Dumble modded VOX AC30

[Bombacaototal]

I just stumbled upon this post. Does anyone have more intel about this amp? I think it is the first AC30 by Dumble I come across

[Aaron]

Woah!!

[Bombacaototal]

Woah!!

Yes, I went to the shop today but it seems these amps are kept elsewhere..and the guys at the shop are far from friendly....and I think this specific one is gone already

[Mr. dB]

Isn't that store another Rick and Justin Harrison enterprise? If so, caveat emptor.

[norburybrook]

Isn't that store another Rick and Justin Harrison enterprise? If so, caveat emptor.

yes, my thoughts exactly...……



M

[Reeltarded]

hahahahaha

Awww.. it is too bad they didn't let you play their Explorer plugged into the Hendrix 8x10 cab.

I have to get an image off my phone. I get industry updates on the hour lmao..

[Mark]

All as I'd imagine it to be. Yes we have one but you can't see it. It sounds like the Monty Python French taunter skit. Maybe, that is the tactic to be used, but does it sound as good as my Dumble modded AC-30?

The Champ modded by Dumble is practically the same amp you have to wonder if the AC-30 falls into this category?

[JD0x0]

The Champ modded by Dumble is practically the same amp you have to wonder if the AC-30 falls into this category?

Well what would you expect with such a simple little amp? Also, the way I've always seen the 'Mods' were they were meant to keep the original amp's vibes, just without all the 'flaws' such as blocking distortion, for example. So I wouldn't expect massive changes, either way.

[Mark]

Well what would you expect with such a simple little amp? Also, the way I've always seen the 'Mods' were they were meant to keep the original amp's vibes, just without all the 'flaws' such as blocking distortion, for example. So I wouldn't expect massive changes, either way.

There are rather large changes that can be made to the Champ, they vary from using a larger speaker which I think is a bad idea before trying a larger output transformer to get the bass response you really require. The stock output transformer is starved of bass response, I tried playing bass through my Champ with the stock output transformer in place and the amp was distorting on three. When I put a Mercury Magnetic fat stack output transformer into the amp I can easily play bass and the bass is louder than my 18 Marshall due to the output transformer in the Marshall. The amp doesn't sound splatty for lack of a better word. Mind you I also have a 10K grid stopper on the output valve and a 470 ohm screen grid resistor.

There is also the Gibson GA-5 version of the Champ to try. This basically has 220K plate resistors and 2.2K cathode resistors. I haven't found signal caps to make a difference to these amps, but the power supply cap values can make a difference. If you use the stock 8uF screen grid filter cap and a 6L6 the screen grid will try and pull the rail voltage down which in turn causes compression in the pre-amp.

An extra triode stage prior to the input also kicks the gain up a bit too. The down side is the Champ is starved of real estate. For this reason the Princeton is the better chassis for the Champ builder.