Vox AC-30cc2 "Tune Up"

[8mileshigher]

In between New Years, NAMM and Paul starting his Law School classes, Paul A. was kind enough to spend a Saturday in his workshop to re-wire the speakers and change the tubes in my AC-30CC2. With Paul having his Handwired cc2 and his 1970's era re-built Top Boost models as examples, and thanks to the wiring diagrams supplied by RRF member and Vox expert Mike S. and Paul's steady hand with the solder iron, we first did the speaker re-wire on his cc2x (with the Alnico Blues) and then on my cc2 (with the Wharfedales).

I tried to take some step-by-step photos that might assist others looking ot change their tubes and by-pass the Neanderthal Vox method of having to unsolder your speakers in order to pull out the chassis, in order to change the tubes.

For anyone contemplating the new or future AC-30 cc2 purchase, the new models on display at NAMM have averted this "problem" with the new AC-30s having the tubes finally mounted towards the back of the amp ...so you can access them easier.... See the photo's at the end of this series.

[8mileshigher]

The wiring diagram supplied by Mike S. (WhoJamFan) and the next steps ...

[8mileshigher]

With success on Paul's cc2x, it was on to do the same speaker re-wire technique on my cc2 with the Wharfedales and to replace the original tubes ....

A side note .... having gotten my amp on Craig's List ---one never knows what the real "good shape" it might be on the inside !!! Looks like someone had spilled a beverage through the Vox top vents and it sizzeled on the chassis ... it's a wonder the tubes didn't shatter if they were hot and someone spilled a beer on them !!!

[8mileshigher]

Next step is to replace the 12AX7s with some Tung-Sols and the EL84s and the Rectifier tube with JJ's
Paul is using gloves to avoid skin oil contact with the glass.

[8mileshigher]

For you Vox fans ... here are some comparative pictures of the "works" of various models they released over the years. I have also included the new AC-30, which picture I took at the NAMM show last week.

I would like to thank Paul A. for all his knowledge, skills and hard work and Mike S. for supplying the wiring diagrams ! I used my cc2 at this weekend's Mini Con Jam and those JJs and Tung-sol's sure sounded good .

Regards

[paologregorio]

Thanks for posting the photos Rich!

The project was a lot of fun. Thanks again to Mike for the schematics.

FYI: In case some of you folks were wondering, I'm using the pair of pointy/needle nose pliers to carefully remove the power tube spring retaining clips in the photos where I'm removing the old power tubes. I'm not removing the actual tubes with the pointy pliers.

Maybe for the next fun how to mod, we can flip the chassis components upside down and to the back like on the newly redesigned AC30C2s we saw at NAMM...

[8mileshigher]

If anyone interested in Vox stuff wants to check out another picture of how the user control panel looks, (with the "blending" of channels function through 1/4 inch jacks) on the new AC-30 as shown at NAMM 2010 --- use this link to pics I posted recently over on the NAMM thread.

viewtopic.php?f=3&t=393167&start=180#p600153



check it out !

[whojamfan]

Looks great guys! Glad those diagrams helped out

[scotty]

Its really good Rich that Paul helped you out.What a great guy Paul is very kind.....Glad it all worked out for you.

[whojamfan]

I must say thanks for your kindness Rich, but I am far from a Vox expert. I just happened to have those in my laptop when I talked to Paul the other day.

[johnallg]

Nice work, guys. Rich, can you hear a tonal difference with the JJs over the stock Chinese? I realize it is also an issue of new vs old too.

[paologregorio]

Nice work, guys. Rich, can you hear a tonal difference with the JJs over the stock Chinese? I realize it is also an issue of new vs old too.

IIRC, Rich's first comments after we changed the tubes, fired up the amp, and played one of the Ricks through the amp, were, "ooh, listen to that; sparky, chimey", but he'll be able to state his observations in much better detail than I can.

When I changed the stock Chinese preamp tubes in my CC2X, I noticed a decidedly warmer tone sith the GT Mullard replicas. I left the original Sovtek Power tubes, and the I forget which rectifier tube was in there (a JJ, IIRC).

[8mileshigher]

John,
Gosh, I don't claim to be a tone expert by any means, but I certainly felt that the amp now has a better sound overall, more chime and prominence. I think it's all pretty subjective.

There are lots of Vox-aholics, Gearheads and Amp Guru's out there, who are posting on other Forums, and Harmony Central, etc. who claim to have all kinds of good karma from using a 12AU7 low gain in the V-2 position of the second stage Top Boost circuit instead of a 12AX7; and using NOS tubes and "pullers" from old military hardware to get more "grunt" and tinkering with this, that and the other .... And they can hear all these tonal differences .... What to believe ?

Come to think of it, I don't recall seeing any posts on any of these other amp-oriented Forums where anybody had much good to say about the factory supplied Vox tubes.... mostly just lots of complaints.

Tone is all in the ear of the beholder ... I did a lot of reading up on replacement tubes and came to the conclusion that JJs had a pretty good reputation for quality and value. I understand the Tung-Sols are Mullard clones of some sort... but don't quote me on this !

And when you get an amp on Craig's List -- one never really knows what's inside, until you do a little project like this.

[johnallg]

Thanks, Rich. I was just curious. I've found the the Chinese tubes (power or low signal) to be more harsh and trebly sounding. In both instrument and home stereo equipment. I was curious what you heard but didn't want to lead you.

[sharkboy]

I hate to be contrary, but I have been quite happy with Chinese tubes. I think a lot of things get a bum rap when they are piled on in internet fora.

Since Ei tubes have become terribly hard to get, I use the Chinese EL84s in my DC30, so I can save my Ei's and NOS tubes for lower voltage amps. They are less "velvety" than JJ's, but frankly, sound much more like EL84s to me than JJ's do (JJ's EL84s sound a lot more like a 6V6 than an EL84 to me). For preamp tubes, I feel generally the same way, but haven't tried the JJ long plates. The 12ax7LPS tubes from Russia are supposed to be good. I'm pretty happy with the Tung Sol 12ax7 reissues (but am glad I have some Ei's in stock.)