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Why does my system now have shrill top end.

The equipment in my system (listed below) has not changed but I now find on both CD and Vinyl a high end shrillness to the sound (treble is very harsh) that has become very annoying, especially at high volume levels. I have no idea why this happened all of a sudden.

Endevour E-3
Pass 30.8
Pass XP 20
Esoteric K01x
Linn LP12 (Ortofon Black cartridge)
Linn Linto Phono Preamp
PS Audio P5 (Amp plugged in directly to wall)
JL Audio F112 v2 sub
OCOS Speaker cable (15 feet)
Pass XLR interconnect (Preamp to Amp)
Harmonic Technology Cable Magic Link (not current version). RCA termination

Any ideas?
proacman

Showing 12 responses by jea48

jea48
2,944 posts
 
Al,

Is it possible the P5 is the problem? Not because he plugged the amp into the P5. I doubt is any Pass amp would liked being plugged into a power conditioner.

When the OP is using the P5 for the front equipment could the P5, because of some  internal problem, be causing the sound problem?

I didn't read any OP responses where he tried removing the P5 from the chain. I would try that. Even so far as unplugging the P5 from the AC mains outlet.

@proacman,

When the kitchen was remodeled did the electrician add any new circuits from the electrical panel to the kitchen? If yes he might have moved existing branch circuit wiring around inside the electrical panel, just physically moving wires with his hands when installing the new branch circuit wiring inside the electrical panel enclosure. Just the side to side moving of solid core branch circuit conductors around inside of an electrical panel can change the wire to branch circuit breaker terminal tightness connection. 

jea48
2,944 posts
 
proacman OP21 posts11-28-2017 8:15am

Unfortunately the problem is getting stranger. When I turn off all the kitchen lights and play a few songs that are very harsh and then turn them back on their is no difference. But, I plugged the Pass amp into the P5 instead of directly into the Wall and all the Bass was sucked out, as if the speakers were out of phase (they are not). Now this certainly makes no sense. Makes me wonder if the Amp is the issue. Have a five channel amp in my surround system that I will switch with the Pass to see if there is any difference in the harshness (and now bass).

@proacman,

Please, please, please, do try the other amp before kosst amojan has a total meltdown and kicks the dog.

.
jea48
2,944 posts
 
@almarg,

+ 1


Jim
jea48
2,944 posts
 
If there is garbage fed to the inputs of the amp there will be garbage on the outputs.
Garbage in  = garbage out.

.
jea48
2,944 posts
 
You two guys need to get room. You're beyond foreplay.
jea48
2,944 posts
 
If you still have the "shrillness" after trying the other amp remove the P5. Unplug the P5 from the wall outlet.

Did you try removing the P5?

Just curious why no one hasn’t suggested the "shrillness " could be caused by the preamp.
jea48
2,944 posts
 
Al,

I agree the speaker cables should be replaced with something else to conduct a test. The most the OP will be out is a few bucks and a little of his time. The OP can pick up something cheap speaker cable at Best Buy or Home Depot.

Al,

What are the chances the OP could connect the Linn Linto Phono Preamp directly to the inputs of the Pass amp without it playing too loud for a test. That would take the Pass XP 20 out of the equation.

SPECS

Input connectors: gold-plated direct circuit board mounted RCA jacks
Output connectors: two pairs jacks (as above)
Audio input level: 150 microvolts nominal, High Gain
500 , Low Gain
Input Impedance: 150 Ohms, in parallel with 4.7nF
Output impedance: 100 ohms both pairs of outputs
Gain: 64dB at 1KHz, High Gain
54dB at 1 KHz, Low Gain
Power consumption: 6 watts, 12VA approximately
Dimensions: 320 x 320 x 80mm
Weight 1.5kg

https://www.audaud.com/audaud/JUL-AUG02/EQUIP/equip2JUL02.html

Unplug the Pass XP 20 from the power outlet.

 Try the Linn Linto Phono Preamp first plugged into the P5. If the " shill" sound is still present plug the phono preamp directly into the wall outlet. Unplug the P5 from the wall outlet.

Jim
jea48
2,944 posts
 
How many GFCI outlets in the house?
If a GFCI can cause a problem with the sound from an audio system, audio equipment designer/manufactures best be solving their problem why.
jea48
2,944 posts
 
All I can say is what worked for me...
dont want my advice, don’t take it.

liquidsky
3 posts                                                                               12-02-2017 9:45am

That may be true in your case. More than likely with poorly designed audio equipment. Pass Labs on the other hand is well designed audio equipment.

At least here in the USA GFCI protection in residential dwelling units is here to stay. At present, Kitchen above counter top outlets, Laundry room outlets, bathroom outlets, garage outlets, outside receptacle outlets, receptacle outlets in unfinished areas, is required per NEC code. (Depending if the AHJ, Authority Having Jurisdiction, adopted that provision of the NEC. 2002, 2005, 2008, 2011, 2014)

AFCI protection is now required on all 120V 15 and 20 amp lighting and receptacle outlet circuits in new homes built pretty much after 2015. (Depending if the AHJ, Authority Having Jurisdiction, adopted that provision of the NEC. 2002, 2005, 2008, 2011, 2014).

