If audiophonics also offers a premium option similar to Apollon's - Weiss Op2-bp with a linear power supply, i would be all over that.
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New Purifi amplifiers coming
- Thread starter mocenigo
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Did you select it based on subjective, objective or commercial considerations?
Do you know if Purifi will produce their own I/O board?
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
Some amp manufacturers accept both types, like VTV.
View attachment 354572
Thanks, thought it might be something like that. It is a socket configuration (packaging for a carrier board rather than a typical opamp). As electronics industry technology goes, there is consumer grade, industrial, mil-spec. They are all different grades of what could be called professional.
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OPA1656 as per the man himself.
Apollon NCx500ST Stereo Amplifier Review
With that responsiveness cherry on top - this is certainly my way to go forward. Just looking for a DAC+preamp that has a configurable sub out and dirac that matches well with this now. You'll be wanting a miniDSP flex then :D
www.audiosciencereview.com
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Just to put myself right...
I recall someone commenting that the OPA1612 was very good, but performance degraded at higher frequencies.
So I looked at the TI datasheet, and sure enough the SINAD got worse above 1kHz, but then I had never seen any THD vs Freq charts for any other OpAmps.
ASR is a goldmine of information, and I found this today:
Rolling (replacing) Op-amps in Topping D10 DAC
This is a study of whether changing op-amps in a DAC makes a measurable difference. Taking a lead form "rolling" tubes in tube products, a trend has started in replacing op-amps -- sometimes with much difficulty -- to improve performance of solid state products like DACs. A few months ago I...
www.audiosciencereview.com
The only niggle is that the bottleneck may be elsewhere.
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MaxwellsEq
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Welcome to OpAmp fundamentals. A way of imagining an OpAmp is a triangle with massive gain near DC and virtually none at Mhz frequencies. This is not a useful feature so feedback is used to get a flat gain with frequency. Because there is so much gain near DC, everything is easy, but as frequency increases, the gain available gets less and less. So, relative to low frequencies all OpAmp designs are trickier at higher frequencies. But the humble 5534 is totally adequate in all line-level circuits.Just to put myself right...
I recall someone commenting that the OPA1612 was very good, but performance degraded at higher frequencies.
So I looked at the TI datasheet, and sure enough the SINAD got worse above 1kHz, but then I had never seen any THD vs Freq charts for any other OpAmps.
ASR is a goldmine of information, and I found this today:
Yes, the OPA1612 SINAD gets worse above 1kHz, but then so does everything else (and this is tested in a DAC, not a power amp):Rolling (replacing) Op-amps in Topping D10 DAC
This is a study of whether changing op-amps in a DAC makes a measurable difference. Taking a lead form "rolling" tubes in tube products, a trend has started in replacing op-amps -- sometimes with much difficulty -- to improve performance of solid state products like DACs. A few months ago I...
The only niggle is that the bottleneck may be elsewhere.
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Perhaps I should have said that I had never seen the THD vs Freq charts for the Weiss or Sonic Imagery OpAmps.
MaxwellsEq
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That may not tell you anything useful, without knowing the circuit design that it's in. It's quite easy to build a terrible circuit using a fine Op-amp.
Getting to grips with Gain Bandwidth Products is key.
Rhodo
Member
This may be the wrong place to ask, but I saw a post in a thread earlier saying that the input voltage was an important factor for Purifi amps. Can't find the actual post now so I thought I'd ask here. Been eyeing a Buckeye Purifi stereo amp but now I'm confused, do I need to fret about the signal my DAC/preamp is sending it?
Right now I'm setup like this: PC -USB-> Topping DX5 -XLR or RCA-> Amp --> Ascend Acoustics Sierra 1-v2
If I wanted to go with a Purifi based amp is there a problem with that signal chain? I got these speakers recently and am pretty in love with them, I'd love to get one these and just be confident and the amp is not a limiting factor in any way.
