JE Labs 2A3 Single Ended Triode
3.5 wpc DHT SET Sound
3.5 wpc DHT SET Sound
Finished on 1/5/08
Since this was going to be a keeper amp, I didn't want to compromise on parts used. I wanted to make sure that the amp was overbuilt with resistors, caps, and irons that were well over the required power rating. I went with James 6123HSs, which BTW was compared quite favorably with Hashimoto OPTs by many fellow amp builders. The schematic I used was JE Labs Simple 45/2A3, with a minor change: instead of 1 k for the 2A3 cathode resistors, I used 900 ohms. I got more out of those Sovtek 2A3s this way. I never really liked the electrolytics in the PS, which I think have a tendency to produce mechanical sound. So I went with all Solens PP caps in the PS section.
Gotta love those gold plated binding posts. Thet are oversized and heavy duty.
Square waves at 40 hz
At 1 kHz
At 10 kHz
At 20 kHz
This is my first attempt to handwire a hi-cost SE DHT amp. I have built several Get*Set*Go amps that are SE DHTs, but they were all built using PCBs. As much as I have liked how the GSG amp sounded, I felt like I would never fully appreciate amp building unless I handwired a SE DHT. Since building a hum-free and low-noise SET is often difficult, I welcomed the challenge of building one that was not only hum-free, but one that sounded good.
Since this was going to be a keeper amp, I didn't want to compromise on parts used. I wanted to make sure that the amp was overbuilt with resistors, caps, and irons that were well over the required power rating. I went with James 6123HSs, which BTW was compared quite favorably with Hashimoto OPTs by many fellow amp builders. The schematic I used was JE Labs Simple 45/2A3, with a minor change: instead of 1 k for the 2A3 cathode resistors, I used 900 ohms. I got more out of those Sovtek 2A3s this way. I never really liked the electrolytics in the PS, which I think have a tendency to produce mechanical sound. So I went with all Solens PP caps in the PS section.
Gotta love those gold plated binding posts. Thet are oversized and heavy duty.
Square waves at 40 hz
At 1 kHz
At 10 kHz
At 20 kHz
Wiring was quite easy, but building the chassis was not. I am not going into details of how the chassis was made, but it suffices to say that I could use some good set of tools, including a table saw. So, how does it sound? Simple awesome! The amp is very musical. It has all the excellence and frailties of SE DHT. Very well balanced with tight bass. Mids and highs are very fluid. I love listening to classical music through this amp. I really think that the James OPTs do a great job at frequency response. Will I keep it? 100% yes. I finally found an amp worth of my collection. I hope this will be a family heirloom.
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