[Tomm11]

Websites that sell those Gold Lion tubes often have a "disclaimer" warning against using them in cathode biased amplifiers.

 

[Kevin.T]

Depending on the day, I can hear the radio come through my QS - interestingly only on the left channel. It's very quiet when the volume knob is up (even when nothing is playing), but turning the knob almost all the way down makes the signal significantly louder to the point where I can hear it clear as day.

I just put 2.5" toroid ferrite cores on each end of the power cord - it worked! No more radio signal at all.

However I can still hear a very high pitch whining coming through at all times, I suspect it all of the 2.4ghz wi-fi signals around me. About to build a faraday cage around the amp and see if that fixes it.

Also, I have to turn my phone to airplane mode around the amp as it sounds like a woodpecker when it's periodically checking in with the towers - crazy!

I just acquired this beast of an amp in a trade (along with the supremely enjoyable Auteur Classics). I am having a bit of noise issues with the amp using the Auteur, and it's almost exactly like luishi5000 describes!

I hear a low level buzz in the left channel. Just like luishi5000, the buzz is louder at the very beginning of the volpot, then quiets down around 8-9 oclock. Maxing out the volpot brings the noise back (but would make me deaf instantly with music playing, so a non-issue).

I can also hear the radio! Using my Modi 3E, I can actually hear it a lot. Using a DAC with a more robust casing, it is significantly reduced, but I can still hear it faintly occasionally. However, the buzzing is more audible, and is the main thorn in my side right now.

I also have a pair of 5751 tubes on hand. Rolling in the 5751, all noise is slightly reduced (along with the gain). Buzzing is reduced (but still audible), radio is practically gone. However, since the builder of the amp discourages use of 12AX7 alternatives in the QHA (including 5751), I would like to be able to use 12AX7 ideally.

The unit is positioned on my office desk, above my PC (the PC is under the desk). Moving my listening station to another room is not really an option right now (limited space in my living situation).

I have already tried some things, with no success in eliminating the buzz:

- Switched the sides on all tubes (EL84 and 12AX7). The buzzing stays on the left.
- I'm using a Morley Hum Exterminator. It doesn't seem to make much of a difference in my situation (still have the buzz with it on).
- I tried plugging the amp in its own wall socket; I tried plugging it in the power bar with other electronics; I even tried running a power cable to another room on an unused outlet... the buzz is still there in all cases.
- I tried moving the amplifier on the opposite side of my desk (moving it a couple of feet away from the PC). It made no difference.
- I have made sure that Wifi is turned off on my PC (and I disconnected the antenna). I'm using a wired network connection. Still hearing the buzz in the left channel, not sure it made a difference.
- Moving my cellphone towards or away from the amp doesn't affect the noise.

If anyone has any tips or ideas, I am all ears! I looove the sound of this amplifier with the Auteur Classic: incredible midrange and out of head experience. If I could get rid of this small noise issue, I would be in heaven!

 

[jamato8]

I just acquired this beast of an amp in a trade (along with the supremely enjoyable Auteur Classics). I am having a bit of noise issues with the amp using the Auteur, and it's almost exactly like luishi5000 describes!

I hear a low level buzz in the left channel. Just like luishi5000, the buzz is louder at the very beginning of the volpot, then quiets down around 8-9 oclock. Maxing out the volpot brings the noise back (but would make me deaf instantly with music playing, so a non-issue).

I can also hear the radio! Using my Modi 3E, I can actually hear it a lot. Using a DAC with a more robust casing, it is significantly reduced, but I can still hear it faintly occasionally. However, the buzzing is more audible, and is the main thorn in my side right now.

I also have a pair of 5751 tubes on hand. Rolling in the 5751, all noise is slightly reduced (along with the gain). Buzzing is reduced (but still audible), radio is practically gone. However, since the builder of the amp discourages use of 12AX7 alternatives in the QHA (including 5751), I would like to be able to use 12AX7 ideally.

The unit is positioned on my office desk, above my PC (the PC is under the desk). Moving my listening station to another room is not really an option right now (limited space in my living situation).

