When you say Ģif anyone knows of designs using a similar principal using a preamp with an extra gain stage of a lo mu hi current driver to push the power tube just a bit more than a typical 2 tubeģ I would say yes but not on those exact terms.
I've seen an old design using a lo-mu triode (a 6C5 or 6J5) for make-up gain after a 6SJ7 in a 6L6 SE amplifier (was it a Masco?). Just an ordinary RC coupled voltage amplifier, not at all a current driver like it appears to be needed for AB2 PP drive. But I have a few ideas...
You (I if I were you) could still use your 6N7 and the 6AH4 for a finite (kind of) design for a small amp (assuming you don't source any more of those tubes). The 6AH4 as a small power triode, using the small Hammond one size-fit-all SE 3 watt 8 ohm tap at 2500 ohms that almost everybody has with a small 4 ohm, 6 or 8" speaker. It might be a gamble, but it seems like it could work or be tweaked to sound good for what it is. The rectifier could even be one of those TV half wave rectifiers (if you have one). I would build a circuit around them if I had a good batch of them and these principles of recycling/saving tubes or energy was a motto of the vintage amp maker, it seems to me, rather than the modern one. Anyways, the ripple might not get that bad through a small speaker and you need to drop to 300V (The text says 250V).
The 6N7 could be used as a pre-amp for two succeeding gain stages sharing its cathode, a bit like the old way of the paraphase inverter circuit in RCA manuals or early Gibson. Fenders. But this time, a bit different since the second triode is not being fed with unity gain but with the full rated gain of the first section, separated by a volume control. I don't think it might cause oscillation problems at that gain level...Maybe on high volume? Suppose it's ok... Sure nobody think it will sound like beef... More like gremlin's beef... A valid sound if you don't already have an amp that fits that role. Some people love vinyls for the cracking sound and short bandwith. Bad engineering in that case would rather mean ignoring safety and allowing the possibility of total auto-destruction of the whole amplifier plus, if not lucky, the whole appartment/house building & neighbors with half a dozen people waiting on the street with blankets freezing at minus 30°C in my part of the country.
The 6N7 could make a dual power section on its own, for a class B PP operation under certain conditions (like I've read that it has to be played loud to have a clean sound. But it felt like it could be interesting for guitar energy-wise and sound wise. I was interested in it, one time... I looked at the old Stancor manuals numbers and I never found any used transformer for this on E-bay.
With little more investing, the 6N7 can be also, a PP drive or parallel into a transformer for class AB2 using two 6L6G push pull, and using the 6AH4 as a voltage regulator to hold the 6L6's screens at their rated 270V or so textbook voltage. That's could be interesting but again, finding the transformers could be a challenge! I know few willing to design around those concepts when not having a good batch of those tubes and right replacements parts lying around...
Topic: anyone every use a 6AH4 GT as a driver in a se amp? (Read 3656 times)