Krell KAV-500 vs S-1500 5 Channel & cables


Hi all,

Wondering if any of you have experience with both the older Krell KAV-500 5 and S-1500 7 channel amps? I read that the S-1500 had some problems (burn ups & hum) when first introduced.

I have a recently purchased/re-capped KAV-500 in my 7.2 HT. The rear surrounds are currently powered by 2 channels of the Marantz Cinema 60 processor.  Front speakers are B&W 804S Nautilus (L&R) and a HTM-1 Center.  Surrounds are 804 Nautilus (not S) and the rear surrounds are B&W SCM-1's on stands. There are 2 JL subs in front.  Cables & interconnects are a mix. Projector is a Sony vpl-5000es laser.

Rooms are combined open living room (13'x19' long, screen on the 19' wall) with "L" into 13'x'13' dining room with rear surrounds against back wall in DR 26' from front screen/electronics &. 20' cathedral ceiling over both.

Question: is it worth pursuing the more powerful used S-1500 or does it have the same sonic signature as the KAV-500? The KAV seems to have plenty of power but some dialog can sound "hollow" and slightly tipped up.  Also, there is some occasional HF distortion during musical passages on shows (not using it for 2 channel listening).

Cabling is single 25' run of Wireworld (not the top of the line can check model) to the surrounds and bi-wire (cables & interconnects we were going to manufacture) to the fronts & center. 14 gauge single long run generic wire to the rear surrounds.

Any input for sonic improvement would be appreciated. No room in cabinet for 2 amps (a 2 & a 3 channel). Won't go crazy$$ on cables/IC's if that's where to look. No dedicated lines yet and everything plugged into Richard Gray box except the amp.

Suggestions for sonic improvement appreciated.

Thanks.

 

 

 

 

 

 

tt1man

Just to be clear, what exact model cables are you using for the front L/R/C?  What amp were you using previously, and did you hear these issues before or is it just with the Krell?  Also, what preamp/processor are you using?  All this stuff matters a lot so more info would be very helpful.

Thanks for the reply!

The L/R/C cables are prototypes my previous DAC company developed. Somewhat similar to Nordost/Goertz. Flat extruded teflon over conductors for the HF and silver coated tubular braided wire for the LF as bi-wired pairs.  They were used in audio shows "back then" and are quite good.  Same for the interconnects which replaced WireWorld which were not as open sounding..

If I did look at experimenting with cables, which reasonably priced brands would you suggest work well with B&W-Krell? 8' bi-wired pair L/R & 4' bi-wire to center.

As mentioned, the receiver/processor is a fairly new Marantz Cinema 60.

Previous amp i still have is a 5 channel Butler Audio TDB-5150, which sounds quite nice but not as clear or transparent as the Krell. I did experience some of the same slight HF distortion with it as well.  Wondering if the lower cost WireWord single run to the surrounds could be contributing factor?

Do you think it's worth pursuing the S-1500 Krell yet? Also, not sure of the break-in period for the re-capped KAV which might have an effect on HF?

All power cords are shielded heavy gauge stock and hopefully won't have to go down that trial path as well ;-)

Cheers.

 

 

I’d maybe give the Krell more time to see if it settles in better as it burns in more, but if not the first place I’d look would be the front interconnects/cables.  I wouldn’t pair any silver cables with older B&W Nautilus speakers and thinking that could be the source of what you’re hearing, especially as it existed with the Butler and got worse with the more transparent Krell.  Plus, of your options cables are probably your cheapest/ easiest option to explore (especially if you’re open to buying used) and are obviously cheap/easy to ship.  If I was you I’d try these Acoustic Zen speaker cables and see if you notice an improvement — you could try them with your L/R fronts and then separately with your center to gauge the effect on all your front speakers.  I’m thinking they’ll have fuller mids and more refined highs that could be a better fit for your system, and if they don’t work out you can turn around and sell them at little/no loss as there’s a liquid market for used AZ cables.

https://www.ebay.com/itm/235430798208

Anyway, that’s what I’d do FWIW, and best of luck.

Good advice. I'll concentrate on the cables/interconnects while the Krell burns in. 

I met "Mr. Zen" years ago at a show in Vegas.  Nice speakers, one of the best sounds there.

