Thinking about some '63 Vibroverb RI mods

[cancelaspirin]

So I've got this idea about having a couple of mods done to my '63 Vibroverb RI by a tech. I could use a little input to get my head around this:

1) I was thinking of having the Normal channel adjusted for something closer to a tweed tone (more gain, mids, etc). Could someone give any specs around that, so I can describe this a bit more specifically to a tech?

2) Additionally I was thinking of a push-pull pot on the Bright channel, so that it would toggle between a 47pf bright cap and a 120pf one. Can that be done so it switches between two different caps?

My reasoning here is that I've also got a tweed Vibrolux clone & a SF Princeton Reverb -- if I wanted to downsize to just the '63 VV I could then get some of that tweed tone from the Normal channel, and be able to switch up the Bright channel for more BF/SF-style sparkle. (I know that these smaller amps are 6V6, and the VV is 6L6, plus other differences I probably can't begin to fathom...) Feel free to tell me just to keep them all too! I could always just leave the VV as what it is...

[cancelaspirin]

Hmm, nuthin'? I've done some forum searching about both these ideas, it looks like they each can be done to some extent. I guess some thoughts about the quality of tones I'd get by doing these mods would still be useful.

[Alex W]

I love the VVRI but I can't offer any expert advice on the merits of the mods you're asking about. My hunch as a consumer is that you can probably do something to the normal channel to make it more tweedy, something like bypassing the tone stack somehow. I don't have any idea about the bright switch concept for the bright channel.

One thing you might consider though before you go modifying the amp is a pedal to help get a more tweed tone. There seems to be a variety of pedals on the market these days for achieving that raunchy tweed sound, like the Formula No 5 pedal from Catalinbread, the Les Luis pedal from LovePedal, and others. (See this thread from TDPRI on tweed pedals.)

[Axis29]

I love my VVRI as well.

And, I also use a pedal to achieve the tweed voicing you describe. I have contemplated modifying my Vibrolux in a similar fashion... Something kinda marshally/tweedy sounding (it's a vintage Vibrolux Reverb, but it has already been modified.) But, the reason I would modify this amp over the VVRi is that the VR is a hand wired amp, not PCB based, so easier to modify.

However, I will be keeping an eye out on this thread. I'll be terribly interested in your results and hearing some audio examples!

[charlie chitlin]

There is somebody on this forum (sorry...can't remember who) who was vary knowledgeable about amps and the Vibroverb RI in particular.
He had isolated what he was sure was a design flaw in the amp that, if I remember correctly, was easily rectified and improved the tone.
Many also feel that those speakers have to go.
I played mine bone stock for years and loved it.
Best sounding amp ever on 10.

[cancelaspirin]

Thanks for the input about the pedals, I appreciate hearing what other VV reissue owners do. I do love how the amp sounds too - original speakers and all! I'm only pondering this to extend what it is, without getting in the way of how I'm already using it.

Also I should mention I'm mostly a clean tone and relatively lower volume player. Having the Vibroverb normal channel end up like a cranked tweed Deluxe isn't what I'm after, just a little closer to a fixed bias tweed (a la my Vibrolux). Not sure in that case how well a pedal would carry it in that direction.

On the other side of things, anybody switched up the bright cap on the VV? I'm interested if this has much effect or not.

[Axis29]

Originally Posted by cancelaspirin

On the other side of things, anybody switched up the bright cap on the VV? I'm interested if this has much effect or not.

Out of curiosity, what is it you are seeking by changing the cap?

[cancelaspirin]

I've learned via back-channel from another forum member that replacing the current pots (attached to the PCB board in the reissue) with push-pull ones is not such a great idea. Without that option I think I'm going to put my musings about this to rest for now. Thanks for all replies.

[uriah1]

Not that it will happen to you, but, I had some mods done to my Vibrolux RI..and I still did not bond with it...and..I parted ways..

I think the best thing I did was 2xalnicos...

[kosmonautmayhem]

No experience modding a VVRI - but I DID mod my CVR to be a VVRI (Moyer Mods) and after going back and forth a few times I couldn't be happier with the VVRI. Its just a great sounding amp and excellent for gigging.

Do what I do....just buy a different amp for different tones. Way more fun!

I also have to agree with Axis...I wouldn't mod the pcb on the VVRI - they're not as forgiving as the handwired amps when you put the iron to it. :)

[firemedic]

I don't have a VVRI but I did build my own VV so here are my thoughts:

The midrange response of the normal channel is easily modified (& reversed) by increasing the resistor to ground (on the normal bass pot) from 6.8k to 10k-25k. Other than that you're looking at some surgery since the RIs have PCBs.

Try a 12AY7 in V1- a "tweed" tube.

Despite the normal preamp being more or less the same 2-stage topology as a Tweed design, the tone stack is too different overall, and the long-tail pair phase inverter sounds different than the "tweed" cathodyne. That's a lot of major surgery.

