Todd, as Kenny pointed out a little judicious tube swapping can lead you to a bad tube if the distortion is channel-specific. You don't mention what "way up" might mean but 15 hrs/week for 1.5 years puts you in the 1,200 hour range. Unless you have a preamp that is know to run tubes exceptionally hard (Audible Illusions comes to mind), preamp tubes can usually be counted on for 5,000-10,000 hours of life. Dick
Preamp tubes ran their life?
I believe I do know the answer, but I would like to hear inputs from the community.
Approximately 1.5 years ago I replaced the stock tubes in my preamp with some vintage Mullard UK ECC83’s. I spend a fair amount of time listening to music. I’d say, on average, anywhere between 10-15 hours a week. For the first year I had them in, I was running my Home Theater with my 2-channel, via HT passthru; which would swing that 10-15 hours/week way up. I liked the tubes and how they’ve sounded, pretty smooth throughout the band. Today, I started noticing weird “slurring/distortion” in certain frequencies, especially with vocals and cymbal crashes. I believe what I’m hearing is the tubes have ran their lifecycle. Note: I do have room treatment and room/speaker correction and what I’m hearing just started happening this morning.
I won’t hold anyone to their words if it doesn’t end up being the tubes, but that’s my initial hunch. Would your educated guess be the same?
Approximately 1.5 years ago I replaced the stock tubes in my preamp with some vintage Mullard UK ECC83’s. I spend a fair amount of time listening to music. I’d say, on average, anywhere between 10-15 hours a week. For the first year I had them in, I was running my Home Theater with my 2-channel, via HT passthru; which would swing that 10-15 hours/week way up. I liked the tubes and how they’ve sounded, pretty smooth throughout the band. Today, I started noticing weird “slurring/distortion” in certain frequencies, especially with vocals and cymbal crashes. I believe what I’m hearing is the tubes have ran their lifecycle. Note: I do have room treatment and room/speaker correction and what I’m hearing just started happening this morning.
I won’t hold anyone to their words if it doesn’t end up being the tubes, but that’s my initial hunch. Would your educated guess be the same?
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Shuguang Treasure12AX7 LS from Grant Fidelity. http://psvanetube.com/wordpress/store/products/shuguang-custom-12ax7-lx-special-edition-pair-low-noi... Give then 20 hours to break in. They best my Telefunkens. |
@kennythekey @djohnson54 thank you for the input. I should have qualified a little more... ”Way up”, they probably ran for about 4-6/day for the first year, due to the preamp being inband of the home theater signal. I’ll swap the L/R channels, but it sounded more as if it was coming from the L channel; which could be due to the pan/mix. I bypassed my preamp all together and am running it direct from my DEQX unit and it’s DAC. I use a McIntosh C2500, I don’t know if those run super hot or not, per your comment @djohnson54 . Running it through the DEQX, the harshness is removed. Faulty tube, very well could be. I probably have about 2.5k - 3.5k hours on them. @kennythekey They are NOS. I bought them from Kevin at Upscale Audio. They’re the Mullard CV4004 12AX7 NOS. |
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