Fascinating how the circuit focused group analyzes the problem as an amplifier issue and dismisses all other possibilities pretty much out of hand, and rather forcefully. A microcosm of how audiophiles tend to think?
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?
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?
125 responses Add your response
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Kosst_Amojan 11-30-2017I could use some clarification on that myself, Uberwaltz. I’m not sure how a multimeter measurement at the output terminals of an amp can determine if the bias is too low (or too high), the main possibility Kosst had cited being low bias. DC offset can be checked for in that manner, of course, but perhaps Kosst can clarify how such a measurement can determine if bias is too low. Best regards, -- Al |
Absolutely, I completely agree. I posted before I had completed my thought.. Cables certainly are possible, but the evidence presented points to the electrical system as a distinct possibility as well. It would at least be worth shutting off the branch circuit at the panel to completely rule effects from the kitchen circuit out. Also, double checking the connections in the panel (after shutting off the power) would be warranted as well. I just wanted to put those other possibilities out there as well, to avoid needlessly shipping an amp around the country. Kosst also offers a reasonably easy test as well.. lots of good ideas for more data points. |
I also agree, Todd, that the cables are not a particularly likely culprit. However, as Uberwaltz said just above, and as I said earlier, it is easy enough to perform a test that would rule the possibility in or out. And as I also said earlier there are very strong reasons to suspect that the OCOS cables have very high capacitance, and ... Almarg 11-27-2017So to be sure it’s clear, the **possibility** I suggested was not that the cables might be the culprit in themselves, but rather that the effects of their presumably very high capacitance on the amplifier **might** be. And, once again, it’s a possibility that is very easy to check. Also, a reason that this possibility has been given what Kosst characterizes as "first attention" is that we certainly want to be sure that it has been conclusively ruled out before other findings may lead the OP to incur the trouble, expense, and risk of sending his amp out for a repair that may prove to be unnecessary. So while Kosst finds himself "befuddled by the persistent recommendations that the least likely culprit, the speaker cables, be given first attention," I find myself befuddled by the objections that have been raised against that attention. Regards, -- Al |
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@toddverrone I would agree the cables or the interconnects are unlikely culprits but as it is a very simple and cheap test it should not be ignored.It is possible it really was not sudden, a connection may have been corroding or degrading for a while but then reached a point where it had gone that far as to now present itself as an audible artifact at last.Unlikely true but not impossible and one that should not be ignored in the greater scheme of things. |
To the OP Did you try replacing the speaker cables yet? Anything will do for a cheap dirty test, zip cord, bell wire even regular SO cord ( no you do not have to use all 3 conductors LoL!). I may have missed this but did this start at the same time as the kitchen refurb grand opening ceremony? If not then even though all the potential kitchen issues may not be helping overall SQ I doubt that it is the cause of this particular gremlin. I am thinking most likely cause (after eliminating speaker cables and checking all interconnect integrity) would be the Pass or the P5 but most likely the Pass. Hoping it is not as yes it is a royal pain and cost to pack up and ship back to Pass for a checkup. On another note entirely (sic) Why oh why do we feel the need for openly hostile, rude, antagonistic and generally arrogant posts? Oh and then the additional purely inane ones to boot that serve no usefull purpose whatsoever. Everybody is a keyboard warrior nowadays........ |
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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. |
Proposition: There are less Morphic fields 👻 👻 👻 floating around late at night. And early in the morning. Especially Sunday morning. Morphic fields are frequently misinterpreted as "power grid activity." You should notice excellent sound quality issuing forth from your system during those times, generally speaking. Very weather dependent, too, low pressure systems bad ⛈ , high pressure systems good 🌞. It’s doesn’t take a rocket scientist 🚀 to realize there are a great many variables involved, certainly not (repeat not) only one or two. |
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Jea48 11-28-2017I would think it’s unlikely, Jim, but I suppose it’s a possibility. For example, perhaps the MultiWave circuitry is misbehaving and doing funny things with the AC waveform, even when it is supposedly not being used. In any event it’s easy enough to find out, as you suggested. Also, another thing I would suggest that the OP do, if he already hasn’t, is to use the P5’s oscilloscope function to look at its incoming and outgoing AC waveforms. And see if either looks dramatically different than a sine wave. Best regards, -- Al |
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@grannyring +1 These forums are meant to exchange ideas and assist members in the world of audio and not insult those who do not agree with their opinions. These forums are not to be used as their personal message board. That is why there is a private message section. No one wants to hear their bickering and personal agendas that have nothing to do with the original topic. It’s time the moderators enforce the forum guidelines. |
