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Parasound 2125 V.2 Amplifier Review

Rate this amplifier:

  • 1. Poor (headless panther)

    Votes: 38 19.6%
  • 2. Not terrible (postman panther)

    Votes: 120 61.9%
  • 3. Fine (happy panther)

    Votes: 30 15.5%
  • 4. Great (golfing panther)

    Votes: 6 3.1%

  • Total voters
    194

pma

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I had a heck of a time getting stable ratings in the dashboard with channel 1 mostly going nuts on its own. I thought this was a grounding problem so tried many things. There was hardly a difference. It was not until the power measurements that I realized something is going on the amp in the 5 to 20 watt range. Anyway, here is our dashboard when both channels were behaving:

Output relay issue?
 

MediumRare

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Is this a used amp?

My amp. Purchased new. Installed in a large theater, bridged into a 4ohm Triad Gold LCR. I have / had 8 of these in the rack. 3 bridged to the LCR channels and 5 running wides/surround/overhead. Felt the LCR was missing some sparkle/sound so I switched to a Nord Acoustics 3 channel running Hypex 500MkII units for the LCR. I gained a lot of clarity and crispness in the high end with the Class D over the Class A/B Parasound. Will swap other channels as $ permits.
Not surprised, given the -55 dB distortion at 10 watts. Add in the distortion in the rest of the chain and that should be audible. I marked this amp as broken - IMHO engineering that results in audible distortion/problems is just not acceptable in new electronics.
 

Shazb0t

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Such as? Buckeye? Any others?
The whole Hypex - based market https://www.audiosciencereview.com/...ds/hypex-ncore-nc252mp-market-overview.31085/
or Crown, even some of the T.amps...
Alternatively I would consider purchasing the Outlaw 5000x for over $100 less. If you don't specifically need bridging, you get similar measured distortion performance, more output power with better stability, balanced input options, and 3 additional channels of amplification.

 

Fahzz

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I Looked at some of these options, but none of them are set up to drive two sets of speakers like this Parasound. I run speakers in the kitchen from the second outputs.
Anybody know of any other power amps that have this capability priced under $1000?
 

Astrozombie

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I remember seeing this one and thought what's the point of an amp if it doesn't do 200W @ 8Ohm (using with a AVR)
 

tifune

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I remember seeing this one and thought what's the point of an amp if it doesn't do 200W @ 8Ohm (using with a AVR)

I've reached that conclusion myself. My first thought is, at least re: Denons I've owned, 170@8 ohm will only extend to around 250@4 ohm whereas an outboard 200@8 will take you to around 350@4. Depending on your sensitivity that's what, an extra 2dB over an AVR? If you have legitimately full range speakers 350@4 doesn't seem like enough, either. With my Revel Be's crossed over at 80Hz on Denon 8500, listening distance 12ft., volume = 33 is adequate for casual listening, volume = 55 for critical listening.

Given the price of this unit has risen almost to that of a base model AVR, which can give you far more useful Audyssey, sub out, and years of upgradeability via multichannel, I dont see the point. For legitimately full range speakers, I probably wouldn't go smaller than a Purifi, NC502, or (if I'm feeling saucy) dual Benchmark
 

Rob63

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I've reached that conclusion myself. My first thought is, at least re: Denons I've owned, 170@8 ohm will only extend to around 250@4 ohm whereas an outboard 200@8 will take you to around 350@4. Depending on your sensitivity that's what, an extra 2dB over an AVR? If you have legitimately full range speakers 350@4 doesn't seem like enough, either. With my Revel Be's crossed over at 80Hz on Denon 8500, listening distance 12ft., volume = 33 is adequate for casual listening, volume = 55 for critical listening.

Given the price of this unit has risen almost to that of a base model AVR, which can give you far more useful Audyssey, sub out, and years of upgradeability via multichannel, I dont see the point. For legitimately full range speakers, I probably wouldn't go smaller than a Purifi, NC502, or (if I'm feeling saucy) dual Benchmark
 

Rob63

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Another excellent and for me, timely review. I just replaced my Parasound 2250 v2 this past week. I was using it to separately power the fronts as part of a 5.2.4 system. While it was a nice but slight improvement over using the Denon for all channels, it also had a fairly noticeable buzz. I had pretty realistic expectations on an amp upgrade not coming close to a speaker upgrade in terms of sound improvement. I'm happy to admit I was wrong.
 
D

Deleted member 50971

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This is a review and detailed measurements of the Parasound 2125 V.2 power amplifier. It is on kind loan from a member and costs US $899.
View attachment 223201
The 2125 has an understated look with just a few touches to keep it from looking boring. The only controls in front are for which set of speakers it drives. There is more however in the back:
View attachment 223202

For those of you wanting to use it with a sub, it has selectable high pass filter of 20 or 40 Hz. Trigger is supported as well as bridging.

