Replacing the Tube in my Preamp

[Shaky Tee]

Hey all!

A long time ago, in my perusings around the internet, I read of someone replacing the resident tube in his ART MP Studio Preamp, and REALLY, REALLY liking the resulting sound. And a bunch of others chiming to say that they replaced the tube in their ART preamp with positive results.

Could someone in here tell me their experiences in replacing the tube in their ART MP Studio Preamp, the results, and if the results were positive, what model # the preamp tube was that was used to replace the one in the ART MP Studio preamp? And where I can get it (I'm assuming Radio Shack has these, and if so, I can just go there during my lunch hour and pick it up.)?

Sorry for the run-on sentence. Thanks for your help!

 

[Rodger Hartlett]

Take the tube out and have a good look at it.It most probably be the 9-pin triode variety.It could be ecc81,ecc82,ecc83, or 12AX7 or 12AT7.These numebers could be written on the tube in one form or another.If there is an extra letter do not streess out.
ecc81,ecc82,ecc83, or 12AX7 or 12AT7 or 12AU7 ( this has less gain ) or even 12AY7 ( less gain as well )
All these are interchangable like margarine is to butter or pepi is to coke.You could even try a 7025 but that's a rough sounding tube for a preamp.Nothing will explode or be damaged in the process.There will be no smoke.
Just relax and unplug the mains always before changing anything on any piece of electrical or electronic equipment.Except guitars.

 

[paddyponchero]

I put an EI 12AX7 long plate in my tube mp. The tube will make a difference but the ART MPs aren't a very good design to begin with so you might be better putting the money towards a VTB1 which will give you plenty of clean gain.

 

[Bob's Mods]

Changing tubes in these "starved plate" (cheap tube circuits) designs will generate a small impact on the actual output. They are not worth putting costly NOS tubes in them. Try some cheap newer Chinese or Russian tubes for the hell of it. You might like the minor change that occurs.

Bob

 

[PhilGood]

Bob's right. In a starved plate you won't notice much. There is a full mod for the Art MP, but it's complicated. I've replaced OP amps that made more of a difference.

If you ARE going to try the tube replacement, go for a used tube of a reputable name. Replacing a cheap tube with a cheap tube is pointless. You'll want a Phillips, RCA , or something good, but not too expensive. It's pretty dumb to put a $65 Telefunken or Mullard tube in a pre if its only going to have a 5-10% effect on the sound.