A very long time ago I found a pair of Altec-Lansing 604B coxial speakers in a big cabinets on the side of the road.
Turns out they were from the Australian Broadcasting Commission radio station, and in the back of each cabinet was an industrial looking tube amp.
This was back in the day when tube amps were being phased out, solid state was becoming dominant and tubes hadn't had the renaissance they enjoyed a decade later.
But you could still buy replacement tubes in the local electrical shop and I'd heard old guys tales that these old fashioned tube amps actually sounded pretty good.
A new 5Y4G rectifier got it going again , and goddam the 604B and amps sure sounded different to the English amps and speakers we were listening to back then.
The tube amp was an Australian made Trimax A52 , a push pull EL34 design with a 6AU6 input tube and 12AT7 driver.
These were built on commission to the ABC , Trimax was mostly a transformer winding company , who had a very clever and enterprising design dept.
They produced quite a varied range of professional gear for the ABC, including some interesting preamps and mixers.
The A52 was loosely based on the Mullard 5-20 EL34 amp. It put about nearly 30 watts with only a minimal amount of feedback, achievable because of the very high quality of the output transformers.
Its a very elegant design, straight out of the Golden Era of tube design. A fantastic output transformer, that would take the very best winders to match today.
Only one electrolytic capacitor in the entire amp, and that was probably installed later in its life.
Todays electronic components have hundreds of electrolytic capacitors , mostly used because they are very economical- the paper in oil caps used back in the 50's and 60's were much costlier, and can be as good as new 60 years later!
The pair of EL34 tubes put out a solid 30 watts, but its not stressed or working hard to achieve this, so it will keep working reliably year after year.
I dont have the original pair I found 40 years ago, but i do have another 2 sets of amps I bought about 5 years ago.
I have a lot of respect for these amplifiers, they are of a good solid, timeless design, have incredible reliability that comes from over engineering of components, and sound excellent.
There are very few audio devices that can maintain this sort of integrity and quality over a 60 year period.
It may be as ugly as sin, but underneath that exterior is a real beauty.
The Trimax A52 inspires me in my own preamp building, my preamps are very over engineered, with massive power supplies, and a reluctance to use those damn electrolytic capacitors with their limited life.
Suprateks built 25 years ago are still working reliably and I'm even more focused on the latest models being super reliable and long lifed.
This is what makes a classic in the vein of the old tube Marantz , Luxman products. They are simply built to last, something that is sadly not a priority these days.
I was using my Trimax's in an active/passive configuration with my Supraxox field coil speakers, but the Supravox are going back to France for a re-cone and i now have the Trimax's on my AR-LST speakers.
These are another high quality, over engineered product from long ago, a fantastic speaker that was very revolutionary when introduced. It has 9 drivers per speaker, a 10 " bass driver, 4 mid range and 4 tweeters per speaker, kind of like a big Bose .
Despite receiving much praise, the LST's never really took off as they came out at the end of the tube era and they needed high power solid state to work well.
They were just ahead of their time, the high power Crown solid state amps they were partnered with were quite horrible sounding amps.
Ive split the crossovers on mine so the three bass, midrange and tweeter sections can be each driven by a separate amplifier, with the Trimaxs driving the mid range and tweeters.
This relieves the need for a really high power amp and the 30 watt Trimaxs are adequate for mid and treble, with a high power SS amp on bass.
I've installed level controls on each amp, so tone can be adjusted to suit. Of course a powerful preamp that can drive 3 sets of amps is also required.
LST stands for laboratory standard transducer and that is pretty much what they are, monitor standard with the ability to colour the tone if required.
There's a real satisfaction using products you know are well designed , engineered and constructed to perform at the highest level, and last a lifetime .
The Trimax was probably the highlight of the Australian audio manufacturing of its era, and I feel privelged to own them.
