Cymax Purifi 1ET9040BA with Weiss OP2-BP Dual-Mono Power Amplifier

[verdun]

vipersg/post 89 wrote "I had the opportunity to bring my Cymax amp to audio shops to have a comparison test."
Excellent work vipersg, it must have a confident shop owner to convene the comparisons.

Old_School_Brad ... "they hold limited value for those who weren’t directly involved in the test."

 

[verdun]

Old_School_Brad ... "they hold limited value for those who weren’t directly involved in the test."

I disagree. According to my comprehension of the English language vipersg wrote fairly accurately what they heard. Being a little pedantic, he didn't claim a test, but a comparison.
"limited value." When did you last hear a comparison with such exotic gear? I regard the comparison as Valuable.

Reminds me of the wonderfully opinionated Ivor Tiefenbrun of Linn who famously said "If you haven't heard it you haven't got an opinion."

 

[vipersg]

Looking at the 1400W rating into 2 ohms from the posted charts, I don't think they used a Hypex PS for these tests. Probably used a reference lab-grade power supply to showcase the best their amps can do. BTW, I prefer the 9040BA by a mile over all other new gen amps they've come up with.

Yeap, agree Purifi probably used a higher headroom lab grade power supply which makes sense from a manufacturer point of view to list the spec of the module and not limited by other external variable.

The 3 most important attributes of the 9040BA to me in order of highest importance first are:

1. The higher switching frequency, the better the sound. 620 kHz on 1ET9040BA versus 550 kHz on 1ET6525SA vs 500 kHz on 1ET400A. - the higher the frequency, sound is less harsh, presentation is more relaxed and engaging. This has been the observation since the early days of Class D had switching frequencies as low as 300-400 and you can see the impact on overshoot/undershoot on square wave measurement graphs.

2. Load impedance invariant frequency response. Fully neutral and transparent performance.

3. High power into sub 2 ohm EPDR loads for demanding speakers. Maintains dynamics, low distortion performance.

I think many people may not need (3) but the 9040BA has a significant lead on (1) that is useful for everyone.

 

[David_M]

David_M Thanks for posting.

re "BTW, I prefer the 9040BA by a mile over all other new gen amps they've come up with."

I'm keen to hear your thinking on that. TIA.

BTW, I'm not saying the 7040SA is defective or lacking in any sort of way but here are my thoughts of my I prefer the 9040BA:

1. Higher bandwidth than the 7040SA and other lesser powered amps (60kHz vs 80kHz, though FR plots show 90kHz)

2. Higher switching frequency (620 vs 515kHz) ... this pushes the switching noise further out from the audio spectrum by 100kHz and is readily filtered out by the output LC filter.

3. Higher power and lower distortion than the 7040SA. Now granted the distortion numbers might be moot since they are inaudible, but still an impressive design.

4. The 9040BA has lower SNR and dynamic range than the 7040SA (-140dB/-140dB vs -129dB/-129dB).

5. THD+N for the 9040BA is between -120dB and -130dB (load dependent), while the 7040SA is more or less -110dB (load dependent).

6. Advantage 7040SA ... its full power specs can be met by the recommended Hypex power module while you need another power supply such as from Micro Audio to fully meet the 9040BA power specs. Purifi did not use the Hypex module to generate their datasheet power specs for sure. The Hypex module is 1200W max while 9040BA output 1400W.

Simply looking at the datasheet plots for IMD and other tests shows the 9040 has much lower noise floors of -150dB vs -130dB for the lower powered 7040SA.


It seems Purifi started out with their ultimate or reference design in the 9040 and looked at what they could do to save money for their lower powered units. These spec differences might not be audible and/or mean much to many, but the EE inside me likes to see and own a superbly designed audio unit. Irrational thinking? Maybe. but there we are.

 

[David_M]

@Bruno Putzeys @Lars Risbo ... I have just been informed by one of your customers that "The 9040 will not work with Martin Logan. We have worked through this with Purifi several times. "

I just want to verify that this is true. The ML are electrostatic speakers with a capacitive load whose impedance has a linear downward slope going down to 0.4ohms - 0.5ohms at 20kHz...basically |Z| = 1/wC, where w = 2 * PI * Frequency and C = capacitance.

 

[vipersg]

BTW, I'm not saying the 7040SA is defective or lacking in any sort of way but here are my thoughts of my I prefer the 9040BA:

1. Higher bandwidth than the 7040SA and other lesser powered amps (60kHz vs 80kHz, though FR plots show 90kHz)

2. Higher switching frequency (620 vs 515kHz) ... this pushes the switching noise further out from the audio spectrum by 100kHz and is readily filtered out by the output LC filter.

