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Parasound Owners Thread - Page 53

post #1561 of 3342
Another thought is to call up a few dealers, which are listed on the Parasound site. Some are willing to give a good price. I got my A21 by calling an ad on Audiogon which turned out to be a dealer. The item I wanted sold, but he gave me a great price on another.

Edit: Oops, it turns out this is not the best advice. Looks like it's best to buy directly at a B&M store or for on line, AA. I just read that other purchases can void a warranty. Sorry for the bad advice!
Edited by runnin' - 2/28/13 at 6:44pm
post #1562 of 3342
I just joined your "club"! 5250 v.2 will be installed this weekend. You can check out my system here: http://www.avsforum.com/t/1452915/you2slos-basement-system

I like overkill!
post #1563 of 3342
OK, so I replaced my RCAs from my C-2 to my newly acquired(used) A-51 with XLRs and happily reported here that the no good nasty hum noise be gone........so I thought. After a couple of weeks of closer analysis, I've come to discover all is not as I thought. Here's my problem...... when I first power up my system, there is virtually no hum noise eminating from the speakers hooked to the A-51. HOWEVER, once the A-51 warms up, the hum returns though no-where near as loud as it was using the RCAs. Weird huh?!!! The level of noise is tolerable and only heard when I put my ear up close to the speaker but knowing that it exists is buggin me.

The other thing I'm beginning to notice is that the A-51 runs quite a bit warmer than the A-31. Case in point, last night I was listening to two channel CDs with no signal going to the A-51. After a couple hours, the A-51 was considerably warmer to the touch than the A-31. It seems strange to me that the amp receiving an audio signal (A-31) was running cooler than the amp(A-51) that was only powered up but not receiving a signal. Weird huh?!!!

I know there's a few of you out there with similar setups. I'm curious to hear your thoughts and experience.

Thanks.
post #1564 of 3342
Quote:
Originally Posted by Torqdog View Post

OK, so I replaced my RCAs from my C-2 to my newly acquired(used) A-51 with XLRs and happily reported here that the no good nasty hum noise be gone........so I thought. After a couple of weeks of closer analysis, I've come to discover all is not as I thought. Here's my problem...... when I first power up my system, there is virtually no hum noise eminating from the speakers hooked to the A-51. HOWEVER, once the A-51 warms up, the hum returns though no-where near as loud as it was using the RCAs. Weird huh?!!! The level of noise is tolerable and only heard when I put my ear up close to the speaker but knowing that it exists is buggin me.

The other thing I'm beginning to notice is that the A-51 runs quite a bit warmer than the A-31. Case in point, last night I was listening to two channel CDs with no signal going to the A-51. After a couple hours, the A-51 was considerably warmer to the touch than the A-31. It seems strange to me that the amp receiving an audio signal (A-31) was running cooler than the amp(A-51) that was only powered up but not receiving a signal. Weird huh?!!!

I know there's a few of you out there with similar setups. I'm curious to hear your thoughts and experience.

Thanks.
My first question would be...why do you have the A51 on if you're only listening to a stereo source, and not running that source thru DPL, dts neo-6. No point having the A51 on. But even sitting idle, the A51 is still a 5 channel not a 3 channel, so there has to be more heat generated.
When I have my Citation amp connected to the L/R mains, I don't turn on my HCA2205A, if I am only listening to a stereo source. And when the 2205A is on its not that hot.

You say you bought the A51 used, maybe that was the reason (the hum) is why the first owner decided to sell it.
Then again, maybe its still something to do with your circuits in that garage.
post #1565 of 3342
Quote:
Originally Posted by 4DHD View Post

My first question would be...why do you have the A51 on if you're only listening to a stereo source, and not running that source thru DPL, dts neo-6. No point having the A51 on. But even sitting idle, the A51 is still a 5 channel not a 3 channel, so there has to be more heat generated.
When I have my Citation amp connected to the L/R mains, I don't turn on my HCA2205A, if I am only listening to a stereo source. And when the 2205A is on its not that hot.

