Need help in trying to trace cause of distortion


I’m trying to track down the cause of distortion which occurs in the range of about two octaves above middle C (around 1000 hz-1500 hz).  I hear it it the flute most  distinctly but it must also be there in other instruments in that range.  I’d like to determine which component is the culprit.
The equipment is fairly new except for a vintage Conrad-Johnson PV-11 preamp recently examined and Teflon recapped by the manufacturer.  I suspect it is in the GoldenEar Triton 1 speakers.
The amplifier is a Benchmark AHB2. I don’t think the other components would cause this phenomenon, so I won’t list them unless requested.  It occurs no matter what source is playing.
Otherwise the system sounds fine. Does anyone have any suspicion as to what component is causing this so I can take it for repair?
7c67ab18 c2ce 4b45 9523 fc4a71684ce0rvpiano
Is it heard in a particular recording or all recordings?
The reason I ask is because ,on Donald Fagen’s Kamakiriad Album , the song "On The Dunes" there is some distorted bass notes. I fought with that for hours, thinking it was my amps. They were mono tube amps , so i suspected a bad tube . What was even furtherly confusing , it was mostly only coming from  one speaker.
It took me quite a while before I realized that it is actually on the recording itself
Grey9hound,

Unfortunately, it happens on more than one recording, but not always!
I wonder if it might be a problem with various records (CDs) but not all.
Could it be faulty recording technique?
I don’t know.
The tubes in the CJ are all very recently bought.
I did not realize how much my preamp tubes had slowly degenerated over time until I replaced them recently.  Made a huge difference, have you considered it could possibly be your tubes?
Start with one speaker and a mono signal if possible
My experience with this sort of distortion was many years ago using a set of Synthesis 310 speakers (Conrad Johnson). In my case, it was just one driver. In short I replaced the driver, but didn't like the fact that it wasn't anymore than a driver off the shelf being a chance that in other ways wasn't as good as the original.
 Your case does sound to me to be something electronic. It is the hardest type to find when as you say it is intermittent. I would be suspicious of the pre amp that was recapped. Yes, even the manufacturer can make mistakes.
This is a room acoustics issue, not a component problem. 
^^^^^  So helpful. Care to enlighten?
Suggestion: no music for three whole days.
Clear your head, clear your ears.

If you agree that "what you pay attention to, expands"
the time off can allow the problem to go away, or at
least, for you to listen anew without paying special
attention to "looking for" the distortion.

I doubt you will do this, but, who knows, it might work?
@4krowme --Agreed. There're a bunch of variables here. I would suggest pragmatism:
  • try something as simple as the cables and IC's. Swap them out and see if that makes a difference.
  • switch the tubes - both for different tubes and for placement
  • take @tomic601 suggestion and try just one speaker
  • then try that one speaker in a different part of the room, in case @millercarbon has a point
  • do you have another set of speakers you can hook up to the CJ?
Your description is typical of dirty power.  Discussion here.
Thank you all for your input.
I will investigate.
I had a similar problem... thought it was the tweeter... traced it to a shorted bypass 150pf cap in the output stage of the DAC. So it could be anything anywhere. It can only be traced by process of elimination. In my case, it was going from single ended to xlr outputs on the DAC. 
Drywall emissions, couch out of phase, the fake Rembrandt generating negative clovid modulations, heart of pine permeating postulations of positive of sine waves.
Good luck with your mystery. Please inform once solved. 

One time that I will never forget was about an unidentified noise in some music but not all. It turned out to be a nearby lampshade emitting a sympathetic vibration from some of the music. Couldn't have guessed that one. My ears spoke to me that day.
With all the possibilities described here, this will be a daunting task!
May have to live with it as it seldom occurs.
But once it does, it’s crazy making!
Hi rvpiano
 it’s not a simple problem but if you do as someone else suggested, by elimination, you will be successful. My guess is similar to yours, I think it’s the speaker. Luckily, this one is the easiest to eliminate. Check to see if it does it with both. If not, move the speaker cables by swapping left for right. If the problem follows the cable, then you know it’s not the speaker. If the problem stays in that channel now it’s time to move the speakers to see whether the problem will follow the speaker. If it does, then you have your answer: it’s the speaker. If not, now do the same thing with the amps. Swap the input cables. If the problem follows the cable, it’s not the amp, move upstream. Hope that helps. 
RV, I think you are right and spenav 1++ Distortion like this is usually mechanical and the obvious culprit would be the driver that handles the midrange. It would only be in one speaker and just listening to each driver close up should be able to locate it. I assume you only use CDs so forget about miss tracking. I have seen cable connections do funny things, bad plugs or bad solder joints. First is to detect what channel has the problem as it is unlikely that both are doing exactly the same thing. If by chance both channels are involved the only common denominator would be the power supply of one of you electronic devices. If an amplification stage is not getting enough power it will clip early and there is a lot of energy at 1000 Hz but I think you would notice the distortion in loud passages and transients. Good Luck!
Both my GE Triton Ones an Triton References both play flute fine with zero distortions. 
Download REW  https://www.roomeqwizard.com/ and purchase a calibrated microphone  https://www.parts-express.com/dayton-audio-umm-6-usb-measurement-microphone--390-808

