chrisdrop
1000+ Head-Fier
For ~4 months, I have been trying to get to the bottom of a painful noise problem in my setup(s). It has been a very persistent and difficult to nail down issue. (Or I am a few sandwiches short of a picnic and quite slow). With hindsight, I do feel like I should have found it easier/ sooner. Live and learn! It is good to stay humble 
As someone on another thread said; "That's the insidious thing about noise: You don't know it's there, until you get rid of it!". So true it is!
I wanted to share the saga here, on the chance that it might benefit someone else. I'd also like to consolidate my update to the many people who helped me. By the way; it sucked
. I am sure it (and I) sucked even more for every person who listened to me whinge about it for months!
Of note, I am in London in the UK. Power issues seem worse in Europe. Advice and products are also less plentiful than in the US. Much of the commentary is specific to my environment here.
Big thanks to: @ZRW0, @2359glenn, @JazzVinyl, @GDuss, @mordy, @teknorob23, @hypnos1, @OctavianH. Others have made helpful comments and if I left your name out - my apologies. It has been a long ride!
The problem:
In short; Two independent, highest quality, valve-based headphone amplifiers had unexpected noise. In some cases they were “bearable noisy” in other cases they had “unbearable buzzing”. Different valves had different noise levels. The issue was present with nothing connected to the amp (except headphones) - not even a source. The issue was invariant to volume.
To be 100% clear, both of the amps are 100% excellent and issue free. There is/ was a clear problem in my home power environment. One amp is a Feliks Euforia and the other is a Glenn OTL, both with stellar makers and reputations - deservedly so.
The punch line; the (a?) solution was an automatic voltage regulator. Perhaps there will be “better" ones of those in my future and/ or more "power products". I am now obsessed with lowering the noise floor limbo-style .. "how low can you go?”. I am very keen to have as silent an environment as possible.
It took a lot of experimentation (fumbling) to get to the end. It also took quite a lot of conversation.
What hypotheses were there throughout the journey:
How did I get to the end?
While on my 2-week holiday break (presently), I spent a good 2 days reading on this thread and a related thread on another forum. While a Topaz isolation transformer is "unobtanium" (especially in Europe), I decided to try a similar setup with lesser isolation transformers. I ordered yet-another-isolation transformer (although I had tried one, with balanced power, I thought I'd try a different kind) and this; APC LE1200I Line-R 1200VA Automatic Voltage Regulator, Input 230V. Now, at work, in my professional life - I have a research team. We run a lot of experiments. For this exercise I have been pretty good about 1) documenting experiments/ results and 2) trying to isolate experiments/ effects (change 1 thing at a time). Before putting the chain of things together, I just put the 1 unit in between my socket and the amp. Then I set to listening. Quiet. Wow. In shock and disbelief. After a while, I put some power valves in that had been unusably too noisy. They were quiet. Wow! I did that a few more times. I has now been the better part of a day - quiet. Finally.
Much of this post has been cut-n-pasted from my notes on this topic. Given that I had communication with various helpful parties (as you see), I needed to keep clear information with and for them. So - this post was an easy job.
What next?
Really? Enjoy listening even more! I may still try a Torus Power TOT MAX AVR UK. This is a well-made isolation transformer with automatic voltage regulation. Why? I believe the higher quality the parts, the bigger the impact. I don’t care what anyone else says, power is insanely important and a key determinant of the quality of what comes out of your setup.
Power cables made a direct and audible difference in my setup through all of this. Right now this voltage regulator is using a crap IEC cable, so I need to re-terminate a good cable with a male IEC end to plug into the thing probably. I wish there was nothing in between the dedicated mains power line and the amp, but - beggars can't be choosers!
Final Thoughts
Through all the experiments several things made positive audible differences, even though they didn’t fix my issue. The dedicated mains power circuit made a clear and positive difference. Isolating your system away from noisy things in your house is undeniably helpful. As a recent video from @Monsterzero agrees - high-quality power cables absolutely made a positive difference.
The captured collective knowledge here on head-fi was immensely helpful. Years of people working through issues and trying to enhance their sound-systems was truly useful. Finally, the community has been excellent. So many people have been generous with their time and tried to help me get to a happy place. Thanks. Well, that was a long post. Sorry about that.
Best,
Chris
N.B. - Even if I am the only one who ever reads this, the catharsis has been worth it!
... and since this is all about listening, this post brought to you by James Blake's - Assume Form album. Here is the one I am on now...
As someone on another thread said; "That's the insidious thing about noise: You don't know it's there, until you get rid of it!". So true it is!
