Oh yes, I am certainly aware of this. But I am not intending in any way to use a 0A2 as the regulator, just as the reference. A set up like this:
But to recall: I want to make a flea power amplifier of about 1 or 2 watts RMS power.......
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Why we need to complicate the build? Go for 250v min. and it will be a simple build with long term satisfaction. My choice of output tube for a small SE amp is El84 or 6v6.
Why we engage ourselves into long discussion for inventing wheels?
Regards
Why we engage ourselves into long discussion for inventing wheels?
Regards
As Shoog wrote earlier, any ECL is satisfactory, or E55L even in spud (with stepup input transformer).
Yes, now it is cooking. E55L with input transformer will be little expensive. It is upto the thread opener if the expense is okay with him or not. ECL build will be strait forward and no brainer. That's it.
Regards
Regards
An ECL82 in SE is good for about 1.5watts and sound excellent. Easy to build with small salvaged SE OT from an old valve radio. Have built one and use it as a bedroom amp.
However ECL82 as a PP is even better, you can expect to get at least 5Watts and you can even use Toroidal Power transformers for the OT. Have just such a beast as a headphone amp with microphone transformers as step down phase splitting transformers at the front end. Quite possibly the nicest thing i ever built.
E55L is just to pricey and the valves are just not very rugged, I have had quite a few failures in use. However you can make a decent 3watt spud with 150V B+ and an active CCS plate load in parafeed.
Shoog
However ECL82 as a PP is even better, you can expect to get at least 5Watts and you can even use Toroidal Power transformers for the OT. Have just such a beast as a headphone amp with microphone transformers as step down phase splitting transformers at the front end. Quite possibly the nicest thing i ever built.
E55L is just to pricey and the valves are just not very rugged, I have had quite a few failures in use. However you can make a decent 3watt spud with 150V B+ and an active CCS plate load in parafeed.
Shoog
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All right, all right guys. Now if you will be so kind to show some circuit diagrams to start with...
So that I do not have to "....engage ourselves into long discussion for inventing wheels?"
🙂🙂
So that I do not have to "....engage ourselves into long discussion for inventing wheels?"
🙂🙂
What design challenge is here? Small PP pentode amps are ubiquitous on DIY & elsewhere. During the time spent on this discussion an amp could have been up & running in the bedroom.
Everyone spinning their wheels & going nowhere. Lots of talk but little action.🙄
I literally haven't got most of the circuits I have built, I would have to trace them. For me the whole interest was in designing and testing ideas. For me this is the best approach, sketch an idea out and test it in spice before building.
Shoog
Shoog
The starting point was low power, perhaps 7W & you have some 0A2s. The 0A2s are a distraction, unless you simply want to watch them glow in the dark. What other parts do you have that might be usable in your proposed amplifier? There have been several suggestions, many of those will satisfy the initial requirement.
What is your experience with this art? These are the factors that should make a decision possible by now.🙂
Unfortunately many of these threads go nowhere, just many people talking among themselves about nothing. And on & on.😀
What is your experience with this art? These are the factors that should make a decision possible by now.🙂
Unfortunately many of these threads go nowhere, just many people talking among themselves about nothing. And on & on.😀
This John Broski amp would be a good one for a 6BQ5 PP, cant get more textbook simple. Its on my to-do list as well using some Edcor OPT's I have already and Antek torroid I have already. For similar purpose, as compact as I can build it.
Its not shown with a screen tapped OPT here but it might be fun to have a triode/ultra linear/pentode switch on the back.
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Why not 'flea power' push-pull 6SN7?
😀 😀 😀 😀
Maybe with an active Baxandall (sp?) tone control stage added?
😀 😀 😀 😀
Maybe with an active Baxandall (sp?) tone control stage added?
from a beginner... what is the purpose of the 1 Meg resistor across the coupling capacitor?
It forms a resistor divider at DC to set the bias of the phase splitter. You could also use a floating cathodyne too.
I initially didn't mention my flea amplifier as the transformer required is a bit tricky unless you kludge toroids into service as I did 🙂
I initially didn't mention my flea amplifier as the transformer required is a bit tricky unless you kludge toroids into service as I did 🙂
jhstewart9 wrote:
"What is your experience with this art?"
To give you an accurate answer your question
what do you mean with "this art"? The "art" of electronics or the "art" of using tubes in electronics?
"What is your experience with this art?"
To give you an accurate answer your question
what do you mean with "this art"? The "art" of electronics or the "art" of using tubes in electronics?
Garter bias works extremely well in these sort of situations. I used it in my ECL82 PP headphone amp.
If you built a similar thing with the ECL82 you can put a LTP using the triodes up front and have a place to return some gNFB.
Shoog
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