Parasound & ATI amps

[AcuDefTechGuy]

I own 4 ATI amps.

I don't own Parasound Halo, but a lot of guys do.

You could get the A21 for under $2K and A51 for around $3K.

I just thought we could talk about both Parasound and ATI here.

 

[RichB]

Jump in the water is fine.

- Rich

 

[slipperybidness]

IIRC, the ATI is fully balanced from input to output, while the Halo is not. That could account for the price difference.

Whether this is important is up to the end user.

 

[macddmac]

Prices going up April 1st on most Halo models.
http://www.parasound.com/pdfs/us-price-increases.pdf

 

[AcuDefTechGuy]

Prices going up April 1st on most Halo models.
http://www.parasound.com/pdfs/us-price-increases.pdf

Yeah, so if you want to buy Halo, do it before April 1st.

 

[PENG]

IIRC, the ATI is fully balanced from input to output, while the Halo is not.

Are you sure? I read the available literatures on the Parasound website but cannot tell if the A21,31,51 are fully differential from one end to the other so i think it is possible that they actually are. I hope Rich can confirm that as he might have inquired that with Parasound before on that topic.

 

[RichB]

Are you sure? I read the available literatures on the Parasound website but cannot tell if the A21,31,51 are fully differential from one end to the other so i think it is possible that they actually are. I hope Rich can confirm that as he might have inquired that with Parasound before on that topic.

I wish I could and I hope you will

It works better when someone who knows what they are talking about asks the questions.

Send a message to support@Parasound.com. Very often, Richard Schram answers.

- Rich

 

[RichB]

There are some nice videos and views of the internals. Click on the Video tab.

Parasound - Halo A21 Two-Channel Amplifier-Audio Advisor

- Rich

 

[Cos]

I found this link, while there is no guarantee that it is 100% accurate, I have little reason to believe it isn't

http://www.htguide.com/forum/showthread.php?6995-Club-Parasound-F-A-Q-(Last-Updated-21-Jan-2012)


Although every Halo model offers balanced connections with XLR plugs, they are not FULLY differential and balanced. This means that they are not true balanced machines. This can be quite confusing to people who are unfamiliar with balanced connections, their design, concept, and operations. To learn more about balanced connections, flip through the Halo C1 or C2 manuals. Parasound actually gives a good basic discussion of balanced connections and to what extent they are included on Halo equipment.

General balanced concept: The design of balanced cables and jacks allows for noise rejection over long cable runs. A good summary is that Parasound partially balanced connectors keep the signal balanced from the external jack all the way through an XLR cable to the other end, providing noise rejection in those components. But because the design doesn't keep it balanced after it ENTERS the Parasound unit, it is not fully balanced. Bottom line, you'll get good noise rejection capability, but not as much as you would if it were fully balanced the last little bit.

 

[MosesMalone]

I just figure if the Parasound Halo Ax1's were fully balanced, differential designs, Parasound would explicitly advertise it as so.

Also, the A21/A51 in stealth black is so damn sleek. I just wish it didn't have that "THX certified" logo on the front, kind of cheapens the look imo.

 

[RichB]

I just figure if the Parasound Halo Ax1's were fully balanced, differential designs, Parasound would explicitly advertise it as so.

Also, the A21/A51 in stealth black is so damn sleek. I just wish it didn't have that "THX certified" logo on the front, kind of cheapens the look imo.

The A51 in black is very nice looking. The writing is subdued.

The blue lights are fine but the Red light P logo was too bright, that was cured with a light-dim.


- Rich

 

[PENG]

I found this link, while there is no guarantee that it is 100% accurate, I have little reason to believe it isn't

http://www.htguide.com/forum/showthread.php?6995-Club-Parasound-F-A-Q-(Last-Updated-21-Jan-2012)


Although every Halo model offers balanced connections with XLR plugs, they are not FULLY differential and balanced. This means that they are not true balanced machines. This can be quite confusing to people who are unfamiliar with balanced connections, their design, concept, and operations. To learn more about balanced connections, flip through the Halo C1 or C2 manuals. Parasound actually gives a good basic discussion of balanced connections and to what extent they are included on Halo equipment.

General balanced concept: The design of balanced cables and jacks allows for noise rejection over long cable runs. A good summary is that Parasound partially balanced connectors keep the signal balanced from the external jack all the way through an XLR cable to the other end, providing noise rejection in those components. But because the design doesn't keep it balanced after it ENTERS the Parasound unit, it is not fully balanced. Bottom line, you'll get good noise rejection capability, but not as much as you would if it were fully balanced the last little bit.

Thanks, I've been that site and noted what was said but I still consider those just hearsays until I read something directly from the manufacturer, Gene of AH, or maybe even Stereophile but not forums. Following is from the manual:

The A 21’s input stage uses matched pairs of discrete
JFETs arranged in a differential configuration. JFETs
are ideal for the input stage because their inherently
high impedance is unaffected by the impedance
of source components. Differential configuration
provides superior noise reduction.

