XPA-1-L thread

[Dark Ranger]

May 1, 2013 8:18:08 GMT -5 audiophill said:

Ok here it comes i could not believe my ears when i hooked up the pair of 1l's i have espesially after hearing nothing negative from you or others, and once again i hate to say this but my pair STILL squeel just like the last 2 times i had them, however it's for only about ten seconds long on each amp! Damn was i dissapointed when i turned them on and heard that! I don't know what i'm going to do yet but i guess i just might live with it unless it becomes worse. Sorry to report that but it is what it is. I'll review more another day but they sound pretty darn good, but so do my xpa-1's and they don't squeel for the first ten seconds when turned on.

audiophill,

My heart sank when I read this.

As an aside, my first amp did not buzz at startup, but the second one did. The third amp does not buzz at startup. Nothing else has changed in the system except the amp. I'm really curious what could be going on since the amplifiers have been fixed.


neekos (2 amps): OK
DR (1 amp): OK
audiophill (2 amps): Buzz/squeal on startup
milt99 (2 amps): OK
bruinsguy (2 amps): OK
wcparks (2 amps): OK
menez (2 amps): OK
sheepdog02 (2 amps): OK


milt99,

I'll be very interested to hear your experience this third time 'round. Fingers are crossed that yours will be OK.


I don't doubt that Lonnie corrected the problem, it's just baffling to me that audiophill experienced a nearly identical symptom as the last two times. What gives?!


EDIT: added bruinsguy to the list; added links.

EDIT 2: updated with milt99's info.

EDIT 3: updated with bruinsguy's info.

EDIT 4: updated with wcparks's and menez's info.

EDIT 5: updated with sheepdog02's info.

[bruinsguy]

I have my first pair of XPA-1L's waiting at home with a XSP-1. I will let you know my initial impression tonight after Bruins / Leafs game.

[audiophill]

I just pmed Lonnie how i have things wired up. The good news is i left for lunch came back after a hour and a half or so and turned the amps back on and NO squeal! It's only been 1.5 hours but that's a good sign. When i received the amps tuesday i hooked them up and as soon as they turned on they squealed for only ten seconds at start up. Listened for four hours ,turned them off went to work. Woke up this morning turned them on after all those hours and they squealed. I will have them off between 2pm this evening and won't turn them on until about 8:00am. I am hoping they don't squeal! My hook up is like this: First is a Monster Power AVS 2000 pro voltage stabilizer, followed by a Monster power signature HTPS power conditioner. Next is a cmx-2 plugged into one of the high power outlets on the conditioner then the pair of 1l-s plugged into the cmx-2. The audio is connected using all rca runs until i get the XMC-1 and run everything balanced! Hope this helps.

[geebo]

May 1, 2013 12:58:37 GMT -5 audiophill said:

I just pmed Lonnie how i have things wired up. The good news is i left for lunch came back after a hour and a half or so and turned the amps back on and NO squeal! It's only been 1.5 hours but that's a good sign. When i received the amps tuesday i hooked them up and as soon as they turned on they squealed for only ten seconds at start up. Listened for four hours ,turned them off went to work. Woke up this morning turned them on after all those hours and they squealed. I will have them off between 2pm this evening and won't turn them on until about 8:00am. I am hoping they don't squeal! My hook up is like this: First is a Monster Power AVS 2000 pro voltage stabilizer, followed by a Monster power signature HTPS power conditioner. Next is a cmx-2 plugged into one of the high power outlets on the conditioner then the pair of 1l-s plugged into the cmx-2. The audio is connected using all rca runs until i get the XMC-1 and run everything balanced! Hope this helps.

Try plugging the CMX-2 directly into the wall outlet and see what happens.

[hemster]

May 1, 2013 12:58:37 GMT -5 audiophill said:

I just pmed Lonnie how i have things wired up. The good news is i left for lunch came back after a hour and a half or so and turned the amps back on and NO squeal! It's only been 1.5 hours but that's a good sign. When i received the amps tuesday i hooked them up and as soon as they turned on they squealed for only ten seconds at start up. Listened for four hours ,turned them off went to work. Woke up this morning turned them on after all those hours and they squealed. I will have them off between 2pm this evening and won't turn them on until about 8:00am. I am hoping they don't squeal! My hook up is like this: First is a Monster Power AVS 2000 pro voltage stabilizer, followed by a Monster power signature HTPS power conditioner. Next is a cmx-2 plugged into one of the high power outlets on the conditioner then the pair of 1l-s plugged into the cmx-2. The audio is connected using all rca runs until i get the XMC-1 and run everything balanced! Hope this helps.

Just for testing purposes and to rule things in or out, try these steps:

- connect the 1Ls directly into the wall outlet.
- connect the 1Ls into the CMX-2 which connects directly into the wall outlet.
- connect the 1Ls to the HTPS connected directly into the wall outlet.


