Erik Mandaville Posted March 30, 2008 Share Posted March 30, 2008 If the 'noise' is the hiss some owners are reporting, the chance that it's related to the AC house supply is very slim IMO. Quote Link to comment Share on other sites More sharing options...
Deang Posted March 30, 2008 Share Posted March 30, 2008 If anyone here who cares about this subject has not read the Crown forums, you really should - even Dean posts over there. I'm surprised I haven't been banned over there for putting their feet to the fire about the issue. Quote Link to comment Share on other sites More sharing options...
Daddy Dee Posted March 30, 2008 Share Posted March 30, 2008 Mark, On the crown forum, I'm curious to know if you ran across any discussion of the (mechanical I suppose) sound from the power supply you found in testing. Quote Link to comment Share on other sites More sharing options...
jt1stcav Posted March 30, 2008 Share Posted March 30, 2008 I dunno...I'm not qualified to say since I never owned one, but IMHO it is a "pro-audio" amplifier that's designed for sound reinforcement in recording studios, live concert venues and such, and not really designed for the home audio market (with their different, more highly refined set of requirements). My brother's XTi-1000 was used only to power his DIY subwoofer system (DSP bypassed), so I can't comment on the buzzing issue (which he did have with his DIY 511B/Usher woofer open-baffles and bi-amped and active-crossovered/EQed setup...now all sold). In the end if this Crown pro-audio amplifier works out with other's home audio systems, then they're indeed the lucky ones and more power to 'em! It's just my observation that this (and other pro-audio devices) doesn't always mesh well with consumer related 2-channel/HT audio systems and shouldn't always be expected to be satisfactorily used for such...YMMV and all that. Quote Link to comment Share on other sites More sharing options...
sfogg Posted March 30, 2008 Share Posted March 30, 2008 For Reference: Here is a class A tube 'home' amplifier playing into an 8 ohm resistor then playing into a reactive load. Shawn Quote Link to comment Share on other sites More sharing options...
NOSValves Posted March 30, 2008 Share Posted March 30, 2008 Interesting -- mine are patched into a Furman AR1215. The Furman is more of a voltage regulation device that offers a small amount of AC filtering. Craig Quote Link to comment Share on other sites More sharing options...
NOSValves Posted March 30, 2008 Share Posted March 30, 2008 For Reference: Here is a class A tube 'home' amplifier playing into an 8 ohm resistor then playing into a reactive load. Shawn Yup Class A, zero feedback Single Ended Triode........ how long did you spend to find that reveiw from 1995? I just spent a good 1/2 hour trying to find a similar graph of some other topology not effected so serverely by impedence swings and it looks to me like Stereophile quit using that testing procedure way back when... Quote Link to comment Share on other sites More sharing options...
NOSValves Posted March 30, 2008 Share Posted March 30, 2008 Interesting -- mine are patched into a Furman AR1215. The Furman is more of a voltage regulation device that affers a small amount of AC filtering. Craig Be careful Craig!! You are about to be sucked into the incredible cosmic vortex of the Xti! From which, there is simply no escape. Yikes........ thanks for the words of wisdom......I'm outta here Quote Link to comment Share on other sites More sharing options...
jt1stcav Posted March 30, 2008 Share Posted March 30, 2008 I didn't quite understand. Are you saying Chops had amp buzzing using the 511B/Usher woofer with Xti? And when you say "DSP Bypassed" I assume you mean DSP OFF. It can't be bypassed. Sorry 'bout that, Mark...the buzzing was not from the XTi-1000 since it was only driving his subwoofer (with its DSP off...bad choice of words there). What he heard seemed to be generated from the other amps/active crossover EQ that were used to power his DIY open baffle loudspeakers (511B/Usher combo). I knew I wasn't qualified to comment on this...[:$] Quote Link to comment Share on other sites More sharing options...
sfogg Posted March 30, 2008 Share Posted March 30, 2008 "Yup Class A, zero feedback Single Ended Triode........ how long did you spend to find that reveiw from 1995" About 5 minutes. Any amp with high output impedance is going to show FR deviations when measured into a load other then a resistor. "and it looks to me like Stereophile quit using that testing procedure way back when..." Nope. Here is the same measurement of a Quad II tube amp done in 2005... The Quad IIs output impedance is 1.83 ohms. Remember.... Lumpy frequency response on the neighborhood of plus minus 1 or 2 dB is not typical of home audio amps. Shawn Quote Link to comment Share on other sites More sharing options...
artto Posted March 30, 2008 Share Posted March 30, 2008 This really cracks me up. 5 or 6 years ago when I first joined this Forum it seemed you would get shackled & stoned if you mentioned the word "Crown". Now, here I am, 6 years later, gradually moving away from Crown & moving more to the (newer) McIntosh camp ( & I never did leave the tube camp), and it seems there's renewed interest in Crown. Go figure. [8-|] Quote Link to comment Share on other sites More sharing options...
DrWho Posted March 30, 2008 Share Posted March 30, 2008 Lumpy frequency response on the neighborhood of plus minus 1 or 2 dB is not typical of home audio amps. Sounds to me like your measurement is crap. I inserted a delay on a circuit that measured +-0.01dB on an older audio analyzer and discovered an oscillating response like you're showing - which to me sounds like your measurement methods are unreliable. I could measure the same circuit with other tools not affected by latencies and the inserted delay went back to measuring the same as before. Quote Link to comment Share on other sites More sharing options...
DrWho Posted March 30, 2008 Share Posted March 30, 2008 As far as the noise goes this could be very much house/neighborhood AC related. Maybe these little babies are very susceptible the noise from the power grid...... I was just thinking the same thing [Y] Quote Link to comment Share on other sites More sharing options...
oldtimer Posted March 30, 2008 Share Posted March 30, 2008 Go figure artto, there are those who swear the linn lp12 is total crap on other forums. To quote from "Repo Man", it's all part of the cosmic unconsciousness! Quote Link to comment Share on other sites More sharing options...
mike stehr Posted March 30, 2008 Share Posted March 30, 2008 Quote Link to comment Share on other sites More sharing options...
oldtimer Posted March 30, 2008 Share Posted March 30, 2008 Are you now saying that the xti's are not as good for making toast? Or that they can't even be used to make toast? Oh the humanity! Quote Link to comment Share on other sites More sharing options...
artto Posted March 30, 2008 Share Posted March 30, 2008 where the hell is Julian Hirsch when you need him? ooops. nevermind [W] Quote Link to comment Share on other sites More sharing options...
BEC Posted March 30, 2008 Author Share Posted March 30, 2008 FR test on Crown XTi 1000 at one watt with resolution of 1 db per major division. Bob Quote Link to comment Share on other sites More sharing options...
jacksonbart Posted March 30, 2008 Share Posted March 30, 2008 . Quote Link to comment Share on other sites More sharing options...
oldtimer Posted March 30, 2008 Share Posted March 30, 2008 http://www.mastersonaudio.com/audio/20040201.htm Quote Link to comment Share on other sites More sharing options...
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