The Amp Garage

Apologies. Please delete whichever is in the least appropriate area.

Question for you guys... I have looked at Hoffman, Mojotone, CE Dist, etc., and don't see any good options for blank aluminum chassis. I was aware of Watts Audio, but it seems as though that source went sour. Are there any other good options? I have contacted a few places that are known for manufact...

You know...I'm a new builder (hobbyist mostly). I don't know which camp I'd be in, honestly. My Bassman build may look as bad as the Jim Kelly amp to some of you, but I was proud of it as my first amp. I'm very green admittedly, so I don't know everything I should about lead dress, grounding, etc. ...

You know...I'm a new builder (hobbyist mostly). I don't know which camp I'd be in, honestly. My Bassman build may look as bad as the Jim Kelly amp to some of you, but I was proud of it as my first amp. I'm very green admittedly, so I don't know everything I should about lead dress, grounding, etc. T...

Great points, guys! I'll be building out a project chassis, so I don't need an original fit. Definitely prefer having an X pattern as well. Trying to buy vertical mount PT's when possible for easy installation (less chassis work). I was a little confused about the 115/125 VAC primary, but the 125 sh...

Here's the math on these two. 290NX is $70 MORE than the 272JX. Hammond 272JX 115/125VAC, 60 hz (would choose the 125V) 300-0-300v CT @ 287mA 5v CT @ 4A 6.3v CT @ 8A Hammond 290NX Univ. Primary 290-0-290v CT @ 262mA 5v CT @ 3.4A 6.3v CT @ 6.8A AC30 (4- EL84, 3 12AX7) 6.3v = .9A x 4 + .3A x 3 = 4.5A ...

In my understanding, if you have them build a custom PT for you, it's going to cost a LOT more than choosing one that's already right for the amp. That's why you'd want to pick those vs others. Basically they know the AC30 is a very commonly built amp, and can sell them so they make up a bunch of t...

Thanks Martin! Yeah, I've seen people having good luck with MC.

Playing devils advocate though....what am I gaining by getting an "AC30" PT instead of just spec'ing out a 290-0-290, 6.3v @ 6-8A, and 5v @ 3-4A?

How far above the tube recommendations are you guys going when spec'ing at PT? For an Vox AC30 (single top boost channel amp), I calculate the current needs to be roughly 4.5A for the 6.3V secondary. I'd get a 3-4A 5V secondary as well even though a GZ34 doesn't need that much. Would you aim for 6A ...

10-4. Thank you.

One last bump about the .047uf cap if you're out there Sluckey. : )

Thanks! I'll put the amp in Standby mode when toggling.

Would you still place a .047uf cap between the V3-Pin 6/Plate resistor junction and the DPDT switch, or is it unnecessary now that the switch is DPDT instead of SPST? Your schematic has the symbol for it, but no value so I wanted to check.

It's just bitten me several times lol Speaking of that... Be careful with that switch. It's pretty hot! :mrgreen: Is your point of this crossbreed just to see how the AB165 preamp circuit compares to the AA864? There's not a lot of gain in that extra stage. If you really want a hot gain stage with ...

Ha! That part I know.

Would this be the appropriate wiring for a DPDT switch?