard in all the low to medium cost preamps.

They were designed to be used in televisions , or as cheap replacements for the older audio only preamp tubes.

They are an inferior audio tube and have no place in a good audio preamplifier.

The 9 pin ECC88, 6922, 6H23, 6H30 have their place in preamp design, but for line-stage use its hard to beat an octal 6SN7 tube transformer coupled to the output.

The Directly Heated Triode (DHT) tubes can be very good , and suit those after a slightly more euphonic sound, but do need some serious engineering to get the best out of them.

5. RECTIFICATION

Rectification is the process of converting the power transformers AC voltage to DC voltage.
It can be done using rectifier tubes or solid state rectifiers.
There's a belief that tube rectifiers have a "warmer" sound but the design of the power supply has more effect on the preamp than using a tube rectifier.
Tube and solid state rectifiers and a hybrid design using both solid state and tubes works quite well.
Tubes have the advantage of a "softer" start than solid state.
The more common tube rectifiers are the 5AR4, GZ34, 5U4G, 5Y3G , 274B, EZ81 and 6CA4.
A common mistake in many preamp designs is to use too much capacitance after the tube rectifier.
Tubes like the 5U4G/274B don't like more than 4uF after them, and I've seen many expensive preamps with far too much capacitance , leading to premature rectifier failure.


6. POWER SUPPLIES

Simply put, bigger is better .  Manufacturers have to choose a fine line between performance and cost,  but the bigger and better engineered a power supply is , the better performance and reliability will result. Its one of the most important factors of preamp design , the faster, cleaner, stronger the power supply is, the better the sound.
Power transformers, chokes , good solid vibrationless cabinets are heavy, and the heavier a preamp, the better indication that it is a quality unit.

Seperate power supplies , connected to the preamp by a umbilical cord, ensure quiet hum free operation , and are essential for phono preamps .

Voltage regulators are a sign of good, knowledgable  design , and give very worthwhile improvements in sound quality.

The king of the regulator is the tube shunt regulator.  This keeps the voltage of the preamp circuit stable and constant, no matter the conditions .


7. OPTIONS

Audiophile capacitors, NOS tubes, "super" volume controls.
When a manufacturer makes a bigger deal out of available options than he does on the actual design of the preamp, be worried.
The design and construction of the preamplifier is far more critical and important than having the option of putting profit driven components in to a preamp.
The quality of the components used is important- paper in oil capacitors do sound different to polypropylene capacitors , but the difference is far less than the difference between a good circuit design and a poor outdated design.
A tired and unimaginative design from 1950 fitted with expensive capacitors will not come close to a modern, innovative design with good quality capacitors.
Similarly ,  you can spend a lot of money on volume controls, but you will never get a "better" sound than from a good quality Alps Blue pot. Different maybe, but certainly not better.
Circuit design and implementation is the beginning and end of quality sound.
Digital volume readouts might look nice, but in a tube preamp?  No thanks.


8. WARRANTY

The warranty given by a manufacturer is a statement of how much confidence they have in the engineering of a preamp.
If the warranty is for a year , then that implies they don't want to take the risk that it might break down after one year.
If a manufacturer gives a lifetime warranty , then the preamp has to be engineered to last a lifetime.
That takes some pretty serious engineering. But it can be done.
I have a couple of sets of Australian Trimax EL 34 power amps that were built in 1956. They've had a few capacitors replaced, but they are performing as good as new.  That is because of the quality of the power transformers, the output transformers and the quality of the original components , and the construction.
As far as I know, Supratek is the only preamp manufacturer that gives a lifetime transferable warranty with its products.  That is enough said.



Supratek Preamp- 6SN7 tubes, output transformer , 600 ohm output Z ,adjustable gain, tube rectifier, tube shunt regulator, 30lbs total weight,

RETAIL or ONLINE

I often get asked why there are no retail "shop" outlets for Supratek products.
Usually from people who want to listen to a product before they buy.

The main reason there are no retail outlets is because the price would almost double.
Retail outlets have a mark up of 50%, often more.
I keep the prices of the Supratek products down to the lowest price I can.
I believe they are the best sounding, and best value preamps you can buy ANYWHERE.

For the level of engineering in them and the quality of design , they compete with products costing many multiples of the prices I charge.
Even if they were sold in retail hi fi shops at double the price I believe they would still be good value, so the big winners are the purchasers who are prepared to buy on the reputation of Supratek .

