New amp listening fatigue: Distortion or ??????


Hello All,

I recently acquired a used Denafrips Hestia/Hyperion amp/preamp combo for my second system. I traded a low power 300B amp for it. It’s class a/b with 80 w/c 8ohms and 150 w/c 4 ohms. I thought it would go nicely with my Denafrips Pontus2 and it does. My first listening session was about 1.5 hours long listening to Beethoven symphonies which I know quite well. My initial impressions were positive. The new amp produces a huge, well defined soundstage and effortless ability to project dynamics. Bass is strong and well defined. Treble is smooth and clean sounding. The mids are rich and accurate, but much more energized than the bass and treble. After an hour, my ears felt pressurized and were ringing and I couldn’t listen anymore. I usually listen around 75-80 dB max. I never heard any distortion or anything suspicious. I repeated the session next day with my other speakers with the same results. Is it possible that there may be distortion present that I can’t hear? Or maybe this amp highlights certain frequencies that irritate my ears?

In years past I discovered I have a sensitivity to certain frequencies in the midrange somewhere around 600 - 1000 Hz and I used to use a graphic EQ to lower the mids. I’ve also gotten rid of any speakers or amps that have that hump in the midrange. My current, everyday rig is a Hegel H95, using the internal DAC for music and video played through Philharmonic BMR Monitors. I never get tired listening to this set up and can listen for hours. The Hegel is clean and clear with a balanced, neutral presentation. The new amp/pre combo has a warmer, stronger more muscular sound and unfortunately, creates listening fatigue. I’m thinking of adding a Schiit Lokius EQ to tame the mids in the new amp. Thing is, I’m also trying to simplify my gear, gravitating towards smaller, lighter weight speakers and components. Maybe just get another Hegel for my second system?

BTW I always protect my hearing when using or loud equipment or around any other loud sound source. My hearing has dropped off over the years, but I still hear up to around 9,000Hz.

Has anyone had similar experiences with a new/different amp?

dtapo

Hello dtapo!  Nobody talks about it anymore, but there is a thing called Transient Intermodulation distortion. I suspect that's what you are hearing. It may go away after about 100 or so hours of operation, as others have said. Leave the amp on all the time for three or four days, and see if it sounds smoother after a few days of being on constantly. You needn't be playing music, but it helps. If there is a warranty on the amp, be sure you don't let it exprire. The same if there is a "free return for XX days."  If it doesn't shape up, take it back. Don't be shy! Be sure your cables are not letting electrical noises get into the system.  I live near a Navy base and had some problems like that - screwball radiation getting into unshielded cables. Happy Listening.

+1 the audiomaniac.  High output impedance 300B amp interacts with speaker load to create response variations that sound just like an equalizer.  If you could measure and replicate that pattern with your new amp using DSP, I contend your listener fatigue would vanish.  But it’s hard to do, so there you are.  Does your Hegel also fatigue you in the second system with the same speakers?  It should, if my surmise is correct…

The amp/pre is used and would be broken in. It seems as if the sound is too intense, if that makes sense.

The Hegel sounds good with any speakers I've tried with it, never fatiguing.

I used the Hyperion with DHT pre, and no impedance issues with this combo. Sound stage compacted, veiled, dark, and fatiguing. My thoughts at time were perhaps Hestia far better match, perhaps offsetting flavors result in more balanced presentation. On the other hand tubes in my pre should have resulted in more relaxed sound quality, I found Hyperion both forced and fatiguing. The Musical Fidelity M2si far more musical, natural in my setup.

I think it has something to do with something really spiritual. You should invite monk or priest to do some exorcism on your unit. 

What you can do yourself is to have some good spirits and listen again. Maybe it will also fix issue.