 Slowly NEC is expanding where GFCI protection is required. With improvements in dependability/reliability made for combination AFCI/GFCI circuit breakers it is only a matter of time before NEC will require all 120V 15 and 20 amp lighting and receptacle outlet circuits be AFCI/GFCI protected.


jea48
2,944 posts
 
Al,

Thanks for your response to my above question directed at you.

Jim
jea48
2,944 posts
 
Hi Al,

After reading your last post it’s obvious I did not consider the resulting initial impact of dropping the stylus onto the record. I agree with your assessment and wouldn’t want the OP to possibly cause damage to his speakers.
Al, thanks for your time spent looking into the specs of the cartridge and phono preamp loading.
.

So where are we in this thread?

Waiting for the OP to try his HT amp in his 2ch system.

Try different speaker cables. (I probably would have started here first.)

Maybe try the front speakers from his HT system, depending on their quality.

Try removing the P5.

Temporarily, for a test, turn off all the breakers in the electrical panel that feed the new kitchen remodel. Especially kitchen appliances/equipment with micro processors. Turn off the LED ceiling lights. (It’s not the LED that can cause noise going back out on the AC mains it’s the electronic transformer in the base of the lamp. Cheap electronic transformers will cause more noise x the number of lamps used.

almarg
7,657 posts                                                                   12-01-2017 3:48pm

Kosst, my hypothesis is not predicated on the cables having changed in any way whatsoever. If it wasn’t clear, when I referred to the condition being "sufficiently marginal that minor aging effects or perhaps even a change in AC line voltage have put it over the edge," resulting in ringing or oscillation, I was referring to minor aging effects in the amplifier. Which in turn might have made the amplifier more prone to ringing or oscillation as a result of the heavy capacitive load.
Something I don’t recall the OP stating in any of his responses is how his 2ch system is powered. Is it just plugged into an outlet fed from a 15 amp convenience outlet circuit that feeds other items possibly including ceiling lighting?
A dedicated branch circuit/s? 15 amp? 20 amp?

Is the P5 plugged into the same duplex receptacle outlet? Does the P5 indicate the input AC mains voltage? If so has the OP checked the AC line voltage at the wall outlet while listening to his system? Does the AC mains voltage maintain a steady state voltage for the Pass amp? Especially when listening to his system (amp) at an above moderate volume level?

Jim
jea48
2,944 posts
 
mre28m5
5 posts 12-05-2017 2:45pm

About a year ago I was experiencing system symptoms virtually identical to those the OP has described. At some point after much thought, frustration and experimentation, I replaced my speaker cables and the harshness disappeared.

30 feet of Monster Cable or 12 gauge TW cable from the hardware store will be an easy and inexpensive experiment. Hope this helps.

almarg
7,718 posts                                                                     11-27-2017 4:21pm

I don’t know what the capacitance per unit length of OCOS speaker cable is, but given that your cable is fairly long and given also that OCOS is a somewhat unconventional design a possibility that occurs to me is that its capacitance might be causing an ultrasonic oscillation in your amplifier. And perhaps the condition is sufficiently marginal that minor aging effects or perhaps even a change in AC line voltage have put it over the edge.

If so, the volume dependency you mentioned might result from the speakers being stressed to a greater degree when an oscillation and a high volume audio signal are both present.

So I would suggest trying different speaker cables, whenever that may become practicable.

Good luck. Regards,
-- Al

almarg
7,718 posts                                                                11-28-2017 11:03am

Kosst, I assume that I was not included among those to whom your last comment was addressed, even though it mentioned cables. But to further clarify my comment about the OCOS cable (and Peter, thanks for the second): As you may be aware there are a few speaker cables which have ultra-high capacitance, such as Goertz and the old Polk Cobra cables. When used without a Zobel network, and especially when used with solid state amplifiers, those have been known to cause ringing and/or oscillations, and in some cases oscillations which have even resulted in severe damage to the amplifier.

After doing some research I have not been able to find an indication of the capacitance per unit length of OCOS, but it is an unconventional coaxial design having an extremely low "characteristic impedance" of about 8 ohms. That suggests a strong possibility that its capacitance is very high.

On the other hand, I would expect that the not especially extended 100 kHz bandwidth of the amp, and the relatively modest amount of feedback I believe it uses, lessen its susceptibility to that kind of effect. But it should be easy enough to rule this possibility in or out, perhaps even by using Home Depot or Radio Shack wire for purposes of the experiment, if the OP doesn’t have any other cables of suitable length on hand.

Your suggestions about the amp are of course also good ones, IMO.

Regards,
-- Al

jwpstayman
248 posts                                                                       11-28-2017 4:44pm

OCOS cables are pretty old ( around 1997 or so). If I remember correctly, they were designed with OCOS standard terminators (Red), but when used with dome tweeters or a speaker with a rising impedance curve, they needed to have the HFC (Black - nobel) network installed on the speaker end in place of the Red ones. They also came in VERY specific lengths (9’10"/13’/16’6",etc) which I have to assume was a performance benefit or to correct a design/engineering issue. I would try and borrow some newer speaker cables and hear if that "fixes" the problem. Those OCOS cables might have oxidized over the years and/or the connectors might have issues. I also suspect that the Black HFC needs to be used for the Endeavor speakers.



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