Edit: Geebo beat me to it...

[Dark Ranger]

May 1, 2013 12:49:17 GMT -5 bruinsguy said:

I have my first pair of XPA-1L's waiting at home with a XSP-1. I will let you know my initial impression tonight after Bruins / Leafs game.

Thanks for the heads-up! I've added your name to the list above.

Enjoy the game!

May 1, 2013 12:58:37 GMT -5 audiophill said:

I just pmed Lonnie how i have things wired up. The good news is i left for lunch came back after a hour and a half or so and turned the amps back on and NO squeal! It's only been 1.5 hours but that's a good sign. When i received the amps tuesday i hooked them up and as soon as they turned on they squealed for only ten seconds at start up. Listened for four hours ,turned them off went to work. Woke up this morning turned them on after all those hours and they squealed. I will have them off between 2pm this evening and won't turn them on until about 8:00am. I am hoping they don't squeal! My hook up is like this: First is a Monster Power AVS 2000 pro voltage stabilizer, followed by a Monster power signature HTPS power conditioner. Next is a cmx-2 plugged into one of the high power outlets on the conditioner then the pair of 1l-s plugged into the cmx-2. The audio is connected using all rca runs until i get the XMC-1 and run everything balanced! Hope this helps.

OK, now that's interesting. Definitely keep tabs on this. Do you remember if other equipment was powered on during this last test compared to the first tests? In other words, was it just the amps powered on for this last time?

EDIT: geebo and hemster have good suggestions to test. Definitely try 'em out.

[Lonnie]

I concur.

My first thought is that you should plug them directly to the wall and bypass the stabilizer and power conditioner.

All of the new amplifiers use a switching power supply for the low voltage part of the amp where in the past we used a small transformer. We had to change to the switching power supply in order to meet the upcoming requirements of Europe. Most power conditioners are voltage choppers or large switching supplies themselves. When you put two in series this will often cause what is know as a beat note effect and you get all kinds of weird artifacts.

Give it a try.

Lonnie

[Deleted]

May 1, 2013 12:58:37 GMT -5 audiophill said:

I just pmed Lonnie how i have things wired up. The good news is i left for lunch came back after a hour and a half or so and turned the amps back on and NO squeal! It's only been 1.5 hours but that's a good sign. When i received the amps tuesday i hooked them up and as soon as they turned on they squealed for only ten seconds at start up. Listened for four hours ,turned them off went to work. Woke up this morning turned them on after all those hours and they squealed. I will have them off between 2pm this evening and won't turn them on until about 8:00am. I am hoping they don't squeal! My hook up is like this: First is a Monster Power AVS 2000 pro voltage stabilizer, followed by a Monster power signature HTPS power conditioner. Next is a cmx-2 plugged into one of the high power outlets on the conditioner then the pair of 1l-s plugged into the cmx-2. The audio is connected using all rca runs until i get the XMC-1 and run everything balanced! Hope this helps.

It's obvious to me that your amps did not get updated. Somehow, something got missed. The noise is exactly what was identified and supposedly rectified.

[garbulky]

So I take it the u-series and the XPR series now utilizes a switching power supply in conunction with its torroidal transformer?

[deltadube]

May 1, 2013 12:49:17 GMT -5 bruinsguy said:

I have my first pair of XPA-1L's waiting at home with a XSP-1. I will let you know my initial impression tonight after Bruins / Leafs game.

go leafs go..

xpa 1Ls landed in Canada eh...

cheers

[geebo]

May 1, 2013 17:55:58 GMT -5 garbulky said:

So I take it the u-series and the XPR series now utilizes a switching power supply in conunction with its torroidal transformer?

Lonnie said it was for the low voltage part of the amp. I would take that to mean LEDs etc. but not the amplifier circuits.

[Gary Cook]

Not once when I have removed a power conditioner, voltage stabiliser and/or surge protector have I heard a degradation in sound from a power amp. Most times I have found a distinct improvement, easily heard after their removal. If the designer of the amp says that they don't need power conditioning, then that simply adds to what my ears have been telling me for many years.


Cheers
Gary

[milt99]

Picked up my 1Ls from Fedex an hour ago.
Mixed a cocktail, then unpacked, hooked up and turned on.
No noise, plugged straight into the wall as all my gear is, except one amp is in a Kill-A-Watt. Drawing 2.5 amps in Class A mode.
Doing a 2 cocktail warm-up to see if it stays where it should.
More later...

[Deleted]

nice....! keep us posted, please

May 1, 2013 20:51:05 GMT -5 milt99 said:

Picked up my 1Ls from Fedex an hour ago.
Mixed a cocktail, then unpacked, hooked up and turned on.
No noise, plugged straight into the wall as all my gear is, except one amp is in a Kill-A-Watt. Drawing 2.5 amps in Class A mode.
Doing a 2 cocktail warm-up to see if it stays where it should.
More later...

