P.S. -- of course try Ralph's suggestion about unplugging the digital. But I thought everything else has been ruled out. ???? :>( |
Fishing, Al (Almarg) and Ralph (Atmasphere). I just read above that there is speculation about the ability of the variosu amps used to drive low impedance speakers. Dunno for sure.
But if that is the culpret, then I see 3 options: (1) change the speakers; (2) change the amp; or (3) Zero Autofomers. Not sure what the least expensive route to take is.
As regards option #3, check the web site. I think the guy who came up with the idea will take the Zeros back if they don't work. I think #3 is about $1,000. Bummer. |
Fish . . . I looked the dealer up on the internet. It appears he carries Bryston. If a Bryston amp can't drive those speakers, nothing can. I like the idea of trying an extremely robust amp like a Bryston.
But do check out Zero the autoformer web site. As I said, I seem to recall, if not satisfied, I think the guy will take the Zeros back and issue a refund. If nothing else, check out the web site to understand what Zeros do. In short, they are an impedance multiplier. Simply stated, under one setting, the Zeros can make your amp think its driving twice the impedance load than it really is, i.e., nominal 4 ohms x 2 equals 8 ohms. Your amp will take a vacation with shades. ;>) |
No way! Are the Bryston integrateds as muscular as a separate Bryston power amps. Call the factory and ask the techs. I can't go back to read all the steps taken to isolate the problem, but I assume working backwards you eliminated your source components (i.e., CDP and phono, as applicable), cables, etc.
If so, that could mean, as has been surmised above, the "true" impedance of your speakers may be lower than the nominal 4 ohms I seem to recall being mentioned. Actual versus "nominal" reported impedance stats can vary quite significantly and often do. Very few amps "like" driving into those kinds of loads. If a monster Bryston doesn't work, I think you go back to "Zeros" and see if that helps.
Btw, just an "fyi" I picked up some time ago when talking to Kal at ARC. He mentioned that ARC tube amps were used to drive Wilsons which have notoriously low impedance stats. Just an fyi.
Otherwise, as Al says, you have to consider the only remaining possibility, no matter how improbable: Poltergeists.
I'm going to see if your PSB speakers were bench tested by any of the reviewers. If so, I'll be back. |
Ok Fish..., here's what I got off the web.
HT Lab Test (12/07): The Synchrony One's listening-window response (a five-point average of axial and +/15-degree horizontal and vertical responses) measures +1.18/2.24 decibels from 200 hertz to 10 kilohertz. The 3-dB point is at 56 Hz, and the 6-dB point is at 50 Hz. Impedance reaches a minimum of 3.32 ohms at 70 Hz and a phase angle of 37.55 degrees at 27 Hz.
SoundStage (1/08):
http://www.soundstagenetwork.com/measurements/speakers/psb_synchrony_one/
The impedance magnitude and phase angle graphs are absolutely amazing!! I've never seen flatter. Problem is impedance over large swathes of frequencies is unbelievably low, especially in the bass frequencies.
Al and Ralph -- take a look at the graphs at the URL above. I'd like to read your thoughts about whether a solid state amp, or any amp for that matter, would get indigestion from those impedances. Fish ..., if Al and Ralph come back expressing concern, the Zeros are seriously looking like the solution.
BIF
|
Lowrider and Al, my sense is that a Bryston separate amp would muscle its way through any power delivery barriers (short of a short) -- if that's the problem. Btw, admittedly, my Paradigms are about 3 db more sensitive than the PSBs. Even still, it's been my experience that my ARC VS-115 has had no problem with power delivery. Indeed, SPLs are painful if I turn the gain up on my line stage more than 50 percent.
Further, if you read some of my other posts in other OPs, you will see that I have neurotrically obsessed about my speaker's wacko impedance and phase angle numbers. At Al's and Ralph's recommendfation, after intense consultations with an audio-shrink, I am now convinced that somehow my poor little VS-115 (120 wpc) has deftly powered my "tube unfriendly" speakers very nicely.
Al, I re-reviewed the impedance and phase angle graphs. The measurements from JA and SoundStage are quite different. BUT I think both bench measurements still raise the same issue -- can Fish ...'s integrated deliver power into those impedance numbers without getting indigestion??
So ... the bottom line is IF (???) Fish..'s integrated is having indigestion driving the PSBs because of the low impedance levels, the Zeros may effectively double what the amp sees. As alluded to above, even if the amp's power output is cut to 100 wpc, I think Fish...'s ears will hurt if he pushes the gain up.
Incidentally, if Fish...'s amp is rated at 200 wpc at 8 ohms, presumably doubling the PSB's 4 ohm nominal impedance number should not significantly affect the amp's power delivery capability.
So Mr. Fish...., as Al or Ralph said above, if every possible logical theory except for one illogical theory has been ruled out, then the remaining goofy theory must, no matter how improbable, be the answer. I suggest you call the Zero guy, tell him your problem and confirm if he'll take the Zerosm back if they don't work. Otherwise, go invest in a monster Bryston or get new speakers. IF you're really satisfied that everything else really is A-OK, then this is the only possible answer.
IMHO of course. |
Ralph, Al, and Mr. Fishing..., just trying to be a detective, if this problem has occurred with other integrateds/amps, do we know if they use mosfets. If not, and all the amps pucker out with bass, what else is left to check.
I've been harping about the PSB's low impedance specs affecting the MF and whether Zeros might help. The only practical way to check is for Mr. Fishing to borrow, if at all possible, another set of "normal" speakers and see what happens. If all is good, the culpret has been identified -- it's the PSB speakers. I highly recommend this reality check.
If not, it's either the amp, notwithstanding that Mr. Fishing thinks its ok, then the cables, and if cables are ok, then lastly, he should rule out para-normal poltergiest activities. By any chance do we know if Mr. Fishing ever visited Amityville, CT (??). I understand that modern day ghosts are quite mobil.
:>')
BIF |
Hah. Problem solved!! I was right. Mr. Fishing.. confirmed it -- ghosts. Your system needs an exorcism. I'm running a 2 for 1 special this week. Send me an e mail and we'll discuss the pricing. So is Amityville on Long Island? |
I've been following this OP with fascination. I'm going to record my stereo too. ;>') Kidding.
Bottom line: should Fishing simply turn the volume up to get to the sweet spot?? If so, 300+ posts later, it sounds like a pretty simple solution. I surmise that Fishing won't need Zeros. Just a remote control to increase gain by roughly 3 db after warm up.
It's actaully quite interesting to me. By contrast, tube amps usually sound better after warm up. Is this a common problem with most SS amps? If so, I wonder why more folks don't raise the same issue?? |
