Adcom GFA-545... running hotter on left than right
nadams
Posts: 5,877
Hey all... long time, no post. Having a little concern about my GFA-545. During a recent listening session, I noticed that the left side of the amp was hotter than the right. Today, I set out to replicate it, and sure enough, the left side was running at 123*F, and the right side was at 108*F, as measured between the rows of grills, with my infrared gun.
Is this a gain issue? Some problem with the crossovers on the SDA's? I've never really noticed this before.
Is this a gain issue? Some problem with the crossovers on the SDA's? I've never really noticed this before.
Ludicrous gibs!
Post edited by nadams on
Comments
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Check the bias in each channel also check dc offset. with age the caps dry out and start "shifting" and change values.Make it simple...Make it better!
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That's normal as far as I know. My 545 always runs hotter on one side than on the other. This is true in a lot of amps, due to where the power supply is located...at least that's the way I understand it.The nirvana inducer-
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comfortablycurt wrote: »That's normal as far as I know. My 545 always runs hotter on one side than on the other. This is true in a lot of amps, due to where the power supply is located...at least that's the way I understand it.
it can be oscillation or bias higher than other channel. just check bias to find out!Make it simple...Make it better! -
Check the bias in each channel also check dc offset. with age the caps dry out and start "shifting" and change values.
This.Political Correctness'.........defined
"A doctrine fostered by a delusional, illogical minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a t-u-r-d by the clean end."
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Exactly, likely a bias mis-match. My Parasound is a little warmer on the left as well, been meaning to adjust it.Source: Bluesound Node 2i - Preamp/DAC: Benchmark DAC2 DX - Amp: Parasound Halo A21 - Speakers: MartinLogan Motion 60XTi - Shop Rig: Yamaha A-S501 Integrated - Shop Spkrs: Elac Debut 2.0 B5.2
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Most Adcom amps are well know for having leaky caps, I would replace all those electrolytic caps for Panasonic fc 105 and then I would adjust Bias and dc offset.Make it simple...Make it better!
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Been busy this week... haven't had a chance to look into it. I intended to recap it a while back, but found that those big cans are expensive... and it needs 4 of them.Ludicrous gibs!
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That always happens when I listen to AC/DCHello Kitty am/fm CD player
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comfortablycurt wrote: »That's normal as far as I know. My 545 always runs hotter on one side than on the other. This is true in a lot of amps, due to where the power supply is located...at least that's the way I understand it.
Actually it's not normal *IF* the discrepancy is quite large. It has nothing to do with power supply location as with an amp like the 545 it's pretty much in the center. The issue is directly related to how each channel is biased. There amps are 20+ years old and parts are worn and out of tolerance. My guess is one side is running less bias through the tranny's, for whatever reason.
It needs to be checked out.
H9"Appreciation of audio is a completely subjective human experience. Measurements can provide a measure of insight, but are no substitute for human judgment. Why are we looking to reduce a subjective experience to objective criteria anyway? The subtleties of music and audio reproduction are for those who appreciate it. Differentiation by numbers is for those who do not".--Nelson Pass Pass Labs XA25 | EE Avant Pre | EE Mini Max Supreme DAC | MIT Shotgun S1 | Pangea AC14SE MKII | Legend L600 | BlueSound Node 3 - Tubes add soul! -
Most Adcom amps are well know for having leaky caps, I would replace all those electrolytic caps for Panasonic fc 105 and then I would adjust Bias and dc offset.
Actually that is patently FALSE. Certain units (not all) of the 565 and 585 had manufacturer defective caps in *some units*, those models were fairly low selling units because of cost (as these were flagship models) and short production runs, so your statement is completely false when you say *most* and *well known*, it's not most and it's relatively unknown outside of some of the DIY websites.
H9"Appreciation of audio is a completely subjective human experience. Measurements can provide a measure of insight, but are no substitute for human judgment. Why are we looking to reduce a subjective experience to objective criteria anyway? The subtleties of music and audio reproduction are for those who appreciate it. Differentiation by numbers is for those who do not".--Nelson Pass Pass Labs XA25 | EE Avant Pre | EE Mini Max Supreme DAC | MIT Shotgun S1 | Pangea AC14SE MKII | Legend L600 | BlueSound Node 3 - Tubes add soul!