[Dark Ranger]

milt99,

Thanks so much for letting us know! I've updated my post at the top of this page with your result.

So far, audiophill is the only one reporting noise with both amps. Neekos may be right with his suggestion or there may be something else going on with audiophill's setup.

[Dark Ranger]

I've had my 1L in Class A mode for a good 5 hours tonight. Played various multichannel music from Diana Krall to Howard Shore to Celtic Woman. My center channel has never sounded better. It's wonderful! This amp is truly a dream come true for me. Thank you, Lonnie!

For those who want to stack the 1Ls, my recommendation is don't. These amps get nice and toasty. Make sure there is plenty of space above the chassis or use forced air exhaust.

I'm considering the Sherbourn C-12 cooling unit for maximum performance. I've got about 4 inches above my XPA-1L. However, the excess heat collects under the shelf above the amp and actually warms up my power conditioner/voltage regulator. By dumping excess heat out the rear with the C-12, I can control temps to the wooden shelf and Furman conditioner. Of course, the amplifier continually monitors the temperature and will throttle down Class A threshold if temps get too high. My goal is to keep the amp pegged at 35 watts Class A, but actually improve heat removal via forced air systems instead of traditional convection.

I can definitely tell a slight increase in ambient room temp with just one amp. Since I plan to add two more down the road, I think it's wise to try out the Sherbourn C-12. That, and it's another excuse to give Dan my money. ;D

[deltadube]

May 1, 2013 22:10:29 GMT -5 Dark Ranger said:

I've had my 1L in Class A mode for a good 5 hours tonight. Played various multichannel music from Diana Krall to Howard Shore to Celtic Woman. My center channel has never sounded better. It's wonderful! This amp is truly a dream come true for me. Thank you, Lonnie!

For those who want to stack the 1Ls, my recommendation is don't. These amps get nice and toasty. Make sure there is plenty of space above the chassis or use forced air exhaust.

I'm considering the Sherbourn C-12 cooling unit for maximum performance. I've got about 4 inches above my XPA-1L. However, the excess heat collects under the shelf above the amp and actually warms up my power conditioner/voltage regulator. By dumping excess heat out the rear with the C-12, I can control temps to the wooden shelf and Furman conditioner. Of course, the amplifier continually monitors the temperature and will throttle down Class A threshold if temps get too high. My goal is to keep the amp pegged at 35 watts Class A, but actually improve heat removal via forced air systems instead of traditional convection.

I can definitely tell a slight increase in ambient room temp with just one amp. Since I plan to add two more down the road, I think it's wise to try out the Sherbourn C-12. That, and it's another excuse to give Dan my money. ;D

wow this is great news xpa 1ls heat your igloo nice benefit...
whats the longest rca cable you could run from avr to the
xpa 1l ? im thinking park them behind or near the speakers
for maximum heating and best convection cooling...

cheers.

[bruinsguy]

Well I got home, unpacked XSP-1 and 2 x XPA-1L. These damn things cost me the first period of the hockey game. I am happy to report no problems whatsoever. They do run a little warm but these things sound awesome to me. Basically, I will be grinning from ear to ear for the next few weeks I'm sure.

Now I was coming from 20 year old Adcom gear so maybe the bar wasn't as high as the folks moving from XPA-2's. For me I will simply leave the amps in class A all the time. I will experiment with A/B for curiosity in the coming weeks.

Oh hey Deltadude, I hope you enjoyed game 1 as much as I did. Sad for the Leafs when Colton Orr is their best player. Thanks Lonnie!

[Deleted]

How come every time I hear about the squeal, I think of Ned Beatty and "Deliverance"?

-RW- You look jes like a hog...

[deltadube]

May 1, 2013 22:39:02 GMT -5 bruinsguy said:

Well I got home, unpacked XSP-1 and 2 x XPA-1L. These damn things cost me the first period of the hockey game. I am happy to report no problems whatsoever. They do run a little warm but these things sound awesome to me. Basically, I will be grinning from ear to ear for the next few weeks I'm sure.

Now I was coming from 20 year old Adcom gear so maybe the bar wasn't as high as the folks moving from XPA-2's. For me I will simply leave the amps in class A all the time. I will experiment with A/B for curiosity in the coming weeks.

Oh hey Deltadude, I hope you enjoyed game 1 as much as I did. Sad for the Leafs when Colton Orr is their best player. Thanks Lonnie!

pretty much what i expected...

was hoping for a miracle eh but i am talking about the leafs eh..

glade to hear your enjoying the new amps.. how much power
did your old adcom have?

cheers.