My mistake Tls49, the tube in question is a cv4003 not cv4004 as I previously reported. I have it in the rear position of the unit which is designed to be a 12au7. The second position , normally a 12ax7 has an RCA cleartop(12au7)for toning down the gain. Modwright suggests the original 12au7 position is the more dominant. I haven't experimented with flip flopping the two 12au7. The cleartop is fast and revealing, the Mullard smooth and rich relatively speaking. Switching might enable a different sound. One thing I'm clear on; two cleartops is too bright in my system.
intermitant phono tube cut out?
when playing records thru mod ls100 phono circuit right channel volume drops off to near zero after 2 hours or so of playing. turning off the system and playing a day later will yield the same results meaning ok for 2 hours then notta.. digital sources thru the modwright play correctly(both channels present). Swapped left for right ics from rc and problem stays in the right channel.
swapped out both tubes in the phono circuit and problem has not reoccurred. reinstalled my sonically preferred tube back in and problem reoccurs.
My conclusion is that my preferred tube is the issue. Being new to tubes,I'm surprised this tube (mullard cv4004- 150 hrs} goes "bad" in this manner. Is this typical tube behavior near the end or am I missing something?
swapped out both tubes in the phono circuit and problem has not reoccurred. reinstalled my sonically preferred tube back in and problem reoccurs.
My conclusion is that my preferred tube is the issue. Being new to tubes,I'm surprised this tube (mullard cv4004- 150 hrs} goes "bad" in this manner. Is this typical tube behavior near the end or am I missing something?
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- 20 posts total
- 20 posts total