Presonus Tube Pre mods?

[LeedyGuy]

Does anyone have any decent Presonus Tube Pre mods? I have 2 of these and a bunch of different 12(xx)7 tubes lying around that I would like to put in it, but I think that it won't make much difference because there's so much shit color weirdo crap in this thing that a different tube may not matter much. What I want to do is bypass any opamps or whatever else might be effecting the sound in here to get it to be just plain 12(xx)7 tube-y. Suggestions? I did a Google to no avail.

Another question: I have a few 12(xx)6 tubes...will that work?

[Andy Peters]

What I want to do is bypass any opamps or whatever else might be effecting the sound in here to get it to be just plain 12(xx)7 tube-y.

The tube in that box is a starved-plate placebo. The unit is a solid-state preamp. Trying to bypass the op-amps means you'll bypass everything in the box.

-a

[mu_amps]

you can't polish a turd

[Jeff White]

EH 12AY7

[LeedyGuy]

The tube in that box is a starved-plate placebo. The unit is a solid-state preamp.
-a

Can you elaborate on this a little?

EH 12AY7

Hahahahaha! Nice. I know all about that box, but I'm looking to make my Tube Pre usable, not pay for a new pre. I have plenty of usable pres like a Sytek and a Black Lion PR8, but I thought this might be a fun project.

Can anyone give me any info on the 12(xx)6 tubes? Will those work?

-Ken

[brianroth]

Which "12(xx)6" tubes are you referring to?

Bri

[LeedyGuy]

I have a couple tubes that are maybe interesting.

Hitachi 12BA6
Hitachi 12BE6
RMS 12AT6


My other ones that I'm considering (if it doesn't have the brand then I don't know it).

12AU7A
12BH7A
RCA 12AU7A
Sylvania 12BY7
RCA 12AU7A

[brianroth]

There is a whole "family of cousins" in the 12A (xxx) 7 numbers. They are dual triodes with identical pinouts and heater voltage/power requirements.

These include 12AT7, 12AU7, 12AX7, 12AY7 and 12AZ7. The main differences are in the mu/gain of each of the triode sections.

None of those other tubes listed in the earlier posting (besides the 12AU7) are compatible...different internals (pentodes, etc).

The 12BH7 has the same pinout, BUT requires 2X heater current.

Bri

[trask]

but I think that it won't make much difference because there's so much shit color weirdo crap in this thing that a different tube may not matter much.

You'd be amazed at the difference in sound. At least worth a try before you go inside and start ripping out IC's. I have little knowledge of this pre, but I know I've found results I was happy with by changing tubes out in other ones.