Can a fender amp be "brownfaced"

[cloudnine]

Just had a thought how cool it would be to have a Deluxe Reverb modified to sound like a brownface, for some chunkier overdrive tones and that sweet vibrato, plus keep the awesome verb intact. Is this practical at all? Would it be a super costly mod to have done?

[jay42]

The 6G3 is a simpler model than the blackface era amps...no tone stack, just a tone knob. Are you asking about using the VTB stack from a brown Pro or Concert? The only hitch is finding a tapped 350K treble pot for the A schematic. You can pretty much kiss off adding one of the more complicated tremolo circuits just because that takes more tubes.

[cloudnine]

Yeah I would probably be shooting for a 6G5-A. I'd like some input on this actually, having played through precious few brown fenders in my day. Anyway Weber now sells a 350K pot tapped at 70K. About the vibrato circuit, would it be feasable in an amp built from the ground up on a Deluxe Reverb chassis for example? I.E. basically a brownface amp, except add reverb?

[cloudnine]

Found this webpage. Aren't these standard brownface tremolo circuits he's talking about installing in blackface circuits?

http://www.lynx.net/~jc/tremoloCircuits.html

[karmadave]

If it were an original BFDR, I wouldn't touch it. Instead I would look into one of these:

http://www.allenamps.com/encore.php

It's basically what you are looking for + it can run at 35 watt (6L6's) or 22 watts (6V6's) like a DR.

-KD

[Brick]

Originally Posted by karmadave

If it were an original BFDR, I wouldn't touch it. Instead I would look into one of these:

http://www.allenamps.com/encore.php

It's basically what you are looking for + it can run at 35 watt (6L6's) or 22 watts (6V6's) like a DR.

-KD

or if you can live without the reverb



the Hot Fudge with Nuts is based on a Brown Deluxe

http://www.allenamps.com/hotfudge.php (scroll down for the 'with Nuts' part)

[phsyconoodler]

That Fender vibrato uses three tubes to achieve a doppler like tremolo that actually fools you into believing it's a vibrato.I like the sound but it's not like the vibrato on Magnatones.
Three tubes and lots of wiring on the Fender Brown amps.I rather like the sound and would build one,but to do reverb too would be quite a task.Too many tubes unless you use a one tube reverb circuit,but they are not as lush as the two tube fender style.

[Rumblefish]

Just get a kit from David Allen or have him build you one.I swear my Fudge with Nuts through my 4-12 stack is scary close to my '68 Plexi.Awesome!

[gldtp99]

It might be best to get an Allen kit or build one from scratch rather than converting a Blackface amp---- there are many differences.
I have several Brownface Bandmasters with the 3-tube Harmonic Vibrato and it's incredible sounding.
I rebuilt/converted a 30 watt PA head to a 6G9-B Brownface Tremolux circuit that uses the simpler 1-tube bias vary trem---- it also sounds very good--- not everything that the Harmonic Vibrato is but better than any "Roach"-type LDR Blackface trems i've heard.
The single tube Bias Vary trem is pretty simple to build.
My Brownface Bandmasters and the 6G9-B Tremolux clone have a much better natural overdrive than any Blackface amp i've ever heard. (i like Blackface Fenders very much for what they're good at--- but killer natural OD isn't their strong suit IMHO).
I've heard it said that Brownface Fenders were the closest amps to the "Classic Marshall" sound that Fender ever made. I'm not so sure i agree with this because my Brownfaces don't sound much like my classic Marshalls but the Brownface amps i have definitely can produce some rich, pleasing, gritty/smooth natural overdrive when cranked up---- my Brownface amps don't need pedals to sound killer--- actually they sound better without my Keeley-modded TS-9 (or any other OD/Distortion we've tried)--- they are very good sounding amps.
Hoffman also has the 350k/70k tapped pot for the Treble.
I have plans to build an 85 watt (Showman/Twin output section) version of my 6G9-B Tremolux clone--- this should be a very impressive amp---- the round, rich cleans on these should sound even better/deeper with 6L6GCx4 headroom----- this type of amp will have to wait for a while because i'm building some Hiwatt clones now---- people have been after me to build some superior pedal-friendly amps with really great clean tone -- the Fender Brownface and Early 70's 4-input Hiwatt circuits seem to be doing the job quite well..................gldtp99

[brad347]

the brown tremolo uses 2.5 12AX7s and the blackface reverb uses 1 12AT7 and half a 12AX7. So if you built a single-channel amp, you could theoretically have the brown tremolo and blackface reverb in an amp that uses the same chassis as the blackface deluxe reverb. But I'd rather just get a brown amp and a 6G15 reverb. In fact, that's what I use.

[Category 5]

wE DO A BROWNFACE DELUXE BLACKFACE DELUX WITH GLOBAL REVERB-THE IVAN WWW.CATEORY5AMPS.COM

[jzilla]

just to let you know you mistyped your url. it's http://www.category5amps.com/.

-j

[mbratch]

Q: How many 12AX7's does it take to make a Fender brown tremolo?
A: It depends upon the model of Fender brown you mean.

Brown Deluxe 6G3 uses .5 x 12AX7
Brown Vibrolux 6G11 uses 1 x 12AX7
Brown Vibrasonic 6G13 uses 3 x 12AX7

(At least that's what it looks like in the schematics.)

A BFDR uses 1 x 12AX7 and an optocoupler. Perhaps the BFDR could be converted without too much trouble to a 6G11 style tremolo.

[Wakarusa]

Changing a Blackface tremolo to a power amp bias vary tremolo isn't really that hard. In addition to the brownface circuits look to the blackface Princeton reverb for clues. The down side is that you get a potentiometer (tremolo intensity control) in the bias path, so you need to keep it clean. Scratchy volume pots sound bad, scratchy tremolo pots in this circuit can make power tubes glow funny colors.

Putting the 2.5 tube "harmonic" tremolo in with reverb is a whole 'nother ball game. I've built two prototypes that did this trick and both gave me fits. The first problem you'll have to sort out is whether you want the reverb to come before or after the tremolo. The second problem is one of gain management. The input to the 2.5 tube circuit doesn't like to be overdriven (note that in the brownface amps it picks off of a 100K/10K voltage divider in the prior stage's plate circuit). The output of the circuit is a pair of 12AX7 with enough gain to drive the phase inverter. It's a lot easier to put the reverb between the tremolo circuit and the PI, but getting it to still sound sweet is pretty tricky. The third, and probably most daunting, problem is that the circuit takes up about 12 in. sq. of circuit board (a pile of big 600V film caps go in it), so finding room for everything can be interesting. If you want two channels, reverb, and 2.5 tube tremolo you're looking at 8 preamp tubes. The one bonus is that you've got 1/2 a 12AX7 left over to turn one of the channels into something a little, errmmm, punchier

[jordy29]

Would it be possible to put a brownface style tone stack in a blackface princeton. I'm after a chunkier drive tone. What differences would I hear if I replaced the original tone stack with the one knob brownface 6g2 or the two knob 'pro' or 'bandmaster' style. Has anyone tried anything like this before?