I havent tested the newest suggestions, neither blind plugs on the rca.
Today the mains supplier have checked for earth errors in the house and outside. Nothing is wrong.
I have also tested the brand New Lyngdorf TDAI-2170 intetgrated amplifier and it is silent, very silent: Lyngdorf Audio - Home
Today the mains supplier have checked for earth errors in the house and outside. Nothing is wrong.
I have also tested the brand New Lyngdorf TDAI-2170 intetgrated amplifier and it is silent, very silent: Lyngdorf Audio - Home
Hi Liam,
Reading the entire thread, it's quite obvious to me that the noise you experience originates in a peculiarity in your mains supply, however it's impossible to know from afar what this peculiarity is.
Possibly, the best solution would be an isolation transformer to your sound setup.
It can be ordered from a local transformer workshop, it needs not be 'audiophile' one, nor 'hospital grade' one.
If you may be interested, I'll elaborate on the transformer details.
BTW,
I also own XA30.5.
On my sound setup there are 4 different isolation transformers, ordered from a local workshop. They were installed not because of I encountered any audible noise problem, but because they improve significantly the sound quality of the setup.
Reading the entire thread, it's quite obvious to me that the noise you experience originates in a peculiarity in your mains supply, however it's impossible to know from afar what this peculiarity is.
Possibly, the best solution would be an isolation transformer to your sound setup.
It can be ordered from a local transformer workshop, it needs not be 'audiophile' one, nor 'hospital grade' one.
If you may be interested, I'll elaborate on the transformer details.
BTW,
I also own XA30.5.
On my sound setup there are 4 different isolation transformers, ordered from a local workshop. They were installed not because of I encountered any audible noise problem, but because they improve significantly the sound quality of the setup.
XA30.5: The Final Verdict on Heatsink Temps?
I know that what follows is off topic from that of this thread, but as some of you XA30.5 owners live in typically warm climates, I reasoned that you might be attuned to this issue perhaps a bit more than others. I found some pleasing, if somewhat questionable news regarding the XA30.5's typical heatsink temps. After reading just about every review and forum comment to be found on the web about this amp, I’m thinking of buying one this year.
Not that the heat issue is an actual deal breaker, but as I recall, most reviewers and/or owners (or former owners) mentioned that by the time it reaches its sweet spot time for best sound quality (1 hour), the amp’s heatsinks, if not actually hot to the touch, were at least very warm. Indeed, to quote the manual: "You should be able to put your hands on the heat sinks without
undue discomfort for 5 seconds or so." Its bit a hard to estimate these things (no Pass Labs dealers within >100 miles from me), but I would think less than 10 seconds may be pretty close to being in the hot category.
On the other hand, it's possible that the manual was rather generically written, where the quote may also be referring to XA models 100.5 thru 200.5, which consume 300 to 700 watts. Clearly, way less cool; excuse the pun. But here’s what surprised me
AudiogoN Forums: Pass Labs heatsinks temperature
Note there what James123 and Map said about their amps. And Map said that he can leave his hands on both of his XA30.5s as long as he pleases.
So between James123 and Map are three XA30.5s, and which, apparently sound very sweet to their ears through their speakers. If so, then it’s unlikely that these amps somehow became under biased-which might have otherwise explained why these guys said that their heatsinks were not hot; perhaps just quite warm. ....….or, maybe they have rather large, thick hands??
But Map said that his home’s hot water temp is set a 120° F and feels a lot hotter than the heatsinks.
However, also note that at the above link, no XA30.5 owners conducted or posted any temp measurements. Measurements were posted there only by owners of the XA100.5 and 200.5; those amps take 50% to 250% more power than the 30.5. And the 100.5 and 200.5 owners were the only ones on that
page reporting heatsinks hot to the touch.
However, the one possible error (?) was that XA100.5 owner Johngp carriedout at least part of his temp measurements with the amp’s needle to the left
of center. But isn’t that out of the Class A bias region-where applied bias current is highest? Thus, not only would he get less than optimal sound quality, but his temp measurements would be lower than typical of Class A operation, as the amp would be idling more in the lower current Class AB mode (?). So should his XA100.5 measure higher or lower than the 121.4° F he recorded?
