2. amps-preamps
  3. 1285350105

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?

Thanks.
gte357s
gte357s OP
281 posts
 
I tried different combination.

Caps on with Main 1 out - harsh or dry
Caps off with Main 1 out - sounds thin, less musical, but easier on listening
Caps on with Main 2 out - it seems it improves the situation a bit, not as harsh. Or according to the manual, it removes tube glare.

I prefer to have caps on and Main 2.

Per the previous owner, the tube is Russia military grade 6h23neb with less than 50 hrs.

I also tried switching the left and right tube, but the buzzing noise is still louder on the left channel, so, it is not because of the tube. It is not a big deal, can't hear it at the sofa.

I am egar to try out the 6922 and see how it sound.
audioconnection
1,270 posts
 
You could have either a bad interconnect on one ch
try swapping them.
A transformer from a CD player or something else located
just inches under or over the pre amps shell could be provoking a hum.
Try moving and or relocating the closely located culprit.
Best Johnnyr
gte357s OP
281 posts
 
Thanks for the advice. I don't think it is because of the interconnect though. I got the noise since the first day I got this preamp, then I upgrade the interconnect, and the noise is still there. Maybe some capacitor are old? Inside, there is a sticker says it is checked in 96. So, it is a 14 years unit. Is it about time to have a service and replace some capacitor?

I did some more listening, the Main 2 out seems work for me. It remains musical with good sound stage, and the harshness or glare is improved.
jefgerard
8 posts
 
I have had L-1 for about 7 years. One day the tubes went bad it made a harsh static kind of sound. I replaced the tubes and all was fine. On the Audible Illusions site they recommend tubes to use and not use. I had a set of brand new Svetlana tubes which I used. I then went on ebay and got some cheap mullards. When I replaced the Svetlana tubes with the Mullard tubes there was a noticeable increase in fullness and base. Also I notice that the highs were less fatiging
gte357s OP
281 posts
 
i finally got the Electro-Harmonix-6922 and listened for an hour, so far, I like it. it doesn't have the glare as in my previous 6h23neb. I also feel the detail and sound stage are improved
More to discover