tube choice for Audible Illusions L1

I have a Audible Illusions L1, and it has humming noise on the left channel. I suspect it is the tube. Also, I would like to smooth the sound a bit more. The recommended and current tube I have is 6h23neb. However, I have someone previously recommends Svetlana 6n1p. I would like to try it out, but it says on the AI FAQ that "6NIP tubes should not be substituted as they require additional filament current and their use will compromise performance."
What does compromise performance means? Does it mean the tube life will decrease? But it won't do any damage on the unit, am I correct?

Also, from the tube store, I can't specify the brand. Is it important to order a specific brand?

Besides the 6h23neb and 6n1p, is there other suggestion that will help smooth out the sound, or make it less harsh?


Showing 5 responses by jea48

I am reading Joe's tube Lore page. He also recommend the Amperex white label PQ 6922. I found a couple posting on eBay, but it is not matched pair and are expensive, average to be $180. =(
09-24-10: Gte357s


Not for the AI

Special warning to Audible Illusions preamp users:
The one you can say for the Sovtek is that you can run it hard and it can take it - and apparently that’s exactly what AI does. Unfortunately the classic NOS tubes in this family just cant take this kind of treatment and will rapidly fail when used in these units (and some of you guys have the fried tubes to prove it!). So you AI users are probably best off limiting yourselves to the Sovtek, the Russian 6H23N & 6N1P, the 7DJ8 and the E288CC. There may be others the range of tube types and variations is quite literally bewildering but these are the ones I’m aware of that should be able to handle the higher stresses of this brand of preamps. I review the Edicron, Siemens E288CC and 6H23N here but there are other brands for some of these. I’ve seen Phillips E288CCs & Amperex 7DJ8s advertised on some web sites in the past and there are probably others. It might be worth your while chasing them down & evaluating them for yourself to increase the number of alternatives for use in your AI.
Previous production Modulus M2, M3, M3a and L1 preamplifiers used Russian 6922 tubes.
09-24-10: Gte357s


You have the L1 correct?

09-24-10: Audioconnection
Go inside the unit and make sure the Cap dip switches are set to on
the amp you are using may better interface this way.
Also call AI with your serial number and they will
get you the right tubes for that unit
Best Johnnyr
Sounds like good advice.

09-24-10: Theduke
Get some choice EH6922. Try "The Tubeman". He has cyro'd tightly matched triode pairs available.
Also good advice
A good rugged tube.
I hear intermittent hissing sound.
10-16-10: Gte357s

That could be a dirty tube socket contact/s. With the preamp turned off try unplugging the tube from the socket and plugging it back in a few times to clean the socket contacts.

Sounds like the tube is bad. It can happen with a new tube.... Call Upscale Audio, 909-931-9686. Explain to them the hiss moved from one channel to the other as the bad tube was moved.

You may have to pay a shipping charge. Can't say for sure.