Thanks again for the feedback.

All the best.

 

 

OP: 

Sorry this took me a little to get back to.  The B&W nautilus speakers need to be aligned on the midrange axis, not the tweeter.  This is an especially big deal with centers that are close to the floor.  Make sure it's tilted upwards so the tweeter "fires" at the top of your head.  This should help fill out the midrange for you.

Erik, thanks for jumping in.

The HTM-1 center on the equipment cabinet under the screen is currently tilted upward using a rubber door stopper.wedge.Center height of bird tweeter is ~ 34" and center of mid/woofers ~27".--do I need to tilt it higher?  The tweeter centers of all 4 front & surround 804's are ~40" high (above seated listeners' ears).

Due to room size and seating limitations the surrounds are close to an end chair and couch end seat respectively.  Last night during a show's dramatic music passage.with multiple HF sounds/instruments there was definite teeth-gnashing distortion (no clarity) at least from the surrounds (possibly from the center as well)..

Do you agree with soix that the culprits are most likely cables, with perhaps some re-cap amp burn-in still needed? There is only a single 25' run of WireWorld STREAM 16/2 Insta-Wire (ST-2) with jumpers to the surrounds (not too worried about the distant rear surrounds right now). .

I'd hate to have to go amp swapping again and not changing the speakers. Just want to enjoy nightly movie/series watching with good dialog clarity and nice music when it happens,without harshness.

Have at it!..

.

 

 

 

The main source of your issue is likely the tweeters in your older Nautilus speakers, but I suggested cables as a cheaper/easier way to help possibly mitigate the problem.  For the side surround speakers, if they’re aimed toward the listening positions I’d try angling them away and maybe also tilting them backward so the tweeters fire above ear level (you may need to rebalance their volume levels after doing this).  Just playing with positioning may help quite a bit, and by angling them more away from the listeners you can achieve a more diffuse surround effect that you may actually prefer (I did in my HT setup) so could be a win win if it helps.  If you’re using the jumper plates that came with the speakers, replacing them with more mellow sounding wire jumpers (Cardas would be a good brand to explore there) could also be a relatively cheap potential remedy.  Just some other thoughts FWIW.

Center height of bird tweeter is ~ 34" and center of mid/woofers ~27".--do I need to tilt it higher? 

I don't know, this is a trigonometry and angle problem. :)  If you put a laser on the top of the case, does it point to your ears?

This is a problem that is amenable to room correction somewhat if the measurement mics are placed correctly while measuring, but also somewhat alterable by reducing an overly reflective environment.

One way to test my theory is to sit on the floor and listen, see if the problems you are having go away, which would indicate this is an angle issue.

Lasers? "We don't need no stinking lasers" I'll just sit on the floor, but at my age might not be able to get back up. At which point I'll be remembering you and your suggestion ;-)

After this, I'll be experimenting with all copper interconnects and cabling (heavier gauge to the surrounds and possibly bi-wire as well), brands TBD including Cardas and even some low cost Monoprice, to see if in fact the silver is causing the nastiness.

OP:

Well, it was just a suggestion to get you to think about the angle of the speaker to your head.  Another possibility would be to put the speaker above the TV, or turn it upside down. 

Yes, actually the tweeter projection angle is a little low and I'll be elevating it a bit.  Projection screen's top valance is too high up on the wall to mount the center. More elevation plus proper wires should hopefully solve the problem.

The KAV seems to have plenty of power but some dialog can sound "hollow" and slightly tipped up. Also, there is some occasional HF distortion during musical passages on shows (not using it for 2 channel listening).

This reeks a bit of a degraded/faulty amp.

- Sell this "recapped"/used amp (that someone passed off to you, he must be breathing easy now) and cut your losses before it becomes more of a headache.

- Run the 4 surround channels off your Marantz.

- Get 3 Schiit Tyr monoblocks for your front stage (front main/center/right main). It should hit your rig with a rich dose of adrenalin and get you up to speed.

 

P.S. if you are a loyal Krell fan/insist on hanging on to it... move additional channels back to the Marantz and run only the 2 fronts with the Krell. See if it improves the sound, no hollow bass, distortion went away, etc.