VOX AC30 CC2

[Siaip Ciuvas]

Hi,

does anybody had experience with theese reissues? I guess they make them in China now, how is the quality of the components used? Is there inexpensive way to make them sound better than they do without mods, or only way is retubbing + Celestion Blues?

D.

[Turdus]

I don't think these amps sound that bad. I owned one for a bit. I never gigged it, so can't really address reliability, etc. I did have to replace the input jacks, as one would cut in and out. I tired some V30's in mine, but did not hear that big a difference over the Wharfdales.

The amp weighed too much for me to gig with. I sold it when I got my TopHat CR 2x12", which I don't think the Vox really compares to tonally. The TopHat also weighed less.

[HAMERMAN]

I do not own one and have not modded one but there is a fellow named Lyle Caldwell who frequents the "U2 recording" yahoo group who has done a few (at least) for other members of the group. Below are comments that he has made on the CC's. Please note that this is a somewhat scrambled collection of notes so please take it with a grain of salt. He has talked about both the AC30CC and AC15CC and there is every possibility that I have mixed up notes on the two.

I am handy with a soldering iron so if I did own a CC I would have definitely tried these mods myself. If I wasn't I wouldn't hesitate to send the amp to Lyle for the mods. Betwen the clips he has posted and the very satisfied customers he has modded amps for it's pretty obvious that he knows what he is doing and that the CC amps are a diamond in the rough, not unlike the Peavey classic 30.

Here is Lyle's website: http://www.psionicaudio.com/main/index.htm

I hope this helps,

Dave

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I change the preamp filtering and install a DC standoff circuit (which lowers any AC hum in the filament

supply by about 30dB)

On older CCs that have the speaker and reverb wires hard-wired to the chassis I install a 1/4" jack for the speakers and RCA jacks for the reverb. This way you can change tubes without having to remove and disconnect the reverb tank, and without having to remove the clip on speaker connectors, which wear out when you remove/connect them a lot. When I install a new cable with a plug I then solder the cable to the speakers for a permanently reliable connection.

On those older CCs I also fix the effects loop so there is no low-end loss and mod the trem circuit so the trem goes both faster and slower without thumping (Change R38 From 56K To 27K Change R37 From 270K To 100K).

On CCs that already have the speaker and reverb jacks, the mods above are not needed, including the effects loop and trem fixes.

On any CC, I remove/change the bright caps on the TB and Normal channels, to eliminate the ice pick attack.

Then I change the circuit in both channels to JMI spec, using high quality low noise resistors and Sozo coupling caps. I increase the gain in the Normal channel (Vox limits this in the stock CC) and I install a switch that toggles the TB channel gain between high ('65 and earlier) and low ('67 and later). The latter position offers more

clean headroom.

All of the power circuit gets upgraded to 1W resistors, using metal oxides where appropriate, for a much more reliable quiet power supply throughout.

I change the screen and grid resistors on the power tubes to give longer tube life and more playing sensitivity, without losing the "AC30 sound".

I change the output transformer to a Mercury Magnetics Tone Clone which is an exact reproduction of the Woden transformer used in most JMI period AC30s. This gives a much nicer more authoritative low end, no nasalness to the mids, and present but not harsh highs, as well as just generally sounding 100x better.

I'm glossing over some of the technical things I do (plate resistor changes, cathode RC filter changes, etc).

There are 4 things causing the stock Custom Classics to be painfully bright:

1) New Celestion Blues are too bright - this is less apparent once they have been gigged for a few months, but they will always be pretty bright.

2) The Wharfedale speakers are WAY too bright, and will always be too bright.

3) JMI used a lot of different "bright caps" on the TB channel, but 100pf was the most common value. The CCs use 120pf. In my experience 68pf is a better value, or no bright cap at all. With Wharfedales the 120pf cap makes things painfully bright and overdrive pedals get fizzy. With Blues it's similar, though not quite as "Manchurian

Candidate".

4) For some unknown yet indefensible reason, Korg went with 100K plate resistors on V1 rather than the 220K plate resistors used in the JMI AC30s. The 220K resistors result in more compression and earlier breakup, with the highs getting smoother as the volume is increased.

3 and 4 together result in some potent brightness, but if you have new Blues it's worse, and if you have Wharfedales it's awful.

With Blues one can put in 220K plate resistors and totally remove the bright cap and then breathe easily.

With Weber Blue Dog/Silver Bell speakers one can either remove the bright cap or put in a 68pf cap.

Change R38 From 56K To 27K Change R37 From 270K To 100K

The stock tubes are crap, with the exception of the Tung-Sol, a new set of JJs will sound much better.

[Siaip Ciuvas]

wow, now I see my question answered in full, better than google did for me

thanks a lot!

[HAMERMAN]

Glad to help. Let me know if you need the service manual, I can email you the PDF.

BTW, Forgot to add this comment on speakers (again from Lyle):

There's a misconception that the Weber is a sub for the Celestion if one cannot afford the Celestion.

I could afford to use either, and I much prefer the Weber. It sounds like a good Vox speaker, while the Celestion is too bright and harsh. I love the pairing of the 30W Blue Dog and 30W Silver Bell.