Werner-Carstens
Hi all. After a long search for a lower wattage valve amp I settled on the VOX AC15 hand wired combo with a celestial blues speaker. After the honeymoon phase I found the amp to be a bit bright for me on both the normal and top boost channels. After doing a lot of reading on this I realised at it seems to be a fairly common critisism on AC15's and that it can be easily remedied with a so-called bright cap modification. I determined that there are 2 bright caps in the amp, one for each channel with different pf values. I would like to know the following:
1. Has anyone ever attempted this mod?
2. If so, what pf values did you use on the new capacitors?
3. Where did you buy the caps?
Thanks
AlanRatcliffe
I had the older one with the EF86 and top boost channels. No problems there. The traditional cure for brightness is turn up the cut control - that's what it was made for.
Gearhead
the easiest way to mod is to just desolder one of the legs of the existing caps, you can simply reverse it if it does not do what you want...
Werner-Carstens
Thanks guys. Alan, I agree with the tone cut but even with it almost fully turned up overdrive pedals still have an annoying fizz in the top-end, at least to my ears.
bottledtone
Most common is snipping one side of the bypass cap on the volume pot. Or unsolder like gearhead said, as you can reverse.
Vox use a 500pf coupling cap into the volume pot, and you could increase this value like matchless do on the lightening/DC series. (1500pf to 2200pf......1n to 2n2 in other terms ?)
Sean
Gearhead did the mod to an AC15 I had a couple of years ago (not the hand wired, with blue speaker you have, the CC1) I did not like it, I forget why. We reversed it not long after.
Werner-Carstens
I decided to go for it and removed the bright cap from the top boost channel volume pot. I am really happy with the result. The high end fizz that bothered me when using overdrive pedals are gone and I have a lot more scope on the treble pot. I left the bright cap on the normal channel for when I want that cutting treble sound it so all in all the amp just became more versatile.
aja
what guitar are you using with the amp? did rolling the guitar tone knob back slightly not help? reason I ask is that I didn't think these amps are so bright, perhaps the guitar has a lot of top end? are the pickups very hot?