In all the time I've been building preamps I've only ever had a couple of people who weren't thrilled with the Supratek sound, and that was related to very poor system synergy rather than an actual problem with the preamp's sound quality.

Another reason I'm not so keen on retail shops is that they have to have high turnovers to make a profit, so they tend to have "flavours of the month" which often have more to do with hype than actual sound quality.
These are the products which get released, get a good review, become fashionable for a while and 6 months later are worth less than 50% of what they cost in the shop.

So what are the advantages of buying direct from Supratek?

Firstly you get a lot of preamp for your money.
You get to establish a direct relationship with the builder of the preamp, and the owner of Supratek.
I've known and become friends with many people of the last 20 years, some people are on their 3 or 4th preamp,  or have had upgrades over the years to their original preamp.
These upgrades (and discounts to multiple buyers) are at minimal cost- I've done many upgrades with the owners only paying for freight.

Custom requirements can be easily met - I'll look at any request and if it makes sense and doesn't compromise sound quality I'm always happy to give the customer exactly what he wants.

The Supratek lifetime transferable warranty is real.

I wouldn't be doing this if I wasn't absolutely sure of the quality of the engineering and design of the Suprateks.
They are so well built and rugged that I know if something does go wrong it will be a minor job to fix it .
I regularly see 20 year old preamps that are performing as well as the day they were first turned on.
The 2 year "conditional" warranty you get from a hi fi shop simply doesn't compare.

As to being able to listen to a preamp before purchase, I am able to offer a 3 day listening period . If a Supratek doesn't fit into your system for whatever reason,  it can be returned after the 3 days.
However as I'm a mostly build to order manufacturer , with low profit margins , there are a few conditions.
Freight is paid both ways by purchaser and refund is sent when preamp is resold.

However the likelihood of this happening is extremely low, 99% of Supratek owners are very happy owners of the finest tube preamplifiers in the world.

Wiring.

Well I've tried to let this go for years, but I guess it's time to address it.

In the past, my preamps received criticism about the internal wiring.

In my opinion it came after my preamps were compared to other manufacturers product and were heard to be clearly superior.

The only recourse these manufacturers , and some miffed owners of other gear ( I guess it's not so much fun when your $25,000 pre gets blown away by something a tenth of the price) was to criticise the internal wiring of the Suprateks, which to be truthful did look a bit messy.

But there was a good reason for this :  I built maybe a hundred prototypes before I decided to go into the audio manufacturing world , they were all point to point wiring, where every component is connected to another either by wiring it to a terminal or using it's own wire leadout. They are wrapped around the connecting terminal and then soldered.

In theory , the pre would work with no soldering at all, just the hard wired connection between each connection.

But all the commercial audio products used printed circuit boards (PCB's) so  I had one designed and made for the first commercial Supratek linestage.

Very quick and easy to build but it didn't sound like a Supratek .

So I asked the PCB designer to do it again, with a different earth configuration , as I hoped that was the problem.

Still not nearly as good as the hard wired prototype. It was ok, but just not as dimensional and open as the hard-wired preamp. It sounded boring.

So I then tried a compromise between a PCB and hard-wiring with small stereo boards containing the electronics components and the signal and output wiring all hard-wired.

This was better but the magic was still not there- it was 90% , but that last 10% was what made the magic happen, and the prototype was still audibly superior.

I then got the idea in my head that it was the fact that all the connections in a PCB are connected by a small round dob of lead (Pb) rather than a direct wire wrap.

 I decided then that I did not want anything to do with PCB's and would just have to hardwire the preamps and power amps.

And I'm not alone in that- there are plenty of manufacturers who hard wire , so I set out to rewire the preamp the way everyone else did it, with a grid of bundled wires folded into straight lines and right angle turns with lots of cable ties.

As an aside , back in the 1930/40's there was a clash between audio guys who wired "spaghetti" style and "new york street" style ( everything at right angles), so this is nothing new.

But this was still missing the magic - I dont know if its the small capacitances between the bundled wires, the considerably longer lengths , but the advantages of spaghetti wiring were certainly audible to my ears.

I keep coming back to talking about dimensionality , the 3D effect you get with good audio.

With PCB's it's diminished drastically, with bundled right angled wiring , much less so, but its still diminished .