Parasound 2125 V.2 Measurements
I had a heck of a time getting stable ratings in the dashboard with channel 1 mostly going nuts on its own. I thought this was a grounding problem so tried many things. There was hardly a difference. It was not until the power measurements that I realized something is going on the amp in the 5 to 20 watt range. Anyway, here is our dashboard when both channels were behaving:

View attachment 223203
Measured noise+distortion lands the 2125 above average ranking:

View attachment 223204
View attachment 223205

Noise performance is not great at 5 watts but naturally improves at full power:
View attachment 223206

Multitone reflect the average distortion rating:
View attachment 223207

Frequency response is very good:
View attachment 223208

I was however surprised that gain dropped when I activated the high-pass filters.

As noted, my first power sweep had instability in mid power. I thought this was instrumentation error so I filtered the heck out of it and got these:
View attachment 223209
View attachment 223210

On reflection though this was amplifier instability as we can see when I sweep the frequency:
View attachment 223211

There is a frequency dependent hump in distortion which is very strange. It is likely due to some kind of voltage rail switching.

There is a lot of power available though in a cool running case:
View attachment 223212

Conclusions
This kind of performance would usually garner my recommendation for the 2125. On reflection though, I am worried about increased distortion in the "sweet" area of power band -- 5 to 20 watts. Company needs to work on mitigating this issue. So for now, I won't be recommending the Parasound 2125 even though it checks many boxes from value to functionaltiy.
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As always, questions, comments, recommendations, etc. are welcome.

Any donations are much appreciated using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/
Thank you for the review Amir! This looks like it performs a reasonably well.
 

Fahzz

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Another excellent and for me, timely review. I just replaced my Parasound 2250 v2 this past week. I was using it to separately power the fronts as part of a 5.2.4 system. While it was a nice but slight improvement over using the Denon for all channels, it also had a fairly noticeable buzz. I had pretty realistic expectations on an amp upgrade not coming close to a speaker upgrade in terms of sound improvement. I'm happy to admit I was wrong.
What did you get to replace it?
 

Highmodulus

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As an engineer I found the commentary in this Audioholics article on how amplifiers can sound different very enlightening. Audioholics Article

While we always like to assume and strive for an amplifier that doesn't color the sound...the reality of economics and manufacturing come in.
So, amplifiers become like wine. Anyone can choose a good bottle of wine that costs $1,000 the real skill is picking a $20 bottle of wine that is good.
It's easy to get a good amplifier that costs $25,000 per channel. The skill is finding them that cost $150-$400 per channel, where most of us can afford 11 to 13 channels for a theater. And this is where ASR comes in and helps the hobby.
 

SEKLEM

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Went back and compared to the Niles SI-275, in basically all metrics I can see other than power, the Niles beats the "audiophile" brand. LOL
 

minus3dB

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I've been curious to see a good set of measurements of the Parasound zonemaster 2350 which is a Class D amp based on ICE modules. 350 into 8 and 600 into 4, stable into 2 are some impressive specs. It's not in the SINAD race to the bottom of distortion + noise but then how many amps that can put out this kind of power continuously for less than $2k are?
 

Jim Shaw

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Thats why the first watt(s) is so important!
@amirm et al: I have wondered if we would do ourselves a favor by also measuring amplifier noise and distortion over the audible range at 1/2 or 1 watt. The reason is that a large segment of listeners frequently listen in a quiet space at SPLs of 76 dB or so, and at near-field or short distances from speakers. If a speaker's sensitivity is, say, 86 dB @ 1 watt @ 1 meter, 76 dB SPL implies an amplifier output in the range of about 0.1 watts. Many amps suffer from zero-crossing non-linearities at low output levels. Both tube and solid-state amps can suffer from this.

ERGO: a very listenable amplifier at half to full output might sound crudgey (arcane audio term) at half a watt or less.

Now back to my nap....
 

milosz

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If the SINAD at 1 watt is 60 dB, and you are listening with speakers that produce an in-room level of 76 dB SPL at this power level, that means distortion and noise are 16 dB SPL (76 dB minus 60 dB ). A typical domestic living room has a background noise level of 28 to 33 dB SPL, so you would be unable to hear the noise and distortion as it would be completely masked by more than 10 dB of ambient noise in your room. ( Reference: https://www.nonoise.org/library/household/index.htm )
 

Jim Shaw

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If the SINAD at 1 watt is 60 dB, and you are listening with speakers that produce an in-room level of 76 dB SPL at this power level, that means distortion and noise are 16 dB SPL (76 dB minus 60 dB ). A typical domestic living room has a background noise level of 28 to 33 dB SPL, so you would be unable to hear the noise and distortion as it would be completely masked by more than 10 dB of ambient noise in your room. ( Reference: https://www.nonoise.org/library/household/index.htm )
But, we do not have a measurement at 1 watt, do we? The zero-crossover distortion may be a much higher percentage of the full-scale signal at 0.1-0.2 watts than that extrapolated from 5 watts. Amplifiers are not perfectly linear devices. I have often seen it written that an average human can readily detect <<1.0 percent distortion in a quality musical signal. Is distortion masked by ambient noise? Or is just noise masked by ambient noise? Noise and distortion may be perceived differently. If just one violin is mistuned, I can hear it above the concert hall HVAC.

I theorize that this is one cause for us to hear significant differences in amplifier-speaker combinations and in broader amplifier topologies. Not to mention the regulation performance of amplifier power supplies at low current draw.

But then, I didn't get where I am today by being right all the time...
 
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