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

I had similar experience with the modded McCormack DNA-225. This was never a problem with this amp prior to having the modifications done.
It’s the amp/speaker interaction. Not a good match.
I never experienced this again with many amps I’ve owned since. 
Only solution is - sell it. Get a good neutral amp like that Hegel you already have. 

How many hours do you have on it?  It’s possible whatever’s bothering you may decrease with further burn in that can take 100 - 200 hours or more depending on the unit. 

It’s not the amount of distortion, it’s the lack of higher order distortion.

I owned the Hyperion couple years ago, couldn't acclimate to it's deficiencies in my setup. I actually preferred a Musical Fidelity M2si to the Hyperion, eventually decided ss didn't work for me, went to 300B SET amps.

This is the classic mark of a really noisy system. Perhaps the bias is too high in the amp. I have been subjected to this in cheap equipment and malfunctioning equipment. The, “can’t quite put your finger on it and pressure on the eardrums” is it. This is exactly the opposite of high end sound. Great sound relaxes you… you fall into the silence. 

 

You don’t want to try and make up for it… like equalization you want to get rid of the offending equipment. I guess, maybe repair. I wouldn’t… but maybe worth a try. 

 

But realize… none of this equipment should ever do this… this is a serious problem. It happens much more often in headphone systems where the transducers are next to your ears and amplification is cheap.

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.

Change power cable to Pangea AC-9SE MKII, you will get significant improvement. Denafrips is made in China, tested on 220 volts. You need a better power cable in US. I recently bought Denafrips Terminator Plus, it does not come with power cable, so initially I used a regular cable from my desktop while waiting Pangea. Once I replaced the cable, DAC sounded ten times better. You can buy Pangea from Amazon, in different price range, this one is the best, as thick as garden hose, a little stiff but creates music nirvana. 

@drbay do you really believe they don't test their products at 120V/60Hz? 🤦‍♂️🤦‍♀️

 

Those Philharmonic BMR are going to experience a 1-3db peak with a low power 300B tube amp around 500Hz, some emphasis of mid-bass, and some comparative shelving of high frequencies compared to with the SS amp. Of course it is going to sound much different.

 

Denafrips use an automatic converter switch between 220 and 110. How are you so sure that they test a product at 110 volt, as much as they tested at 220 in China. Even if there were some differences in terms of sound and distortion will be identical at two different voltage. Do you think Denafrips will not sell a product in US market, because there is a bit more distortion at 110 volt?

I think trying a better power cable can make significant difference, I know it because it actually did for me.

OP… “It seems as if the sound is too intense, if that makes sense.”

That sounds like the bias in the amp is set too high. I got an amp on loan one time… it sounded terrible (high end audiophile amp of great repute) and it almost sounded like being in an auditorium when the gain on the PA system is turned up too loud… but no one is saying anything… it puts pressure on your ears. I returned the amp… the dealer sent it in… that was exactly the problem. Somehow in transport it changed.

 

Following this thread with interest as I sometimes experience similar situations.

i should add that I suffer from tinnitus, some days less so.

On days without tinnitus I can listen to music for hours, on other days not even 10 minutes.

Currently I think it’s my ears / mind that make the difference, not my system.

Another thought: room interactions? Maybe you need to reposition the speakers and or add room treatment now that your system is more revealing than before?

Your speakers have ceramic midrange drivers and RAAL ribbon tweeters- extremely revealing and downright brutal with a neutral revealing amplifier.  I have only heard two speakers that use ceramic drivers sound good to my ears- Marten and Von Schweikert.   Nothing else including Revel sounded good- at all. 

You are also coming from the ultra refined world of 300b tube amps, no wonder you are shocked.  

I also suspect phase / crossover interaction between the midrange and tweeter. 

I can't comment on the sound of your amplifier but do agree that many hours of run in can help it to sound better- e.g. 200-300 hours.  

I do not recommend EQ because it can cause just as many issues as it fixes and is not benign to the sound quality. 

Some things you can try-

1) Speaker positioning- you want to increase bass and smoothness.  Be careful and deliberate moving the speakers in 1-foot increments as your room will allow. 

Move them wider, closer to the wall, then farther from the wall.  At each position experiment with toe angle- from aiming perpendicular to the wall to aiming at a spot a few feet in front of you. 

Also experiment with stand height.  Too high and you lose bass reinforcement and increase midrange / treble energy.  Try lower stands that bring the tweeters 2-3 inches below ear level.  

Finally try different interconnects and speaker cables- with resolving speakers like yours they matter greatly.  Avoid silver plated hybrid cables and use only OCC copper.  

Although it is not a synergistic match with some burn in, positioning adjustments and re-cabling you might be able to salvage your system. 

My Philharmonic BMR monitors are the older style with scanspeak paper cone drivers. I built them from a Meniscus Audio kit and used all high-end Clarity Caps in the tweeter and mid driver circuits, for a smoother sound. It's true they are the most revealing and transparent speakers I've ever had, and I really like the way they sound. The thing is, they are not fatiguing with my Hegel. All my cables and interconnects are Canare copper. I may consider going back to a push/pull tube amp to use with these speakers. The reason I traded my 300b set amp is because it really couldn't drive those speakers and I feel the low power is a real limitation in speaker selection.

Before throwing more money into the system I would suggest to try optimising your current setup:

- Check speaker placement, toe in, distance to walls, room damping

- Check placement of components, do not stack but rather use a dedicated rack

- Check quality of source: Sometimes highly revealing systems might show shortcomings of the source

 

Your current system should be capable of sounding wonderful. 
 

Good luck!
 

This is a very timely thread for me but mine is a speaker change. Last week I hooked up a new pair of Falcons to replace my Harbeths. Both speakers are rated at the same sensitivity (83db).

Over the years I have owned many speakers ( 30+ pairs ) and never had this problem. The Falcons sounded so nice that I could have been playing them a bit too loud. Hopefully I didn’t do any permanent damage to my ears!

 

 

 

@yogiboy 

 

So your experiencing some fatigue? Your speakers are 83db efficiency and you are powering them with small tube amps?… sorry, it is hard to see the components in your system. 
 

What are the components? Are the photos current? Do you have a photo of the venue? 
 

Be helpful in seeming what is going on.

@ghdprentice

No fatigue. I just got the speakers and I was playing them too loud. Everything is fine now that I backed off on the volume. I am using 70 watt Quicksilver tube amps. The Falcons that I just got seem to be a lot more efficient than the Harbeths. It might be that the Harbeth rating of 83 db is lower or the Falcon rating of 83db is higher. My photos are current.

 

Thanks @yogiboy
 
Good to see your components. Looks like a nice system. I could see the reflections on the windows behind your speakers limiting the volume, glad to hear fatigue is not a problem… at least for me, one of the most irritating problems.