Recommendations for swapping out tubes in a mic preamp

[UstadKhanAli]

I asked this question in Phil's forum a while back, and for some reason cannot find the thread at all, or in my email, where I was sure I saved it. Grrrrr....

 

I have a Peavey VMP-2 tube mic preamp. It has the stock tubes, which are, according to Sound on Sound:

 

Amplification inside the VMP2 is performed by six valve triode stages (three 12AX7 (ECC83) double triode valves per side), plus a 12AT7 (ECC81) double triode driving the balanced output to a healthy +22dBu into loads of greater than 2k(omega).

 

I like the sound of it, but was wondering if there were recommendations for tube swaps that would make the mic preamp more "interesting" or stereotypically "tubey" or "better" (whatever that may mean). If you're wondering what exactly what I'm going for, well, so am I. I'm essentially fishing for ideas. I like the sound, but just like anyone else, am wondering what - if anything - I could do to change the sound.

 

I currently use it mostly for drum overheads and guitar cabinets, as well as a DI for keyboards.

 

Sound on Sound article on the Peavey VMP-2

[UstadKhanAli]

I should have changed the subject header to "modifying" or something like that since I would be interested in hearing if there are different transformers that could make the Peavey sound "better". And again, I am admittedly fishing for ideas, and am not dissatisfied with how it sounds.

[D Charles]

Well, I'm not Phil, but I think he'd say Jan/Phillips NOS tubes might be cool.

 

You can check many NOS brands and they'll be nicer than most of the Asian and modern European ones. The Telefunkens for example can get really pricey, but many NOS's are pretty reasonable.

 

Also, if you're wanting to try a new set and the vintage guys are wearing you out, you can go with Electro Harmonix as they are graded.

 

Your bad luck is needing 12ax7's. The 12at7's are not nearly so much in demand for guitar amps and aren't zonked out price wise by supply and demand.

 

Good luck and let us know if you hear a cool difference!

 

[gtrbass]

Swapping out tubes is a simple, reversible upgrade. If you have a budget tube pre, you will often hear a huge difference swapping out the Chinese or Russian made "bulk" tubes for better grade E-H or GT versions. The reason is that the E-H and GT audio tubes are hand selected.

 

The Peavey pre's are really nice, but I'll bet the tubes are Russian made standard Sovteks.

 

New Tubes:

E-H makes a Gold series 12AX7 that sounds great.

GT makes a Mullard re-issue that has nice features.

JJ Tesla also markets a great sounding 12AX7.

 

NOS Tubes:

You can hear a difference with vintage NOS telefunken, Bugle Boy, and Mullards, but it probably isn't worth the investment. These tubes are in high demand, limited supply, and cost a lot of money. If a NOS tube is dead after 6 months, you're out a but of money. If an E-H dies in 6 months, you're out about $20.00.

 

There are also cryogen treated new and NOS tubes available out there, but I have no idea whether this is worthwhile or audio alchemy/snake oil.

 

Some examples:

I have a couple of the ART Pro MPA units built in 1996. They aren't everybody's cup of tea but I like them for certain things. Replaced the stock Sovtek 12AX7's with GT mullard reissues in one and EH Golds in the other. They made a nice difference.

 

I have a couple ART Pro VLA compressors. Replaced the stock Sovtek 12AY7's with E-H golds. They sounded great before and even better after.

 

I have a Rode K2 mic. Replaced the stock Chinese made 6922 with an E-H gold... WOW!!! Massive improvement.

 

Total upgrade costs - $160.00 About what I'd pay for one NOS telefunken.

 

I get my tubes from http://www.tubedepot.com/

[UstadKhanAli]

Cool, thank you very much for the advice!!!