I've kept some of them and will do a story on one or two over time.
I was reminded of this one when I did the article on impedance matching and put up a graph of a SE amp driving a simulated speaker load.
It showed that SE amps dont have low enough output impedance for linear response and the resultant coloured response.
If the output impedance of the amp can be lowered the result will be better, and the way to get low output impedance is to use a low plate resistance tube.
The Russian 6C33C-B tube is one of the lowest Rp tubes available and with a good transformer can give quite good results with a broader range of speakers.
I built quite a few of the MERLOT amps with the 6C33C-B tube with 6SN7 input tube and 300B driving the 6C33C-B .
The best ones used Plitron output transformers and they were awesome amps, unfortunately you cant get this transformer any more , mores the pity.
This amp I built for myself about 10 years ago- it has Sowter transformers , and uses 6SN7 driving 300B , driving the 6C33C-B tubes. The other tubes are a rectifier tube and a 6AS7G used as regulator for the power supply.
Monoblocks , so two for stereo.
Very nice amp , puts out a solid 18 watts and can drive most speakers .
It can be configured as cathode follower , which lowers the output impedance even more, but the consequent feedback generated does take some of the sweetness from it.
Its sitting in my collection , and unused for a few years now, but will be used again when I get a horn system going again.
