The Amp Garage

Sorry for the long delay on this ... working on a 5e3 clone now. I'll get back to this as soon as I have that together.
Again, thanks for all the help.

p.s.: No 6SJ7 tubes on stock ?? Thanks Franco, sorry work got in the way this week. No 6Sj7 either, besides 12AX7's I have these: 12BH7A - Noval (similar or equiv: CV5042) 6973 - Noval (similar or equiv: 6CZ5) 6CB6A - 7-pin (similar or equiv: CV8926, EF190) 6DJ8 - Noval (similar or equiv: 6N23P, CV...

Kagliostro wrote: ↑Sat Mar 25, 2017 11:41 pm Based on the 5F2 this will be a start point, then I think you must tweak R1 - R2 - C2 (may be only C2)

Thanks Franco, this looks good.

BTW, have you an ef86 ?

No, no ef86 / 6267.

I think that idea came from using the Champ as the basis for the preamp model - where the 1st triode provides the initial amplification & the 2nd triode acts as the Phase Inverter. In this case the PI is already provided by the existing 12AX7 (as I understand it). If using both sides is beneficial t...

OK, here's a new version incorporating all of your input. I tried to simplify things as much as I could, both in the preamp & power supply sections.
Please let me know what you think.

A 6AV6 has a consumption of 300mA on heaters, a 12AX7 the same no advantage to use a 6AV6 instead of a 12AX7 (OK may be each triode B+ consumprion is around 3mA, so a 12AX7 consumption will be 3mA highr than a 6AV6, but 3mA didn't seems a value that can give problems to the PT) If you prefer to use...

thanks Phil, that makes sense

OK, now I'll demonstrate my ignorance. Have a look at this diagram: I just plugged in the Champ pre-amp circuit to see how that might fit. So we have the existing 12AX7 there acting as both an AF (Audio Frequency) amplifier and Phase Inverter, the start of the power section. Then the new 12AX7 works...

Phil_S wrote: ↑Mon Mar 20, 2017 1:43 am OK then. It will take a bit of effort. It might take a bit for you to ramp up. I suggest going for something relatively simple and with a low parts count ...

Thanks Phil, all good info. This sounds like it's going to be a fun project.

I am wondering about your level of experience ... Good point. I have some varied electronics knowledge from the military & school (both long ago), but not a lot specifically about tube amps beyond general understanding of electronic principles - and a healthy respect for safety issues. I've recappe...

martin manning wrote: ↑Sun Mar 19, 2017 6:36 pm It's push-pull, cathode bias, like a 5E3, with basically the same power supply. You'd need to add another 9-pin, but that shouldn't be hard. Got a shot of the inside?

Yes, here it is:

I have a neat little Magnavox 164BA donor amp & can't decide which way to go with it, so any suggestions you have are welcome. It features a 5Y3, one 12AX7, and two 6V6's so it's ideal. Downsides: as I recall, the 2 6v6's are not in a push-pull configuration, the transformers a bit on the small side...