New Sensor makes some duds, regardless of whether they are branded Mullard, Tungsol. EH, etc... I have actually had better luck with EH tubes than any other brand made by New Sensor. Despite what I've read about JJ reliability, I decided to re tube with JJ in my amps and pre and they have been rock solid so far and the tone is perfect in my set up. Awesome tone, so good I don't want to mess with it . Prior to the retube I cleaned and tightened the tube sockets and it made a big difference and with new tubes both components are dead quiet. FWIW , I had two "Mullard" 12AX7 fail within 6 months and had a Tungsol 12AX7 go noisy after a few weeks. If they were real CV4004 , I would chaulk it up to the fact that NOS tubes have been cherry picked for years.... how many choice ones are left?
Crackling and hiss - Preamp tubes not seated right?
I've posted here before about the cracking and hiss I get from my Primaluna Dialogue Premium. It became very noticeable during listening last week, so I took another stab at trying to isolate it.
When the amp is on, but with out anything playing, I can hear a low hiss and an intermittent crackle - the volume knob does not effect it.
It was only happening in the right speaker, when I swap the speakers it stays, so I figure it has the be the amp.
I swapped the three preamp tubes in 1,2 and 3 positions with the tubes in 4,5 and 6 position and it moved to the other speaker, so I assume it's a preamp tube problem.
I swapped out the 6 Mullard CV4003 for the original stock tubes, and it's silent. That felt good to finally get ahead of the problem.
I started to swap back in the Mullards one at a time to see when the 'bad' tube appeared. Swapping into position 1 and 2 were good, but it came back on when I added a tube to position 3, so I went back down to positions 1 and 2, and it was there again! But it was silent before? Very frustrating. I went back to all 6 of the stock tubes and it's silent again.
So my question is this - could it be that the Mullards don't seat as well as the stock tubes, and there is some arcing and other interference getting through? Should I give the pins and sockets a cleaning? Any advice on how to do that? Maybe I need an adapter to go into the socket to seat the Mullards?
I also think this may be the source of some distortion I was hearing, particularly on piano at certain higher frequencies. Does anyone have any thoughts on that?
When the amp is on, but with out anything playing, I can hear a low hiss and an intermittent crackle - the volume knob does not effect it.
It was only happening in the right speaker, when I swap the speakers it stays, so I figure it has the be the amp.
I swapped the three preamp tubes in 1,2 and 3 positions with the tubes in 4,5 and 6 position and it moved to the other speaker, so I assume it's a preamp tube problem.
I swapped out the 6 Mullard CV4003 for the original stock tubes, and it's silent. That felt good to finally get ahead of the problem.
I started to swap back in the Mullards one at a time to see when the 'bad' tube appeared. Swapping into position 1 and 2 were good, but it came back on when I added a tube to position 3, so I went back down to positions 1 and 2, and it was there again! But it was silent before? Very frustrating. I went back to all 6 of the stock tubes and it's silent again.
So my question is this - could it be that the Mullards don't seat as well as the stock tubes, and there is some arcing and other interference getting through? Should I give the pins and sockets a cleaning? Any advice on how to do that? Maybe I need an adapter to go into the socket to seat the Mullards?
I also think this may be the source of some distortion I was hearing, particularly on piano at certain higher frequencies. Does anyone have any thoughts on that?
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- 21 posts total
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You can try taking 4-0 steel wool to the pins to clean them but I suspect your unit just does not like the Mullards. If you want the best tubes go here
http://www.tubeaudiostore.com/. |
- 21 posts total