Parasound Zamp V.3 Amplifier Review

[Blur]

That’s one of the nastiest noise spectrums I’ve ever seen and add over 12dB of extra noise on one channel I’m surprised this made it out of the factory.

 

[yodog]

Don't bother. Curl has nothing. He's been saying the same incorrect stuff for the last 40 years and is impervious to any actual data or evidence that gets in the way of commerce.

I just got an Audio Advisor paperback catalog in my mailbox a few days ago and I actually opened it up and looked at it for a couple of minutes. The first page I opened up to was a whole page on John Curl and the special power amplifiers he makes. The top “JC” model actually uses one or some of these Bybee Quantum things in them and sells the amp at a price far above $5000 (I think closer to $10,000). I almost said to myself I want to save up some money and buy one of his JC amp one day. If what you say is true, is really true then please reiterate this one more time to help a man (me) save 5 grand and get a Benchmark AH2B instead. Thank you.

 

[RickSanchez]

I just got an Audio Advisor paperback catalog in my mailbox a few days ago and I actually opened it up and looked at it for a couple of minutes. The first page I opened up to was a whole page on John Curl and the special power amplifiers he makes. The top “JC” model actually uses one or some of these Bybee Quantum things in them and sells the amp at a price far above $5000 (I think closer to $10,000). I almost said to myself I want to save up some money and buy one of his JC amp one day. If what you say is true, is really true then please reiterate this one more time to help a man (me) save 5 grand and get a Benchmark AH2B instead. Thank you.

When you say "Bybee Quantum things" you're talking about their purifiers, correct?
https://www.bybeetech.com/products/#purifiers–diy-and-oem

These devices work on the quantum mechanical level to eliminate sub-audible noise—i.e., noise unmeasurable by typical test-bench instruments. The results are previously unattainable resolution and beauty in home audio and video. For more than twenty years Original Equipment Manufacturers (OEM) and customers have used Bybee Quantum Purifiers to enhance the performance of nearly every level of audio and video system.

Experienced audiophiles with knowledge of electronics and good soldering skills can improve the sound of their system components at very reasonable cost by installing Quantum Purifiers themselves. Loudspeaker upgrades are just as easy. These purifiers will require a break-in to sound best.

(emphasis mine)

I don't think you need to wait for @SIY to reply; that product description says it all. Save your $5000 (or $10,000?) and just get the Benchmark AH2B.

 

[SIY]

I don't think you need to wait for @SIY to reply; that product description says it all.

Hey, a 5 cent 25 or 30 milliohm resistor wrapped in bullshit is nothing to scoff at.

Curl's relentless promotion of that scam artist, along with his refusal to keep current with technology, has pretty much guaranteed that his reputation will never recover, and that he'll be totally forgotten after he's gone. It's a sad thing to witness, John was capable of much, much more.

I've had three amps on hand over the past few months which are miles better than anything based on 1968 thinking. And at drastically lower cost, size, and power consumption. What they have in common is clever design by very capable engineers who understand modern technology to a deep level. I haven't tested the Benchmark, but I'm confident it would also fall into that class.

 

[RickSanchez]

Hey, a 5 cent 25 or 30 milliohm resistor wrapped in bullshit is nothing to scoff at.

And wrapped in a $180/unit MSRP.

 

[Deleted member 13999]

Back to the subject, four or five people here have said this unit is probably faulty. Can this be addressed?

 

[AudioTodd]

Back to the subject, four or five people here have said this unit is probably faulty. Can this be addressed?

Indeed. @amirm even states that the thermal management issues probably mean these units frequently have hard lives. This one is clearly not of recent production based on the pictures and the one I just bought - like 3 days before the review - so may have quite some time on it.

I would send mine in except I bought it to use in an upcoming month-plus temporary relocation and that is a LONG time for me to be without SOME sort of loudspeaker-based sound system (I’m not a headphone guy). The size and price were right for my needs, at least, with the runner up - a nuprime amp - having twice the price and not appreciably different published distortion and other specs except a lot more power. Perhaps after my trip I can send it if nobody has done so by then.

 

[AudioTodd]

Back to the subject, four or five people here have said this unit is probably faulty. Can this be addressed?

The Audio Critic measurements here from May 8, 2005 look better.
https://www.biline.ca/audio_critic/audio_critic_web3.htm#pm

 

[wwenze]

One thing in general worth pointing out is crosstalk is often power supply related, and ESR of electrolytic caps can double after a few thousand hours.

https://hal.archives-ouvertes.fr/hal-00141553/document

Then again many things are power supply related... including distortion

A new vs old comparison would make for an interesting study. And a message for old geezers to stop asking high prices for their 40yo NAD 3020

 

[flohmann]

It's not just about measurements, friends. Especially at this (used) price point.

I own two of these amps and have been using them happily for several years. I bought both (used) primarily for their "convenience features," which no one has mentioned yet. First, they have an auto-sensing power on/off circuit based on audio input. Super useful when you have the amp tucked away somewhere and no 12v trigger stuff. I love this feature and am surprised how rare it seems to be. Second, they have pots to adjust input levels (well, it says "gain," but I'm guessing it's just attenuating input level). Those are also useful, especially to put an upper maximum on overall system volume based on the input source. The amp also has 12v trigger and looping line out jacks, neither of which I use.

The amps have been reliable and sound fine in my applications (one drives speakers in my kitchen, the other drives speakers attached to my TV). I've never had overheating problems, doubtless because I'm not using more than a few watts in my set-ups. But I had a very hard time finding comparable convenience features in any other amps in this price range, especially the used price that I paid. (Interesting note, these same features are also offered on Parasound's much more substantial Halo A23 amps.)

 

[AnLaoJin]

Amirm always likes to evaluate some low-cost junk products. Why can't I evaluate HI-END products? Is it because of fear of offending the manufacturer?

