#1
I like the sound of my amp...a LOT. The cleans are beautiful and the crunchy tones are not too shabby, but there is more brightness than I would EVER think of using and it's effecting how well my pedals go with the amp. I got good tones by putting the tone cut about 90% up, keeping the treble on about 11oclock, and putting the master volume on about 3oclock or dimed, but I'd like more a more controlled range of brightness and more pedal friendliness into the top boost channel.

I like what I've seen and heard of the bright cap mod results, but I'm afraid that my perception of how simple the procedure will be result in another of my "dead Proco Rat" incidents. The process looks dead simple. I mean it seems almost idiot proof. But you understand my apprehension as a Vox AC15 is quite a lot more expensive than a distortion pedal. My main question is if the mod is REALLY as simple as the pictures and directions suggest (clipping C67 and C8)?

Also, is there a tube set that will also help smooth out some of the harshness of the stock tube and get a little bit more improved clean headroom (just a slight notch more)?

Thanks.
Fender Telecaster
DeArmond M series
Vox Night Train 15 head w/Weber loaded 1x12
Dunlop DVP3 Volume (X)
Klone circuit/Russian Big Muff 2in 1
Fulltone Fulldrive 2 MOSFET
TC Electronic Nova Delay
TC Electronic Nova Repeater
Line 6 M5
Last edited by sg4ever at Nov 16, 2011,
#2
Isn't the normal channel like the top boost but without EQ and less bright?
#3
It's still pretty bright unless the tone cut is turned pretty high, but it definitely handles overdrive pedals better. I like having the eq options on the top boost channel though, so I was hoping to get more pedal friendliness out of it by doing this mod (most everyone who did it loves how their dirt pedals worked after it was done and the tone didn't suffer according to them).
Fender Telecaster
DeArmond M series
Vox Night Train 15 head w/Weber loaded 1x12
Dunlop DVP3 Volume (X)
Klone circuit/Russian Big Muff 2in 1
Fulltone Fulldrive 2 MOSFET
TC Electronic Nova Delay
TC Electronic Nova Repeater
Line 6 M5
#4
I think the bright cap mod will work just fine, but I'd like to increase the clean headroom of the amp if only a little. It gets pretty loud for my needs, but I feel like if I could go just a tad bit higher on the volume knob that it would be just right. Any suggestions for a tube set that could accomplish this?
Fender Telecaster
DeArmond M series
Vox Night Train 15 head w/Weber loaded 1x12
Dunlop DVP3 Volume (X)
Klone circuit/Russian Big Muff 2in 1
Fulltone Fulldrive 2 MOSFET
TC Electronic Nova Delay
TC Electronic Nova Repeater
Line 6 M5
#5
Get a JAN Philips or GE 5751 for V1, JJs for the rest of the preamp, perhaps a NOS 12AT7 to try in V1 in case the 5751 doesn't give you enough headroom. Matched set of JJ power tubes, and if you get them from somewhere like Doug's tubes you can ask for a set of high-headroom power tubes so they break up a little later.

And yes, the mod is as simple as it looks. The hardest part of the whole procedure is pulling the chassis, which is a major pain on Vox amps. Still, as long as you don't touch anything other than the chassis and those two caps when you're clipping them, you'll be safe and happy.
#6
Wouldnt a 5751 give you less headroom? I was gunna suggest that... But theyre quieter anyway, 12at7 is a good 6db or so quieter ran in V1 of my amp. THeyre harder to break up i guess because theyre lower gain, but really it is a 15 watt EL84 amp...

JJs should help make it a bit darker anyway. Id probably try valves before you go removing capacitors, im guessing vox come stock with some cheapy valves.
#7
A less gainy V1 tube gives you more headroom throughout the preamp by hitting the subsequent gain stages less than usual. 5751s tend to be quite close to 12AX7s gainwise, so there may be no difference there, hence the 12AT7 suggestion. The higher headroom power tubes ought to make a more significant difference.