From bruce@ashbysolutions.com Fri Oct 04 18:19:33 2002
Subject:In praise of tubes (valves)

All,

I just replaced the tubes in both of my ART Dual MP preamps. (They are both 5-6 years old, and it's probably time to change them.) I called ART to get replacements. The last time I talked to a tech there, he told me: a) the tubes are hand-selected to ART's specifications; and b) no other tubes will work quite as well, thanks to the unusual design of the ART preamp. This time, the new tech confirmed a), but said b) was really not true; any quality 12AX7 would work. In fact, he seemed very reluctant to pass me over to the parts department to order replacements. So ...

I went to my trusty tube dealer, Bob P. at Eurotubes (www.eurotubes.com) -- who is also a member of this forum -- and ordered some of his JJ ECC83's. I used JJ's exclusively in my hot-rodded Peavey Classic 30 during my last foray into pretending to be a guitarist, and they performed so well that it seemed like they were worth a try. For a few more dollars, he matched them into pairs for my Dual MP. I bought three sets, and each set had ratings of between 85-90 on both parameters (gain and transconductance, I think -- Bob?).

Oh, the SOUND!!! The JJ's are much smoother than the (unlabeled) ART tubes, and they stay clean longer when pushed, finally breaking up rather quickly but musically -- a lot more like a pentode power amp, rather than the triode tubes that they really are. I highly recommend them to list members for their preamps. Oh, and JJ also makes a KT88 that is supposed to be terrific in Leslies, although I've never heard them.

And no, I don't get any sort of kickback or discount for saying this. I just really like the tubes.

Regards,

-BW

--
Bruce Wahler
Design Consultant
Ashby Solutions™ http://consult.ashbysolutions.com
CloneWheel Support Group and HiNote moderator
978.386.7389 voice/fax
bruce@ashbysolutions.com