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I have a Fender Custom Vibrolux Reissue. It has reverb and vibrato on both the Normal and Bright inputs.
What I need to do is remove the vibrato and reverb from the Normal channel. I still want the vibrato and reverb in the Bright channel.
The Vibrolux Reissue is really close to the 65 Deluxe Reissue which has the inputs exactly how I need so that's what I've been looking at to try and figure this out.
Any ideas?

Here are the schematics:
Vibrolux Schematic:
http://griffineffects.webng.com/images/ ... page_6.png

65 Deluxe Schematic:
http://griffineffects.webng.com/images/ ... page_1.png

Bside2234 wrote:I have a Fender Custom Vibrolux Reissue. It has reverb and vibrato on both the Normal and Bright inputs.
What I need to do is remove the vibrato and reverb from the Normal channel. I still want the vibrato and reverb in the Bright channel.

I have to say I'm a bit surprised to hear that; the Custom Vibrolux RI is one of the few modern Fender amps that sounds great from the factory IMO.
It's warmer and raunchier than the BF amps, and sounds fatter at lower volume levels. The BF amps have more clean headroom, and the changed location of the reverb circuit allows for a huge increase in reverb depth and "wetness" over the Brownface amps. This is useful if you play surf guitar, but most other users never get the reverb level above 3.

Why do you need to remove the tremolo (vibrato) and reverb from the normal channel?
You can download the '65 BF schematic and board layout from numerous websites and make your Custom Vibrolux RI into a '65 BF if that's what you really want.

Disclaimer: Building and modifying amplifiers is DANGEROUS (like most fun things). Valve amplifiers invariably contain both very high voltages and high currents, capable of killing you. Whilst anyone can learn the skills to build an amazing amplifier, it goes without saying that you must never work on a live amplifier! Unless you are highly familiar with the internal workings of tube amps, I recommend taking your amp to a qualified tech.

It's not possible to remove the Vibrato on the Normal channel as Vibrato is global on this amp and not channel specific. As well without seeing the pcb layout, I would have to say it would be very difficult to remove the Normal channel from the Reverb feed and return. Since the recovery stages for both the Normal and Bright stages are wired in parallel, you would have to cut traces for the plate of V1B and wire in 2 plate plate resistors in series. A 22k 1/2W and a 47k 1W. At the center junction of these 2 resistors you would need to wire a .022uF 400v capacitor. The second leg of the new cap would be wired to a 470K 1/2W resistor. The second leg of this resister would be wired to the junction of R32 and R31. This will effectively isolate the Normal channel from the Reverb circuit and should maintain volume balance between the two channels. On a modern Fender this will most likely require removing the entire pcb. Unless you are VERY familiar with modern tube amps, I highly recommend taking it to a skilled tech.

What you are asking for is actually a common mod. The CVR started off as the Vibroverb RI, which had a more start-forward vintage-design. The differences between the two are a handful of mods that were commonplace for decades but people seem split on their benefits/issues. Personlly, I find them too noise and unrefined in stock form.

The biggest complaints about the CVR is the excessive amount of noise. This is because both channels are bridged by the universal reverb splitting the channels back to Normal and Vibrato lowers the noise-floor considerably.

The other complaint (some people love it) is the significantly reduced headroom and difficultly to tame the amp and room clean. This is mostly because of the lack of negative feedback. This also adds to the amp's famous noise BTW.

Changing the model back to the Vibroverb RI (or even closer to the original) is quite common. The most common mod is known as the "Mark Moyer Mod". I believe Groovenut may be right about the global vibrato. While they may not make a DRRI out of the CVR, I think you'll find you'll make a huge step toward the signature Fender Tone of the Blackface era.

Directions...
http://www.thefenderforum.com/forum/sho ... hp?t=36220
http://www.tdpri.com/forum/amp-central- ... rolux.html

Thanks guys.
I understand the dangers of tube amps and I am pretty comfortable working on them. I've actually repaired quite a few over the years. Funny thing is I know very little about how they work. I'm just good at figuring out what's wrong with things.

So I glanced through the links. These seem to address the reverb which is great. Nothing is ever mentioned about the vibrato. At least I didn't see anything. This leads me to believe that it can't be removed from the Normal channel or the original Lux had it on both channels also so nobody addressed it???

My first thought was I was going to have to redo the whole middle section of the amp to convert it to the same as the 65 Deluxe. According to that mod, changing the reverb section doesn't look too difficult at all but if I can't get the tremolo out of the Normal channel, there really isn't any point in doing anything.

The setup used necessitates a clean channel on the normal while maintaining use of the vibrato and reverb on the Bright channel.

Yeah, Groovenut is dead on.

The CVR uses the brownface-era (and Princetone Reverb) bias-modulated tremolo, the trem/vibrato is in the power amp, not the preamp.

wyatt wrote:Yeah, Groovenut is dead on.

The CVR uses the brownface-era (and Princetone Reverb) bias-modulated tremolo, the trem/vibrato is in the power amp, not the preamp.

Exactly. I have converted a Brownface / bias feed tremolo circuit to a Blackface circuit, but it was a LOT of work to do it on the old fibreboard, so it would be a blimmin' NIGHTMARE to do on a PCB.