PS Audio M700 Monoblock Amplifier Review

[GaryMnz]

So...crest factor and power under the curve don't matter. Got it.

That strikes me as erroneous, almost comically so. I wonder how many HF driver failures happen to those who follow
the methodology proposed occur. Because reasons.

OK last reply to you. You're arguing for the sake of it without offering anything relevant.

Counsel: "Your honour I object, argumentative"

Judge: "Sustained"

Counsel: "I rest my case"

 

[cistercian]

OK last reply to you. You're arguing for the sake of it without offering anything relevant.

Counsel: "Your honour I object, argumentative"

Judge: "Sustained"

Counsel: "I rest my case"

That works. Goodbye.

 

[amirm]

1/ No I haven't based my argument on this approach. I am actively involved in the industry as a manufacturer and engineer. I have taken measurements as I mentioned, at audio shows (CES etc), in dealers showrooms, and in domestic situations, all using either a portable oscilloscope or a self designed peak voltage detector. Lots of data over 20 years.

Manufacturer and engineer of what? What measurements? You have shared nothing of all that you say you have.

I have been to CEDIA theaters where gun shots would make my pant legs flap! In our own reference theater at Madrona before we moved, we measured 116 dB SPL peak playback level.

CES as a show is not a suitable place whatsoever for this kind of measurements. Unless you mean the suites in Venetian. In which case Harman had a demo of their Revel subwoofer. My pants were flapping again. It had such dynamics that a reporter that was sitting next to me ran out of the room!!!

If you think you can generate such bass with a few watts, or even a few hundred watts, you are sadly mistaken:

 

[Bruce Morgen]

Back


Crown designed their own chip. They are proud how many components they eliminated. There is a video out there that covers it!

Actually, they collaborated with TI's Europe-based Class D design team -- the same folks who a few years ago came up with a dirt-cheap monolithic chip that outperforms all but the very best of the previous century's Class AB amps in its output power range. Folks doubt me when I tell them that the little TPA3255-based "chip amp" I use to drive the vintage JBLs in my nearfield/desktop setup outperforms the Adcom GFA-535 -- a widely acclaimed Nelson Pass design -- I swore by for decades, but I stand by that assertion. FWIW, several of the leading figures of that TI team now work with Bruno Putzeys at Purifi -- enough said...

 

[cistercian]

Manufacturer and engineer of what? What measurements? You have shared nothing of all that you say you have.

I have been to CEDIA theaters where gun shots would make my pant legs flap! In our own reference theater at Madrona before we moved, we measured 116 dB SPL peak playback level.

CES as a show is not a suitable place whatsoever for this kind of measurements. Unless you mean the suites in Venetian. In which case Harman had a demo of their Revel subwoofer. My pants were flapping again. It had such dynamics that a reporter that was sitting next to me ran out of the room!!!

If you think you can generate such bass with a few watts, or even a few hundred watts, you are sadly mistaken:

Epic.

 

[Blumlein 88]

For another perspective, I once owned some Acoustat Two electrostats. Very inefficient speaker. They somehow rated it as 84 or 86 db/2.83v/m which I believe was rather optimistic. I think they were 80 db at most.

For a time I used a McIntosh 752 ss amp with them. 75 wpc 8 ohms, and 100 wpc 4 ohms. Audio mag reviewed the amps and they were a bit better than spec, but not much. That amp had the McIntosh Powerguard circuit on it. It was an optical system that would indicate clipping and reduce the signal to not exceed 1% distortion. It responded very rapidly.

At my loudest listening I would light those clipping indicators up now and again though only at my loudest listening. Most of the time I was fine at lesser levels. Even then I sometimes wanted just a little more, but didn't want to push the amp further.

 

[cistercian]

Actually, they collaborated with TI's Europe-based Class D design team -- the same folks who a few years ago came up with a dirt-cheap monolithic chip that outperforms all but the very best of the previous century's Class AB amps in its output power range. Folks doubt me when I tell them that the little TPA3255-based "chip amp" I use to drive the vintage JBLs in my nearfield/desktop setup outperforms the Adcom GFA-535 -- a widely acclaimed Nelson Pass design -- I swore by for decades, but I stand by that assertion. FWIW, several of the leading figures of that TI team now work with Bruno Putzeys at Purifi -- enough said...

The video said they collaborated with TI. Thanks for the additional info!

Here is the link!

 

[Blumlein 88]

The Quad ESL-63 suggested amps of 20-30 volt output capability. Which basically means 50-100 wpc into 8 ohm amps. Protection circuits started kicking in with inputs greater than 40 volts and if you hit 55 volts it threw a short across the speaker inputs. Protected the speaker, but maybe not so good for the amp.

The old Quad ESL-57 suggested no input more than 33 volts. I made an indicator when I had some that lit up at 16 volts and another at 32 volts so I wouldn't over drive them.

 

[GaryMnz]

Manufacturer and engineer of what? What measurements? You have shared nothing of all that you say you have.

I have been to CEDIA theaters where gun shots would make my pant legs flap! In our own reference theater at Madrona before we moved, we measured 116 dB SPL peak playback level.

CES as a show is not a suitable place whatsoever for this kind of measurements. Unless you mean the suites in Venetian. In which case Harman had a demo of their Revel subwoofer. My pants were flapping again. It had such dynamics that a reporter that was sitting next to me ran out of the room!!!

If you think you can generate such bass with a few watts, or even a few hundred watts, you are sadly mistaken:

Gun shots? I'm talking about music, at normal domestic listening levels.

