New Purifi amplifiers coming

[mocenigo]

I think measurements, would help.
What's a 'Db'?

“Db” is a weird typo

S/N at -150dB, look here https://weiss.ch/wp-content/uploads/2022/07/OP1-BP-Datasheet-R1.pdf of course this is the manufacturer’s claim.

For instance for the Neurochrome universal buffer we get +-15V max, and 15V/2.1μV = 0.7*10^7, a ratio (of absolute magnitude RMS values) that corresponds to about 137DB, as claimed by Neurochrome themselves.

 

[MAB]

“Db” is a weird typo

S/N at -150dB, look here https://weiss.ch/wp-content/uploads/2022/07/OP1-BP-Datasheet-R1.pdf of course this is the manufacturer’s claim.

For instance for the Neurochrome universal buffer we get +-15V max, and 15V/2.1μV = 0.7*10^7, a ratio (of absolute magnitude RMS values) that corresponds to about 137DB, as claimed by Neurochrome themselves.

OK!
Yeah, that's a heroic claim. Would be nice just for the see it backed up. I do like the low noise floor since I use with compression drivers and other high efficiency speakers. These OpAmps really don't limit the design though, or am I missing anything?

 

[mocenigo]

OK!
Yeah, that's a heroic claim. Would be nice just for the see it backed up. I do like the low noise floor since I use with compression drivers and other high efficiency speakers. These OpAmps really don't limit the design though, or am I missing anything?

I do not understand your last sentence. Is it about the Weiss opamp, both the Weiss and the 1612, or in general?

 

[Fidji]

Too bad that there is no 45V version of the SMPS3k...

I stumbled upon new Purifi amps, when ordering some watts for my HT.

I could see here in EU only 2 offers - Apollon with "wrong" PSU, and Audiophonics with "wrong" OpAmp.
Will you a) include it in your portfolio b) will you have "right: both PSU and OpAmp?

 

[Matias]

Apollon probably copied the web page from another model and changed the module name but forgot to change the PS name. Happens to the best of us. @Apollon Audio

 

[welwynnick]

I bet that the Apollon actually uses the right PSU, and there's just a typo in the spec sheet.
I'm not sure that Audiophonics use the wrong OpAmp either.
The Sonic Imagery, Burson, Weiss and Sparkos get a lot of attention, but the OPA1612 has great specs, too. OK, it does it's best work at 1kHz, but I think people only latch onto that because the TI spec sheet is more comprehensive, and I don't think there's any evidence that the expensive OpAmps are better. Some do prefer them, but I've also read people on the DIY forums preferring the 1612.

 

[Fidji]

I bet that the Apollon actually uses the right PSU, and there's just a typo in the spec sheet.
I'm not sure that Audiophonics use the wrong OpAmp either.
The Sonic Imagery, Burson, Weiss and Sparkos get a lot of attention, but the OPA1612 has great specs, too. OK, it does it's best work at 1kHz, but I think people only latch onto that because the TI spec sheet is more comprehensive, and I don't think there's any evidence that the expensive OpAmps are better. Some do prefer them, but I've also read people on the DIY forums preferring the 1612.

from Audiophonics website (on 1et400)

“A Texas Instrument LM4562 OPA per channel is used, these are very low distortion AOPs offering the greatest transparency with a very low THD. They are mounted on socket allowing their replacement if necessary”

I am absolutely OK with OPA1612, I have it in my Apollon 1et7040 amp.

 

[welwynnick]

from Audiophonics website (on 1et400)

“A Texas Instrument LM4562 OPA per channel is used, these are very low distortion AOPs offering the greatest transparency with a very low THD. They are mounted on socket allowing their replacement if necessary”

I am absolutely OK with OPA1612, I have it in my Apollon 1et7040 amp.

I thought that was used on the AUDIOPHONICS MPA-M400ET Power Amplifier Class D Mono Purifi 1ET400A ?

AUDIOPHONICS MPA-M400ET Power Amplifier Class D Mono Purifi 1ET400A 1x400W 4 Ohm - Audiophonics

Class D mono power amplifier based on a PURIFI 1ET400A module and a HYPEX SMPS600A400 power supply.

www.audiophonics.fr

My memory might have failed me, but now I can't see any mention of the OpAmp used on the HPA-DM750ET?
Yes, I'd be OK with the OPA1612 as well.

 

[mocenigo]

I stumbled upon new Purifi amps, when ordering some watts for my HT.

I could see here in EU only 2 offers - Apollon with "wrong" PSU, and Audiophonics with "wrong" OpAmp.

As Apollon confirmed to me, they copied over the page for the 7040 amps and the did not fix everything — they are definitely using the right PSU. They also have a luxury chassis, an opamp claimed to be the best measuring in the world with its own PSU. But of course everything has a price.

As for Audiophonics, not sure what they use as a buffer

Will you a) include it in your portfolio b) will you have "right: both PSU and OpAmp?

Why shouldn’t he? But Fred is very attentive to details.

 

[mocenigo]

I thought that was used on the AUDIOPHONICS MPA-M400ET Power Amplifier Class D Mono Purifi 1ET400A ?