A question for Nelson?
Thus, for Johngp’s XA100.5’s needle to deflect from center seems to imply that the meter gauge and/or associated circuitry are defective and/or that the amp is under a considerable load-enough to begin nudging it out of Class A bias. And if only the latter is true, then his speakers are what??....partially shorting??? Nah. So then wouldn’t it be that Johngp is driving his speakers quite loudly, his speakers have at best moderate sensitivity, his room is on the large side, and/or his music has a lot of bass content-which combined to push the needle to the left? But again, how does all of this square with his measured 121.4° F? Is Zen Mod in the house?
However, regardless of what would be the outcome from my own speaker choice, or the temperature findings of those at Audigon, what have been
your own experiences with the XA30.5?
Do your XA30.5s’ heatsinks remain hot or only somewhat warm to the touch? Do they remain so when at correct operating temp (i.e. out of Standby mode and after the 1 hour warm up)? Do they remain so when you play music at
levels that keep the needled always or nearly always centered?
If yes, what sensitivity are your speakers? Is your room size small or medium?
I know that what follows is off topic from that of this thread, but as some of you XA30.5 owners live in typically warm climates, I reasoned that you might be attuned to this issue perhaps a bit more than others. I found some pleasing, if somewhat questionable news regarding the XA30.5's typical heatsink temps. After reading just about every review and forum comment to be found on the web about this amp, I’m thinking of buying one this year.
Not that the heat issue is an actual deal breaker, but as I recall, most reviewers and/or owners (or former owners) mentioned that by the time it reaches its sweet spot time for best sound quality (1 hour), the amp’s heatsinks, if not actually hot to the touch, were at least very warm. Indeed, to quote the manual: "You should be able to put your hands on the heat sinks without
undue discomfort for 5 seconds or so." Its bit a hard to estimate these things (no Pass Labs dealers within >100 miles from me), but I would think less than 10 seconds may be pretty close to being in the hot category.
On the other hand, it's possible that the manual was rather generically written, where the quote may also be referring to XA models 100.5 thru 200.5, which consume 300 to 700 watts. Clearly, way less cool; excuse the pun. But here’s what surprised me
AudiogoN Forums: Pass Labs heatsinks temperature
Note there what James123 and Map said about their amps. And Map said that he can leave his hands on both of his XA30.5s as long as he pleases.
So between James123 and Map are three XA30.5s, and which, apparently sound very sweet to their ears through their speakers. If so, then it’s unlikely that these amps somehow became under biased-which might have otherwise explained why these guys said that their heatsinks were not hot; perhaps just quite warm. ....….or, maybe they have rather large, thick hands??
But Map said that his home’s hot water temp is set a 120° F and feels a lot hotter than the heatsinks.
However, also note that at the above link, no XA30.5 owners conducted or posted any temp measurements. Measurements were posted there only by owners of the XA100.5 and 200.5; those amps take 50% to 250% more power than the 30.5. And the 100.5 and 200.5 owners were the only ones on that
page reporting heatsinks hot to the touch.
However, the one possible error (?) was that XA100.5 owner Johngp carriedout at least part of his temp measurements with the amp’s needle to the left
of center. But isn’t that out of the Class A bias region-where applied bias current is highest? Thus, not only would he get less than optimal sound quality, but his temp measurements would be lower than typical of Class A operation, as the amp would be idling more in the lower current Class AB mode (?). So should his XA100.5 measure higher or lower than the 121.4° F he recorded?
A question for Nelson?
Thus, for Johngp’s XA100.5’s needle to deflect from center seems to imply that the meter gauge and/or associated circuitry are defective and/or that the amp is under a considerable load-enough to begin nudging it out of Class A bias. And if only the latter is true, then his speakers are what??....partially shorting??? Nah. So then wouldn’t it be that Johngp is driving his speakers quite loudly, his speakers have at best moderate sensitivity, his room is on the large side, and/or his music has a lot of bass content-which combined to push the needle to the left? But again, how does all of this square with his measured 121.4° F? Is Zen Mod in the house?
