And you need to verify that it is not a speaker issue.

Quote from: Roly on April 15, 2013, 01:43:35 AMThat's what the little "[informative][useless]" buttons are for.

Thanks Roly, did not even realize those buttons existed (under posters name). 

  That sticker is specifications regarding the incoming power from your wall outlet.  It will tell you voltage, frequency, and power consumption of the amp.  So in your case the amp uses 120 watts from the wall (to deliver 50 watts to the speaker, not very efficient).

  If you need, here is a picture of series and parallel wiring of the 2  speakers.  Pay close attention to the + and - terminals of the speakers in the series arrangement.
http://www.svvintageamps.com/images/2-speaker-wiring-diagram.gif

Quote from: g1 on April 11, 2013, 11:42:03 AM

Quote from: J M Fahey on April 11, 2013, 02:40:51 AM
afaik the Vox has 16 ohms only output, or maybe 8/16 , but that pair of Frontman speakers is wired for 4 ohms.

Oops! Thanks JM, I had forgot to consider impedances.
The Fender speakers wiring will have to be changed from parallel to series (simple).  Then it will be an 8 ohm cabinet.
  The Vox has an 8/16 switch on the back which will have to be set to 8.  The Fender cab will have to be plugged into the EXTERNAL spkr. jack, not the extension jack.  This will mean the Vox's own speaker can not be used at the same time.
  When used by itself, the Fender amp will give a tiny bit less power into the 8 ohm cab than the 4 ohm stock  cab wiring.
ctguy1955, I hope this is still a workable scenario for you.

Sorry about this, it is incorrect.  To quote you from an earlier post "I should just delete that last entry as it makes me look like the jerk that I feel I am" 
JM is completely correct,  if you rewire the fender speakers in series, you will have a 16 ohm cab. (not 8 ohm as I incorrectly stated).
  Then you can set the Vox amp to the 8 ohm position and use the EXTENSION spkr. jack.  All 4 speakers will be working.
  As I mentioned earlier, when you use the Fender by itself, it will be putting out a little less power than with the stock wiring, but I doubt you will even notice the difference.

Quote from: g1 on April 10, 2013, 07:47:52 PM

Quote from: Andy54 on April 10, 2013, 03:47:36 AM
The attached pic I think shows the transformer in question. It has three red wires attached to the board.

  That is the power transformer.  It is not "stepping down" 240 to 120V, it is transforming the 240V to the voltage the power supply uses.  You plug it in to a 240V outlet, yes?  So it is already wired up for 240V operation.
  It is the same size/weight as a north american version of the amp would use, you can't downsize.  Yes, new amplifiers deliver more power and weigh less, like modern cars do. 

Sorry about that post, the picture showed the power transformer and I did not realize there was another "step down" transformer in the cabinet.
  Sounds like you are getting it sorted out, good luck.

Quote from: J M Fahey on April 11, 2013, 02:40:51 AM
afaik the Vox has 16 ohms only output, or maybe 8/16 , but that pair of Frontman speakers is wired for 4 ohms.

Oops! Thanks JM, I had forgot to consider impedances.
The Fender speakers wiring will have to be changed from parallel to series (simple).  Then it will be an 8 ohm cabinet.
  The Vox has an 8/16 switch on the back which will have to be set to 8.  The Fender cab will have to be plugged into the EXTERNAL spkr. jack, not the extension jack.  This will mean the Vox's own speaker can not be used at the same time.
  When used by itself, the Fender amp will give a tiny bit less power into the 8 ohm cab than the 4 ohm stock  cab wiring.
ctguy1955, I hope this is still a workable scenario for you.

Quote from: Andy54 on April 10, 2013, 03:47:36 AM
The attached pic I think shows the transformer in question. It has three red wires attached to the board.

  That is the power transformer.  It is not "stepping down" 240 to 120V, it is transforming the 240V to the voltage the power supply uses.  You plug it in to a 240V outlet, yes?  So it is already wired up for 240V operation.
  It is the same size/weight as a north american version of the amp would use, you can't downsize.  Yes, new amplifiers deliver more power and weigh less, like modern cars do. 

