Help -- my system is too bright

Recently, I upgraded my amplifier to a Krell FPB 350 MCX. I am getting amazing detail and clarity, bass is
tight and extended. I turned off my sub-woofer. The highs are also extended, but now my system seems to have a bright edge at the very top and is slightly fatiguing. Anybody else have this type of problem? What did you do about it?
Discovery Signature Speaker cable would do some good as it is very balanced from top to bottom, but "slightly" rolled off in the treble region. This cable worked well on my original psb Stratus Gold loudspeakers to tame a rather energetic HF response, while still retaining excellent musicality and tonal balance. I have a 6 foot bi-wired pair for sale here on the 'Gon if you are interested.
Another solution would be to try Cardas interconnects, as they are a bit on the warm side, but still very detailed.

What preamp do you use with the new Krell amp? Was your old amp Krell also?
Is the new Krell amp fully broken in?, ie how new is it? I've used Syn Res Master couplers to tame a bit of brightness, and also Syn Res Sig. #10 spkr cables are a warm sounding cable that I like. Good Luck. Craig
I appreciate the interesting feedback.

The old amp was an anthem MCA-50, which I still use
for the Center and Surrounds. It was a nice mellow amp, but not as detailed or extended as the Krell. I bought the Krell used, so I'm assuming it was broken in by the previous owner, but it may need more break-
in time. I am using a Proceed AVP2 pre-amp and a Yamaha s2300 Universal Player.

Does "digital hash" or noisy AC cause high end brightness?
Your system may now be so good that it's revealing how many bad recordings there are. After all, that is your system's "job-1". It's amusing when someone suggest using this-or-that tweek to make the sound "warmer" or whatever.
If a recording sounds bad either accept it or find a better one.
The Yamaha is not a good choice with the Krell, It is, as all universal players are: A little to universal sounding and your Krell can reveal poor upstream source with ease. I have two Krell amps and went through the same thing.
Now, this brings up another point. Already, some posters are counseling cable and power cord adjustments to give this system ___. This, IMO, is how people get
duped into blowing a lot of unneccessary money on cables.
Cables will not produce ___ in speakers that are not built to accomodate it.
This the Krell sound that I also experienced - hyperdetailed. I SHOULD have experimented with various cabling & tweaks before selling the amp for something different, but I *thought* that I knew better. I didn't listen though & now I wish that I had. Because that *next* amp, while not sounding hyperdetailed, exhibited some other issues, as did the next one & the one following that.
Possibly a different amp (but only possibly) yours may synergise better when everything else is tweaked in. I would approach the fine tuning issues by trying & applying some tweaks instead.
Here are some possible examples:
cones under your speakers
Speaker cables.
Upgrade AC cords.
AC line conditioning.
Footers & Pods.
If you have tried the Cardas Golden Reference interconnects but you still get the harshness and/or brightness then you should consider Shunyata Black Mamba or Python power cord and need to use Black Diamond Racing shelves or cones to eliminate the brightness. Good luck.
Dweller --

There's no doubt the Krell's are exposing some bad
recordings. They have also given new life to others.
So far, it has been a nice trade-off.

Bob --

I just ordered the Balanced Power Techonology
BP-3.5 [About 30 minutes ago] to clean up my AC,
so hopefully, I can eliminate dirty AC as the problem.

Sogood --

Excellent point. The Universal player is definitely the
weak link in the chain. I've been mulling over CD
players. Suggestions?
You might try a Shunyata Research power cord on your Krell. I've had customers report that their Shunyata helped take that bright edge off an otherwise fine-sounding Krell amp. If you find an older King Cobra for sale, you might try it out. If you don't like it, you can probably re-sell it for approximately what you paid for it.

I find it very interesting that so many recommendations can be confidently suggested despite the fact that Rsbeck has told us nothing about what speakers and cables he is presently using.

Me, I'm waiting for the day when an audiophile posts here complaining that his system is lacking brightness... :-)
Does "digital hash" or noisy AC cause high end brightness?
I hadn't noticed this question initially...
Yes it certainly does - the radiated noise emanating back out onto your AC line contaminates the AC power supplying other components. Line conditioning can significantly attenuate that phenomenon, as can a filtered AC cord. The JPS Digital (filtered) AC cord is one common cure for brightness issues. Custom Power Top Gun or BMI Eel are other filtered cords, & of course I'm only barely scratching the surface regarding these filtered cord offerings. But do try the line conditioner, which should also benefit in that regard.
Duke --

Thanks for the suggestion. The Krell FPB 350 MCX's
have dedicated Power Cords, so it isn't an option to
swap PC's on the Krells.
Zaikesman --

My speakers are Monitor Audio Studio 60's. I am using
12 AWG 99.999% OFC Speaker cables.
Bob --

The AC filter is ordered and on the way. Might take a few weeks, but when I get it, I will post a review.