 

[wwenze]

Amirm always likes to evaluate some low-cost junk products. Why can't I evaluate HI-END products? Is it because of fear of offending the manufacturer?

His most expensive reviewed products are high 4-digits, if not 5-digits if I recall correctly.

Most of it is loaned by other owners to prevent any bias.

Perhaps a better question would be, why aren't HI-END products offering themselves to be evaluated. Also a better question would be the definition of HI-END. Because the last I checked, Benchmark AHB2 measures at a 113dB SINAD. Interesting if that is not HI-END enough.

 

[AnLaoJin]

His most expensive reviewed products are high 4-digits, if not 5-digits if I recall correctly.

Most of it is loaned by other owners to prevent any bias.

Perhaps a better question would be, why aren't HI-END products offering themselves to be evaluated. Also a better question would be the definition of HI-END. Because the last I checked, Benchmark AHB2 measures at a 113dB SINAD. Interesting if that is not HI-END enough.

Because using a sine wave test signal has no reference significance, the music is not a sine wave

 

[CDMC]

Just my two cents. I have run one of these amps in my desktop system for a couple of years (Totem Mite Speakers). It has worked great in that role, never skipping a beat or overheating. Realistically, even cranked up with my low efficiency speakers in the nearfield, I am not exceeding 1-2 watts continually, so there is little in the way of heat being created. It fits a real need for me, fitting on my desk and perfectly under my Schiit Saga (thank you to Schiit for closing out the first generation for $200).

It is probably not the most transparent amp, as I can't tell the difference between redbook CD's and 192/24 sources. (Note that was firmly tongue in cheek).

 

[Xulonn]

Amirm always likes to evaluate some low-cost junk products.

That statement is false on its face. If you believe that, you obviously are not familiar with the list of audio hardware that Amir has measured. And the interesting part is that a fair number of expensive, so-called "high-end" audio products perform very poorly.

Because using a sine wave test signal has no reference significance, the music is not a sine wave

So how should they be evaluated, taking into consideration the fact that sighted listening has been proven to be a horribly flawed technique that claims differences where there are none?

Science, e.g., properly designed double blind testing tests have demonstrated that amplifiers that measure well (low noise and distortion, and enough power and current for a given set of loudspeakers) cannot be distinguished from each other. If you do not understand that fact, you are not accepting of exceptionally strong scientific evidence.

If you want some particular "high-end" products tested, please loan them to Amir for testing.

This internet forum is most definitely about music-lovers sharing their thoughts on audio systems - regardless of price - that perform well, but without making claims that cannot be independently verified and confirmed. It is a challenge to find good value and performance in audio hardware at all price levels. Plus, ASR has a reputation for exposing B.S. in audio marketing and at so-called "audiophile" magazines and websites B.S. We are not about drooling over subjectively reviewed blingy audio hardware that performs poorly, or about polishing sensitive egos of audiophiles, hardware designers and manufacturers. But if they earn and deserve praise, they will get it.

 

[peanuts]

i remember reading pages and pages about John Curls bybee nonsense over on diyaudio. it was gold. i cant believe he still endorses it lolmao.

 

[CDMC]

This internet forum is most definitely about music-lovers sharing their thoughts on audio systems - regardless of price - that perform well, but without making claims that cannot be independently verified and confirmed. It is a challenge to find good value and performance in audio hardware at all price levels. Plus, ASR has a reputation for exposing B.S. in audio marketing and at so-called "audiophile" magazines and websites B.S. We are not about drooling over subjectively reviewed blingy audio hardware that performs poorly, or about polishing sensitive egos of audiophiles, hardware designers and manufacturers. But if they earn and deserve praise, they will get it.

I think this is so well stated it bears repeating. For me, somewhere in the 90s audio jumped the shark. Products like NAD, Hafler, Boston Acoustics, Vandersteen, and a plethora of others, built with good engineering and providing a reasonable value, started to be pushed aside with the industry pushing ever more expensive products touting magical benefits. Some of us don't want magic, we just want good sounding equipment at reasonable prices that we can enjoy listening to our music. Being able to get factual data instead of marketing BS allows us a way to filter out marketing BS from decent products.

One other thing to keep in mind, is that the more measurements that are done along with subjective listening, the more we are able to correlate measurements to perceived sound. This is a great tool for helping in the development of new products and to identify potential products one might like. Take a look at the work of Floyd Toole and the understanding that total power sound curves have brought to being able to give a good idea of how a speaker will actually sound. Amir's work was also instrumental in pushing Schiit to provide actual measured performance and improve their measured performance, even though Amir was initially crucified (and still is in some cases) by other forums.

 

[preload]

The measurements of this Zamp v3 unit here are really interesting.
I read the Audio Critic's review back in the day, and I was a little surprised to see such different measurements posted here.

For instance:

Channel Separation 1khz:
ASR: -59dB
Audio Critic: -65dB

Channel Separation 20khz:
ASR: -35dB
Audio Critic: -56dB, -64dB

THD+N
ASR (5W-40w, 8 ohms, ? Hz): -64dB in bad channel, -80db in good channel
Audio Critic (5-40W, 8 ohms, 1khz): -87dB (5W-40w)

How do we reconcile these differences? The measured values are way different, even in something fairly straightforward, like channel separation. Were there differences in the measurement parameters or methodology? Or is it possible the tested unit here was defective in one channel?

 

[preload]

The measurements posted here versus those in The Audio Critic are so different that they cannot both possibly be simultaneously correct and representative of the amp’s performance. Either there was a problem with the measurement technique or one of the units tested was different (or more likely defective).

 

[SIY]

Audio Critic was always unclear about details of their measurements. For example, what’s the bandwidth for the THD+N? Amir is far more thorough in that regard.