I knew that spaghetti wiring is generally frowned upon, it does look messy and gets viewed as unprofessional, but I and others were clearly hearing that "spaghetti" was audibly superior.

To me its all about the sound quality, nothing more, nothing less.

I decided to do it my way, and a a result of that , my preamps got some pretty good reviews and I made a lot of people happy with their purchase of a Supratek.

That's when the criticism of the wiring started, and I could see it was going to be an issue that could polarise the situation.

Lets be clear- I could have made a lot more profit, and built many more preamps if I had used PCB's or bundled wiring.

It definitely affected some sales as the criticism did get through to some potential buyers .

But I like to think I stick to my ideals and I was, and still am 100% committed to getting the highest sound quality out of the preamps.

Point to point wiring may look a bit less "anal" but it actually provides the most direct route for a signal to travel. Unencumbered by length or the need to be on the same plane and direction.

I admire good engineering , and the Suprateks are a  fine example of it, massive power supplies, expensive chassis and most important of all, a state of the art design that's focused on one thing only - the finest sound quality that can be got from a tube.

The $2000 Chardonnay linestage preamp has its own separate power supply, tube recification, tube shunt regulation  (this is a big deal), a highly evolved circuit that will drive any power amp and  exquisite looks to boot.

There is nothing comparable to it at this price, and yes it is completely handmade with internal wiring that would still attract criticism from the anal audiophiles that seem to care more about this than how it sounds.

The other issue is reliability. PCB's have all the resistors , sockets and other heat generating parts all stacked on the same plane and in close proximity to each other - PCB's get hot and heat is the number one enemy of reliability.

All of the "spaghetti" wired Suprateks are still going strong , some are nearly 20 years old, and some are on original tubes.

And if something does go wrong it's a hell of a lot easier to fix than having to remove a PCB or unbundle a heap of wires.

Having said all this, over the years I have changed the wiring - lots of built preamps, and the experience that comes with it has resulted in minimising the wiring , getting the lengths between components even shorter and more direct.

I know there will be still be some who think it "untidy" - sorry but your ideals about what is important about audio are different to mine.

Below is a pix of the inside of a phono/linestage  preamp.  It has 6 tubes and 8 transformers which are positioned in place with a heat resistant adhesive.   Notice how close to each other the components are, there's a direct solid connection between each part that forms a flow of the circuit with minimal disruption and maximum effect.

The signal and output wiring is still to go in, but its all as direct and short as possible .

I know this wont be the end of the criticism, some audiophiles are focused on what they've been told and nothing can be done about that.

I'll continue to do it my way, which I believe delivers the finest sound and reliability.

                      Chardonnay Line Stage  , comes with matching power supply $US2000

www.supratek.com.au

More questions...

I received an email with questions about a Cortese phono preamp.
Quite interesting questions so i thought I would make a blog with the answers.

 I have a good idea when I hear things if i like them or not. But I’m in no way an engineer and while I can tell you I like silk domes much more than metal domes or that I like the timbre and space tubes can add. That some of the things I appreciate are saturated timbres and dynamics  vividness and an alive  quality some refer to as musical. I like to hear space but I’m not overly concerned w the size of the soundstage and image specificity   I don’t like a bright etched or grainy top end or tipped up highs masquerading as details. 

Sounds exactly like a Supratek preamp, but you do get a big soundstage, much appreciated with the right speakers.

Dynamics are the big thing with The Suprateks- the high gain is there for a reason- it results in BIG dynamics with the added realism that brings. The gain control at rear end of circuit can bring gain down to suit any power amp/speaker , but doesn't affect the dynamic nature too much. 

  So I have a Kiseki Purple Heart I will keep I like a lot its .48 mV. So I think would be ok w your lcr at 70db my pre has only 10 dB gain I think and pass power amp may be 25dB.

0.48mV is getting up there for a MC cartridge, but the LCR (and the standard Cortese) has a very high overload tolerance. Its capable of much higher inputs, with a very clean  output, up to 20V which , while low distortion,  is very high,  so I like to recommend no higher than 0.5mV. I think you'll find that you like the really low output cartridges  a lot more with a Cortese. 

Dont forget you can adjust linestage gain .