You say you bought the A51 used, maybe that was the reason (the hum) is why the first owner decided to sell it.
Then again, maybe its still something to do with your circuits in that garage.
Thanks. It's "on" because I have it hooked to the C-2 using a trigger cable that is very difficult to access. So when I power up, everything comes on.

Yeah, I understand that the A-51 is a 5 channel amp and should inherently run warmer than the A-31. But I'm not so sure it should be running warmer than the A-31 when there is no signal flowing and the amp is just basically idling while the A-31 is passing a signal.

Also, none of this addresses the fact that the hum increases as the amp warms.
post #1566 of 3342
If the A51 and A31 are on the same circuit, and only the A51is humming, then there may be something wrong with it. If they are not on the same circuit, try putting the A51 on the same circuit, if it doesn't stop humming, it may need service. I gather you've talked to Parasound about it? And you've tried the ground lift to no avail?
post #1567 of 3342
Contact Parasound support. They will help you.
post #1568 of 3342
Quote:
Originally Posted by runnin' View Post

If the A51 and A31 are on the same circuit, and only the A51is humming, then there may be something wrong with it. If they are not on the same circuit, try putting the A51 on the same circuit, if it doesn't stop humming, it may need service. I gather you've talked to Parasound about it? And you've tried the ground lift to no avail?
Same circuit. The ground loop switch is engaged and completely eliminates the hum when the amp is cold.

Yeah, I've conversed with Richard and he said to call the service dept. I just thought I would inquire here to see if any others with similar setups have had a similar experience.
post #1569 of 3342
Quote:
Originally Posted by Torqdog View Post

Thanks. It's "on" because I have it hooked to the C-2 using a trigger cable that is very difficult to access. So when I power up, everything comes on.

Yeah, I understand that the A-51 is a 5 channel amp and should inherently run warmer than the A-31. But I'm not so sure it should be running warmer than the A-31 when there is no signal flowing and the amp is just basically idling while the A-31 is passing a signal.

Also, none of this addresses the fact that the hum increases as the amp warms.
Because the A#1 series have a high class A bias they will use about 75w per channel. A21 - 150w, A31 - 225w, etc. if you are driving speakers and not exceeding the class A region (which likely most the time) then the energy used to drive the speakers goes to sound and not just waste heat (but I could be wrong on that assumption).
post #1570 of 3342
Quote:
Originally Posted by Torqdog View Post

Same circuit. The ground loop switch is engaged and completely eliminates the hum when the amp is cold.

Yeah, I've conversed with Richard and he said to call the service dept. I just thought I would inquire here to see if any others with similar setups have had a similar experience.

Was that the same situation when you used RCA cables? Or was it loud all the time?
With the current situation, obviously there is a component heating up more than it should or working out of spec, after warm up.
post #1571 of 3342
Quote:
Originally Posted by Torqdog View Post

OK, so I replaced my RCAs from my C-2 to my newly acquired(used) A-51 with XLRs and happily reported here that the no good nasty hum noise be gone........so I thought. After a couple of weeks of closer analysis, I've come to discover all is not as I thought. Here's my problem...... when I first power up my system, there is virtually no hum noise eminating from the speakers hooked to the A-51. HOWEVER, once the A-51 warms up, the hum returns though no-where near as loud as it was using the RCAs. Weird huh?!!! The level of noise is tolerable and only heard when I put my ear up close to the speaker but knowing that it exists is buggin me.

The other thing I'm beginning to notice is that the A-51 runs quite a bit warmer than the A-31. Case in point, last night I was listening to two channel CDs with no signal going to the A-51. After a couple hours, the A-51 was considerably warmer to the touch than the A-31. It seems strange to me that the amp receiving an audio signal (A-31) was running cooler than the amp(A-51) that was only powered up but not receiving a signal. Weird huh?!!!

I know there's a few of you out there with similar setups. I'm curious to hear your thoughts and experience.

Thanks.
I don't have an A31 but it looks from the pictures that the A31 has larger heat sinks than the A51 on a per channel basis. There's just not as much room on the A51's chassis. So I would expect the A51 to run a bit warmer on that basis alone. I think that when the amp is "idling" it is still amplifying whatever tiny signal is being sent to it, even if that signal is just a small amount of noise.