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I second what @jea48 said: check, or have your electrician check, the connections in the panel. Not just on the circuit feeding your system, but every connection: hot, neutral and ground for every breaker. You may even consider reseating all the breakers. (Please stay far away from the lines coming in from outside. If you don’t understand what I’m saying, please hire an electrician or ask lots of questions) I know that loose connections can add significant noise to the electrical system. Definitely try the amp swap too. Give us more data points! Good luck! |
Moderators please remove all the insulting posts, perhaps kosst_amojan himself, from this site. He continuously insults and brings down the enjoyment and civility of this once fine audiogon community. This cannot continue without many of the long time and civil members opting out of these forums. |
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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 |
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Do you leave your front end equipment on all the time or turn it off when not in use? Warmup could be in play. Is this for both LP and Digital playback? Second on Almargs comment about the OCOS Speaker Cable - 15 feet is a long cable - try a set of Canare 4S11 they are pretty inexpensive and a great value. Best of Luck Peter |
Next up, the absolute polarity thing. Or the Cable Directionality thing. Or the fuse directionality thing. Otherwise it looks like we’re back to them old Morphic fields back home. Waves of...information! "When you control the mail you control...INFORMATION." - Newman There are no standards for absolute polarity. - audiophile axiom |
Is the P5 set to output a pure sine wave, or is it set to one of the MultiWave choices? If the latter, which as I understand it flatten the peaks of the P5’s output waveform (in other words, the MultiWave modes intentionally distort the AC in certain ways), I would suggest that you see what happens with the pure sine wave mode. Also, it would be interesting to know what the P5’s status screen shows for input and output voltages, and input and output distortion. Good luck. Regards, -- Al |
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). Thanks for all your comments. |
Plus one for electrical issues in your new kitchen. I would try listening to your system with the new kitchen fully operational as a baseline, then try: 1. Turning off all kitchen lights - listen 2. Turning off all breakers to your new kitchen (if possible) - listen 3. Try plugging your amp into P5 with all kitchen electrical devices on including the lights - listen, then repeat 1. & 2. above with amp plugged into P5. This should tell you if something in the kitchen is the culprit, and if power conditioning is helpful. If you do not already, you may want to put your system on a dedicated AC supply line(s) and breaker(s), especially if as has been mentioned it now shares a line with the kitchen or some other potentially offending circuits as a result of the new construction. My main system is on a dedicated 10 gauge supply line with its own 30amp breaker. I have a dimmer in the listening room (with incandescent bulbs), but it is on a different circuit. Amp plugged directly into wall with no direct filtering (but do have a conditioner plugged into the same socket for sources) and system is dead quiet, treble never sounded better. Good luck! |
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I havd been personally working on 2 specific areas to address digital if you have a player, or dac the cable possibly warmer meatier. My cables are all set totally happy with the Unique Verastarr cables. I have a different type of Loudspeaker that gives you options for example in open baffle I can put whatever Brand components in the cross over I currently have a 1 big Clarity Capacitor for the midrange. Duelund just came out with a less expensive version Of their top Cast cap except with a smaller Aluminum case vs The Big paper case hd JAM cap. Sonicy this cap feeds directly just the mid range in the Voxativ driver . This eliminates all excessive CD brightness from bad recorded digital. The $400+ dollars for 2 caps sounds like a lot of money but far cheaper then s stack of fuses csbles or a component -and a huge dividend in warmth depth and musicality .their new Silver wax oil .01 bypass caps put in amps,preamp digital is another worth wild venturefor less thrn s good fuse each.the new Duelund Jam capacitors. You will be hearing a Lot more on these one of the best in the World by far the biggest impact . They do take some 400 hours . I am just letting play got 3 weeks straight.Shoot for at least 5-10 %capacitor value to use Minimum, more if you have small values and room .3.3uf is max size on Jam caps they pack a punch. |
dimmer bad does it have an all the way OFF detent on it? dimmers work by 'chopping' up the voltage - this creates a lot of high freq. noise on the line (maybe radiated RFI too) if setting it all the way down - whether you feel a detent in the knob or not - doesn't solve the problem then either power the lights on a different circuit from the stereo or get rid of them or use an isolation transformer on your system (often a good idea anyway) if the detent Off doesn't work and you don't need those lights on when listening (i.e. you have another light source), then you can wire in an old-timey (off is off) light switch ahead of the dimmer circuit |
Not sure it would be room acoustics as there is no improvement as I walk around the room. That only works for bass modes. Room acoustics is more than that. In particular, I’m talking your room’s overall power response. How quickly the top end decays. If it is lingering longer, or reflecting more, it will give the exact issues you describe. So, again, did you move furniture, curtains, etc around? If no, then that’s not likely, but still there is a free experiment you can do. Throw some blankets or pillows on the floor, especially between and behind the speakers. Experiment. This may not be your issue, but it’s free. |
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