 I got a new table a thorens 124 I had rebuilt and got an arm for it ordered another so I will run one mono cart the Miyajima zero   I had asked you about  because it is per the designer developed specifically for step up transformer as opposed to active gain. Now I understand that not all engineers/ designers agree so I was planning to ask a few people I know what they thought about this. I do see the importer is selling a current phono pre now so I was under the impression this IS ACTIVE so he must feel it ok. 

Well I've made it pretty plain that I dont like step up devices, even the really expensive ones cant relay the dynamics of an active device. 

Most manufacturers go to step up devices because they cant get an all active MC phono stage quiet. It is a big task as with so much gain , the noise floor can become audible.  It took me years to figure out how to do it, with stereo ground lines, layout and power supply design all contributing.

I've been told the LCR Cortese is quieter than the $30,000 phono M.Fremer uses with a step up. 

  In addition I had bought a cheap Denon DL103 to play around w till I have the carts. For the stereo cart I was thinking to go w an Ortofon SPU a Miyajima stereo or a Koetsu rosewood. Still not decided. 

Ive got a lot of experience with the Denon, the SPU and the Koetsu. All are fantastic, I get the 103 rebuilt by Expert Stylus in London, who put a special cantilever and diamond in it, worth every penny. 

The SPU is the most musical, engaging cart you will hear, a little warm perhaps, but again Expert Stylus revamped it , and its my favorite cartridge.

The Koetsu's are always special.

  Too the best of my knowledge have never heard an lcr phono just that they sound really great. So I believe most I’m familiar w would be cr type. Is there anything you can tell me that could be thought of as generalized differences ?or typical sound traits / characteristics of the lcr type? 

Kind of like the difference between the Expert 103 and the Expert SPU- both are very good, but the SPU is just more engaging, fun and exciting to listen to. 

Essentially the signal is straight through on a LCR, while with the CR it goes through a couple of capacitors. Thats quite simplified explanation, there's more to it than that, but that's how it sounds.  

  Also could I get it w 2 inputs? 

Yes

And would it be possible to switch the loading from the front / top/ side so I can switch between carts w out move the unit?

No, but the switch is at extreme back side and really easy to access. Its a slide switch that goes from top to bottom. 

When you dealing with a voltage that is 5 ten thousandths of a volt (0.0005V) you dont want too much wiring , switches etc. 

  And I think I read balanced is available as a cost extra? Is there a benefit in terms of noise resistance?  It would not be a balanced circuit just allow balanced cables?  

RCA and XLR balanced are standard. But there is absolutely no advantage in using balanced cables if the following power amp isn't fully balanced, better to use a good set of RCA cables with the RCA output.

Yes if the following power amp is fully balanced there is a noise reduction, but the Suprateks are already so quiet you wont hear any difference. 

  One last thing. The information available is slim.

True, I need to put more info on web site- I will do that. 

 Not many reviews but they are usually b s anyway. I do think Srajan from 6 moons is great and conveys what I think of as very accurately the sound of a product ( from the few reviews of his I’ve read AND know the product) I have found a few things on forums  people who claim to be owners have for the most part great things to say.

Thats what I rely on, I'm too small a company and not enough profit to advertise and get reviews , and as you say, they dont mean that much. 

I tend to sell to people who are on the end of their audio journey, they've been through the bullshit and know what they want, and recognise it in the Suprateks. 

Unfortunately, for me, they are very happy and dont spend much time on forums listening to the baying of the hounds. 

 I do want to ask you about I have read a few complaints about the wiring scheme and the way the caps are secured or not secured. I only read this and saw a few photos. Is there a reason that it appears to have no organization?

Many years ago, a  few manufacturers didn't like that in a comparism, my preamps were obviously superior to theirs, their only comeback was to incessantly carry on about my wiring , which is all point to point , hardwired and soldered. 

It is true that the first preamps, 20 years ago, were a bit messy, but they sounded so different to PCB boards, I couldn't bring myself to go down the (cheaper) road.

The preamps I build today are much neater , but they are still point to point. 

Here's a reply I made to one of the internet "gurus" who posts pix from many  years ago.

"

The wiring I do these days is maybe a lot neater , but what makes people think PCB boards are superior to hard wiring.
PCB's are used to simplify construction and because they are great for economics. 

It takes me a week to build a LCR preamp. If I used PCB's, which isn't hard to do , it would take a day.
Why dont I use PCB's then? Because they sound like plastic, they sound like they look, one dimensional and boring. 

