Hi Stuart,

I retubed my Pro MPA's with Westinghouse 12DF7's and Mullard 12AT7's, both are lower gain (Gain factor of 70 instead of 100 for a 12AX7, the stock tubes). They're much warmer than the stock 12AX7's. I also bought some Raytheon 12AX7's which are better sounding than the stock tubes that came in them, a bit smoother and more "air".
Here are a couple of places to find replacements:

http://www.vacuumtubes.com

Link removed

thanks for the recos! very helpful.

would changing the tube in the ART MP Studio V3 make any difference in the sound? it's a starved plate "toob" unit

I don't have any experience with the MP series, but others here have said that the quality boost would be negligable, since the rest of the circuitry is so-so........but for a few bucks, why not try?

changeng wrote: thanks for the recos! very helpful.

would changing the tube in the ART MP Studio V3 make any difference in the sound? it's a starved plate "toob" unit

Changing the tubes on your pro vla will not void the warranty.

Jon has some good recommends for alt. tubes. Also, the NOS JAN Philips 12AT7WC is the coolest tube I've heard in the pro vla yet for acoustic instruments and voice. They're quiet, richly bright (like a bright orange/yellow) and very vibrant. They can also provide a nice bit of crunch when you push them hard.

The Mullard AT7's are very nice too. They're a little softer than the Philips, silkier, rich in complex harmonics with pretty fast transients. I also like the Westinghouse tubes as Jon mentioned.

If you can change the tube in the V3 you really notice a difference if you put a lower gain tube in there, like a 12AU7 or 12AT7 or even a 12AY7. Using a lower gain tube will even out the overall response of the unit, provide you a lower noise floor (depending on the mic and room) and reduce microphonics that otherwise make the signal muddy and/or gritty.

it was I who mentioned the tube change in the Pro Channel..... i replaced the pre-amp tube with a tube from:

http://vintagelectron.com/

the tube was 12ax7a shuguang no silkscreen, 9th generation tooling

works great for me...... and no it will not void the waranty

Peace,
BEN

Thanks guys! :D

I'm getting great ideas here. I should be receiving the Pro Channel today or tomorrow. I just put an old EH 12AX7 from a VOX Pacemaker amp that's not working and I'm already noticing a subtle difference in the V3.

twenty5south - is there anything about the Pro Channel you don't like? If so, how do you work around it? Any feedback would be great - I kinda have to hit the ground running when the Pro Channel gets here.

I dont have any complaints about the pro-channel.... very nice piece of gear in my opinion, considering its a "budget" piece

Peace,
BEN

twenty5south -

did you choose the 12ax7a shuguang over a different brand for a reason? I'm trying to learn what makes tubes different.

CoyoteTrax -

for the different tubes you suggested for the V3, are there brands you'd recommend over others?

actually that tube was recomended by another pro-channel owner who had made the switch and liked the result.... for what reason he chose that tube i have no idea, other than its "tonal qualities".

Im no expert but i think the things that make the biggest difference in tubes made by different manufac. is the quality of the build, materials used, and some internal design differences..... add all these factors (plus some im sure) together and the result is gonna be different sounds for different tubes.... experiment pick up a few different manufac. tubes and try them...you may find one that you like better. Just remember (and i prob. dont need to say this, but.....) you can only use 12ax7 tubes in the pro channel. Let me know if you decide to try some other tubes and find one interesting.

Peace,
BEN

twenty5south wrote:

Just remember (and i prob. dont need to say this, but.....) you can only use 12ax7 tubes in the pro channel.

The 12AT7, 12AU7, 12AY7, 12DF7 are all in the 12AX7 family. If you snoop around the 1st link I provided, there's a 12AX7 page with the various models and what they're designed for. These are all lower gain models and will work very well in the preamp stage. They're much harder to clip, so dialing in levels is a breeze.

Ditto what jonyoung said.

12AX7 is a "type" and you can use any tube in that type, or family as a replacement.

changeng, you asked about specific brands for the V3 and as for 12AX7's specifically I prefer NOS tubes like RCA, GE, and Philips. For newly manufactured 12AX7's I really like Tesla/JJ's 12AX7/ECC83S because they're silky smooth with very low microphonics. IMO the Tesla's are some of the very best being manufactured today and they're dirt cheap. I also like Ei's 12AX7 (Yugoslavian) and Groove Tubes Gold series.

As a note, the EH (electro harmonix) 12AT7's aren't bad.

BTW, tube dampers aren't a bad investment either.

Thank you so much for all this info! I'm learning TONS here.

I'm looking for weird sources for sounds and tones and I'm thinking of getting an old Vox Pacemaker repaired and modified to be an ugly preamp. It's a tube model, has 5 tubes, tremelo, no reverb. If it's not too much to repair, I'm planning on getting a lineout, phantom power and a XLR input installed and am looking for ways of making this primitive thing less noisy than your standard late sixties 15 watt noisebox.

Along with tube dampers (thanks!) do you have any suggestions for what to add to bring down it's noise/hum content?

Youse guys is GENIUSES, I tells ya, GENIUSES !

The tube complement probably has nothing to do with the noise. It probably needs to be re-capped by a tech. Even then, you'll still get some noise from that amp. Guitar amps are just noisey man, even new ones. They hiss. That's where a noise gate comes in for me personally. I'm all for using old electronics as a mic pre or line amp and actually make weird audio paths like that all the time. But get yourself a little noise gate to help "get the hiss out", if you don't already have one. Noise gates are great for vocals, electric guitars, and of course drums. Old tube driven reel to reel recorders make for great mic pre's to be used in the fashion you're talking about too. Talk about a cheap way of adding pure analog nostalgia to your recordings... Talk about ugly mic pre's that impart interesting color to your soundscape... Old RTR's are great for that. Not to mention also the fact that they make better guitar amps for recording than most guitar amps do.

Oh, and by the way I'm actually kind of an amateur idiot. Beware. But, at least I only speak from experience.

I'll probably do the gating on my puter after the fact, so I can really control things (sometimes a little noise is kinda needed for a track, yes?)

I LOVE the idea of the RTR ! Maybe I'll garage sale up an old Wollensak this weekend.