Measurements of Gustard P26 Preamplifier

[jsrtheta]

Dunno why not? But I guess they sound the same so nevermind. I guess I got the answer to my question either way.

You don't have an answer that you can substantiate. There is a way to establish whether you can perceive a difference or not: double-blind testing. Without that, you can't really say if you hear a difference or not.

 

[stuartmc]

yee

I wrote quite a bit about rolling the opamps over at head-fi. Here is one representative post. https://www.head-fi.org/threads/gus...phone-amplifier.735828/page-235#post-12064494. I ended up with the Burson discrete opamps in both the single and dual positions.

 

[PaulD]

I wrote quite a bit about rolling the opamps over at head-fi. Here is one representative post. https://www.head-fi.org/threads/gus...phone-amplifier.735828/page-235#post-12064494. I ended up with the Burson discrete opamps in both the single and dual positions.

Did you do a properly controlled double blind, level-matched listening test? If not, then the differences are most probably imaginary... There has been too much evidence that op-amps sound the same unless they are misbehaving. Changing them may actually change the sound, but that would be because the change has caused an opamp not designed for the circuit to misbehave.

You could measure the differences, because we can measure more accurately and to greater precision than we can hear (and everything audible can be measured). That would be the most reliable way of knowing if there are any differences. Here are a couple of links:
Sean Olive's The Dishonesty of Sighted Listening https://seanolive.blogspot.com/2009/04/dishonesty-of-sighted-audio-product.html
and Archimago's round of opamp fiddling https://archimago.blogspot.com/2016/01/measurements-asus-xonar-essence-one-dsd.html

 

[stuartmc]

Did you do a properly controlled double blind, level-matched listening test? If not, then the differences are most probably imaginary... There has been too much evidence that op-amps sound the same unless they are misbehaving. Changing them may actually change the sound, but that would be because the change has caused an opamp not designed for the circuit to misbehave.

You could measure the differences, because we can measure more accurately and to greater precision than we can hear (and everything audible can be measured). That would be the most reliable way of knowing if there are any differences. Here are a couple of links:
Sean Olive's The Dishonesty of Sighted Listening https://seanolive.blogspot.com/2009/04/dishonesty-of-sighted-audio-product.html
and Archimago's round of opamp fiddling https://archimago.blogspot.com/2016/01/measurements-asus-xonar-essence-one-dsd.html

Thanks for that. It's a good reminder of the perils and pitfalls of the subjective approach. I'm new here, but I do know this site caters more to the measurement/objectivist crew. I'm a fair bit of both, sort of like Donnie and Marie - "Im a little bit country. And I'm a little bit rock 'n roll." I was asking a measurement question and yodog pops in to ask me an experiential question, so rather than get into it here ( which I gather would be inappropriate), I point him to a place where, should he be into that sort of thing, he could follow our discussion. Was that the proper way to handle it from the ASR perspective?

 

[PaulD]

Was that the proper way to handle it from the ASR perspective?

I'm not sure exactly what you mean by that. If you mean "what's the way to handle subjective reviews from an ASR perspective?" Then the answer would be to do a level-matched, blind (double blind might be useful) test. Some people here do do them on a fairly regular basis. They take time to set up, but the methodology is designed to remove biases. I have found them highly instructive to do and take part in. They even convinced a friend of mine that vinyl does not sound better than digital. There are a couple of good articles in Jan Didden's journal Linear Audio. Search for "Analogue Hearts, Digital Minds" by Michael Uwins (found it in an open access forum http://eprints.hud.ac.uk/id/eprint/27345/), and "Testing, One Two Three" by Stuart Yaniger (SY).

If you mean "What's the best way to advise my friend from an ASR perspective?" Then I would suggest education. There are plenty of papers and sites that explain the evils of sighted listening, or how op-amps work and measure etc. I have been caught by the op-amp sound BS, it's a rabbit hole of nonsense. A competent designer will choose a high-quality and properly functioning op-amp that matches the requirements for the circuit. There is nothing to be gained by swapping to another part, the performance is more determined by the layout and other components than the op-amps. I could go off and find references, but at the moment I'm frankly too tired. Maybe others will chip in with some more information.

 

[frieddr]

I am running DAC with its own volume control straight balanced into my amp and the sound is a bit thin. Have read that an adding a line pre-amp can make the sound richer. This model is attractive to me because I need a small sized balanced preamp. Considering this or the new Burson soloist 3x which is also a headphone amp. Hard to believe that adding a unit at this price range to my chain will improve sound...

