Tube Hiss on X-CAN v2
Sept 9, 2020 16:21:15 GMT
Post by pcowandre on Sept 9, 2020 16:21:15 GMT
Firstly .. let me start with some thanks to all for such an excellent source of information. It really looks like a great community pulling together here.
Next, the somewhat stumper. I've read everything I could find (including the other hiss threads, which seemed to all point to bad tubes), and either I've been exceptionally unlucky or I've missed something.
I'm trying to swap some different tubes into the X-CAN v2. With the stock tubes, no hiss, no noise, nice black background. With everything else, there's an annoying level of hiss. I've tried a pair of Mullards (hiss central) and a pair of Genelex Golden Lion (one is almost silent, the other hisses with enough force to drown out quiet music).
I've walked through the schematic (to an extent!) and checked voltages with a multimeter -- everything seems to be within reasonable order, although heater voltages are closer to 6V than 6.2 and the +/- 22.9V rails are around 22.4. I've checked the sockets, cleaned them (and the tube pins) and swapped tubes in and out quite a bit. This amp had TR206 come loose and tear the tracks, I repaired that damage but didn't replace TR206 since it seemed to be fine.
There's not much difference in the hiss level from cold turn-on and settle vs being left on for an hour.
No capacitors look problematic and the sound quality with the stock tubes is fine; I'm just hoping for a little more with finer tubes. Instead, I seem to be getting more hiss.
Ideas? Thanks for taking the time to read this.
Next, the somewhat stumper. I've read everything I could find (including the other hiss threads, which seemed to all point to bad tubes), and either I've been exceptionally unlucky or I've missed something.
I'm trying to swap some different tubes into the X-CAN v2. With the stock tubes, no hiss, no noise, nice black background. With everything else, there's an annoying level of hiss. I've tried a pair of Mullards (hiss central) and a pair of Genelex Golden Lion (one is almost silent, the other hisses with enough force to drown out quiet music).
I've walked through the schematic (to an extent!) and checked voltages with a multimeter -- everything seems to be within reasonable order, although heater voltages are closer to 6V than 6.2 and the +/- 22.9V rails are around 22.4. I've checked the sockets, cleaned them (and the tube pins) and swapped tubes in and out quite a bit. This amp had TR206 come loose and tear the tracks, I repaired that damage but didn't replace TR206 since it seemed to be fine.
There's not much difference in the hiss level from cold turn-on and settle vs being left on for an hour.
No capacitors look problematic and the sound quality with the stock tubes is fine; I'm just hoping for a little more with finer tubes. Instead, I seem to be getting more hiss.
Ideas? Thanks for taking the time to read this.