AUDIOPHONICS MPA-M400ET Power Amplifier Class D Mono Purifi 1ET400A 1x400W 4 Ohm - Audiophonics

Class D mono power amplifier based on a PURIFI 1ET400A module and a HYPEX SMPS600A400 power supply.

www.audiophonics.fr

My memory might have failed me, but now I can't see any mention of the OpAmp used on the HPA-DM750ET?
Yes, I'd be OK with the OPA1612 as well.

I would prefer a composite amplifier with a 1612 driving a 1656 (but: some phase rotation kinks require some extra care - hence more resistors and caps on the feedback and thus a potential increase in noise). 140dB THD+N and ability to deliver a ton of current. Or cascaded LME49720.

I forgot to mention what is the actual advantage of the Weiss op2-bp. The CMRR stays quite high (at least 88dB) over the whole audio band. Most composite amplifiers inherit the CMRR from the opamps and tends to fall regularly above 1Khz.

 

[Fidji]

I thought that was used on the AUDIOPHONICS MPA-M400ET Power Amplifier Class D Mono Purifi 1ET400A ?

AUDIOPHONICS MPA-M400ET Power Amplifier Class D Mono Purifi 1ET400A 1x400W 4 Ohm - Audiophonics

Class D mono power amplifier based on a PURIFI 1ET400A module and a HYPEX SMPS600A400 power supply.

www.audiophonics.fr

My memory might have failed me, but now I can't see any mention of the OpAmp used on the HPA-DM750ET?
Yes, I'd be OK with the OPA1612 as well.

Audiophonics seems to use 4562 also in 1et7040, but you are right, no mention of op-amp used ins 9040 specs. Maybe they come with skmething new for 9040.

Anyway, will wait for some measurements first, curious about “eigentakt gen2” and what it brings. Only thing that ever bothered me a bit about modern d-class amps was this ballooning of distortion at higher frequencies. Nothing audible, but still .

 

[boXem]

I stumbled upon new Purifi amps, when ordering some watts for my HT.

I could see here in EU only 2 offers - Apollon with "wrong" PSU, and Audiophonics with "wrong" OpAmp.
Will you a) include it in your portfolio b) will you have "right: both PSU and OpAmp?

a) yes, but not before a few months
b) most probably SMPS1200 (1.2 kW - 200W losses = 1 kW at the binding posts at 20Hz in 2R) and a composite gain stage.

 

[Fidji]

a) yes, but not before a few months
b) most probably SMPS1200 (1.2 kW - 200W losses = 1 kW at the binding posts at 20Hz in 2R) and a composite gain stage.

Thanks a lot - let' stay in touch, will write you directly, I am in no hurry.
7040 works very well, but I have 26 CH to feed, so I can for sure accommodate latest and greatest in D Class into my setup, as I have combined 2Ch/HT room, with L-R getting special treatment in amplification.

Actually I am more interested in behavior at the other end of the spectrum - I have hybrid electrostats with active bass section [up to 270Hz] so no issue there, rather with 0.5R at 20kHz.

 

[soerenssen]

Audiophonics seems to use 4562 also in 1et7040, but you are right, no mention of op-amp used ins 9040 specs. Maybe they come with skmething new for 9040.

One LM4562 OPA per channel, according to the updated product page of the HPA-DM750ET.

 

[welwynnick]

Indeed. That's a little disappointing, though they say it's mounted on a socket.

 

[mocenigo]

Indeed. That's a little disappointing, though they say it's mounted on a socket.

It is a DIP8 socket though, so you can replace is with an OPA1656 if you want better driving capability, but also slightly more noise. The discrete opamps for that socket are not better. The Weiss uses a pro opamp socket.

 

[Ra1zel]

OK!
Yeah, that's a heroic claim. Would be nice just for the see it backed up. I do like the low noise floor since I use with compression drivers and other high efficiency speakers. These OpAmps really don't limit the design though, or am I missing anything?

I don't have a direct proof of how good are the Weiss op amps but their new flagship DAC the Helios uses them in the output stage... it's also the best measuring DAC in stereophile ever with estimated ENOB of 21.5 bits. Guess they can't be that bad if this DAC would top the chart here on ASR.

 

[Rick Sykora]

It is a DIP8 socket though, so you can replace is with an OPA1656 if you want better driving capability, but also slightly more noise. The discrete opamps for that socket are not better. The Weiss uses a pro opamp socket.

May be a translation (or marketing hype), but what is a pro opamp socket?

 

[Matias]

May be a translation (or marketing hype), but what is a pro opamp socket?

It is the larger size opamp socket that the manufacturers call "Pro" as opposed to the smaller sized DIP8.
Examples:

Sparkos SS2590

Pro Discrete Op Amp

Audio Op Amps Discrete Sparkos Labs SS2590 for amplifying audio signals in an API package for studio, professional, mic preamp, and console use.

sparkoslabs.com

Sonic Imagery 990Enh-Ticha

Model 990Enh-Ticha Discrete Operational Amplifier

Some amp manufacturers accept both types, like VTV.

VTV Amplifier Custom Input Buffer Hypex NC500 NC1200 NC2K Purifi | VTV Amplifier

 

[Audiophonics]

Indeed. That's a little disappointing, though they say it's mounted on a socket.

Yes we selected a versatile and common model that offer good performances and availability in DIP8 format.

What models would have been more relevants ?
Any suggestion welcome for future updates.