 

[Bruce Morgen]

So...crest factor and power under the curve don't matter. Got it.

That strikes me as erroneous, almost comically so. I wonder how many HF driver failures happen to those who follow
the methodology proposed occur. Because reasons.

Yes, many an unfortunate tweeter has succumbed to a low-power solid-state amp driven ever so briefly into hard clipping. Been there, endured that circa 1975, got a heftier amp and it happened no more. I remember Electro-Voice having to come up with a "tweeter saver" gadget to protect the little Danish "phenolic ring" cone drivers Ray Newman had designed into some of the early "Interface" home speaker models. They subsequently had to give up on those otherwise quite decent tweeters because of the cost of replacing them under warranty to customers who figured their 20-25 WPC amps were adequate for partying to Cream and The Who on Saturday night.

 

[GaryMnz]

The Quad ESL-63 suggested amps of 20-30 volt output capability. Which basically means 50-100 wpc into 8 ohm amps. Protection circuits started kicking in with inputs greater than 40 volts and if you hit 55 volts it threw a short across the speaker inputs. Protected the speaker, but maybe not so good for the amp.

The old Quad ESL-57 suggested no input more than 33 volts. I made an indicator when I had some that lit up at 16 volts and another at 32 volts so I wouldn't over drive them.

Yeah, I've had ESL57s. Domestically, normal music listening level, I measure about 10 watts equivalent at the speaker.

I measured Von Schweikert Endeavour E5s at their factory listening room, a large domestic sized room. I was using my peak detector. Peak power noted when loud was about 50 watts. Leif from Von Schweikert later reported to me winding the same speakers up to ear bleeding levels in his home listening room (large) and measuring peaks of about 200 watts.

I assume most here are in typical domestic spaces and hence my assertion that required power levels are modest.

 

[cistercian]

Yes, many an unfortunate tweeter has succumbed to a low-power solid-state amp driven ever so briefly into hard clipping. Been there, endured that circa 1975, got a heftier amp and it happened no more. I remember Electro-Voice having to come up with a "tweeter saver" gadget to protect the little Danish "phenolic ring" cone drivers Ray Newman had designed into some of the early "Interface" home speaker models. They subsequently had to give up on those otherwise quite decent tweeters because of the cost of replacing them under warranty to customers who figured their 20-25 WPC amps were adequate for partying to Cream and The Who on Saturday night.

I remember those days too. I had friends who had to replace a LOT of tweeters under warranty. Mine is pretty bullet proof but I am using
ridiculous speakers compared to most home users. Hard clipping and square waves are evil to tweeters.

 

[amirm]

Gun shots? I'm talking about music, at normal domestic listening levels.

The heck is "normal domestic levels?" You have a study on that? Everyone listens at a different level. It is not your job to mandate a limit to that. And people have different size spaces. Ours is massive with huge volume so requires a lot of power.

Yes, you can listen to elevator music at 1 watt. So?

The papers I referenced you to shows that live concerts and standard seating location can have peaks of 120 dB+.

Are you going to tell me I am not allowed to replicate that in my home?

 

[amirm]

I was using my peak detector.

What peak detector? I thought you said you were using a scope. Meters have integration time and that can royally screw up the readings of power. And what was the playback SPL?

 

[pjug]

Yeah, I've has ESL57s. Domestically, normal music listening level, I measure about 10 watts equivalent at the speaker.

I measured Von Schweikert Endeavour E5s at their factory listening room, a large domestic sized room. I was using my peak detector. Peak power noted when loud was about 50 watts. Leif from Von Schweikert later reported to me winding the same speakers up to ear bleeding levels in his home listening room (large) and measuring peaks of about 200 watts.

I assume most here are in typical domestic spaces and hence my assertion that required power levels are modest.

This seems pretty much in line with what I have found with my own listening. When I play dynamic music a lot louder than I would want to play it I see peaks something like 100W or 150W.

 

[GaryMnz]

What peak detector? I thought you said you were using a scope. Meters have integration time and that can royally screw up the readings of power. And what was the playback SPL?

You're not paying attention.

 

[Sir Sanders Zingmore]

You're not paying attention.

I am. I see exactly what the plan is

 

[JohnYang1997]

You're not paying attention.

Now you just triggered the boss.

 

[GaryMnz]

The heck is "normal domestic levels?" You have a study on that? Everyone listens at a different level. It is not your job to mandate a limit to that. And people have different size spaces. Ours is massive with huge volume so requires a lot of power.

Yes, you can listen to elevator music at 1 watt. So?

The papers I referenced you to shows that live concerts and standard seating location can have peaks of 120 dB+.

View attachment 77244

Are you going to tell me I am not allowed to replicate that in my home?

I'm not telling you anything about what you're allowed to do. I just challenged you to do a measurement topic on actual power requirements in domestic situations. You're just putting up barriers. You're the measurement guy... go for it.

And I wager that very few music lovers are listening in a situation where they want to replicate 120 dB peaks in the home environment. Music is scalable otherwise we wouldn't ever be able to enjoy it at home.

 

[JohnYang1997]

I'm not telling you anything about what you're allowed to do. I just challenged you to do a measurement topic on actual power requirements in domestic situations. You're just putting up barriers. You're the measurement guy... go for it.

And I wager that very few music lovers are listening in a situation where they want to replicate 120 dB peaks in the home environment. Music is scalable otherwise we wouldn't ever be able to enjoy it at home.

He measures the amp and provides the data. YOU get to choose what data is important for you and your listening environment. Whether you have to listen at what level is not his business.