ET3SE volume challenges

[BarneyB]

Bought a unit on Agon summer 2015 and noticing a few issues with volume;

When powering up and after warm up I can hear music (not source dependent) when the unit shows zero volume. When I turn the volume up then back to zero; no music heard at zero. Is this normal?

I recently tried a few different tubes in the unit; both had static in the right channel, I returned to the tube it came with and static is gone. Odd that both tubes displayed the same sonic problems yet both checked out OK on a tube tester. Is the ET3SE that particular about tubes and has anyone experienced a similar issue or am I just lucky.

Replaced speakers recently; added Tannoy DC10A's. When playing CD (Musical Fidelity 3.2CD), the volume at lowest setting (1) is too loud for background music when people are talking and visiting; same challenge with FM from my Magnum Dynalab MD90. Turntable is fine (ProJect Xtension 10 through a Zesto Andros 1.1). I swapped out the ET3SE with an Allnic T1500 integrated (12.5wpc); ran the pre-out to my mono-block amplifiers (Odyssey Stratos 180+wpc) and had the same problem, could not adjust the sound low enough with the volume control. I then bypassed my amplifiers and used the Allnic and I was able to control volume to my satisfaction. Very strange, looks like my new speakers (93db sensitivity) don't like the amplifiers OR the high gain of the ET3SE and the Allnic is the culprit and I need a new pre-amplifier.

Before I head down the path of buying new gear I was hoping to hear if others had experienced the same or similar challenges and have any advice to offer or ideas on how to narrow this down to the problem.

Cheers

Barrie

[admin]

Hi Barrie,
I moved this post the troubleshooting section of the site so it would get the appropriate attention.

Not sure where to start with the issues. First with the music being heard on zero volume, is it very low level? Can it be some kind of ground loop feedback issue? Is it only with startup and after never reoccurring again?

The tube issue seems on the surface to be a problem with the new tubes you bought. Have you tried swapping the tubes in the unit you have now to see if anything changes? I have to admit that the chance of getting two bad tubes in a row is pretty low.

The too much gain issue seems to indicate that your speakers are very sensitive considering you had issues with the high powered amp but not the low powered Allnic. Do you have the same issue with other speakers or is it only with the Tannoy's?

[BarneyB]

Hi and thanks for the quick reply.
The sound at zero volume is low level and the effect disappears after I turn the volume up and return to zero. I have checked all the connections including ground and am baffled. I have e-mailed CJ support to see what they say.

I have replaced the two tubes I purchased with the one that came with my CJ and everything is fine. I just thought it was very odd to have two NOS tubes, both different manufacturer, fail with the exact same characteristics; static from the right channel.

I did not bring up my old speakers (Monitor Audio Silver 9i's - 91db) to test. May do that this weekend; getting tired of switching out gear already.

Cheers

[admin]

I would try some new speakers on the setup, even if they are some $50 cheapo speakers from walmart. Just to see if it's speaker dependent.

It would have been interesting to see if rotating the current tubes in the unit has any effect. When you say static, is it really static or microphonics? If you touch the tubes gently with a pencil eraser, does it make it go away?

I hear your frustration, I used to have a ground loop issue on my system, was an absolute headache to try and get rid of but solved it at the end. Don't give up.

[BarneyB]

Yeah I do need to try my old speakers. I just boxed up them up but luckily they are relatively small and light. They also are high sensitivity; 91 vs 93 for my Tannoys but it should tell me something. Either that or confuse me further.

The ET3SE only has one tube so I am unable to rotate tubes. The "sound" I heard was identical to static from a tuner that was slightly off-channel; that was the best way I could describe it. I do not know what "microphonics" would sound like; please described the effect.

What would you suggest I do to test for ground loop feedback issues?

[admin]

Yeah I do need to try my old speakers. I just boxed up them up but luckily they are relatively small and light. They also are high sensitivity; 91 vs 93 for my Tannoys but it should tell me something. Either that or confuse me further.

Ideally a low sensitivity speaker would be a better test, but at least you can get a comparison.

The ET3SE only has one tube so I am unable to rotate tubes. The "sound" I heard was identical to static from a tuner that was slightly off-channel; that was the best way I could describe it. I do not know what "microphonics" would sound like; please described the effect.

Oh sorry about that, I probably was looking at the optional phono stage component which has an extra 3 tubes. My bad. As for microphonics, this explains it:

What would you suggest I do to test for ground loop feedback issues?

It doesn't sound like you have a ground loop issue, but the easiest way to test it is with a "ground loop isolator". Something like this: http://www.amazon.com/Raptor-GL15-Groun ... p+isolator

[BarneyB]

The sound I heard from the other tubes was not "microphonic" as described here; this is more of a ringing tone whereas the two tubes I had were displaying a static sound as I described in my posts.

CJ service tells me that the low volume sound at zero is a known software result and nothing to be concerned about and I agree with you; I do not believe I have a ground loop problem.

The only thing to work on is the lack of volume control.

Thank you for everything; this has been a great help.

[plurn]

How much gain does the Odyssey Stratos have - it is not mentioned in the specifications on their website. I can't find an input sensitivity rating either. If it is a high gain amp, say 35dB (or to put it another way has high input sensitivity, say 0.75V to rated power), then this would contribute to the issue you have with not being able to set the volume control low enough, since the ET3 is a high gain preamp and its lowest volume setting is not very quiet. The efficiency of the speakers also contribute to this as mentioned by admin.

One thing you could try is putting an RCA inline attenuator attachment between the pre and the power amp. I don't know if this would be detrimental to sound quality? It might mean you won't need to replace any of your gear though. No promises.

This sort of thing:
http://www.rothwellaudioproducts.co.uk/ ... ators.html Rothwell In-Line Attenuators
http://www.amazon.com/gp/product/B0006N41AG Harrison Labs 6 dB RCA Line Level Attenuator Pair
http://www.amazon.com/gp/product/B0006N41B0 Harrison Labs 12 dB RCA Line Level Attenuator Pair

Not sure how much dB attenuation you would need.

Good luck
Anthony

[BarneyB]

Thanks Anthony, I believe I have stumbled into a component compatibility challenge that requires a component swap. I am concerned about introducing noise with an in-line attenuator so have begun sampling some tube amplifiers to start with. Will be trying a pair of Audio Space Nova M34 mono-block amplifiers then an Allnic integrated. Not all that happy with having to do this but my wife is not happy with the volume issue and if momma ain't happy, well, nobody is happy.

Thanks for the input; I truly appreciate the assistance.

[Big Dog RJ]

Can very easily relate to the wifey not being happy- "see this sort of silly thing going on with you so called high-end audio doesn't happen to jewelry does it eh?" and the record plays on...

Oh boy! They're never happy nor to they get it, anyway sleeps like a baby when Tracy Chapman and Nora Jones is playing all fine, gets up the next morning claiming "hey Nora Jones sounded so real, wow"... go figure.
Being married 15 years now, her B'day is around the corner, hence the system will be parked for a while, as all eyes and hears on the Mrs.
Cheers to the wifey's!
RJ