 

[Scottwhit]

I am running DAC with its own volume control straight balanced into my amp and the sound is a bit thin. Have read that an adding a line pre-amp can make the sound richer. This model is attractive to me because I need a small sized balanced preamp. Considering this or the new Burson soloist 3x which is also a headphone amp. Hard to believe that adding a unit at this price range to my chain will improve sound...

I have a P26 for sale in the gear for sale forum. I found the P26 to be very open and clean sounding. It is a really nice preamp. I purchased a preamp with both analog and digital inputs so I am selling the P26. LMK if you have any questions

 

[frieddr]

I'm considering adding a preamp to my chain even though I only have one input, my DAC, which has its own volume control. I'm hoping that a preamp will actually improve the sound, as I find running DAC straight to power amp sounds thin. Is it unrealistic to imagine that a $700 preamp will improve the chain?

 

[Scottwhit]

I'm considering adding a preamp to my chain even though I only have one input, my DAC, which has its own volume control. I'm hoping that a preamp will actually improve the sound, as I find running DAC straight to power amp sounds thin. Is it unrealistic to imagine that a $700 preamp will improve the chain?

I found the P26 to be very dynamic and clean sounding when I added it to my system. I am selling mine for $500 if you are interested.

 

[Harmonie]

I'm considering adding a preamp to my chain even though I only have one input, my DAC, which has its own volume control. I'm hoping that a preamp will actually improve the sound, as I find running DAC straight to power amp sounds thin. Is it unrealistic to imagine that a $700 preamp will improve the chain?

Don't hesitate to post a feedback once you experienced

 

[Phrangko]

More than a month ago, an old friend asked me, would you measure a Gustard P26 preamp?In fact, I didn't know Gustard was going to launch this product until he asked me.I then contacted Gustard, who said at the time that P26 had not been officially completed. After the official release, I will send me a retail version for measurement.

Just a few days ago @Max Also ask me if I will measure this unit?In fact P26 was on the road the next day.

Today I got the P26, and the measurement took me a lot of time. Because the preamplifier is very different from the DAC, there is basically no SOP at all. If there are any shortcomings in the following measurements, if you want to know something else, please let me know.

Look at things first:

View attachment 43208

View attachment 43209

Actually I always wanted a decent preamp

In fact, I always wanted a decent preamp, but the tragic fact is that it is almost full of garbage (maybe I didn't find it) under $ 1,000. It is not just a defect in the measurement data, but a question of completion.

What I mean by completeness refers to the appearance, function (input and output interface), operation friendliness, function implementation results (such as noise when switching volume), and even the ability to clearly show what you want What you know (input, output, volume, etc.)

This even forced me to do a preamp to achieve what I wanted.But although I realized most of what I wanted, it still couldn't satisfy me. Because the interior is composed of various small modules, and some modules are purchased (such as input and output switching and display), it cannot be said to be a "finished product" at all, but only a "usable" thing
And the cost of making it is close to $ 1,000 (not including the time I spent!!)

And Gustard's long-term adherence to the discrete voltage amplifier circuit has made me have a little more expectations for the sound of this preamp.

Well, don't talk nonsense. Measure it!

View attachment 43211
Update: Left channel PS Noise issue has been fixed and the manufacturer has been notified of the fix. Since repairs do not require costs, manufacturers will immediately produce to new standards. :
View attachment 43319



View attachment 43212

View attachment 43213
View attachment 43214

We can see that there seem to be two sets of very different input stages. One is responsible for the input of the balanced signal, and the other is responsible for the input of the unbalanced signal.

In fact, I also got this information from the developer, and the circuit of unbalanced input will also be used for "input gain + 6db setting". This means that the input gain +6 will also affect some basic measurement results in the same way as above.
Fortunately, we generally do not need a large input gain. And if you really feel that the sound is too low (this preamp is actually close to 0db gain by default) you can start "output gain +6" Settings ---- This function does not affect the basic measurement results.

View attachment 43215

View attachment 43216

View attachment 43217

The following measurements were made at XLRin XLROut 4VRMS：

First and foremost: volume control:
View attachment 43218

View attachment 43220

View attachment 43219

You can see that the volume control is very linear and the channel balance (green line) is very good. At the same time, the effect of volume adjustment on SINAD is minimal. The disadvantage is that the limit value of the volume control (-60db)may not be low enough in some cases.

Output impedance:
View attachment 43221


THD+N Vs Freq：

View attachment 43222
View attachment 43223

View attachment 43224

View attachment 43225

View attachment 43226
View attachment 43227

View attachment 43228

View attachment 43229



All of the above, I think for a preamp of less than $ 700, it is very, very, very good.

