[Spirit]

Okay, here's the deal.
I own a preamp that I am sure is not familiar to most of you.
It is a Musical Desigm SP2B Vacuum Tube line stage.
There are 2 tubes, one for each channel.  The tubes are 6DJ8 design, and each twin triode operates as a single push-pull voltage gain stage.
I have never tried playing with different tubes and I don't even know for sure which tubes are in the unit, because they are inside the chassis and I have never bothered to check inside.
I know there are many ACers who are real tube afficianados.  Would experimenting with different brand name tubes really make a differnece to the overall sound of the unit?
I have a feeling that the tubes are Sovtek's.  Any advice/direction/opinions who be appreciated.
Thanks

[hmen]

In most cases the 6DJ8 can be swapped with 6922 or the EC88. Changing the tubes will almost certainly change the sound, for better or worse. There are usually good NOS 6DJ8's and 6922's on ebay for reasonable prices that would be an improvement over stock tubes. It's definitely worth a try.   

[WEEZ]

Spirit,

You might check with John Hillig...he has a stash of tubes that he really likes with the SP2B. And as you know, John has a pretty good ear. You might also ask if there is enough heater current to run 6N1P's in the SP2B. If so, you might be pleased.....

WEEZ

[avahifi]

The 6N1P pulls about twice as much heater current as the 6DJ8 (600 mA vs 300 mA).  But if you have enough power supply for it, and the circuit is biased well for it, the 6N1P can provide significantly better musical results.

Frank Van Alstine

[WEEZ]

Frank is correct...

I think I remember reading, however, that John had found some 6922's that worked really well in his curcuit...they may well be the Sovtek's you have...best to check w/ John re: compatibility and stuff...

WEEZ

[Spirit]

Frank is correct...

I think I remember reading, however, that John had found some 6922's that worked really well in his curcuit...they may well be the Sovtek's you have...best to check w/ John re: compatibility and stuff...

WEEZ

You are right WEEZ... I will give John a call on Monday.  I know that his website states that the tubes are Sovtek but he mentions a "Special Plate" version.  I should open the SP2B and see what is in there.
Thanks for the kick in the head.  I should have remembered to call John.

[sturgus]

Hey Spirt, what is the rest of your gear? The SP-2 is a nice pre. The sound you are looking for will determine what tubes you use. Right now I am using the tubes that John is selling (Matsushita National brand).These tubes have very good focus and nice balance. I also like the (Amprex 7308 white lettering). Depending on the version of your pre you might be able to run the 6n1p with out modification. This is also a very nice sounding tube. When you talk to John ask him about upgrades, that pre can be made to sound even better.
Sturgus

[Spirit]

Hey Spirt, what is the rest of your gear? The SP-2 is a nice pre. The sound you are looking for will determine what tubes you use. Right now I am using the tubes that John is selling (Matsushita National brand).These tubes have very good focus and nice balance. I also like the (Amprex 7308 white lettering). Depending on the version of your pre you might be able to run the 6n1p with out modification. This is also a very nice sounding tube. When you talk to John ask him about upgrades, that pre can be made to sound even better.
Sturgus

Hi Sturgus:
I have the SP2B that has been upgraded to Platinum level.  I don't think there is much more that I can upgrade.  I never bothered to ask John which tubes were in it because...well, I just didn't ask.  I bought this pre new from John a few years ago.  It is an unusual model because this was a one-off unit that John had built with an outboard power supply.  I sent it back to him a few months ago and he replaced the outboard supply with a better one and he did some further mods to bring it up to Plat level.

[Spirit]

The 6N1P pulls about twice as much heater current as the 6DJ8 (600 mA vs 300 mA).  But if you have enough power supply for it, and the circuit is biased well for it, the 6N1P can provide significantly better musical results.

Frank Van Alstine

Thanks for the info Frank.
Would you be able to elaborate a little more on this advice?
Is it the 6N1P itself that can potentially augment musicality or is it the fact that the tube pulls twice the heater current?
I Googled a little this afternoon and could only find one tube like this whcih is a Sovtek.  Do you have any further tube information?