Vox AC30 Custom Classic Common Issues

bluedot

Junior Member
Joined
Aug 22, 2011
Messages
6
Reaction score
0
I said I'd post some pictures but my camera is being spotty. I'm leaving tomorrow morning on business so I won't be able to take pics for a week. I reopened the board and the R38 resistor was fell off - poor connection. After resoldering it and jumpering the R49 I still have the same problems - nearly no volume and tremolo doesn't work. :(

Thanks guys for the help, hopefully will get this worked out when I return home.

Jason
 

Lyle Caldwell

Senior Member
Joined
Dec 31, 2010
Messages
2,114
Reaction score
1,323
Wow, you did it the hard way. I never remove the pots board to do the mods; I just put the components on the bottom of the board. Everything looks OK in the photos though I can't see the solder joints on the bottom of the main board - that's where to triple check.
 

nedhogan

Junior Member
Joined
Feb 21, 2011
Messages
26
Reaction score
0
Lyle, the comps were the mod that I took out and put back in, by un-modded I ment like with the 100k films dude.

I think that with V1 amplifying the signal so much from such a low level, the quality of the work really shows through there. Your right, it probably has nothing to do with resistor types. The last time I put the resistors back in I really taken my time and sanded and cleaned the resistor wires and the board. You will be pleased to know they are now carbon film. To be honest I think right there at V1 is where the personality of an amp comes from; yes I'm probably talking BS!

I hope you with the amp problems have it storted.... Its the back of the board that Lyle or someone probably needed to see. I had a problem with resin, didn't think it conducted but it does, very much so!!!
 

bluedot

Junior Member
Joined
Aug 22, 2011
Messages
6
Reaction score
0
I'm still working on it guys. Thanks for the advice.
 

bluedot

Junior Member
Joined
Aug 22, 2011
Messages
6
Reaction score
0
So I found a loose cap, and resoldered it. These wires came off the first time I changed the caps in September. They go to terminals 2 and 3 of the master volume pot, right? I saw a picture of a PCB online and they didn't appear to be soldered to anything, but the guy may have taken them off the pot board as I did.
 

Attachments

neutronrobot

Junior Member
Joined
Nov 1, 2011
Messages
4
Reaction score
0
Hey Lyle-
I actually had a question about your reverb mod for this amp.

I've switched out the stock Ruby tank for the recommended Accutronics 9EB2C1B tank, and although it sounds better, the signal's weak.

I want to have a tech replace the R18 resistor with the 28K metal film 1/2 watt resistor you suggested to boost the signal.

My question is, do you have to remove the PCB board to switch out this resistor? It's easy to find when the back's off the chassis. I just want to know what to tell the tech. It's been hard to find anyone in Austin who's worked much with these.

BTW-I've really enjoyed reading all your info about the Custom Classics. It seems to be a very misunderstood and under appreciated amp. I've been tweaking mine for two years and really love it.

Thanks!
 

neutronrobot

Junior Member
Joined
Nov 1, 2011
Messages
4
Reaction score
0
Thanks, Lyle.

So I'm guessing that lowering the resistor on R18 boosts the reverb signal, but I'm not sure what adding the 1 meg resistor across lugs 1 and 3 of the reverb switch does.
Does that adjust the levels between the "low" and "high" reverb drive settings somehow?
Sorry for all the questions. I see your reverb mod recommended on a lot of forums, but I haven't seen a description of what the end effect is.
 

ManMartin

Junior Member
Joined
Jan 30, 2012
Messages
2
Reaction score
0
Thanks Lyle for the mods. I must to try them.

I changed the reverb tank for an Accutronics (they ensure me that was one of the last american made ones) and the reberb is still to long to me and too hidden at the same time (even the new tank is in theory shorter in time).

I wonder, once I took a look into the schematics if it is possible to use the tone pot of the reverb as an input level of the reverb to easier control the in and out of the reverb signal. The reverb switch seems to increase/decrease the signal that goes to the reverb. What do you think?

Cheers from Spain.
 

ManMartin

Junior Member
Joined
Jan 30, 2012
Messages
2
Reaction score
0
Bad idea, I tried to change the resistor for a bigger one 22k in R112 and it was a lot of distortion coming from the reverb tank, so it seems the original values are ok.

Try to change the resistor at the output of the reverb as suggested (28k in R18), it seems to work great.

cheers.
 

Soef

Member
Joined
Dec 5, 2008
Messages
81
Reaction score
15
I'm preparing to do the effect loop fix, but how about the polarity. Any hints in which side should be the + and which the -?
 

gypsyseven

Senior Member
Joined
Oct 16, 2010
Messages
2,712
Reaction score
1,236
Thanks for posting, but to be honest i really love my AC30 C2 pretty darn stock!
I have the one with the greenback speakers and just changed to TAD tubes and love both channels, alone or combined...
 

Mat_P

Senior Member
Joined
Jul 16, 2010
Messages
124
Reaction score
114
Thanks for posting, but to be honest i really love my AC30 C2 pretty darn stock!
I have the one with the greenback speakers and just changed to TAD tubes and love both channels, alone or combined...
This is all about the forerunner CC2, not the current production C2. :cool:
 

AlvisX

Senior Member
Joined
Oct 20, 2009
Messages
801
Reaction score
984
Scored an '06 cc2x for 300 bones .
Interesting thread . I wonder how much "gain" does one look for out of such an amp ?
I get plenty o' gain with a Les Paul & p-90
Lookin to tune in the tone though
Playing & working on Marshalls for a couple decades ,I have no real clue what a real AC30 is supposed to be about . I just know some badass playas used 'em throughout history.

I think got a good deal on this amp though. Was blowin heater fuses when I got it . The guy had it sittin for a couple years .Turned out it was a heater tab touchin where it should not have been on a pwr tube socket (a common issue)

I actually find the normal channel the useable one and the TB channel a bit annoying .
 

bluefrog

Senior Member
Joined
Mar 15, 2009
Messages
1,003
Reaction score
274
Hi all
I have an AC30 TB/6 from 1968 and i allways use the brilliant channel.
this is not brittle but glassy and has enough bottom,too.
(there was capacitor mod to tame the brill. channel.

The tubes are all JJs brill. V1 ecc83s the normal channel V1 is a TubeTown 12AX7LPs.
The AC30 is quite different to my Linnemann M45 with a 1987x preamp stack.
the vox is clear but in a rougher dedency, the jtm is rounder but clear as a bell.
Think off Edge vs EC beano. but absolute great in there direction.
 

sallyg

Junior Member
Joined
May 1, 2012
Messages
7
Reaction score
0
Lyle,
I have a CCH and am going to do the mods you suggest.
How is the Vox Chinese output transformer and choke?
I was told to get a Mercury Magnets output transformer and choke. Do you agree?

BTW - do you ever get to Nashville? I'd love to hire you and have you do it.
 


Latest Threads



Top