Hi,
I have a small pair of PP 12k about 10w electra-print OTs. I would like to build a screen drive amp with them. Any ideas for a good design or schematic?
Thanks
Chris
I have a small pair of PP 12k about 10w electra-print OTs. I would like to build a screen drive amp with them. Any ideas for a good design or schematic?
Thanks
Chris
No expert by any stretch but don't screen drive amps often use sweep tubes? And IIRC a fairly low primary impedance OPT? I could (probably) be way off base.
Why not build a conventional PP amp using 6BM8 (4 tubes = stereo PP amp) or 6AQ5 tubes? 12K might be about right for them.
S.
Why not build a conventional PP amp using 6BM8 (4 tubes = stereo PP amp) or 6AQ5 tubes? 12K might be about right for them.
S.
I just took a look through some posts under "screen drive" and "crazy drive". A LOT (!) has been hashed out over these circuits by some of the most experienced guys in the forum. A few design schematics as well as discussion of pros/cons etc.
A screen-drive amp requires a low impedance drive that can source significant current. It also has large voltage drive requirements so you have to develop lots of swing at low distortion.
It is an advanced-level amp to make. If you are at the level where you need to copy a schematic, it is probably better to go with a more standard approach.
If you are up to the significant design challenges, I have a circuit with some experimental results for developing large voltage swing at tiny distortion that may be relevant here.
It is an advanced-level amp to make. If you are at the level where you need to copy a schematic, it is probably better to go with a more standard approach.
If you are up to the significant design challenges, I have a circuit with some experimental results for developing large voltage swing at tiny distortion that may be relevant here.
Yeah, I figured it would be a bit of a stretch, especially since most work with screen driving sweep tubes is getting higher wattage than I'm looking. Will probably just do a class A el84 pp, maybe triode.
For a one board solution, if that's what you'd like, have a look at a Tubelab,com SPP. There's a Tubelab forum here. The SPP can be wired UL, pentode or triode.
S.
S.