I wanted to share the saga here, on the chance that it might benefit someone else. I'd also like to consolidate my update to the many people who helped me. By the way; it sucked
. I am sure it (and I) sucked even more for every person who listened to me whinge about it for months!Of note, I am in London in the UK. Power issues seem worse in Europe. Advice and products are also less plentiful than in the US. Much of the commentary is specific to my environment here.
Big thanks to: @ZRW0, @2359glenn, @JazzVinyl, @GDuss, @mordy, @teknorob23, @hypnos1, @OctavianH. Others have made helpful comments and if I left your name out - my apologies. It has been a long ride!
The problem:
In short; Two independent, highest quality, valve-based headphone amplifiers had unexpected noise. In some cases they were “bearable noisy” in other cases they had “unbearable buzzing”. Different valves had different noise levels. The issue was present with nothing connected to the amp (except headphones) - not even a source. The issue was invariant to volume.
To be 100% clear, both of the amps are 100% excellent and issue free. There is/ was a clear problem in my home power environment. One amp is a Feliks Euforia and the other is a Glenn OTL, both with stellar makers and reputations - deservedly so.
The punch line; the (a?) solution was an automatic voltage regulator. Perhaps there will be “better" ones of those in my future and/ or more "power products". I am now obsessed with lowering the noise floor limbo-style .. "how low can you go?”. I am very keen to have as silent an environment as possible.
It took a lot of experimentation (fumbling) to get to the end. It also took quite a lot of conversation.
What hypotheses were there throughout the journey:
- A grounding issue. A 100Hz buzz signature pointed to that.
- Ground loop (factored out early)
- EMI/ RFI in the environment. I live in London, maybe it is crazy with the stuff!
- Very distorted mains power
- DC on the AC line
- I purchased a perfectly kept and beautiful Feliks Eufora from another great head-fier. Exciting! It eventually came to me and I got to listening ...
- At some point early on I noticed that the Euforia did not have a “black” background (when using the stock valves). I was puzzled by this. It was usable, but certainly, there was an audible hum when the music was off or quiet.
- Using very highly regarded valves popular on the Euforia thread, which the seller had been regularly using, the buzz was not usable. This really puzzled me. The seller and he was absolutely awesome at helping to investigate the issue. You have my apologies for being sucked into my issue!
- I brought the Euforia to another location and plugged it in. I got the same issue. I assumed something was wrong with the amp and decided to send it back to Feliks Audio to debug. Off the amp went to Feliks Audio.
- As fate would have it, I had been trying to get on the Glenn amp waiting list. Fortune favoured me and for reasons I will spare you, an amp to my specs became available from Glenn! I had to say yes to getting a GOTL. The Euforia - perhaps it would go to my office, 2nd listening location. Perhaps (crazy?) I’d keep both at home? Who knows. Glenn sent me the amp and after much ado about customs, importing and waiting, the amp came home!
- Guess what. I think you can see where this is going … same story! The amp also sounded amazing, but it did have some noise. Higher gain valves produced a lot of noise. The amp was 100% new and worked perfectly through testing and use. I was now 100% sure it was an issue at my place.
- I did a lot of valve experimentation. One puzzling session was with @GDuss and @JazzVinyl. We thought there were some noisy valves. We moved them around and the noise stayed on one side? Crazy. Eventually, this was explained; the vibration on the transformer side of the amp vibrated the tubes on that side of the amp, generating noise. Higher gain output tubes manifest the noise the most.
- Experiments/ changes:
- Upgrade all power cables (I assembled top-quality UP-OCC cables with top quality parts.). Most parts from Hificollective.
- Power off everything in the house, leaving just the socket for the amp. Same.
- (Temporarily) Ground-lifted power to the amp (from power strip to device) [DO NOT DO THIS]
- Sent the Euforia amp to the manufacturer - absolutely no issues to be found!
- With an electrician; installed a dedicated power circuit with an additional dedicated ground line, using high-grade low gauge (fat) power cabling and top quality sockets, etc. Parts from MCRU
- .. and many products
- What products did I buy (and almost exclusively return - sorry)?
- AirlinkTransformers conditioning balanced power supply
- Isotek Evo3 Syncro Uni
- Furman Ac 210 A E HIFI Power Filter Mesh Filter Power Distribution AC Power Conditioner
- Isol-8 Powerline Axis
- iFi AC iPurifier
- Tacima Mains Conditioner
- ... probably more that I am forgetting ...
- Other oddball items:
- EMI Meter to measure the EMI/ RFI environment. There is no hard-core EMI happening FYI.