There are many hundreds of hardwired joints in my pres, everyone making solid contact, before its soldered.  With a PCB the lead solder is making all the contacts.
The other isssue is reliabilty, the 20 year old preamp with the "messy" wiring is still going strong, with only one change of tubes , no reliability issues at all, unlike some other manufacturers I could name. 

The Suprateks aren't a 1950's tube design tarted up with "options" .
They are state of the art tube designs which will drive any or multiple power amps. They have power supplies which would drive a big tube power amp, with tube rectification, and tube shunt regulation, which makes for a big sound that is as quiet as a tube pre can be.

They have a signature sound which is unlike any other tube preamp, and if you like 3D imaging and realism, which a lot of people seem to do, then thinking outside the box and looking past conventional  constraints (PCB, 1950 design, soft power supplies)  might be very rewarding.

 Do you have many units returning for repairs. As I live in the states it would be long and expensive to ship.  

There are many Suprateks 10-20 years old still running on the original tubes, they are very reliable, I get a few back , but mostly for upgrades. Point to point is also very easy to work on, dissipates heat better than any PCB can do. 

I make a big deal out of reliability, there is no preamp more over-engineered than the Suprateks. 

  One more thing if I was to go w a phono and was happy could a line stage be added later ?

Yes, but the Cortese is a complete preamp that is designed for phono and linestage to be optimum package , and its incredible value.


 And would the high gain be too much for my system. My speakers are Devore 0’96 @96dB phono(current) 50-70dB pre(current)10dB amp 25 dB . 

No one of my systems is a full horn 4 way system of 110dB - its perfect with Cortese.

More on Gen3 Cortese Preamp.

I've had a few people ask me for more detail on Gen3 , what's it about , and is it a big deal?

For the first time in years my backlog of orders has diminished and I can deliver an order within 1-2 weeks - very quiet at the moment.

On a positive note this has given me some time to do some listening and I've enjoyed pulling out some of my older preamp designs and listening to them and comparing them with the latest 2018/19 design.

I've also done some service work on some very old Supratek preamps, going back to the start of the century.

This usually consists of undoing well intentioned, but uninformed modifications - the internet forums are the bane of audio manufacturers with so many gurus making nonsense claims of huge improvements in sound quality with their recommended "upgrades" .

Despite a long production lifetime of over 20 years all of the Supratek preamps have a recognisable "signature" sound , which is not surprising as they all are two stage triodes , with tube shunt regulation , massive power supplies and completely handbuilt.

The older preamps were mostly pure tube based , whereas the newer preamps from the second decade of this century had some solid state "transistor" componentry, mostly in the form of constant current sources.

The later were arguably more accurate , although the difference was minor and almost inaudible.

Specifications were slightly better with lower output impedance, although again whether that was subjectively better is debatable.

For quite a few years the Supratek preamps used Directly Heated Triodes (DHT) firstly with the 300B, then the 300B/45 followed by the 101D and finally the 4P1L.

DHT tubes are definitely more "tubey" sounding, they are warmer and this can often appeal to audiophiles, although one thing they almost universally dislike is the tube microphonics that come with DHT tubes.  (I dont think a little microphonics is a bad thing btw)

I still make the 300B/45 DHT preamp on order - these tubes have minimal microphonics - its there but constrained and these preamps do have a "magical" quality -it's tube euphonics but still very accurate and engaging.

But in my experience the king of preamp tubes is the 6SN7 tube, and I'm still in awe of it as much as I was 30 years ago. I have used hundreds of other tubes for line-stage circuits and no other tube has the balance of sound capability and technical performance.

It does require good circuitry to get the best from it , and it is possible to get absolute perfect specifications from it.

Which I have done , the later Supratek 6SN7 designs were near perfect in terms of frequency response and drive capability (low output impedance)

But a preamp must be more than perfect technically, it must provide the ideal interface between source and power amps , and create a sound that is realistic and musical.

I believe the difference between a good preamp and the hundreds of ordinary preamps is the magnitude of dimensionality between them- quite simply the better the preamp the bigger the 3D effect. The sound recreation is just deeper/wider, more open , more exciting . Its more "real".

(Strangely, in my experience , not everyone can hear differences of dimensionality, or its not important to them,  some people rate bass slam and frequency extension over realism- these are the people who dont hear the effect of a good phase coherent preamp and think a passive , or no preamp is all you need.)