If you can only hear the hum when you put your ear close to the speaker, then why worry about it? If the unit were new and/or under warranty, then I could see that you would want to pursue it further. But moving the 80 lb beast and shipping it in for repairs that are at your expense is a big price to pay for something that is inaudible except when your ear is next to the speaker. By analogy, would you be equally concerned if you heard a bit of hiss when you placed your ears up close to the tweeter? Someday the unit may begin to hum louder and at that point you may want to repair it but in the meantime you could have years of good service from it.
post #1572 of 3342
Quote:
Originally Posted by davee70 View Post I don't have an A31 but it looks from the pictures that the A31 has larger heat sinks than the A51 on a per channel basis. There's just not as much room on the A51's chassis. So I would expect the A51 to run a bit warmer on that basis alone. I think that when the amp is "idling" it is still amplifying whatever tiny signal is being sent to it, even if that signal is just a small amount of noise.

If you can only hear the hum when you put your ear close to the speaker, then why worry about it? If the unit were new and/or under warranty, then I could see that you would want to pursue it further. But moving the 80 lb beast and shipping it in for repairs that are at your expense is a big price to pay for something that is inaudible except when your ear is next to the speaker. By analogy, would you be equally concerned if you heard a bit of hiss when you placed your ears up close to the tweeter? Someday the unit may begin to hum louder and at that point you may want to repair it but in the meantime you could have years of good service from it.

I have a question is the A31 Fully differential balanced?

They are not just called Parasound :(
post #1573 of 3342
^^
None of the Parasound amps are fully balanced differential design - not even the top of the line JC1 monoblock.

Here is what Parasound has to say:

"The JC 1 is not a fully balanced differential amp. It is fully complementary symmetry with matched P and N input drivers, main drivers and outputs. It has all the same advantages of a high CMRR (common mode rejection ratio) for its balanced input.

John Curl advised that comparable performance with a differential amp would be far more costly and would have issues with very high power at very low impedances. The JC 1 design is optimum for its purpose.

The JC 2 is fully differential because this is easier to achieve at line level.

The A21, A23, A31 and A51 are of the same topology as the JC1"
post #1574 of 3342
Quote:
Originally Posted by WillyJ View Post

^^None of the Parasound amps are fully balanced differential design - not even the top of the line JC1 monoblock.

Here is what Parasound has to say: "The JC 1 is not a fully balanced differential amp. It is fully complementary symmetry with matched P and N input drivers, main drivers and outputs. It has all the same advantages of a high CMRR (common mode rejection ratio) for its balanced input.

John Curl advised that comparable performance with a differential amp would be far more costly and would have issues with very high power at very low impedances. The JC 1 design is optimum for its purpose.

The JC 2 is fully differential because this is easier to achieve at line level.

The A21, A23, A31 and A51 are of the same topology as the JC1"

Too bad I guess maybe I will stick with Classé then :)

post #1575 of 3342
^^
Makes sense if you can maintain the fully balanced differential path all the way through your system............If your pre/pro or AVR is fully balanced differential, it would be nice to see how much better it can sound with the source and amp also fully balanced differential. The Halo line and the JC1 are highly rated amps despite not being fully balanced differential.
post #1576 of 3342
Quote:
Originally Posted by you2slo View Post

I just joined your "club"! 5250 v.2 will be installed this weekend. You can check out my system here: http://www.avsforum.com/t/1452915/you2slos-basement-system

I like overkill!

Congrats,

In the on goin process of re-vamp and hooking up my 5250 as well. If you put yours in cabinet you should make sure it's vented, got a fan kit for mine.

They definitely play loud and clear and don't break a sweat while doing it. A friend of mine has one in an open shelf and it gets warm at louder levels. Like any other heat sinked non fan cooled unit, it needs breathing room.

P.S. Hook it up to a non shared power source(i.e. not the same power strip/conditioner as your other components), or you will trip the internal circuit breaker on the power supply strip.

Good luck with the install, mines takin for ever(no time).