- Put a copper spike in-ground outside and ran a copper cable to amp casing. This helped someone on the Elise thread at some point.
- Went nuts with ferrite chokes. Nada.
- Put isolation feet on the amp (really 1st 4x 1/2 tennis balls as feet, then cheap springy ones off of Amazon!). This actually helped a lot! The noise dampened down quite a bit (but it was still there).
- Try tube dampers (Herbies and Golden Dragon tube rings). These helped a bit. Recommended.
- The Spectroid audio spectrum analyser app was really handy to see the 100Hz cycles kicking off the amps. I could point it at the amp, or shove my phone into the headphones and see the noise-signature.
- Power Line EMI Dirty Electricity Meter to measure the mains noise. Only detects higher frequency "dirty mains", not distortion lower in the audible region.
- What vendors did I talk to for guidance/ product advice? Many. I think this is a comprehensive list of exceptionally generous and helpful people.
- Mike at Puritan Audio was excellent and very willing to try to help. He offered to come to my house from his place and measure my mains distortion. He does not live close to me!
- Peter at Igloo Audio was extremely helpful. He let me come to his place with my kit to see how it was there https://www.iglooaudio.co.uk/
- Mike at AirlinkTransformers https://airlinktransformers.com/. Although I returned their unit, they were immensely helpful in trying to diagnose the issue.
- PS Audio in the US and their UK distributor (most people suggested not using a regenerator, although this may have worked (expensive too))
- Nic at Isol-8 about their product line.
- Adam at Futureshop was helpful when I returned an Isol-8 unit.
- David at MCRU was helpful with my dedicated circuit cabling and parts.
- Helpful support people at IsoTek. FYI they advised their regenerators were not for any amplifier products, only sources.
- Enrico at Sonic Syndicate here in London. He came by with an engineer. They had been planning on getting hold of some loaner units of very high end (expensive) power conditioning units.
- My local power provider was largely baffled and unable to help
- I was planning an engagement with Ben Duncan who was very pleasant and well informed.
- Peter at Russ Andrews
How did I get to the end?
While on my 2-week holiday break (presently), I spent a good 2 days reading on this thread and a related thread on another forum. While a Topaz isolation transformer is "unobtanium" (especially in Europe), I decided to try a similar setup with lesser isolation transformers. I ordered yet-another-isolation transformer (although I had tried one, with balanced power, I thought I'd try a different kind) and this; APC LE1200I Line-R 1200VA Automatic Voltage Regulator, Input 230V. Now, at work, in my professional life - I have a research team. We run a lot of experiments. For this exercise I have been pretty good about 1) documenting experiments/ results and 2) trying to isolate experiments/ effects (change 1 thing at a time). Before putting the chain of things together, I just put the 1 unit in between my socket and the amp. Then I set to listening. Quiet. Wow. In shock and disbelief. After a while, I put some power valves in that had been unusably too noisy. They were quiet. Wow! I did that a few more times. I has now been the better part of a day - quiet. Finally.
Much of this post has been cut-n-pasted from my notes on this topic. Given that I had communication with various helpful parties (as you see), I needed to keep clear information with and for them. So - this post was an easy job.
What next?
Really? Enjoy listening even more! I may still try a Torus Power TOT MAX AVR UK. This is a well-made isolation transformer with automatic voltage regulation. Why? I believe the higher quality the parts, the bigger the impact. I don’t care what anyone else says, power is insanely important and a key determinant of the quality of what comes out of your setup.
Power cables made a direct and audible difference in my setup through all of this. Right now this voltage regulator is using a crap IEC cable, so I need to re-terminate a good cable with a male IEC end to plug into the thing probably. I wish there was nothing in between the dedicated mains power line and the amp, but - beggars can't be choosers!
Final Thoughts
Through all the experiments several things made positive audible differences, even though they didn’t fix my issue. The dedicated mains power circuit made a clear and positive difference. Isolating your system away from noisy things in your house is undeniably helpful. As a recent video from @Monsterzero agrees - high-quality power cables absolutely made a positive difference.
The captured collective knowledge here on head-fi was immensely helpful. Years of people working through issues and trying to enhance their sound-systems was truly useful. Finally, the community has been excellent. So many people have been generous with their time and tried to help me get to a happy place. Thanks. Well, that was a long post. Sorry about that.
Best,
Chris
N.B. - Even if I am the only one who ever reads this, the catharsis has been worth it!
... and since this is all about listening, this post brought to you by James Blake's - Assume Form album. Here is the one I am on now...
Last edited:
. Congrats.