Since it only mentions input, it is not clear what's in between the input stage and the final output stage. I will try to get a response from Parasound as Rich suggested.

 

[PENG]

I just thought we could talk about both Parasound and ATI here.

I agree, both are at unbeatable price point, relative to perceived quality. That is, high end quality at affordable price (relaively speaking).

 

[RichB]

Thanks, I've been that site and noted what was said but I still consider those just hearsays until I read something directly from the manufacturer, Gene of AH, or maybe even Stereophile but not forums. Following is from the manual:

The A 21’s input stage uses matched pairs of discrete
JFETs arranged in a differential configuration. JFETs
are ideal for the input stage because their inherently
high impedance is unaffected by the impedance
of source components. Differential configuration
provides superior noise reduction.

Since it only mentions input, it is not clear what's in between the input stage and the final output stage. I will try to get a response from Parasound as Rich suggested.

I understand that a fully balance design can provide better performance but it is the implementation.
Here are two amps measured at HomeTheaterHifi

The Mark Levinson No.5233H (Since the ML is manufactured by ATI, the assumption is a fully balanced design):

Mark Levinson No533H Three Channel Power Amplifier - Secrets of Home Theater and High Fidelity

EDIT:

It has come to my attention that HomeTheaterHifi measurements of the Mark Levinson No533H may be flawed.

These measurements of the Mark Levinson no532H at StereoPhile are correct:

http://www.stereophile.com/content/mark-levinson-no532h-power-amplifier-measurements

The Parasound A31:

Parasound Halo A 31 Three-Channel Power Amplifier - Secrets of Home Theater and High Fidelity


- Rich

 

[AcuDefTechGuy]

I just figure if the Parasound Halo Ax1's were fully balanced, differential designs, Parasound would explicitly advertise it as so.

Also, the A21/A51 in stealth black is so damn sleek. I just wish it didn't have that "THX certified" logo on the front, kind of cheapens the look imo.

Oh, man, I wish my four ATI amps had those THX logos on them. I love those things. Seriously.

If only Parasound had huge metal handles on the FRONT or at least the OPTION for them.

Big metal front handles, THX Logo, man that would be great for me.

The Parasound Halo comes in silver and black, so I would get the silver.

 

[Adam]

You guys were getting me all riled up to get an amp again , but then I check the dimensions of those Halos. Whew. I doubt it would fit - I'm not even going to measure. That, and the fins on the side look like they'd make moving it into place potentially a bit painful.

Ahhhh. At peace once again.

 

[AcuDefTechGuy]

I understand that a fully balance design can provide better performance but it is the implementation.
Here are two amps measured at HomeTheaterHifi

The Mark Levinson No.5233H (Since the ML is manufactured by ATI, the assumption is a fully balanced design):

Mark Levinson No533H Three Channel Power Amplifier - Secrets of Home Theater and High Fidelity

The Parasound A31:

Parasound Halo A 31 Three-Channel Power Amplifier - Secrets of Home Theater and High Fidelity

I am not saying the one sounds better, you can read the reviewers commentary.
There is no question which one measures better and it is not the ML. Not at 2V and not at 5V and these are low levels.
The ML has considerably more ringing.
Personally, I wonder if an rings more with two tones, wouldn't it be more so with a complex signal?


- Rich

Ok, if someone offered me either a Parasound Halo or Mark Levinson for free, I would take the Mark Levinson 100% of the time. And since you know how I feel about amps, it isn't about the sound quality.

 

[RichB]

Ok, if someone offered me either a Parasound Halo or Mark Levinson for free, I would take the Mark Levinson 100% of the time. And since you know how I feel about amps, it isn't about the sound quality.

So would I, then I would sell the Mark Levinson on eBay, buy a Halo and pocket the extra money.

- Rich

 

[RichB]

You guys were getting me all riled up to get an amp again , but then I check the dimensions of those Halos. Whew. I doubt it would fit - I'm not even going to measure. That, and the fins on the side look like they'd make moving it into place potentially a bit painful.

Ahhhh. At peace once again.

It is not that bad:

1. Place a small towel on the shelf
2. With one person on either side, lift the back feet onto the towel
3. Slide it in and adjust (front handles are helpful here, but the Halos are not front heavy)
4. Lift and remove the towel. (rear handles are helpful here )

Getting the damn things in and out of the box, is bad.

- Rich

 

[slipperybidness]

Thanks, I've been that site and noted what was said but I still consider those just hearsays until I read something directly from the manufacturer, Gene of AH, or maybe even Stereophile but not forums. Following is from the manual:

The A 21’s input stage uses matched pairs of discrete
JFETs arranged in a differential configuration. JFETs
are ideal for the input stage because their inherently
high impedance is unaffected by the impedance
of source components. Differential configuration
provides superior noise reduction.

Since it only mentions input, it is not clear what's in between the input stage and the final output stage. I will try to get a response from Parasound as Rich suggested.

The Halo line is not a balanced design from input to output. I have seen it at a credible source before, maybe I'll try to find it again when I can.