I have already tried some things, with no success in eliminating the buzz:

- Switched the sides on all tubes (EL84 and 12AX7). The buzzing stays on the left.
- I'm using a Morley Hum Exterminator. It doesn't seem to make much of a difference in my situation (still have the buzz with it on).
- I tried plugging the amp in its own wall socket; I tried plugging it in the power bar with other electronics; I even tried running a power cable to another room on an unused outlet... the buzz is still there in all cases.
- I tried moving the amplifier on the opposite side of my desk (moving it a couple of feet away from the PC). It made no difference.
- I have made sure that Wifi is turned off on my PC (and I disconnected the antenna). I'm using a wired network connection. Still hearing the buzz in the left channel, not sure it made a difference.
- Moving my cellphone towards or away from the amp doesn't affect the noise.

If anyone has any tips or ideas, I am all ears! I looove the sound of this amplifier with the Auteur Classic: incredible midrange and out of head experience. If I could get rid of this small noise issue, I would be in heaven!

Have you tried to float the ground by using an adapter? The amp or source could be floated with one still connected to ground as the RCAs carry the ground to one or the other. The 5751 should be no problem and would reduce the low level sound due to the lower gain as you mention. I don't think you can get rid of all the sound, just the nature of the beast. There would need. to be more shielding and a separate power supply vs on the same chassis. Well shielded internal wiring carrying the signal from the RCAs to the volume control and for radio interference a Grid stopper resistor. I don't remember if looking at the internals if Mike uses a grid stopper, but they are used for interference for RF.

 

[David A Silva]

Have you tried to float the ground by using an adapter? The amp or source could be floated with one still connected to ground as the RCAs carry the ground to one or the other. The 5751 should be no problem and would reduce the low level sound due to the lower gain as you mention. I don't think you can get rid of all the sound, just the nature of the beast. There would need. to be more shielding and a separate power supply vs on the same chassis. Well shielded internal wiring carrying the signal from the RCAs to the volume control and for radio interference a Grid stopper resistor. I don't remember if looking at the internals if Mike uses a grid stopper, but they are used for interference for RF.

Thx for this @jamato8 ! Where does the grid stopper(s) go?

 

[jamato8]

Thx for this @jamato8 ! Where does the grid stopper(s) go?

They are soldered between the volume control and the input tube to the pin, with a very short lead to the pin of the tube. Normally 1200 ohms to a couple of K ohms. No current so they don't drop voltage but clean up the signal. Often carbon are used, good quality ones. He doesn't use grid stoppers. I opened up the amp. Took a couple of images. Wire from RCAs to volume control aren't shielded but are twisted, which is normal as that does confer rejection for some signals (interference).

Red and white wires would have the grid stopper at the pin where they are attached so they would be at one end of the resistor and then the resistor is soldered to the connection to the tube.

And there is plenty of space between bare wires and they are all solid in place. The best dielectric is no dielectric, if possible or loose teflon tubing, which is what I normally use. I also put the Duelund caps in.

 

[luishi5000]

I just acquired this beast of an amp in a trade (along with the supremely enjoyable Auteur Classics). I am having a bit of noise issues with the amp using the Auteur, and it's almost exactly like luishi5000 describes!

I hear a low level buzz in the left channel. Just like luishi5000, the buzz is louder at the very beginning of the volpot, then quiets down around 8-9 oclock. Maxing out the volpot brings the noise back (but would make me deaf instantly with music playing, so a non-issue).

I can also hear the radio! Using my Modi 3E, I can actually hear it a lot. Using a DAC with a more robust casing, it is significantly reduced, but I can still hear it faintly occasionally. However, the buzzing is more audible, and is the main thorn in my side right now.

I also have a pair of 5751 tubes on hand. Rolling in the 5751, all noise is slightly reduced (along with the gain). Buzzing is reduced (but still audible), radio is practically gone. However, since the builder of the amp discourages use of 12AX7 alternatives in the QHA (including 5751), I would like to be able to use 12AX7 ideally.

The unit is positioned on my office desk, above my PC (the PC is under the desk). Moving my listening station to another room is not really an option right now (limited space in my living situation).