However, regardless of what would be the outcome from my own speaker choice, or the temperature findings of those at Audigon, what have been
your own experiences with the XA30.5?
Do your XA30.5s’ heatsinks remain hot or only somewhat warm to the touch? Do they remain so when at correct operating temp (i.e. out of Standby mode and after the 1 hour warm up)? Do they remain so when you play music at
levels that keep the needled always or nearly always centered?
If yes, what sensitivity are your speakers? Is your room size small or medium?
Zen Mod is always in the house 
and he sez - you're spending way too much time on Audiogon
go to FW and PL and read , articles and product sheets , then you'll know first hand about famous Klunk! and temperature
for palm rule , look at attachment
for peace in heart , make Babysitter for amps , if needed in summer time
edit : answer on all of your questions could be - buy that sissy amp , plug it , switch on , wait 30min and enjoy ........ in 15 or 20 years start thinking about changing all electrolytic caps
and he sez - you're spending way too much time on Audiogon
go to FW and PL and read , articles and product sheets , then you'll know first hand about famous Klunk! and temperature
for palm rule , look at attachment
for peace in heart , make Babysitter for amps , if needed in summer time
edit : answer on all of your questions could be - buy that sissy amp , plug it , switch on , wait 30min and enjoy ........ in 15 or 20 years start thinking about changing all electrolytic caps
Attachments
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Kent commented on the temperature of the amps at the factory:
http://www.diyaudio.com/forums/pass...fer-one-class-stereo-model-2.html#post3837715
23C above ambient sounds pretty reasonable.
Cheers,
Dennis
http://www.diyaudio.com/forums/pass...fer-one-class-stereo-model-2.html#post3837715
23C above ambient sounds pretty reasonable.
Cheers,
Dennis
Yes, I re-read the XA30.5 manual
and the stated temps coincide with those in your attachment. But whatever you
may think about those at that Audigon link, I merely found it extremely strange that two owners with three of these amps between them claimed that at all times their XA30.5s never got hot to the touch, and yet they had no complaints at all regarding their performance. How would you account for this?
Its too bad there's no one I know in around the metro NY area that has one for me to check out. I spent alot of time editing that last post; I was really hoping to get more feedback from actual XA30.5 owners, before I consider buying one of these 62 lb beasts. And which evidently draws enough inrush current that, unlike the FW amps, a standby mode 15w relay switch is added, to remain energized all year round.
I know, silly me and climate change from 15 watts/forever. But, frankly, it really does bug me! Indeed, I've been scouring the web for power conditioners that have soft-power ON/OFF management that would offer a slowly decreasing impedance path when the user powers on the XA30.5. The closest thing I found is this http://www.surgex.com/pdf/surgex10004_ICE.pdf
But I can't determine if this feature could substitute for the amp's standby switch. lol, I know.
excuse me for my overly short answers , but , after all these years , I'm still finding tiresome discrepancy between speed of my thoughts and typing slowness ... which is being just (for some reason) more annoying when doing that in English (not in my native)
however - regarding soft start issues - you're contemplating about products of two established production houses , both of them selling products all over the world , with safety - as every decent and honest engineered item - as sine qua non .
so - regarding that - take it or leave it ; if you insist on upgrading any (not just PL ) amp with auxilliary soft ramping start gadget , you're just gambling , with significant probability of burning something . That fact is well known to anyone who ever tried to start an amp via variac , observing output offset - due to voltage slow rise , there is period of either unstable output offset or stable one , but in bvoth cases significant and certainly enough potent to destroy speakers
second question - I'm certainly more willing to believe that each PL amp (type) is getting out with same bias (or , if you wish , heatsink temperature in same bracket) , than to believe to anyone else , saying some arbitrary things ; that was the case from Treshold era , backed and illustrated with fact that in Treshold service manuals there is no specific Iq value but specific temperature on left top heatsink screw hole .....