A1
post #1577 of 3342
I have an A52 connected to a C2, but my system behaves the opposite way. When i turn it on, the hiss is louder, and after 10 minutes when it warmed up, it is much more silent. Still audible from close, but not annoying.
post #1578 of 3342
Quote:
Originally Posted by wse View Post

Too bad I guess maybe I will stick with Classé then smile.gif
My thoughts are I have no need or desire to go into any gear costing more than Parasound. Quality/price ratio, anything over Parasound is a waste of money, imo.
Even if I were to buy Revel Salon2 speakers, I'd only go as far as the JC1 mono, mostly b/c of the Salon's low sensitivity.
And I'm not running cheap speakers now. One-of-a-kind customs with biased crossovers.
post #1579 of 3342
One man's waste of money is another man's wheel house! Some buy nothing but pro amps and laugh at us throwing money away, but personally I think everybody has a different level of priorities and income. A fully balanced differential system done right is going to sound better than a single ended one, but I'm not willing to spend that kind of money. Some are.
post #1580 of 3342
What is meant by the "differential system" ? I have never heard of that term.
post #1581 of 3342
^^
Check this thread out.

EDIT: And I should add that just because a component has balanced in/out connections it doesn't mean that it is fully balanced internally.. Also, there is a term called balanced electrical which is entirely different as it refers to power supply voltage (household current).
post #1582 of 3342
I finally got around to calling Parasound tech. As far as the hum noise, the guy said that if it was only heard with my ear against the speaker, it's not a problem and could most likely be attributed to the A-51's inherent noise floor. So I guess I am anal........ go figure! LOL

As far as it running much warmer than the A-31 even at idle when the A-31 is pumpin sound, he agreed with 4DHD with his 5 channel vs. 3 channel analogy as to why it might be running warmer. He did say that there is a chance that the bias settings might need adjusting because if not properly set, it can cause the amp to run warmer than normal.

I guess I'll just fuggetta 'bout it for now and simply enjoy the sound.

Over and out! smile.gif
post #1583 of 3342
^^^^It can be very easy to over analyze one's system, instead of just sitting back and listening to the music. Although it never occurred to me about the bias setting causing extra heat.
post #1584 of 3342
^^^ So true well said !
post #1585 of 3342
I know this is a touchy subject,but...is anyone out there using a upgraded power cord on there halo amps?
I just replaced mine with a pangae ac-9 with some very impressive results!
post #1586 of 3342
By "impessive results," I hope you mean that the amp powered on and played music just like it did with the stock cord.

If you're claiming it made a difference in sound, well.....
post #1587 of 3342
Quote:
Originally Posted by beaveav View Post

By "impessive results," I hope you mean that the amp powered on and played music just like it did with the stock cord.

If you're claiming it made a difference in sound, well.....
Well..it eliminated the him that my a-23 had and it also seems to have a deeper dead quiet background and it also gave me a bigger soundstage with more bass!
post #1588 of 3342
Quote:
Originally Posted by esh516 View Post

Well..it eliminated the him that my a-23 had and it also seems to have a deeper dead quiet background and it also gave me a bigger soundstage with more bass!
Sorry ,eliminated the hum
post #1589 of 3342
Quote:
Originally Posted by esh516 View Post

I know this is a touchy subject,but...is anyone out there using a upgraded power cord on there halo amps?
I just replaced mine with a pangae ac-9 with some very impressive results!

Glad to see someone else taking advantage of an easy upgrade for there Halo, believe it or not the stock cord was so good AA use to sell them as an aftermarket cord , I've tried 4 to date on my A21 and have settled one an PS Audio AC12 which in my opinion to it to a new level of performance in refinement, bass slam crystal clear highs and the best midrange I've heard its just beautiful sound, this coupled with an HiFi tunning Silversatar fuse on the main power fuse is a no brainer if one is looking to extract that last bit from an already killer amp!

thereI said it tongue.gif
post #1590 of 3342
Quote:
Originally Posted by audiofan1 View Post

believe it or not the stock cord was so good AA use to sell them as an aftermarket cord
I hope so, I did'nt want to throw my beautiful stock grey Parasound AC cord away smile.gif

I just make an effort to route my wiring as clean as possible, trying to isolate AC power cords on one side, and all other cables on the other
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