I have already tried some things, with no success in eliminating the buzz:

- Switched the sides on all tubes (EL84 and 12AX7). The buzzing stays on the left.
- I'm using a Morley Hum Exterminator. It doesn't seem to make much of a difference in my situation (still have the buzz with it on).
- I tried plugging the amp in its own wall socket; I tried plugging it in the power bar with other electronics; I even tried running a power cable to another room on an unused outlet... the buzz is still there in all cases.
- I tried moving the amplifier on the opposite side of my desk (moving it a couple of feet away from the PC). It made no difference.
- I have made sure that Wifi is turned off on my PC (and I disconnected the antenna). I'm using a wired network connection. Still hearing the buzz in the left channel, not sure it made a difference.
- Moving my cellphone towards or away from the amp doesn't affect the noise.

If anyone has any tips or ideas, I am all ears! I looove the sound of this amplifier with the Auteur Classic: incredible midrange and out of head experience. If I could get rid of this small noise issue, I would be in heaven!

Glad to know I am not alone. Is the buzzing consistent or intermittent?

My buzzing is intermittent, I'm starting to believe it's caused by dirty power as my Quicksilver makes external buzzing noise similar to the noise that comes from the tubes.

I fixed the radio interference by looping each end of the power cord through ferrite core rings.

 

[Kevin.T]

Glad to know I am not alone. Is the buzzing consistent or intermittent?

My buzzing is intermittent, I'm starting to believe it's caused by dirty power as my Quicksilver makes external buzzing noise similar to the noise that comes from the tubes.

I fixed the radio interference by looping each end of the power cord through ferrite core rings.

I hear it as consistent. There are no "swings", it's just a constant low buzzing in the left channel. My unit doesn't make an external buzzing noise that would be concerning (I mean, I can hear a very faint hum if I put my ear riiiight up to the unit, but I imagine this is normal).

Thanks for the tip on the ferrite core rings! I might swing for that if RFI becomes too much of a problem (right now, I'm more focused on the buzzing).

Also @jamato8, I didn't try to float the ground. I'm actually not sure how I would do this? Am I correct in thinking that plugging the 3 prong power cable in a 2 prong adapter would be the way to to it? If it helps, I tried unplugging the DAC from the RCA in on my amp (which is plugged in it's own outlet), and it does not affect the buzzing (still there).

 

[jamato8]

I hear it as consistent. There are no "swings", it's just a constant low buzzing in the left channel. My unit doesn't make an external buzzing noise that would be concerning (I mean, I can hear a very faint hum if I put my ear riiiight up to the unit, but I imagine this is normal).

Thanks for the tip on the ferrite core rings! I might swing for that if RFI becomes too much of a problem (right now, I'm more focused on the buzzing).

Also @jamato8, I didn't try to float the ground. I'm actually not sure how I would do this? Am I correct in thinking that plugging the 3 prong power cable in a 2 prong adapter would be the way to to it? If it helps, I tried unplugging the DAC from the RCA in on my amp (which is plugged in it's own outlet), and it does not affect the buzzing (still there).

Yes an adapter so that just the amp is grounded.

I get no perceptible noise, hum etc. with sensitive headphones. I am using 12AX7 input tubes and Gold Lion EL84 tubes.

 

[luishi5000]

I hear it as consistent. There are no "swings", it's just a constant low buzzing in the left channel. My unit doesn't make an external buzzing noise that would be concerning (I mean, I can hear a very faint hum if I put my ear riiiight up to the unit, but I imagine this is normal).

Thanks for the tip on the ferrite core rings! I might swing for that if RFI becomes too much of a problem (right now, I'm more focused on the buzzing).

Also @jamato8, I didn't try to float the ground. I'm actually not sure how I would do this? Am I correct in thinking that plugging the 3 prong power cable in a 2 prong adapter would be the way to to it? If it helps, I tried unplugging the DAC from the RCA in on my amp (which is plugged in it's own outlet), and it does not affect the buzzing (still there).

Odd, if there are no grounding issues it may be a defective part? Try running your DAC off your phone and see if it fixes it.

I just moved my amp to a completely different house in a different area to see if it's the power quality, same buzzing.

