Ok, so that build has a high chance of issues that a first time builder would struggle troubleshooting. thanks for keeping me know, i really don't have the experience with analogue stuff to know what I'm looking at. what about something like this, i found it on a Canadian audio forum and know the little Yaqin amp it's based on has glowing reviews.
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I'll stand by my earlier suggestions - e.g. this (Claudio Bonavolta - Photography - Web Design)
It's basically a Mullard 5-10 without feedback. Mostly.
It gets even easier if you use an IT to drive the outputs (parts count 4 resistors, 2 or 3 caps and two bits of iron)
like this
The problem you have is you want simple, cheap and fool proof. You might be better served by some of the simple guitar amps out there like The Laminton
It's basically a Mullard 5-10 without feedback. Mostly.
It gets even easier if you use an IT to drive the outputs (parts count 4 resistors, 2 or 3 caps and two bits of iron)
like this
The problem you have is you want simple, cheap and fool proof. You might be better served by some of the simple guitar amps out there like The Laminton
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Mea Culpa, I definitely overlooked those two 680k resistors connected to earth 😱.
But anyway, due to the feedback applied in this design it gives trouble to prevent oscillations when one takes the wiring for granted.
I would also recommend a bottlehead kit and for this reason. They go into good detail about solid and safe grounding/build practices. No schematic will tell you how to build something safely. Having your hand held through that will pay off in future builds when you do your own.
A first time build should be a well supported kit. Remember there are most likely very high voltages involved, and you'll need to troubleshoot it (or confirm test points) after you build it.
I'll stand by my earlier suggestions - e.g. this (Claudio Bonavolta - Photography - Web Design)
It's basically a Mullard 5-10 without feedback. Mostly.
Has anyone here built this one? I've been wanting to do a push pull one and even though I have extra el34 and 6l6gc tubes an el84 might not be bad. It is hard to find threads on builds that don't have specific names and I'm still new enough at this that it is very helpful to follow other people's builds.
If you do build it, consider replacing the ECC82 (12AU7) with a 6C4. They're only using 1/2 of the 12AU7.. and that's what a 6C4 is. Same heater voltage, too, but different pin assignments, as the 6C4 is a 7-pin tube.
I hate to admit it (i un-drank the coolaid), but a Bottlehead kit may be the way to go. Just take a look at the forum at all the first time builder questions and you'll feel right at home. From very high level questions down to my "1k resistor measures 1.01k, is that ok?"
Mistype?
Unless I'm misreading something, somewhere, running 2ma through that stage leaves Vg = -10V with Va = 150V, which is more of a 12ax7 operating point than a 12au7 (which really wants 10mA )😕
The original Mullard used an ECC83 but as a longtailed pair. I nearly built a 6S4A PP amp driven by 12au7 and ended up with much smaller resistor values in the design.
....12AX7 !
Unless I'm misreading something, somewhere, running 2ma through that stage leaves Vg = -10V with Va = 150V, which is more of a 12ax7 operating point than a 12au7 (which really wants 10mA )😕
The original Mullard used an ECC83 but as a longtailed pair. I nearly built a 6S4A PP amp driven by 12au7 and ended up with much smaller resistor values in the design.
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My comment was directed at the fact that only 1/2 of the 12AU7 is in use, which seems wasteful (unless the other 1/2 was being used for a second channel). But as a single channel, the 6C4 is the same as 1/2 of the 12AU7.. it's the more economical approach.
That said, I'm not used to seeing a 12AU7 type used in a balanced phase splitter such as this. Typically, it's a 12AX7 / 7025 type.
Necrothreading. But I found something old, something new. And a whole lot borrowed.
Try GingerTube's
Baby Huey PP EL84 amplifier
Pretty much all you want.
Try GingerTube's
Baby Huey PP EL84 amplifier
Pretty much all you want.
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