Quote from: ctguy1955 on April 09, 2013, 08:57:21 PM

Quote from: g1 on April 08, 2013, 12:09:49 PM

Quote from: ctguy1955 on April 07, 2013, 08:44:20 PM
I will be able to not only have a nice 2 x 12 Cab for my extension speakers for 199 bucks, I will also be gaining a 100 watt head for free !!!!!!!!!!!

  Just so you don't get ahead of yourself, this jack is only a "speaker in" , not "amp out" so you do not have a separate head available.  That would be another scenario.

  yes, but the subject tells you I want to use my ac15c2 extension out as the amp (head) that will drive just the speakers of the Fender FM 212R speakers.

Sorry about the confusion here, I am talking about the Fender amp.  You said you now have a 100W head.  All I'm saying is it will not be able to be used as a "head" to drive some other speaker cab.  That would require a different wiring scheme.
  With the extra jack wired the way I have shown, the Fender can be used as a combo amp with it's own speakers, or as a speaker cabinet.  It will not be able to be used as a separate amp "head".
  You did not indicate you were interested in that, so I did not consider it.

  The amp is from 1976, are you looking at a schematic that old?  The values used would likely have changed since then, also the caps may have been replaced since '76.
  As far as the tremolo pot, maybe it just needs a cleaning?

P.S.  You said it was an "import type" amp, I thought in '76 the were "made in USA" and marked as such on the rear of the chassis?

Quote from: ctguy1955 on April 07, 2013, 08:44:20 PM
I will be able to not only have a nice 2 x 12 Cab for my extension speakers for 199 bucks, I will also be gaining a 100 watt head for free !!!!!!!!!!!

  Just so you don't get ahead of yourself, this jack is only a "speaker in" , not "amp out" so you do not have a separate head available.  That would be another scenario.

  Have you got the schematic yet?  Enzo showed you where to get it from in the other forum:
http://forums.peavey.com/viewtopic.php?f=27&t=30657
  He posts here also, it is probably best to choose one forum and stick with it.
The schematic does not seem to be available, so until you can get it from Peavey and post it here, it will be hard for anyone to help you.

  Don't feel bad, we all start from the same place, the beginning!  Sounds like you've got it now.
  The tip connection does not lift as high as the others because of the "notch" of the male plug tip.  However, it still lifts enough to break the connection between tip and tip switch.
  So the way you have drawn the jack connecting to the amp is correct.
You said "The tip is the white ( ground ) and the single circle around the shaft is the power", but it is the black that is ground, which is why it connects to the sleeve.  Tip normally carries the hot signal, sleeve is ground.
  The two contacts that you are not using here are called "ring" and "ring switch".  They are usually only used when the jack will be used with TRS (or stereo) plugs.

  Yes, you can do that with a switching jack like in the article you linked to.  However, don't do it that way as they are creating an amp output jack but you want to create a speaker input jack.  It is also very important that you label your jack as "speaker input".
  You will find a white and black wire coming out of the amp chassis going to the speakers.  You will need to cut those wires so you can wire the jack in series between the chassis and the speakers.
So after you cut them, you will have a white and a black going to the amp chassis, and a white and black going into the speaker cab.
  Here is a drawing with the type of jack you referenced.  I have labelled the pins with their proper names and shown where they should connect to.  Hope it will make sense to you.

Quote from: Roly on March 27, 2013, 08:11:33 AM
I also have to say that I'm mildly astonished a) by the manufacturers' claim of 100 watts out of a pair of 6L6's, then b) by the HT voltages shown on the circuit, 585V for the 60 watt version, and 715V for the "100 watt" version.

Just wanted to comment on this even though we are now dealing with a different model of amp.  The gv60 or gv100 power amps are basically copies of later (cathode driven) Musicman amps.  The cathodes are not at ground due to the transistors, so the full B+ is not across the tube.  Also, the screens are run at around half the plate voltage.  I believe this is how these circuits get away with running 6L6's at such high voltages (see Musicman schematics).  I believe the higher power Musicman amps claimed 150W from a quad of 6L6.