Hi. Pregnant pause at the moment. Have order some, ehem, Lundahl 1679s. Not really cheep anymore, but I sold some stuff and had a bit of extra cash. Also they are relatively more huge than I had allowed for in the original design, so have stopped building as I will work out where everything will fit, when they turn up... Hope they turn up. Was supposed to be 2 weeks, but nothing as yet.
I am building the the circuit in post 72, as it is a little un usual with a transformer input, and promises low distortion. I have enjoyed all the other circuits, and quite like the idea of the non symmetric triode amp, and introduced me to some other nice valves, like the CV6040, which is a 12E1 in a smaller bottle.
Nice. Looking forward to hearing how it turns out.
I think the 6AS7/6080 route make a cost effective PP triode amp. Check this out - http://lilienthalengineering.com/100-amplifiers-chapter-1/100-amplifiers-part-2-1945-54 Scroll about half way down for 3-4 6AS7 schematics
I think the 6AS7/6080 route make a cost effective PP triode amp.
I do feel drawn to a push pull 6080, although the voltage swing is a pain, I recently did an amp closely related to Tim de Paravicini's 6080. It is one of my favorites. I may do one one day.
https://www.diyaudio.com/community/...inis-hifi-world-6080-amp-modded-by-me.369493/
Let the rats nesting comence.... Starting with 12W Amorphous C-type Core Push-pull Output Transformer Pr10K Se 0-4-8 Ohm from Aliexpress, it works and seems quite nice transformer, not a bass monster, but pretty clean, just about getting 10 watts at 400vHT, chickened out here (to many exploding caps in recent memory). the original design using an 8k transformer, so I guess that makes sense, will have to push up the HT to get to my target 15 ish watts, but not not a bad start. all looks pretty civilised. Actually I should recap now and try a bit harder, as my other transformer, the Lundahl is almost the same at 9.7k, and for this amp I think I want to try that one, was hoping to get away with the Ali, but it is rated at 12W, and I think I would be pushing my luck at 15 watts.
Pleasingly simple looking after my 859 adventure and more recent active crossover build.
Pleasingly simple looking after my 859 adventure and more recent active crossover build.
Got put off by the tangle of wiring, but have been chipping away of late. Fired it up last night on one channel and looking quite promising.
grovergardener,
Can I joke a little, please?
You said: "Looking forward to hearing how it turns out."
The new beautiful amplifier in the UK lacks the power to drive a loudspeaker so it can be heard all the way to the US.
I am old enough to remember the Black Tornados and Grants Pass Cavemen.
grovergardener, guess where I grew up? The sports rivalry was wonderful, and you never knew who was going to win.
Can I joke a little, please?
You said: "Looking forward to hearing how it turns out."
The new beautiful amplifier in the UK lacks the power to drive a loudspeaker so it can be heard all the way to the US.
I am old enough to remember the Black Tornados and Grants Pass Cavemen.
grovergardener, guess where I grew up? The sports rivalry was wonderful, and you never knew who was going to win.
Pity really it sounds quite nice, especially driving NS1000ms. I have been running it on my Dovedales, with a Quad 33. Not a happy combination, trying transformer volume control now, sounding somewhat more promising.The new beautiful amplifier in the UK lacks the power to drive a loudspeaker so it can be heard all the way to the US.
It is how named "The Beautiful Amplifier".
It feels like it is settling down now, and I feel more comfortable now the empty hole in the front now has a a HT fuse. About when this picture was taken I was cautiously waving my hand over the power transformer, and there was a quiet click, and the meter pegged and one channel went silent. Fortunately I was there to switch it off. Don't know what happened and it hasn't happened again, but I am running a random pair of EL34 on one channel.
Downsizing the high power first capacitor from 10uF to 4.7uF has sorted my excessively high power supply problem, with the HT now at 415 ish full power and 380 in less power eco mode. It is nice that it is surprisingly cool running, most of my previous efforts run a bit on the hot side. Eco mode is working, this picture is Full Fat, the previous Eco.
I have been having some adventures with the balanced inputs, having never done it before, not really sure what to expect, but my music first TVC has an XLR output and is "floating", if not "balanced" will have to try it with smsl dac which has balanced outputs.
Sound wise, it is not sweet like an SE but quite clear sounding with good clarity and a greater feeling of power and dynamics, maybe due to less even order. bass sounds a little rubbery compared to what I am used to but good timbre.
Last edited:
- Home
- Amplifiers
- Tubes / Valves
- Help deciding on a low cost 15-20 watt triode push-pull amplifier design