So where are we at with Supratek preamp design?

The first thing I do when I finish a preamp is connect it to an oscilloscope and run a 1Khz square wave through it. On the scope a 1Khz square wave will , if the preamp has perfect response and can easily drive the load, be a perfectly straight upended rectangle , which indicates flat response from 20Hz to 20KHz. Its the most basic requirement for a preamp.

All the Supratek preamps over the last 20 years have been able to easily pass the square wave test, but it doesn't mean that a perfect square wave is the defining characteristic of sound quality.

I've been saying for years that phase coherence is the key to dimensionality , and this is what enables one to hear the difference between two preamps that have the same square wave character.

Gen3 is the result of going over all of the Supratek designs and re-designing for maximum phase coherence.  Not so much a re-design but more of a refining process, the circuit is changed but essentially it's still a two stage 6SN7 design that is transformer coupled .

How big a difference?

Well if you hear in 3D , and have speakers that image well , you will like it, and might even find it a very big deal.

The line-stage is quieter , gain is still highish-for dynamics , but a switchable gain control is supplied if gain needs to be reduced to suit high gain power amps.

The whole rationale for Supratek over the last 20+ years was to design the most realistic sounding preamp, nothing more/nothing less.

I've built over 500 preamps and countless prototypes investigating all sorts of concepts and approaches.

I seriously doubt that there is a preamp concept that I haven't tried.

Gen3 is the pinnacle of all my work , and in my opinion is as good as a preamp can be.

It's a pure tube based design , with minimal solid state components , and  I've made just as much effort to ensure very long term reliability and lifetime as I have towards sound quality.

I've named it Gen3 as I believe it is the third and final stage of Suprateks evolution .

I'm not sure where high end audio will go in the next decade - it is under pressure from all sorts of influences.

I'm grateful that I had the opportunity to do something that I had a great deal of satisfaction doing, and I hope I can continue to bring the engagement and enjoyment of owning a Supratek preamp to people who love music.

Next blog  a more detailed explanation of the design for linestage and phono preamps.

Customers response to owning a Supratek preamp.

Over the years I've received very many positive comments about the Supratek preamps, here's just a few comments from 2018/19.

Supratek preamps are available at short notice now, email me for details on how you can own a preamp that will completely transform your system.

Michael,

The preamp is everything I hoped for and more. The sound is engaging and very musical. I am happy that I had you build the Cortese LCR preamp for me.

Looks good. Sounds great. Truly amazing.

Hi Mick

Absolutely fantastic pre that will only improve with time and better tubes. 

My Cortese has never sounded so good - dead quiet background and magic sound in my system

Thanks for the info. I have many good 6922 tubes. Will try. May try the 6h30 also. You should know that the preamp is now in place of $70,000 of preamp plus 5 k of cables!  I think I prefer it already and it’s not yet settled in. Sure is nice to have one component. I’ve always used separates. I will update you as things progress. 

Mick - It is going well.  It has gotten more refined and the sound is cleaner and more detailed, but still has good weight.  I am really enjoying it, and have not yet tried my other preamp.  I will wait until it has been a couple of months to insure complete break in.  In my expereince it takes a lot longer than people think to really get a component to optimal performance.  Also, I am preferring the ypsilon phono stage at this point, but am alternating since I have two arms, with one in the cortese phono and one through the ypsilon into the line stage.  the cortese is still breaking in, so I will wait a while before I know for sure.  The cortese phono section is quieter than the ypsilon phono.  Thanks for checking in!

I borrowed a pair of NOS WE 300B from a friend and put in the Preamp.  To cut the story, this combination sounds really georgous.  That is the sound exactly what I am looking for.  Thanks for the great creation.

I can tell you that I don’t think there is any way I could get better sound from any other pre. I have had so many ‘high end’ components over the years but no singular component gives me as much joy as the Supratek LCR Cortese. The combination with my Michell turntable and Soundsmith Paua MkII cartridge is superb. My biggest problem is trying to stop a listening session once I start.

The phono sounds astonishing

Over the years I have changed a lot of my gear but, your preamp is a  permanent fixture in my setup. I love the way it sounds and looks!

ATTN: Mick Maloney

Greetings from the USA!