3. Higher power and lower distortion than the 7040SA. Now granted the distortion numbers might be moot since they are inaudible, but still an impressive design.

4. The 9040BA has lower SNR and dynamic range than the 7040SA (-140dB/-140dB vs -129dB/-129dB).

5. THD+N for the 9040BA is between -120dB and -130dB (load dependent), while the 7040SA is more or less -110dB (load dependent).

6. Advantage 7040SA ... its full power specs can be met by the recommended Hypex power module while you need another power supply such as from Micro Audio to fully meet the 9040BA power specs. Purifi did not use the Hypex module to generate their datasheet power specs for sure. The Hypex module is 1200W max while 9040BA output 1400W.

Simply looking at the datasheet plots for IMD and other tests shows the 9040 has much lower noise floors of -150dB vs -130dB for the lower powered 7040SA.


It seems Purifi started out with their ultimate or reference design in the 9040 and looked at what they could do to save money for their lower powered units. These spec differences might not be audible and/or mean much to many, but the EE inside me likes to see and own a superbly designed audio unit. Irrational thinking? Maybe. but there we are.

These are great points David

 

[BDWoody]

It was a sighted A-B test, so I’m sure to be shot down by various folks in this forum.

Why does it take the forum to 'shoot down' your anecdotal comparison? Do you not recognize on your own that this type of 'test' really isn't?

Compared against the D’Agostino Progression, it was similar except the Progression had a slightly more weighty authoritative bass, and slightly richer mid.

Uh huh.

Seriously... Try setting up a proper test sometime.

 

[JustJones]

@BDWoody may you could start adding subtitles to these types of threads.

" Warning Thread is basically a marketing advertisement full of audiophool babbling"

 

[verdun]

X

BTW, I'm not saying the 7040SA is defective or lacking in any sort of way but here are my thoughts of my I prefer the 9040BA:

1. Higher bandwidth than the 7040SA and other lesser powered amps (60kHz vs 80kHz, though FR plots show 90kHz)

2. Higher switching frequency (620 vs 515kHz) ... this pushes the switching noise further out from the audio spectrum by 100kHz and is readily filtered out by the output LC filter.

3. Higher power and lower distortion than the 7040SA. Now granted the distortion numbers might be moot since they are inaudible, but still an impressive design.

4. The 9040BA has lower SNR and dynamic range than the 7040SA (-140dB/-140dB vs -129dB/-129dB).

5. THD+N for the 9040BA is between -120dB and -130dB (load dependent), while the 7040SA is more or less -110dB (load dependent).

6. Advantage 7040SA ... its full power specs can be met by the recommended Hypex power module while you need another power supply such as from Micro Audio to fully meet the 9040BA power specs. Purifi did not use the Hypex module to generate their datasheet power specs for sure. The Hypex module is 1200W max while 9040BA output 1400W.

Simply looking at the datasheet plots for IMD and other tests shows the 9040 has much lower noise floors of -150dB vs -130dB for the lower powered 7040SA.


It seems Purifi started out with their ultimate or reference design in the 9040 and looked at what they could do to save money for their lower powered units. These spec differences might not be audible and/or mean much to many, but the EE inside me likes to see and own a superbly designed audio unit. Irrational thinking? Maybe. but there we are.

You've covered it v well David_M (and vipersg). I was fully zeroed in on the higher bandwidth (the other aspects less so) and will in due course land on a 9040.

 

[goryu]

@Bruno Putzeys @Lars Risbo ... I have just been informed by one of your customers that "The 9040 will not work with Martin Logan. We have worked through this with Purifi several times. "

I just want to verify that this is true. The ML are electrostatic speakers with a capacitive load whose impedance has a linear downward slope going down to 0.4ohms - 0.5ohms at 20kHz...basically |Z| = 1/wC, where w = 2 * PI * Frequency and C = capacitance.

I have discussed low impedance loads with Purifi and was told that the 9040 is basically stable down to almost a dead short. Also, it isn't just the net impedance but the capacitive reactance portion that is important. I have Acoustats that get down to 2 ohms but only in the high frequencies where there is little energy/power content.

 

[goryu]

Yeap, agree Purifi probably used a higher headroom lab grade power supply which makes sense from a manufacturer point of view to list the spec of the module and not limited by other external variable.