Learn how to use them and you will be able zero in on problems like this in short order.
Many years ago, during the period when I had gone over to the dark side (Muse Model 150 monoblocks, Thiel 3.8s), there was a particular passage in one particular Martinu piano CD (Chandos) that excited some kind of distortion in one channel.  "Luckily" it followed the monoblock when swopped, but I never found out whether it was just the monoblock, the interaction with the speaker, or something anomalous on the recording itself.  No other CDs, even of piano music, created the problem.  Muse went out of business shortly thereafter (surprise?), and I moved on to an SET + Proac.  Moral of the story: yes, these are very irritating and yes, they can be very hard to track down.
RV, to add to the good suggestions above I'll mention that one thing I've found to be very useful in diagnosing sonic anomalies, as well as determining if it is the recording or the system that is responsible for them, is to have a headphone and headphone amp in my system.

In normal use a headphone amp would be connected to a tape output of your preamp, which would exclude the power amp, the speakers, the room, and most of the preamp circuitry from contributing to what you are hearing. For experimental purposes, though, it could also be connected to the preamp's main outputs, or to the output of a source component, or even (using a speaker-level to line-level converter) to the power amp outputs.

A good low priced headphone I can recommend based on personal experience is the Audio-Technica ATH-M50x ($149 at B&H). I have no specific recommendations for a headphone amp, though. (I use Stax electrostatic phones in my main system, which require specialized amplification that is not suitable for conventional dynamic headphones).

Good luck. Best regards,
-- Al

I second starting with headphones for troubleshooting  That is my first goto.
If you have none I recommend 7506's
https://www.amazon.com/Sony-MDR7506-Professional-Diaphragm-Headphone/dp/B000AJIF4E/ref=sr_1_1?keywor...
Not great for extended listening (bright) but good analytical monitors.
However not recommended for dry environments.  They will static zap your ears. I switched to Focal Listen for recording after 25 years of anti-static spray in the winter.
A good enough complimentary amp is
https://www.amazon.com/Nobsound-NS-08E-Integrated-Amplifier-Headphone/dp/B014FASL1A/ref=sr_1_3?keywo...
It sounds better than my Topping TP21 and Schiit Magni 2.
Especially if you roll the tubes.
The whole sets you back $150.

Does this distortion come from one speaker or both? This would be a good starting point.
What makes this problem hard to pin down is that I’ve heard it while streaming a few times and stupidly don’t remember where.  I’m going to have to check through what I’ve streamed to find it. 
First thought...

-make certain that the distortion is actually coming from the speaker/speakers and not something vibrating in the room

Second thought - if it's coming from the speaker/speakers... 

-gently check the exposed screws on all the drivers for loose ones

Third thought...

-your preamp has a rapid/measured (Stereophile) increase in distortion in the 1000-2000Hz region that quickly spikes down afterwards.

The 3rd is highly unlikely, and I assume that the spike may be dependent on the tubes used when measuring the unit, but it's STILL there in the review.

I once has an intermittent "distortion" with Castle speakers, and it was emitting from the speakers.

Think I described it @ the time as a sound "accompanying" the music, but not a part of such.

The remedy ended up being the placement of small felt circles over the mounting screws of the woofer as they were dome headed screws in the sound path of the tweeter.

DeKay



Hello rvpiano. Let's start at the beginning. Be sure all the connections are tight and solid. Swap the speaker wires at the amp. The right channel is now connected to the left speaker and visa versa, right? Did the problem switch to the other speaker? If yes, it's NOT the speaker. If the problem is still in the speaker in which you first noticed it, it IS the speaker. If the problem moved, swap the wires from the preamp to the power amp. Did the problem move? If it moved, the power amp is OK. If not the power amp has the problem. You didn't say where the music is coming from. CD player? Phono cartridge? Where ever it's coming from, and the problem has moved every time you swapped wires, swap those wires that carry the signal to the preamp. Did the problem move? If it did, the problem is in the signal source. It could be as simple as the phono cartridge is not trackng the groove. Clean the record. Give it an extra quarter gram and see if that changes things. If it's a CD player, you know it's acting up. If the problem did not move, the bug is in the preamp. Happy testing.
Rvpiano, I have heard some corrupted files while streaming, so don’t rule that out.