I've measured DACs from Gustard before, and to be honest, I'm a little disappointed-let's say the A22 finally achieved the result with double 4499.

I also said that Gustard's insistence on discrete output stages may be the main reason that affects the measurement results of their products.

But on this product today, I really have nothing to say.

A low-cost, high-performance, good-looking preamp. Sorry I have never met before.

What's past is prologue. The future can be expected.

How does it sound then as measured by your ears?

 

[DiegoV]

More than a month ago, an old friend asked me, would you measure a Gustard P26 preamp?In fact, I didn't know Gustard was going to launch this product until he asked me.I then contacted Gustard, who said at the time that P26 had not been officially completed. After the official release, I will send me a retail version for measurement.

Just a few days ago @Max Also ask me if I will measure this unit?In fact P26 was on the road the next day.

Today I got the P26, and the measurement took me a lot of time. Because the preamplifier is very different from the DAC, there is basically no SOP at all. If there are any shortcomings in the following measurements, if you want to know something else, please let me know.

Look at things first:

View attachment 43208

View attachment 43209

Actually I always wanted a decent preamp

In fact, I always wanted a decent preamp, but the tragic fact is that it is almost full of garbage (maybe I didn't find it) under $ 1,000. It is not just a defect in the measurement data, but a question of completion.

What I mean by completeness refers to the appearance, function (input and output interface), operation friendliness, function implementation results (such as noise when switching volume), and even the ability to clearly show what you want What you know (input, output, volume, etc.)

This even forced me to do a preamp to achieve what I wanted.But although I realized most of what I wanted, it still couldn't satisfy me. Because the interior is composed of various small modules, and some modules are purchased (such as input and output switching and display), it cannot be said to be a "finished product" at all, but only a "usable" thing
And the cost of making it is close to $ 1,000 (not including the time I spent!!)

And Gustard's long-term adherence to the discrete voltage amplifier circuit has made me have a little more expectations for the sound of this preamp.

Well, don't talk nonsense. Measure it!

View attachment 43211
Update: Left channel PS Noise issue has been fixed and the manufacturer has been notified of the fix. Since repairs do not require costs, manufacturers will immediately produce to new standards. :
View attachment 43319



View attachment 43212

View attachment 43213
View attachment 43214

We can see that there seem to be two sets of very different input stages. One is responsible for the input of the balanced signal, and the other is responsible for the input of the unbalanced signal.

In fact, I also got this information from the developer, and the circuit of unbalanced input will also be used for "input gain + 6db setting". This means that the input gain +6 will also affect some basic measurement results in the same way as above.
Fortunately, we generally do not need a large input gain. And if you really feel that the sound is too low (this preamp is actually close to 0db gain by default) you can start "output gain +6" Settings ---- This function does not affect the basic measurement results.

View attachment 43215

View attachment 43216

View attachment 43217

The following measurements were made at XLRin XLROut 4VRMS：

First and foremost: volume control:
View attachment 43218

View attachment 43220

View attachment 43219

You can see that the volume control is very linear and the channel balance (green line) is very good. At the same time, the effect of volume adjustment on SINAD is minimal. The disadvantage is that the limit value of the volume control (-60db)may not be low enough in some cases.

Output impedance:
View attachment 43221


THD+N Vs Freq：

View attachment 43222
View attachment 43223

View attachment 43224

View attachment 43225

View attachment 43226
View attachment 43227

View attachment 43228

View attachment 43229



All of the above, I think for a preamp of less than $ 700, it is very, very, very good.

I've measured DACs from Gustard before, and to be honest, I'm a little disappointed-let's say the A22 finally achieved the result with double 4499.

I also said that Gustard's insistence on discrete output stages may be the main reason that affects the measurement results of their products.

But on this product today, I really have nothing to say.

A low-cost, high-performance, good-looking preamp. Sorry I have never met before.

What's past is prologue. The future can be expected.

How does the Gustard p26 compare to the Benchmark HPA4? Noise? Sound?

 

[ohnonate]

Any advice. Would one rather get the Topping Pre 90 or the Gustard P 26?
Here in Australia the prices.

Pre 90 $900 AUD
Gustard P26 $1000 AUD

Simone is selling a GUSTARD P26 for $600. I think this is good value. or would one suggest waiting and saving for the Topping PRE 90

 

[Red@]

Any advice. Would one rather get the Topping Pre 90 or the Gustard P 26?
Here in Australia the prices.