Here is the URL for Balanced Power Technologies


I ordered the BP-3.5

I have read that people get results from Filtered PC's
on their digital sources. The Yamaha has a detachable
power cord, but the PC on the Yamaha is only a two
pronger -- what do you make of that?

In any case, I will keep the Yamaha for it's DVD
capability, but I am looking to upgrade my CD
player and then -- is a filtered PC redundant if
you are plugging it into a filter?

I am open to CD player suggestions.

Been reading great things about the Audio Aero Mark II.

Finally, when someone says a speaker wire "rolls
off the top end" -- how is that achieved?

Anyone know the science behind that?
Zaikesman, lack of brightness (which is dullness in my vocabularly) is frequently my complaint with the ProAc speakers I currently have. So there! Maybe I should get a Krell. :-) /dan
Ditto the ProAc/brightness comment from Drubin. I loved them when I had them, but when getting new speakers, I wanted speakers that could make all the bells and whistles in Hi Fi...well, sound like bells and whistles.
I think the "problem" is your the Monitor Audio's ultrasonic ringing. I've never heard the 60s but I've had the Studio 50s for three years and I (still) own a pair of Studio 20s. The MA tweeter has a very prominent ultrasonic peak that some people find fatiguing. It's possible that the Krell is exposing this peak more clearly than your previous amp. If you haven't already done so you should remove the mesh tweeter guard. You can carefully pry it off. The speaker is also sensitive to toe-in angle. Try listening slightly off axis.
Onhwy61 --

There's no mesh tweeter guard on the Studio 60's, but
you have a point with regard to off-axis listening. There
does seem to be less fatigue. I have been experimenting
with the toe-in. These speakers seem to sound good no
matter where you are in the room, or even whether you're
in the next, room, etc. You've piqued my interest in
the "ultrasonic ringing." This feels right. How did you find out about it? What causes it? How do I get rid
of it? In addition to other remedies, I'm thinking about some room treatments.

perhaps an RC Zoebel network installed across each of the tweeter's terminals may help, if in fact the ringing phenomenon is occuring. Dunno exactly how that could be verified, but it may be a fairly easy experiment to try out a network. I've never done one so can't explain how the RC values should be correctly calculated - member Sean may be able to assist with that; he's done this before.
Speaker cable HF rolloff can be related to cable capacitance / inductance; higher values of distributed capacitance in parallel with your load (the speaker) would somewhat attenuate the HF response, as would higher values of series inductance. MIT speaker cables may be worth trying here; they're internally networked by design, & can help to smooth out a brightness problem (it worked for me).
Regarding the 2 prong CDP AC cord: here's some ideas. If you want to experiment with a 3 prong style cord, then temporarily use a short (4" to 6" long) external handmade adapter device to convert from 2 to 3 prong IEC. During the experiment, the AC cord's shield will only go as far as the adapter, but if you like the sonic results then the IEC on the CDP can be changed to a 3 prong style, leaving the 3rd ground conductor unterminated if desired, or perhaps tied to chassis if no undesirable effects are introduced by doing so. Or the IEC on the end of the cord could be changed to fit the CDP's socket. Or the adapter harness could remain permanently if it's very short length & is made from quality conductor materials. Lots of options here. A Highwire Powerwrap helical adjustable filter installed onto the AC cord may be anoher inexpensive option to try.
The ringing is somewhat inherent in the design of their tweeter. I remember seeing evidence of it in an old Stereophile review of the Studio 20s. They showed a waterfall graph with a severe resonant mode in the 22KHz-25KHz area. It was reported as being the first breakup mode of the metal dome tweeter. When I had the 50s I had them in a system with either Rowland or Pass electronics and Discovery and Sumiko OCOS cables. With the toe-in adjusted so that I could still see a substantial portion of the inner speaker panel and a listening height several inches below the tweeter level I never noticed the resonance "problem". I've read that it's relatively easy to design a crossover that traps out the offending frequencies, but I believe Monitor Audio purposely has not taken this approach because they think it does more harm than good.