for even slightly serious conversation on that matters , one need to give exact temperature measurement on amp heatsinks , along with room temperature and power draw (or Iq , whatever)
just then we can contemplate is there any possible issue with amp itself or not
so - if you believe in PL , stop worrying and buy the amp
if not - you can always buy Musical Fidelity ........... more than often confirmed as amps with which life is never boring ...... sometimes even having unexpected party with Fire Department guys
however - regarding soft start issues - you're contemplating about products of two established production houses , both of them selling products all over the world , with safety - as every decent and honest engineered item - as sine qua non .
so - regarding that - take it or leave it ; if you insist on upgrading any (not just PL ) amp with auxilliary soft ramping start gadget , you're just gambling , with significant probability of burning something . That fact is well known to anyone who ever tried to start an amp via variac , observing output offset - due to voltage slow rise , there is period of either unstable output offset or stable one , but in bvoth cases significant and certainly enough potent to destroy speakers
second question - I'm certainly more willing to believe that each PL amp (type) is getting out with same bias (or , if you wish , heatsink temperature in same bracket) , than to believe to anyone else , saying some arbitrary things ; that was the case from Treshold era , backed and illustrated with fact that in Treshold service manuals there is no specific Iq value but specific temperature on left top heatsink screw hole .....
for even slightly serious conversation on that matters , one need to give exact temperature measurement on amp heatsinks , along with room temperature and power draw (or Iq , whatever)
just then we can contemplate is there any possible issue with amp itself or not
so - if you believe in PL , stop worrying and buy the amp
if not - you can always buy Musical Fidelity ........... more than often confirmed as amps with which life is never boring ...... sometimes even having unexpected party with Fire Department guys
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forgot to reply on that ....... stand by on PL amps is serving as described:
-PSU (xformer , cap bank) energized fully all the time
-front end energized fully all the time
-output stage having full voltage , but killed Iq
all that with intention to save your wallet (electricity bill) while decreasing warm up time ............ which is , as you know , unavoidable with A class
NB that I didn't mention inrush current ........... stand by in PL products is not having anything with it ..... at least not as primary role/goal
I
But one thing I am very sure that I was told was this: You power up the XA30.5 and give it the full 1 hour warm up time. Then you put it in Standby mode and go away for 24 hours, a few days or whatever. Then you come back and take it out of Standby to play music. Will you then have to do another 1 hour warm up for best sound quality? I am certain that I was told yes.
First, I want to be clear that it's not my intention to contradict anyone connected with Pass Labs, since compared to them I know next to nothing about amplifier design. And I certainly hope that I don't misquote anyone either. But about two years ago, I phoned or emailed Pass Labs regarding the XA30.5's Standby mode switch. When I asked if the feature was added to amp to avoid the need to use the main power switch-and also to reduce the number of times the amp would otherwise be subjected to high inrush current-I believe that I was told yes and yes.
But one thing I am very sure that I was told was this: You power up the XA30.5 and give it the full 1 hour warm up time. Then you put it in Standby mode and go away for 24 hours, a few days or whatever. Then you come back and take it out of Standby to play music. Will you then have to do another 1 hour warm up for best sound quality? I am certain that I was told yes.
I am sure that there was some misunderstanding in your phone call with PL:
In old XA.5-series the amps don't warm up in stand/by-mode either you have switched them on or off some time before or not: they cool down or stay cool in stand/by-mode.
And ZM is wrong: front end is NOT energized in st/by-mode, and that's the reason why there flows no bias current.
In old XA.5-series the amps don't warm up in stand/by-mode either you have switched them on or off some time before or not: they cool down or stay cool in stand/by-mode.
And ZM is wrong: front end is NOT energized in st/by-mode, and that's the reason why there flows no bias current.
With XA30.5 the front end is biased in stand-by mode, also the output is biased to a low current, though the heatsinks are at about the room temperature.
Yet, each time turning the amp on from stand-by mode (when the heatsinks are at about room temperature), it requires about 1 hour of warming up to reach optimal sound.