I  picked up a vintage Chardonnay off eBay this week, SN 207, dated August 2003. I couldn't resist as it ticked all of the important design boxes for me:

(a) 6SN7 driver (my favorite preamp tube)

(b) tube rectification

(c) PS shunt regulation

Just listened to it this evening... what a wonderful musical experience! 

Generation 3 Supratek Preamp.

The Supratek preamplifiers have always been tube based high gain preamplifiers built around a two stage triode design, and transformer coupled outputs.

The basic design has remained the same for 25 years, although there has been some small, some big changes in how I've utilised componetry and technological advances as they've become available.
I've always strived for the designs to be state-of-the-art technically , but always mindful that this does not necessarily result in the finest sound.

The purpose of a preamplifier is to invoke realism. A preamplifier must be technically excellent in terms of frequency response, able to drive any power amp, buts it's most important task is to have you believe you a listening to the closest recreation of a performance.

The strongest attribute of the Suprateks are their phase performance which leads to very precise and realistic 3D imaging- this is what provides musical realism.

I'm often told of the almost magical transformation of the sound of Magico speakers when used with a Supratek.
It would seem the Magicos really need a phase coherent preamplifier to get the best out of them, to get them to become multi dimensional and fill a room with music.


I've recently reviewed all of my designs going back many years and after building many prototypes I've made some changes to the basic design which I am very happy with.

3D imaging is even better with even more distinct separation , wider width and deeper depth.

I've also managed to get noise levels to the lowest levels possible with a tube preamplifier.

This helps with the already outstanding dynamics , especially the micro-dynamic performance.

Gain had been decreased by a small amount, but is still fully adjustable.

I like these benefits so much I'm calling the latest range of Suprateks Generation 3 .

For a short while I'm offering a Gen3 Cortese , with moving coil phono stage for $US3000- incredible value when it competes directly against a famous $30,000 phono only stage.

(Yes one of my customers has both and is very happy with the Cortese.)

Class D is affordable and sounds as good or better the SS/Valve why buy anything else

Class D is affordable and sounds as good or better then SS/Valve why buy anything else.

This is the heading of a post on the Audiogon forum.
I dont normally spend any time on forums , but I advertise there and get feeds on my email, so ended up clicking on this one.

It ended up going the way of most posts- one-up-manship, guru pontification and commercial influences. No way I was getting involved in that one!

But I can make my observations here and it seems to me the poster is listening with his ears and not his heart. 

Yes ClassD can sound pretty good in an initial listening session, and if your into frequency response, power and slam they do a pretty good job. 

Long term I've never been able to settle into a Class D amp, I have a couple of Hypex in storage somewhere , and while I haven't listened to any of the newest models the basic operating principles of Class D remain the same- that damn low pass filter on the output. 

Sure it gets rid of the grunge , but it also introduces phase problems , which screw up imaging and soundstaging , all the 3D stuff that helps to recreate realism.

Its weird to me, but there's a big pile of audiophiles that don't hear in 3D , or they dont think its important.

To them its all about frequency response, power and slam. Or detail- lots of it. 

Which is fine, audio is subjective and whatever turns you on is right for you. 

From my perspective however, this is a way of listening that is less subjective and more objective , more listening with the ears and not with the heart.

Let me post this page from a book I'm reading at the moment- Greg Milner's 
Perfecting Sound Forever, An Aural History of Recorded Music. (you can click on page to enlarge)

Its more about digital V analog than ClassD but it makes the same point, albeit in a rather oversimplified way.  That the newest, greatest technology isn't. 

Another great quote from the book- "digital perfects approximation , analog approximates perfection". 

You cant tell people that imaging and soundstaging are more significant to realism than frequency response and power , and I suspect these people dont want to listen to realism anyway- they want to listen to what they think is important in hi fi - slam/power/detail or whatever turns them on.

Fortunately there's just as many audiophiles who value a more holistic, ethereal way of listening that is focused on realism. 

And these audiophiles value equipment that delivers , whether its tubes or solid state , maybe even class D one day, or an evolved version of it that can actually do 3D sounds. 

I'm convinced that the closest way to realism is to have at least one piece of tube/valve equipment in your system, and the best method is to use a high quality ,accurate (not warm!) tube preamp. 

I know from my experience the only way I could tolerate ClassD was with a tube preamp , but I'm not holding my breath waiting for the Class D guys to agree!