Assuming that the 60s are even better than the 50s, you've got a very fine speaker. I hope you can work out this issue.
Having an ultrasonic peak is not unique to the MA tweeter - most metal-dome tweeters have such a measureable ultrasonic resonance point, of differing magnitudes and frequencies depending on the design. It is assumed that the higher this peak can be pushed up in frequency and the lower it can be pushed down in magnitude, the better. It is also assumed that any deleterious effect this peak may have on the sound would be more caused by possible interference artifacts, reflected lower down the spectrum, than by the peak frequency itself (which is, let us remember, above the range of normal hearing). The perceived 'brightness' range actually occurs below the top octave (below 10KHz), well away from a 22KHz peak even for those few listeners who do hear up that high. With typical CD sources, the steep HF filtration usually employed by that format would tend to make tweeter resonances at or above 22KHz a less suspect issue.
Z-Man -- interesting stuff.

Right now, I am going on the assumption that my amps
need a little more break-in time, my AC needs to be
cleaned up, my room needs a little treatment, and that
it is possible that some of the fatigue is being caused
by room resonances mixed with a little AC distortion
and low level noise from the Universal player amplified
and passed on by the extra sensitive amps, and possibly
even by simply hearing more detail accross a wider spectrum
than that to which I have become accustomed.

If more break-in time, a high end AC isolator and filter,
some room treatment and a new CD player don't solve the
problem, which -- remember -- is slight to begin with --
I will have to consider other alternatives.

I appreciate all the interesting information y'all have offered -- I have learned a few things from this discussion.


I am not sure of your budget, but the new Ayre CD deck is outstanding! If you are considering new, add this to your list.
Rsbeck, I have been through exactly what you are experiencing. Krell amps are neutral, accurate, powerful, and painfully revealing. This is great when the source and the rest of the system are up to the task, but otherwise they can drive you crazy. I have the MC version of the FPB 350's and love them. However, it has taken some time and money to get the rest of the system up to par and I still need a first class cdp. I once had B&W N802's connected with junk speaker wire and it sounded horrible at medium to high listening levels. There was no bass and the highs would peirce your ears. I added Cardas GR speaker cables and that made a huge difference in bass extention and mellowed out the highs significantly. But I was still not satisfied. At the time, I was using the Krell HTS 7.1 as the pre with a old Denon cdp connected with a digital coax. I began to realize that the AV preamp was not going to give me the first class 2 channel performance that I was seeking. So, I sold that and the N802's. The N802's were purchased as a temp until I could find the speakers that I really wanted. I recently added a Krell KCT preamp and Wilson WP 7 speakers and now things are starting to gel. The resolution is unreal and the sound is smooth, powerful, full and sweet but I can hear the old Denon cdp in the chain. I am currently shopping for a cdp but have not made a decision yet.

I am not suggesting that you need to go through the changes and expense that I have. Your goals may be totally different than mine. But, if you are ever to be happy with Krell amps in your system, the rest of the system must be on par. They will definately let you know if something else in the chain is noisy. They are extremely revealing.
Noble -- thanks for the suggestion. Have you heard the
Ayre? How does it compare with, say, the Audio Aeros,
Naims, and Tri-vistas of the world? Tell me what you
like about it.
WVick --

I'm curious. Did you do anything to clean up your AC?

I have ordered a BP-3.5 from Balanced Power Technologies
and I am dying to see what kind of difference this makes.

I will post a review after I get it in my system, which
will take a few weeks.

I love my speakers, but I have also auditioned the
Watt/Puppy 7's and loved them. I can imagine how
the Krells and WP 7's would make a great pairing.

I have not heard the WP 6's, but I keep an eye on the
Wilson page for a deal on a pair. I'm not ready to spring
for the price of new WP 7's, but for the price of a
used pair of 6's, I may just have to get a pair into
my system and play with 'em.

How close are the 6's to the 7's?

Also, how long did it take to burn in your Krells?
Rsbeck, I am not using any power conditioner but I did install 2 dedicated 20A outlets for the amps. I may add a power conditioner for the pre amp and cpd but I do not plan to add anything for the amps.

Wilson Audio and Krell are a classic match. The WP 6's are great speakers and I planned to get a pair until I listened to the 7's. The 7's are a bit smoother, more refined and musical from top to bottom. I could have lived with the 6's but I knew this was going to be my last speaker purchase for a long time so I went for the 7's. I am very happy with them. There is a very good reveiw on the 7's here:

I don't really know how long it took to burn the amps in. They seem to get better as time goes on. They have been in my system for 8 months and I have made several changes along the way. With the exception of the cdp, I don't plan on making any more equipment changes. Hope this helps.
Wvick -- Very helpful -- thanks!