Pre 90 $900 AUD
Gustard P26 $1000 AUD

Simone is selling a GUSTARD P26 for $600. I think this is good value. or would one suggest waiting and saving for the Topping PRE 90

Topping amps (A90 / Pre90) have very low impedance xlr inputs. Which is very detrimental to dynamics (see the Pre90 discussions). It is what would make an amp sound "flat" (in a dynamic sense) and not engaging.
I don't have experience whith the P26, so no opinion here. But the X26pro dac from gustard has epic output stage, so I would guess the company pays attention to this detail.
In my opinion the Pre90/A90 are made to measure well in a specific set of conditions (generally amir test conditions). But in real usage, they are very average amps, in terms of transcient, current output... (You'll see in their threat discussion that they may push a dac to shift to an AB class state from a typical A class, further more diminishing the dac capability.
Looking at Gustard X26pro components (and measurements), I would have more faith in them.
I myself is patiently waiting for a TOTL @gustard HP Amp (H26pro maybe ?) That is more oriented towards low impedance inefficient planars, with high current needs.
And this is another area where the topping stuff very limited at, the seem to have lots of power in measurements, but when you plug an inefficient planar, they struggle to drive it with their limited current output.

 

[Veri]

Topping amps (A90 / Pre90) have very low impedance xlr inputs. Which is very detrimental to dynamics (see the Pre90 discussions). It is what would make an amp sound "flat" (in a dynamic sense) and not engaging.
I don't have experience whith the P26, so no opinion here. But the X26pro dac from gustard has epic output stage, so I would guess the company pays attention to this detail.
In my opinion the Pre90/A90 are made to measure well in a specific set of conditions (generally amir test conditions). But in real usage, they are very average amps, in terms of transcient, current output... (You'll see in their threat discussion that thamey push a dac to shift to an AB class state from a typical A class, further more diminishing the dac capability.
Looking at Gustard X26pro components (and measurements), I would have more faith in them.
I myself is patiently waiting for a TOTL @gustard HP Amp (H26pro maybe ?) That is more oriented towards low impedance inefficient planars, with high current needs.
And this is another area where the topping stuff very limited at, the seem to have lots of power in measurements, but when you plug an inefficient planar, they struggle to drive it with their limited current output.

Most if not all of Amir's listening tests also test the low impedance Ether CX. I recall none of those Toppings 'struggling' with the CX, where do you get this; are you making this up?

 

[Red@]

Most if not all of Amir's listening tests also test the low impedance Ether CX. I recall none of those Toppings 'struggling' with the CX, where do you get this; are you making this up?

I wouldn't call The CX inefficient. On the contrary.
Won't degnify your accusation with an answer. You got the topping threads here, have at it.

 

[Veri]

I wouldn't call The CX inefficient. On the contrary.
Won't degnify your accusation with an answer. You got the topping threads here, have at it.

You're the one making the statements but fine.

 

[misterdog]

SMSL M400 >Topping Pre 90 > Benchmark AHB2 > Quad 989 ESL's sounding fine here.
All connected with Van Damme starquad balanced cable.

 

[raif71]

Anyone can explain why this preamp has input gain as well as output gain? Input gain here is 0 and +6db and output gain is also the same. Why not have just output gain of +12db an no input gain. I'm just trying to understand. Thanks

 

[alexbilchuk]

Using P26 preamp 2 weeks.
My system before was: Denon DP-47F with MC cartridge + Pro-Ject Phono DS2 + Pro-Ject Pre Box DS2 Digital (DAC+preamp+HP amp) + Pro-Ject Amp Box RS Mono + Tannoy XT6 (considered to be bad by ASR review, but I'm still happy with its sound, really).
Have a problem when change loading for MC cartridge to nominal 100 Ohm - big hum. At 10 Ohm - no hum. Sound was not so bad but lacks a little of dynamic and has not enough volume level even at maximum at Pre Box. I've tried Ortofon ST-7 SUT with Phono DS2 and got same problem - big hum.
Volume level from Pre Box DAC was too high - I can use max 50% of volume control.

After connecting P26 into system (DS2 DAC -> RCA input, Phono DS2 -> XLR input, XLR output -> Amp RS):
1. Hum at 100 Ohm loading eliminated
2. Hum with ST-7 SUT eliminated
3. Vinyl sound improved a lot (I'm using SUT now (47 kOhm loading, 40 dB gain - Phono DS2 settings)
4. DAC volume level normalized (using fixed output at Pre DS2)
5. DAC sound improved (better sound-stage localisation, a little more detail)
6. Can use almost whole range of volume control (100 positions)
7. I'm happy with P26)

I think it's happened because of impedance conformity (P26 input impedance is 47 kOhm, output 100 Ohm).