The 3 most important attributes of the 9040BA to me in order of highest importance first are:

1. The higher switching frequency, the better the sound. 620 kHz on 1ET9040BA versus 550 kHz on 1ET6525SA vs 500 kHz on 1ET400A. - the higher the frequency, sound is less harsh, presentation is more relaxed and engaging. This has been the observation since the early days of Class D had switching frequencies as low as 300-400 and you can see the impact on overshoot/undershoot on square wave measurement graphs.

How do you measure the quality of the sound?

 

[d3l]

I had the opportunity to bring my Cymax amp to audio shops to have a comparison test. It was a sighted A-B test, so I’m sure to be shot down by various folks in this forum. There was no time to setup a blind test. Also, whatever I describe below will sure be shot down also because I don’t have side by side measurement graphs. But nonetheless if you are interested in the subjective impressions from 3 listeners, here it is:

The Cymax was compared against a Burmester 032 integrated amplifier and a Dan D’Agostino Progression integrated amplifier connected to Burmester B038 speakers. Each of these were around US$25-30k each. It was also compared against a T+A A3000HV power amplifier connected to Sonus Faber Amati G5, these were around US$24k and $36k each.

The outdated bias against Class D amplifiers being thin, lean and harsh was definitely not what the Cymax is. My initial impression on first listen was smooth and fairly relaxed, musical and engaging, top end was detailed and airy, clear instrument separation, neutral mid, bass that is powerful, precise and tight, has effortless drive, speed and dynamics.

Compared against the Burmester 034, it was hard to discern a difference. All 3 listeners said they were very close and could not call a winner.

Compared against the D’Agostino Progression, it was similar except the Progression had a slightly more weighty authoritative bass, and slightly richer mid.

Compared against the T+A A3000 HV, there was a wider difference with the T+A sounding more engaging with a richer tonality. T+A was running in Class A.

So if you have heard these components before, they are all very good amplifiers, each having a sound signature that one may like or prefer one over the other. Shop owner commented that the Cymax is a good amp. As the Amati G5 speakers goes down to 2.3 ohm at 93Hz with the amplifier seeing an equivalent of sub 2ohm EDPR across half the frequency range, the Purifi 1ET9040BA drove it really well and sounded effortless. Overall the Weiss OP2-BP coupled with Purifi 1ET9040BA makes for a super compelling value, especially if you have components that are of great quality to show up the difference it brings to the stage.

Thanks! Super nice that you made the effort. I think its a strong contender for my next amp, maybe paired with AR or some other higher end tube pre.

TT

 

[David_M]

I have discussed low impedance loads with Purifi and was told that the 9040 is basically stable down to almost a dead short. Also, it isn't just the net impedance but the capacitive reactance portion that is important. I have Acoustats that get down to 2 ohms but only in the high frequencies where there is little energy/power content.

Makes sense, since I used to drive them with classic analog amps (Bob Carver) and they had zero issues at all. So I was surprise when VTV told me what I alluded to earlier.

 

[David_M]

I had the opportunity to bring my Cymax amp to audio shops to have a comparison test. It was a sighted A-B test, so I’m sure to be shot down by various folks in this forum. There was no time to setup a blind test. Also, whatever I describe below will sure be shot down also because I don’t have side by side measurement graphs. But nonetheless if you are interested in the subjective impressions from 3 listeners, here it is:

The Cymax was compared against a Burmester 032 integrated amplifier and a Dan D’Agostino Progression integrated amplifier connected to Burmester B038 speakers. Each of these were around US$25-30k each. It was also compared against a T+A A3000HV power amplifier connected to Sonus Faber Amati G5, these were around US$24k and $36k each.

The outdated bias against Class D amplifiers being thin, lean and harsh was definitely not what the Cymax is. My initial impression on first listen was smooth and fairly relaxed, musical and engaging, top end was detailed and airy, clear instrument separation, neutral mid, bass that is powerful, precise and tight, has effortless drive, speed and dynamics.

Compared against the Burmester 034, it was hard to discern a difference. All 3 listeners said they were very close and could not call a winner.

Compared against the D’Agostino Progression, it was similar except the Progression had a slightly more weighty authoritative bass, and slightly richer mid.

Compared against the T+A A3000 HV, there was a wider difference with the T+A sounding more engaging with a richer tonality. T+A was running in Class A.

