The humble VMP-2: mods?

[OzNimbus]

Ok, here's a question that's been burning in my mind for a while. Consider the Peavey VMP-2.... Most guys won't touch anything labeled "Peavey" with a ten foot pole, with good reason too. However, the VMP-2 seems to be an exeption to the "Peavey=Crap" equation.
I've heard various stories, none actually confirmed, that Audio Media Research actually designed the VMP2, then Peavey came along and bought the company so they could slap thier name on someone else's product. Hence the "Peavey Audio Media Research" logo on the VMP-2.

So unlike just about every other sub $1000 US "tube" preamp, which are usually tube/solid state hybrid bastardisations, the vmp2 is actually a purebred. 3 12ax7's in the input stage, per channel, and one 12at7 in the output stage, per channel, for a grand total of eight tubes. Not to mention a hefty power supply, and very solid construction all around.... it also wieghs an fn' ton!

Now I'll just say up front: This preamp sounds ****ing great. If you use the -10 outputs as opposed to the +4's, you get an amazingly transparent sound. That's what seems to be the big secret about this piece of gear. This is based on 'Recording's Paul J. Stamler's findings. Something about the output transformers on the +4 outputs not bieng up to snuff, and they colour the sound in a not so nice way. As long as you stick with the -10 outs, you're golden.

Now some might consider this sacrilige, but I actually prefer my Vmp-2's to my 1272's on certain applications. On blind tests, I've had clients and friends pick the Vmp-2's over the 1272's on more than a couple of occasions as well. Then again, it's all dependent on the instrument bieng recorded. On drums, the 1272's absolutely smoke the Peaveys.

So, now to my question: I've got 3 of these things sitting in my racks, and I've heard about some people "hot rodding" them. I'm not to sure how it's done, but I'd love to do a little science experiment on one, so I can add to my "preamp palette" so to speak. Any suggestions?

-0z-

[Jay Kahrs]

The 1/4" outs are actually +4 unbalanced. The XLR out gives you the tranny and the 1/4" is transformerless. AMR has been a part of Peavey for years and years. Remember the big consoles they used to make like the 2400 and 3600? They also make lots of install stuff and things like zone delays.

The only hot rodding I've heard about is people experimenting with different tubes. I'm sure that you could probably replace or remove some of the caps to open it up a bit more. That probably wouldn't be a bad thing since it can be rather dark and thick. I don't think I'd use six channels of them while cutting basics but I like the one I have and I'd pick up a second if it was cheap enough. If anything I'd mod them to add a phase reverse switch.

[Paul Turpin]

I've got one of these that is on quasi - permanent loan from a client. One of these days he might run out of money and pay us with it. After that point - I might consider mod-ing it too.

What about creating a balanced transformerless output - would that sound better than either of the regular ones?

Not knowing much about the unit - I've only used the XLR's so far. And, yes - its one of only two peavey products I've ever enjoyed using. The other one was their PC1600 midi fader. Although - that was fairly safe seeing as though audio never went through it!

[Jay Kahrs]

Originally posted by Paul Turpin
What about creating a balanced transformerless output - would that sound better than either of the regular ones?

Not really. You'll get another 6dB of gain because it's balanced but that's all.

[Paul Turpin]

How about a switch to chooses whether the Tranny is IN or OUT of the XLR?

[OzNimbus]

Ok, I dug up the article, take it for what it's worth. This is a quote from "Recording's" review of the unit.. July 1998.

"Peavey has made a noble effort with the balanced outputs, but I can't recommend them, given thier distortion performance. Instead, I think the VMP-2 should be considered a very fine tool for use with unbalanced inputs at -10dbv. In that envrionment it's distortion performance is beyond reproach."


Jay pointed out the 1/4 inch outs are +4's. Am I missing something here? Somone please clarify this!

It's been my experience, that setting my Daw's inputs to +4 while using the 1/4 unbalanced connectors didn't give very satisfactory results. In fact I had to crank the gain over so far that it sounded downright ugly.

I've always had great results with the unbalanced outs feeding a -10 input. You should give it a try, Paul.

And Jay, I like the phase reverse idea.... as for swapping tubes, any recommendations?

[Screws]

So based on the common understanding that the output transformers are crap, is it feasible to swap them out with something top-notch?

[Paul Turpin]

I've always had great results with the unbalanced outs feeding a -10 input. You should give it a try, Paul.

Yeah - I gotta get me a -10 snake for the unbalanced inputs on my 192.

[OzNimbus]

Originally posted by Screws
So based on the common understanding that the output transformers are crap, is it feasible to swap them out with something top-notch?

Well, that's just the thing. I'm not sure the trannys are that bad, its just that the tubes don't want to push out that hot of a level. At least, that's what Stamler's review was getting at.