It's almost certainly the Gold Lion EL84 on my end. I have a new 3rd pair coming in to test again.

 

[gefski]

Glad to know I am not alone. Is the buzzing consistent or intermittent?

My buzzing is intermittent, I'm starting to believe it's caused by dirty power as my Quicksilver makes external buzzing noise similar to the noise that comes from the tubes.

I fixed the radio interference by looping each end of the power cord through ferrite core rings.

After a year plus with mine, there have been very intermitent noise situations. It’s a very soft crackle/buzz with no music playing. Doesn’t increase with volume. Not 60 cycle hum. Since it seems to occur during the day, then not that night and not for a week or so, I concluded it has to be a power grid issue. i have a dedicated “quiet room” so any noise in it is audible, but interestingly, I also have dedicated outlets, one for digital and one for analog, but some crud still gets through. The usual care, ferrite on cords, short cables, signal cables not touching power, all tabletop not bunched behind a rack, etc.

But as others here commented, it sounds so great, true timbre of instruments, voices, and sounds, that I just won’t sell it and move on, especially since the problem is very infrequent. I’ve settled on old stock GE/Wurlitzer 12AX7s and the alive touch and texture of Polam EL84s (which I got from a Ukraine seller).

 

[jamato8]

Pretty much unless you have a regenerator, noise can and will creep through on the AC. I have an excellent toroid made specifically for AC and another filter in the system and it does a great job but things get through. This AM on the QS I was getting some noise and still have some. Yesterday, almost dead quiet. The same on my Cayin 300BMK2. People complain about it but it can be super quiet or pick up noise and it runs out of the the same toroid (which weighs around 40 pounds (copper).

Using some Russia tubes (I am not buying Russian now) I bought years ago, that are NOS gold grid military tubes I got from Ukraine (as least the money went to Ukraine).

They are very good sounding and rugged tubes. Test super close to each other and some Amperex made in Holland 12AX7. The noise floor is so low though, you don't hear it with music or between songs, unless you listen for it.

I notice I used the Duelund tin plated copper. I wouldn't use them again. The slightly less expensive Duelund cast copper are more even in sound, IMO and are excellent. Stock is .1 uf but I would most likely go with .22. Won't cause adverse effects and will go a little deeper into the bass but .1 does ok.

 

[luishi5000]

Pretty much unless you have a regenerator, noise can and will creep through on the AC. I have an excellent toroid made specifically for AC and another filter in the system and it does a great job but things get through. This AM on the QS I was getting some noise and still have some. Yesterday, almost dead quiet. The same on my Cayin 300BMK2. People complain about it but it can be super quiet or pick up noise and it runs out of the the same toroid (which weighs around 40 pounds (copper).

Using some Russia tubes (I am not buying Russian now) I bought years ago, that are NOS gold grid military tubes I got from Ukraine (as least the money went to Ukraine).

They are very good sounding and rugged tubes. Test super close to each other and some Amperex made in Holland 12AX7. The noise floor is so low though, you don't hear it with music or between songs, unless you listen for it.

I notice I used the Duelund tin plated copper. I wouldn't use them again. The slightly less expensive Duelund cast copper are more even in sound, IMO and are excellent. Stock is .1 uf but I would most likely go with .22. Won't cause adverse effects and will go a little deeper into the bass but .1 does ok.

What toroid do you have? And the other filter? I've been considering some filtering, though it's hard to tell what works well without spending a ton.

 

[jamato8]

What toroid do you have? And the other filter? I've been considering some filtering, though it's hard to tell what works well without spending a ton.

A toroid manufacturer on the east coast of the US. Bought the huge toroid and then build my own unit. A couple of hundred years ago just for the toroid, for that much copper I don't know what it would cost now. They also make hospital system, very exacting so an excellent company. And I got something like 30% off.

I think it was this company. It was years ago. https://toroid.com/

 

[David A Silva]

Thanks for the link @jamato8 , really good price on their standard unit 500 watt balanced unit. Great stuff!

 

[luishi5000]

Interesting! I wonder how they compare to this for example:

https://www.decwareproducts.com/zlc