Right now I'm setup like this: PC -USB-> Topping DX5 -XLR or RCA-> Amp --> Ascend Acoustics Sierra 1-v2
If I wanted to go with a Purifi based amp is there a problem with that signal chain? I got these speakers recently and am pretty in love with them, I'd love to get one these and just be confident and the amp is not a limiting factor in any way.
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The input 'buffer' OpAmp used with the Purifi module provides additional gain. Some amps, like the MarchAudio 462, have switchable 20 or 26 dB gain to optimise system gain performance. Though most 'non-exotic' DAC's, Pre's and Amps available nowadays will happily sing together with no fuss or bother.
March Audio posted the measurements for their 1ET9040BA based P801 mono amp. As expected, crazy low levels of distortion. I suppose all implementations will have SINAD limited by noise on the buffer and gain settings used.
forum.marchaudio.com
P801 Power Amp
Hi everyone We are releasing our new flagship monoblock at the Australian HiFi Show in a few weeks time. Just thought I would share a little test data. Below is a plot of the P801 running at 5 watts as you would typically see on sites such as ASR. Distortion levels beat anything I have seen...
forum.marchaudio.com
Should be just fine but should plan to use XLR to XLR cable between the Topping and the Buckeye amp.
EdW
Senior Member
Practically the best high power amp on the market? It would be interesting to understand where the noise/distortion floor of Alan March’s measurement system lies. In any case the measurements must be quite challenging to take at this level of distortion.March Audio posted the measurements for their 1ET9040BA based P801 mono amp. As expected, crazy low levels of distortion. I suppose all implementations will have SINAD limited by noise on the buffer and gain settings used.
P801 Power Amp
Hi everyone We are releasing our new flagship monoblock at the Australian HiFi Show in a few weeks time. Just thought I would share a little test data. Below is a plot of the P801 running at 5 watts as you would typically see on sites such as ASR. Distortion levels beat anything I have seen...
View attachment 357302
Maybe, but cannot judge from just one measurement alone. Would need full set of independent measures to claim any top ratings. Since Amir is not going to do and Erin is not equipped to do, guess will have to see what Amir gets from other vendors.
Would like to see some internal pics. Last March amp I serviced was a PIA to work on and had the power management board mounted on the SMPS heatsink. Was actually pleased to find I did not have to replace the power supply.
Coming from Purifi and Bruno, I expect nothing but excellence in other important metrics such as IMD and reliability of the module. So it comes down to PS choice, buffer and opamp, and general assembly quality and chassis design to differentiate between other amps based on this marvel module.
At the same time, the 7040 and the NCx500 are no slackers either AND likely much better values. Even the Audiophonics 9040 is 2500 euros. The Apollon 7040 is that much so you know the 9040 will be more. Will be interesting to see March’s pricing.
restorer-john
Grand Contributor
He's talking about his source generator's noise floor, its inherent distortion and of course the amplifier's residual noise floor. We really have no idea what's from the source D/A, the A/D front end and what's from the amp. Putting a measurement system loopback alongside would show what differences there are, but that can also be deceptive.
He's at the limits of his test gear, just as many of us are. He'd have to pony up for an APX555B and it's associated AUX filter, along with some expensive loads (lift brake resistors are no good for that) just to characterise the amp. In Australia, it'd be close to AUD$100k all things considered.
Working back from the plot, there is around 13uV of unweighted total noise on the outputs from 20Hz-20kHz, which is amazing for an amplifier of any type, letalone a SMPS driven very high powered switching amplifier. And again, some of that may be coming from the D/A front end.
The SNR figure however is likely under-quoting the actual figure. It will likely be better due to the measurement method being not being true S/N.
Which load resistors are suitable for this sort of super high accuracy metering?
EdW
Senior Member
Looks like the measurements Alan March has made are at/below the limits of the AP555B? The load resistor linearity is certainly a challenge although extremely high damping factors from the amplifier might help mask marginal non linearities here.