I'm afraid I agree with Alex & Axis. I am generally pedal-averse, but the pedal sounds like the way to go for tweed tone. If you must mod your amp, try the 12AY7, you don't need a tech for that.

Pick a bright cap you like & use that. In general the one the amp came with usually sounds best with Fenders. Don't forget you have a tone control on your guitar. I feel the stock tone control on most guitars bleed off too much treble to sound good at less than 1/2 rotation. Replacing your tone cap with a smaller value makes the usable range much bigger.

For the record, my homebrew VV normal channel is pretty heavily modified. I was also going for a kinda tweedier sound; it does have its own tone but I wouldn't call it Tweed.

Anyhow, that's my soapbox rant.

[gmann]

If I was gonna mod one I'd put a tube recto in it and a bias pot.

[kosmonautmayhem]

Originally Posted by gmann

If I was gonna mod one I'd put a tube recto in it and a bias pot.

Tube Rectifier: That's the one thing makes me wonder if I'm missing something. How it would compare against the SS recto...

[gmann]

Originally Posted by kosmonautmayhem

Tube Rectifier: That's the one thing makes me wonder if I'm missing something. How it would compare against the SS recto...

Well it would have the sag everyone seems to miss with the SS. I don't know that it would be better but it would be vintage accurate for whatever that's worth. I had a '64 VV RI that had a switch that enabled you to go between the SS and tube rectifier. Big difference and easy to tell. I kept it on SS most of the time. The amp just seemed tighter overall to me. It did sound really good with the tube rectifier it's just that I liked it better with the SS. With the '63 VV RI I imagine the biggest differences could be made with good speakers and a bias pot. I had one of those and used Weber C10Q's in it. It sounded like a different amp.

[cancelaspirin]

Originally Posted by firemedic

Try a 12AY7 in V1- a "tweed" tube.

Interesting suggestion, I'll pick one up and try it out for kicks. I'd been thinking of having one handy to pop into my other amps as well.

Originally Posted by gmann

With the '63 VV RI I imagine the biggest differences could be made with good speakers and a bias pot.

Luckily my VVRI already has the bias pot. And believe it or not I like the speakers it came with. On occasion I've tried swapping one out to compare, and immediately wanted the original back in there. Go figure.

[Axis29]

I've been seriously contemplating the bias pot... and the Tube rectifier as well. But, I am hesitant to mess with this amp too much. I love it so. It is my #1 amp.


I ditched the Oxfarts soon after acquiring the amp and replaced with Jensens (C10R and P10R). I could not be happier with the tone!

I like the added sparkle of the non-Oxford speakers. The Oxfords were very creamy, very jazz sounding. But they lacked a bit of bite I find useful in a band situation... I like the particular note definition I have now. Maybe my oxfords were faulty? Just not clear enough.

[cancelaspirin]

Originally Posted by Axis29

I like the added sparkle of the non-Oxford speakers. The Oxfords were very creamy, very jazz sounding. But they lacked a bit of bite I find useful in a band situation... I like the particular note definition I have now. Maybe my oxfords were faulty? Just not clear enough.

Yeah, I feel like the oxfords can contribute to a more "acoustic" sound...if that makes sense. I've found tone control settings that give punch and chime, but the speakers tend more towards warmth rather than "bite", which has to be coaxed out of the amp.

[firemedic]

[QUOTE=firemedic;4201502]

Try a 12AY7 in V1- a "tweed" tube.

QUOTE]

Okay, I should clarify this statement. Using this tube will not make your normal channel sound like a 5E3.

But since you are considering trying it, let me say that swapping different type preamp tubes (types, not cork-sniffing tube brands) is a worthwhile endeavor in any amp. Any 12AX7 socket can take 12AU7, 12AY7, 12AT7, 5751, et al. And it's so easy.

Experiment. You may really like the sound. I personally use a LOT of 12AY7s to carry the signal in my preamps. I only use 12AX7s where I desire serious overdrive. Any of these tubes may be used as the phase inverter as well. The reverb send tube should be a 12AT7 or 12AU7 since it works really hard and they are designed for that. Plus they're cheap & plentiful.

As always, your results may vary.

[72 reissue]

I have the 63 vvri, is anyone having reverb troubles. I have had to have the springs re-soldered twice and its down again. Also, how can I get more clean volume out of it? Anything above a 5 on the volume starts gettin dirty. I am playing a 72 thinline tel ri thru this amp.

[kosmonautmayhem]

Originally Posted by 72 reissue

I have the 63 vvri, is anyone having reverb troubles. I have had to have the springs re-soldered twice and its down again. Also, how can I get more clean volume out of it? Anything above a 5 on the volume starts gettin dirty. I am playing a 72 thinline tel ri thru this amp.

You may need a new reverb tank if yours has become unreliable.
Replacements are cheap and easy to swap out yourself.

For more headroom, the best place to start is probably with some efficient ceramic speakers...

Cheers,
kM