Fender BF Vibro Champ mod clarification

[Justin Thomas]

Also, re: bass response on a Champ/Vibro-Champ...
What speaker are you using? If you're talking the Original or vintage-style 8", there's half the problem. Try it through a 15" or two. The amp should have as much bass as any Fender amp; what it doesn't have is a large output tranny or a very good speaker.

I had a 20W Eminence PA speaker in my 79 Champ. The amp had enough bass to give the famous Fender fart.

Justin
EDIT: to clarify: my Champ has LOTS of bass. What it DOESN'T have is PUNCH or snap. You'll have to go bigger for that.

[The Dude]

It was actually Ken Fischer who mentioned disconnecting the vibrato. Read pg 133 of the Weber book "A Desktop Reference"

I am not here to debate anything. I simply want to increase the bass response and gain of the Vibro Champ.
If by any chance there is an amp expert in the room, please speak up and tell me which cap and/or resistor to change.
It should not be so difficult

You've changed this and that through the course of the thread. Where are you with the amp at this point and what are you looking for? This thing won't ever be a gain monster- not enough gain stages. You could ditch the vibrato and use that tube for an additional gain stage, but that's not something as easy as just changing or adding a part. One thing you might try would be to add a small cap in parallel with the NFB resistor. That'll give you a cut in the high frequency, effectively a bass boost.

[The Dude]

......famous Fender fart.......

[Chuck H]

In another thread you have regarding a Harvard, which is the same amp as a VC by the way, you are asking about the same improvements. What has already been covered here is accurate. But I'll mention another option. You could restore the tone stack to stock so that you have EQ control at clean settings and then use a dirt box for the distortion.

[Chuck H]

In another thread you have regarding a Harvard, which is the same amp as a VC by the way, you are asking about the same improvements. What has already been covered here is accurate. But I'll mention another option. You could restore the tone stack to stock so that you have EQ control at clean settings and then use a dirt box for the distortion.

Edit: Correction. It's the Bronco that's the same as a VC. Not the Harvard. My bad.

[Ben N]

As noted, trying to get real bass out of a Champ, Vibro- or otherwise, is like trying to get blood from a stone. I put a Weber replacement speak in mine, and the overall tone improved some, but bass? Nah. And don't boost it with a full range booster either: it'll just fart out on you.
Yeah, you could run it through a bigger cab with bigger speakers, but what's the point? If you are recording with it, you can squeeze a little more out with mice placement, or by blending it with DI (although phase cancellations can be an issue). With some radical surgery, you might be able to fit a 10" speaker in the cab--not that that will set the world on fire with bass response either.
Otherwise, accept it for what it is, with its limitations--a very cool, sweet sounding, old school living room amp. (JM2¢.)

[Randall]

In my experience, a re-cap and a Warehouse Guitars G8C 20 watt replacement speaker will bring a VibroChamp up a level or two. I have done four this year with satisfying results.