So if you have heard these components before, they are all very good amplifiers, each having a sound signature that one may like or prefer one over the other. Shop owner commented that the Cymax is a good amp. As the Amati G5 speakers goes down to 2.3 ohm at 93Hz with the amplifier seeing an equivalent of sub 2ohm EDPR across half the frequency range, the Purifi 1ET9040BA drove it really well and sounded effortless. Overall the Weiss OP2-BP coupled with Purifi 1ET9040BA makes for a super compelling value, especially if you have components that are of great quality to show up the difference it brings to the stage.

Frankly, I appreciate these type of reviews even though they are poo-pooed on this forum, which is fine (no need to rehash the issue ad nauseum). I recall when I went to an audio show and listened to a high end tube amp with Thiel 3.7 speakers. It sounded really nice and 'sweet' at first but after about 30 minutes, I felt fatigued by the sound and had to leave the room. It was time to leave anyways.

 

[verdun]

Why does it take the forum to 'shoot down' your anecdotal comparison? Do you not recognize on your own that this type of 'test' really isn't?



Uh huh.

Seriously... Try setting up a proper test sometime.

Why? Because it happens so often.

I think it is unfortunate vipersg used 'comparison test' - I took it to be a comparison.
We do such comparisons at my audio society fairly often: no we don't turn all lights out, so it is sighted. I've yet to hear a single member complain about the setup as it is a COMPARISON, not a lab test.

I described to my retired audio engineer friend the "goings on" here. He said "Well it is easy for them, they are not listening to anything."

 

[vipersg]

Thanks! Super nice that you made the effort. I think its a strong contender for my next amp, maybe paired with AR or some other higher end tube pre.

TT

I’m just trying to be helpful because @d3l asked for impressions about the amp. It’s not easy to arrange such comparison, I had to convince the shop to allow a product they don’t sell and play it against their products. They have other customers as well.

Thank you @verdun and @David_M for your helpful comments and sharing. It’s an impression comparison …. better than unhelpful anti-China and falsehoods about Covid, so thank you @Buckeye Amps for making a stand here in this thread, even though it’s not your product. #salute

 

[AdamG]

No more COVID comments. This is not the place for that.

 

[David_M]

No more COVID comments. This is not the place for that.

Even mentioning that term triggers me. Good riddance! It will not be missed!

 

[d3l]

I’m just trying to be helpful because @d3l asked for impressions about the amp. It’s not easy to arrange such comparison, I had to convince the shop to allow a product they don’t sell and play it against their products. They have other customers as well.

Thank you @verdun and @David_M for your helpful comments and sharing. It’s an impression comparison …. better than unhelpful anti-China and falsehoods about Covid, so thank you @Buckeye Amps for making a stand here in this thread, even though it’s not your product. #salute

Yes i know. For me the idea that you put well implemented purifi against 25K class A amp is nothing more than astonishing. We've come a long way in the past years.

 

[yuesecolorful]

BTW, I'm not saying the 7040SA is defective or lacking in any sort of way but here are my thoughts of my I prefer the 9040BA:

1. Higher bandwidth than the 7040SA and other lesser powered amps (60kHz vs 80kHz, though FR plots show 90kHz)

2. Higher switching frequency (620 vs 515kHz) ... this pushes the switching noise further out from the audio spectrum by 100kHz and is readily filtered out by the output LC filter.

3. Higher power and lower distortion than the 7040SA. Now granted the distortion numbers might be moot since they are inaudible, but still an impressive design.

4. The 9040BA has lower SNR and dynamic range than the 7040SA (-140dB/-140dB vs -129dB/-129dB).

5. THD+N for the 9040BA is between -120dB and -130dB (load dependent), while the 7040SA is more or less -110dB (load dependent).

6. Advantage 7040SA ... its full power specs can be met by the recommended Hypex power module while you need another power supply such as from Micro Audio to fully meet the 9040BA power specs. Purifi did not use the Hypex module to generate their datasheet power specs for sure. The Hypex module is 1200W max while 9040BA output 1400W.

Simply looking at the datasheet plots for IMD and other tests shows the 9040 has much lower noise floors of -150dB vs -130dB for the lower powered 7040SA.


It seems Purifi started out with their ultimate or reference design in the 9040 and looked at what they could do to save money for their lower powered units. These spec differences might not be audible and/or mean much to many, but the EE inside me likes to see and own a superbly designed audio unit. Irrational thinking? Maybe. but there we are.

Very good comparative analysis, I also have some doubts in choosing 7040SA and 6525SA, after all, 7040SA has more output current and lower output impedance, but the difference in output power is not too much, and 6525SA hav the second 2nd generation Eigentakt While I'm not particularly aware of the second generation advantages，so can you help me analyze and compare these two products.