Tube Amp Archive

yeah - they do run hot. the 30 gets really hot with the extra tubes. I always thought it a bad design to have the tubes right up against the board like that - who knows what going on with the ohm values of those cc resistors once they're at like 180deg. but it seems to work fine - and I play it a lo...

Well, either I got lucky or the orientation doesn't matter: Tranny's installed. Sounds great.

OK. Howling = bad. Got it :lol: Gut shots: [IMG:160:120]http://i14.photobucket.com/albums/a322/tmge/vox/th_ac15012.jpg[/img] . [IMG:160:120]http://i14.photobucket.com/albums/a322/tmge/vox/th_ac15007.jpg[/img] . [IMG:160:120]http://i14.photobucket.com/albums/a322/tmge/vox/th_ac15005.jpg[/img] . [IMG:...

I'm installing a new tranny in my AC15. I'm not sure how to orient the primary leads. I know where the center tap goes. Here's what I don't know: One lead from each side of the primary goes to one of the power tubes (i.e. one lead goes to one tube and the other lead goes to the other tube). Does it ...

You cannot directly compare DC resistance with AC impedance. Where am I doing that? I'm just trying to figure out why the 8 & 16 ohm taps are called 8 & 16 ohm? And more to the point, whether the ohm readings I get on my MM unit mean it's OK to install. For instance, the primary of a 2 x 6L6 output...

So, the actual "ohms" readings that you get are used to compare to each other to figure out the lengths of the windings parts, but are meaningless otherwise. Hope that makes sense. OK, I get what a xformer is & does on a rudimentary level but what I don't get, then, is why the taps are called 8 & 1...

Email from MM support: You have to have a circuit to measure the secondary. Blue to red should measure approximately 194 and brown to red 193 etc. Have you tried installing it? My guess is that it is fine. Thanks. I like the wall wart idea. Ha! What about a 9v battery :) I will for sure do a light b...

Looks like the primary is open. That's too bad, somebody probably ran the amp without the speaker attached. HI TOM!! How are things? So, fried primary. Yay. What about the low readings on the secondary? With a lot of xfmrs, you cant get a dc resistance measurement from plate to plate. Go ahead and ...

Bob - I was asking about the RF ferrite clip thingy... ...the blue and the brown wires are the primary plate connections and the red is the CT. The black is the secondary common, the yellow is the 8 Ohm tap and the grey is the 16 Ohm tap. Yep! Confirmed by Mercury. BUT.... I measured the OT thus: bl...

Bob -

So you're saying:
- determine which are the primaries
- apply limited (via the lightbulb) current to those
- measure the output of the other leads - without getting blasted by the HV


any idea about the wire clip thing?

This set didn't come directly from MM - it was used - so no documentation. [IMG:120:160]http://i14.photobucket.com/albums/a322/tmge/vox/th_ac15031.jpg[/img] Check this out: What's the thing cliped onto the leads? [IMG:160:120]http://i14.photobucket.com/albums/a322/tmge/vox/th_ac15022.jpg[/img] . [IM...

Hello! Power Chord Hack, here. New to this forum but I'm sure a few here know me from other places on the interweb :) For amp experience I've built an Allen Encore & BFed and fully recapped my 78 Princeton Reverb. I've also built a few pedals. OK - So I've got an AC15HWH and want to install a MM OT ...