Help with Bugera V5 Bright Caps Mod & Reverb noise

[deepmojoman]

I have owned a V5 since '10 and have been generally satisfied with it even though I readily admitted that I had the same general complaint about its tone that every other Bugera V5 owner has had: it's tone is excessively dark (think: blanket over the speaker).

About 2 months ago I thought I'd research any solutions, and lo and behold, I found many accounts out there in the Web-isphere that sounded identical to mine, along with a world of modding solutions to go with it. I finally found my way to TDPRI.com, and there lay a post by a gent who chronicled his success with brightening up his V5! Here's a link to the post: http://www.tdpri.com/forum/shock-brothe ... rcuit.html

Earlier this week I went over to friend's house-one whom has a lot more experience working on amps than I do-and together we put into effect much of the mod. In a nutshell, we soldered in two 390pf/600v ceramic caps across the two center lugs of both the Gain and Volume pots. Yes-it did brighten up the sound, very considerably. I am actually planning on taking them out and replacing them with 220s (this will be more to my liking, I think), but in the meanwhile, another, unexpected issue has arisen: the V5's Reverb (digital Spring (nicely done, imho) has developed a grainy noise, somewhere between a hiss and shaker-like shimmer, that tails off behind certain frequencies. I have assumed that this is the Reverb doing it's best job to emulate what an actual Spring would do with all these newly abundant higher frequencies that the caps have provided, but at any rate, it sounds very unnatural, and I'd like to get rid of it.

Thus I am requesting assistance here: I will include a schematic of the V5. I would like to know if anyone out there feels that inserting a signal cap somewhere on the circuit-which sends to the reverb (which runs parallel to the main signal), and thus intercept all the added high frequencies from the bright cap mods-could be possible? If so, could anyone, looking at the schematic, figure out where, in the circuit, that signal cap would go, and what it's values should be?

Thanks for the help

[TUBEDUDE]

Find R 21 the 20k and try strapping gradually increasing values across it until you get the sweet spot of enough highs and minimal artifacts/noise. I'd start with a 500 pf or so.

[deepmojoman]

Thanks for the reply. By "strapping" did you mean to say "swapping"? Or did you mean "strapping", like to strap onto-like as in Piggyback?

And: what is that line (R16, R21, and that line to "BDM2") do? Incidentally, I can see, up in the Reverb area, where it says 7 X9, is going to 8 X9, so I can see how this line I somehow connected. Thanks for seeing that.

[TUBEDUDE]

The cap should be paralleled with the resistor. That will shunt higher frequencies to ground. That line of resistors is a voltage divider that acts as a load, isolates the tube from the verb module, sets the signal level and impedance to the module. I'm guessing BDM2 is a Belton delay module. A solid state "reverb pan".

[deepmojoman]

Ok, I'll try it out. Thanks much!

[RCGPNY1]

I hate to be the one to say this but the best thing you could do is sell the amp. I have worked for many years in the repair buisiness and although I wont dispute that Bugera amps sound ok, their build quality is among the worst many of us have seen. So bad , in fact I know of a few amp repair buisiness that will not work on them, as they become a timebomb of
problems which have so much to do with Bugera's contruction techiques.
One of the biggest problems is thier use of molex connectors and ribbon cable --even in the high voltage sections of the amp..I have seen many of them that have to be handwired in sections that have failed...it's always expensive and usually not worth it. It has decent iron so IMHO gut it and use it to build a clone. With all the knowledge available to you here a TAG
you should be able to build something sonically equal(if not better) and built much better.

[deepmojoman]

Tubedude:what's the highest DC voltage I can expect on that particular circuit line? I'm trying to see what wattage rating R21 should be?

[TUBEDUDE]

R 21 dissipates little power. I'd use a half watt resistor.