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Tube Question - Significance of Tube Noise at Listening Position

Hello all.  I need some advice on tubes.  I use a BHK preamp that has a tube input stage (12AU7).  I recently replaced the PSvane tubes that came with it with some GoldLion gold pins.  The sound is much better, more holographic, warmer.  However, after 6 months, I started to get tube noise with my ear near the speaker.  I put back in the PSvane tubes and the noise was reduced in half so it is the tubes, but with the old tubes, the sound quality of course dropped. 

I am thinking about buying some new tubes, either Ray Select tubes, which are considered to be very low noise, or NOS Brimars. 

My question is: does the tube noise matter at the listening position if it can't be heard where I sit?  Although I don't think I can hear the noise at my listening position, I am still bothered by it because, well, its there.  We work so hard to get black backgrounds and I would never use a cable, power cord, streamer or conditioner, that adds hiss.  We would never accept that, so even if I don't hear it at the listening position, I just feel like it must have some detrimental effect and why should we accept that from a tube if I won't accept it from any other component?  

I am looking for advice on this topic and if I should get the Ray Select tubes to hopefully remove the noise, or go with the good sounding GoldLions even though I know they are adding noise/hiss/garbage to the sound near the speaker. 

Finally, anyone have any comments on the Ray Select 12AU7.  I don't want bright or hard, and the competition is the GoldLion gold pins. 

Thanks everyone.

12many
markcasazza's avatar
markcasazza
51 posts
 

I've been doing some tube rolling in my Cronus Magnum III. Like the OP I found a bit of tube noise when I rolled a Mullard 12AU7 that I acquired in a lot of tubes from an estate auction into the Gain Stage socket. The tube tested strong but introduced some tube noise into the system. However, the sound is so much richer and holographic that it exceeds the NOS Brimar that was previously installed. I kept it.  

I then rolled a matched pair of long plate RCA 12AU7As into the Driver sockets. Same source. The change compared to the New Electro Harmonix was much more subtle. 

The resulting sound is much more to my liking. Tube noise, yes (but I can't hear it from my chair), but it is a small price to pay.

If you have a tube tester, keep an eye out for audiophile estate auctions. You may have to drive a few hours to pick things up (or pay for shipping), but the hunt can be as much fun. I currently have 19 12AU7s and 7 12AX7s. Plenty of variety if I want to change up the sound. Also, plenty of backups. 

 

wsrrsw's avatar
wsrrsw
1,477 posts
 

@inna  You can message on the Agon side. 

inna
8,240 posts
 

wsrrsw, thank you, found it. But they want my phone # and payment info before I can send messages. They don't ask for DNA sample, though. 

inna
8,240 posts
 

Speaking of tube hungry VAC preamps/amps, vintage from late 1950s Mullard 12AX7 in line stage of Avatar integrated have accumulated about 2500 hours so far. Bought NOS from Audiotubes. No change in sound or background noise level.

tadcaster
7 posts
 

OP - I recently bought a pair of Ray's Select 12au7s and was favorably impressed. Also had a noise issue with amp but turned out it the tubes were not the culprit. 

Last month I picked up a used Primaluna evo 400 power amp as a backup while one of my SS monos was in the shop. Upon hooking up the 400, there was notable noise from both speakers when no music playing, a low frequency static audible up close and higher frequency "squelching" akin to Morse code which I could hear from listening position about 11-12 feet away. The amp is fairly new with low hours on the tubes, but I removed and reseated all the input tubes, rotated their positions, inspected pins, etc. but no effect on noise. I then replaced the two stock input stage tubes with Ray's select 12AU7's which provided a noticeable bump in sound quality (improved bass extension and tonal depth overall), which for me was easily worth the couple hundred bucks they cost. However the noise remained. 

Was beginning to think that the amp itself was simply defective and was considering taking it to a local tube shop or shipping to Upscale Audio to have checked out. After some more troubleshooting finally located the culprit: the cheap switching power supply for my Roon core, a dedicated Dell Optiplex 3050, which is separated from the amp by 3 components and 4 cables. I bought a 19-volt LPS from Small Green Computer, plugged the Dell into it and noise disappeared. So if you have any switching power supplies in your signal chain  worth checking those out to see if they might be the cause of your issue.

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