Tubes for a Conrad Johnson 17LS?


I just purchased a (used) CR 17LS Pre. This is not the 17LS2 version. I haven't got it home yet, but I'm already wondering if there's some experience out there with 6922 tubes. Also, are there other tube types that will work in this unit that are not 6922s? Thank you in advance, for your time!
128x128mdrummer01

Showing 3 responses by dopogue

There's a section of FAQ (Frequently Asked Quesions) devoted to tubes over at Audio Asylum with a LOT of information about 6922s and equivalents. I just bought a quartet of Amperex 6DJ8 tubes (6922 equivalents) and they are much better than the stock Electro Harmonix 6922s that came with my used 17LS2.

You can also play with pairs of tubes, recognizing that tubes 1&2, looking at the four tubes from the front, serve the left channel and tubes 3&4 serve the right channel. I've used Siemens 7308s (another equivalent) in positions 1&3 and Mullard E88CCs (yet another) in positions 2&4 with great success. Still trying to decide whether these sound better than the Amerex 6DJ8s.

Have fun tube-rolling. There are PLENTY of options. Dave
Regarding the use of different tube types (2 of each), you're on your own here. I was told by someone I trust and respect in this area that there is no problem in doing so, and I've tried various combinations with no ill effects. I guess I'd like to see a definition of "unwise," Jtimothya -- what is the real downside?

I agree that you should get the measure of the stock tubes first, and they're really not bad. But I don't plan to go back to them anytime soon! Dave
Jtimothya, thanks for the info. I take it to mean that best results would come from using the same tube type in positions 1&2 and 3&4 rather than 1&3 and 2&4, assuming you have only two tubes of the same type. My unit is a 17LS2. Dave