Yet, each time turning the amp on from stand-by mode (when the heatsinks are at about room temperature), it requires about 1 hour of warming up to reach optimal sound.
That's at least part of my point: Where's the advantage of a Standby mode that makes you do another 1 hour warm up if the XA30.5 was then put in Standby for 1 hour or more, since it would have cooled down by then?
That's why I reasoned that the Standby mode may have been included primary for one or more other purposes.
Precisely. Again, that's why I reasoned that the Standby mode might have been included primary for one or more other purposes.
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Sorry, that's not correct:
Though in st/by-mode big elcaps are energized and therefore supply output power devices, there flows no bias current because of missing bias voltage.
With switch on frontpanel big elcaps supply frontend via a small relay resulting into a bias voltage and bias current.
Therefore heatsinks will always have ambient temperatur regardless if st/by-mode is switched on or off.
I think that's pretty correct, and there are two other points:
1) The .8 series has to conform to the less-than-one-watt requirement.
2) The original .5 front end had enough thump that it was nice to leave it on.
And to the comment about varying temperature, keep in mind two things,
which is that it's the rise above ambient in open air - ambient temperatures
can be different and the ventilation circumstance is often different.
Humans are very sensitive (that is to say non-linear) in the range between
about 45 and 60 deg C., so a few degrees can give a large perception
of difference.
Historically, we like to bias these things as high as we can, and when you
look at the typical amount of hardware you can see that temperature is
generally the limiting factor, so we tend to simply bias to temperatures that
are short of injuring consumers.
1) The .8 series has to conform to the less-than-one-watt requirement.
2) The original .5 front end had enough thump that it was nice to leave it on.
And to the comment about varying temperature, keep in mind two things,
which is that it's the rise above ambient in open air - ambient temperatures
can be different and the ventilation circumstance is often different.
Humans are very sensitive (that is to say non-linear) in the range between
about 45 and 60 deg C., so a few degrees can give a large perception
of difference.
Historically, we like to bias these things as high as we can, and when you
look at the typical amount of hardware you can see that temperature is
generally the limiting factor, so we tend to simply bias to temperatures that
are short of injuring consumers.
xa30.8 standby mode mod for xa30.5
As Nelson said, the 30.5 has rather serious speaker thumps-which will almost certainly be dangerously loud over my 97db speakers. Need I mention how priceless hearing sensitivity is? And my room’s only 14 ft x 19 x 8.
I’d like to convince myself to get this amp if the 1 watt standby could beadded.That would be a long awaited and excellent year round greener solution; no powering the amp off so dangerous speaker thumps will never happen. And the supply filter caps then won’t get hit with high inrush current, thereby extending their life.
So again, now that the 30.5 is retired who here are game for designing the 1watt standby mod?
And while you’re at it, why not speculate on some performance mods to further improve its sound quality compared to the 30.8, that wouldn’t require increased bias current. https://forum.audiogon.com/discussions/comparing-the-pass-labs-xa30-5-to-the-xa-30-8?page=2
I’m likely to get thrashed again on this but as the XA30.5 has since been discontinued for a full year, could someone here please devise a standby mode modification that reduces its 15 watt draw down to the XA30.8’s 1 watt?
As Nelson said, the 30.5 has rather serious speaker thumps-which will almost certainly be dangerously loud over my 97db speakers. Need I mention how priceless hearing sensitivity is? And my room’s only 14 ft x 19 x 8.
I’d like to convince myself to get this amp if the 1 watt standby could beadded.That would be a long awaited and excellent year round greener solution; no powering the amp off so dangerous speaker thumps will never happen. And the supply filter caps then won’t get hit with high inrush current, thereby extending their life.
So again, now that the 30.5 is retired who here are game for designing the 1watt standby mod?
And while you’re at it, why not speculate on some performance mods to further improve its sound quality compared to the 30.8, that wouldn’t require increased bias current. https://forum.audiogon.com/discussions/comparing-the-pass-labs-xa30-5-to-the-xa-30-8?page=2
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