[Paul Turpin]

Well, that's just the thing. I'm not sure the trannys are that bad, its just that the tubes don't want to push out that hot of a level. At least, that's what Stamler's review was getting

All the mic pre's I actually like have a seperate and nice sounding output Gain circuit and control - which is what the VMP-2 lacks. Adding one internally would be cool - but a fair amount of work. And would it be tube or SS or what. This is certainly a mod out of my league. But at the same time - I don't want to use up other outboard gaining it up either AND I want the option to go straight into the recorder with it rather than into the board fist - it would be so much more conveinient in the box!

I do plan on going the -10 output route - but I think what we are talking about here is what we wish we had rather than what we do have.

[groundcontrol]

If you change the output tranny with one that gives you some step-up gain, you could get back some of the headroom you're lacking.

There are two different output points too on a Neve 1073. An unbalanced one at minus -8 (that in the board fed the solo buss) and the main transformered balanced out at 0 (+4dB). There is actually more than 8 db of gain wound in that output tranny. Actually most signals travel unbalanced at -10 inside a mixing board and most don't have a direct output with transfo. So retrofitting an output tranny on them is a somewhat common mod when you want to use them standalone. (Brent Averill does exactly that on a lot of the vintage modules he refurbs/racks.) Frankly the fact that my Helios modules have an unbalanced output at -10 certainly doesn't prevent me from getting great sound out of them, it's just more of a hassle to use them and I have to watch not to overdrive them... until I take the time to do a mod exactly like that...

Hope that helps!

[Jay Kahrs]

Originally posted by Paul Turpin
All the mic pre's I actually like have a seperate and nice sounding output Gain circuit and control - which is what the VMP-2 lacks. Adding one internally would be cool - but a fair amount of work. And would it be tube or SS or what. This is certainly a mod out of my league. But at the same time - I don't want to use up other outboard gaining it up either AND I want the option to go straight into the recorder with it rather than into the board fist - it would be so much more conveinient in the box!

Usually that's just an output fader which is really just an attunation circuit. Adding one to the VMP-2 might be more work then the box is worth. Maybe the 1/4" out is -10. I don't know for sure. But, I tried both the 1/4" and XLR when I got it and preferred the tone of the XLR out. I haven't swapped the tubes in mine. It's just something I haven't had time to get around to.

[Fibes]

Attenuation on the output isn't gonna help with the distortion "issue," in fact, it will hurt. Gee whiz, a lot of my favorite preamps don't have attenuation pots on them. Hmmm?

Leave the VMP-2 alone. It's a good pre that happens to be a bit squishy. Use it where it excels and you won't have anything to complain about. If you were to mod three units with good output trannies you could be close to one or two OSA preamps.

[s2n]

Joe Barresi's favorite mic-pre. It's all over the new QotSA.

[OzNimbus]

Originally posted by Fibes
Attenuation on the output isn't gonna help with the distortion "issue," in fact, it will hurt. Gee whiz, a lot of my favorite preamps don't have attenuation pots on them. Hmmm?

Leave the VMP-2 alone. It's a good pre that happens to be a bit squishy. Use it where it excels and you won't have anything to complain about. If you were to mod three units with good output trannies you could be close to one or two OSA preamps.

I take it you're referring to the "Old School Audio" pres?

BTW, I just want to mod 1 of 'em to have a little more on my palette. Anyone have any ideas when it comes to different tubes?

-0z-

[Rader Ranch]

Jim at Audio Upgrades.com (...in LA) has around $400 worth of upgrades he does to these things, but strangely enough the one thing that doesn't include is the output transformer....that would be even more $$$. but he certainly isn't short on ideas if you're thinking other tubes and the like.

i still haven't played with mine enough to get a feel for it....though:

Originally posted by s2n
Joe Barresi's favorite mic-pre. It's all over the new QotSA.

really worries me, 'cause i finally gave a listen to that CD, and it left with a burning desire to resurrect a long dead thread from around here somewhere..because god DAMMM does it sound bad!!!! holy mackerel...

[mplancke]

Originally posted by OzNimbus
BTW, I just want to mod 1 of 'em to have a little more on my palette. Anyone have any ideas when it comes to different tubes?
-0z-

I thought the Peavey used Jensen transformers, oh well...

Anyway, try some Telefunken tubes in there, very nice but pricey.

Mark

[Fibes]

Originally posted by mplancke


I thought the Peavey used Jensen transformers, oh well...

Anyway, try some Telefunken tubes in there, very nice but pricey.

Mark

I thought I already posted this... The Peavey is voiced for the tubes shipped in it. People I've talked to that have swapped the tubes out for Telefunkens and other NOS gems didn't notice any REAL difference. Once again you could buy another pre for the cost of the tubes.