MBL Pre-amp De-Thrones Benchmark?

[Purité Audio]

Does he take requests?
Keith

 

[Kal Rubinson]

Does he take requests?
Keith

Only polite ones.

 

[JohnYang1997]

The Freya uses a resistor ladder for volume control. Distortion will not increase when turned down as the amp section is running its hardest when at full volume. In passive mode all that is in the path are the resistors for each channel, nothing more.

https://www.audiosciencereview.com/...s/schiit-freya-s-preamplifier-review-2.11543/

Resistors and switches. Also the value of the resistors. The VCR of the resistors. Two resistors at a time or more? Input impedance, output impedance? These affect noise, distortion. If there's ground connected there may be ground related issues.

 

[Purité Audio]

Only polite ones.

I wouldn’t want to end up with Enya.
Keith

 

[MattHooper]

I've heard those before in a terrible room at a show (small like a child's bedroom, with flimsy double doors barely blocking the din from the entrance lobby). Despite that they were really good. Exciting to hear hard-panned left or right elements show up around the edges of the room.

Maybe because it was a small room there was less issue with the too-diffuse, indistinct imaging these are sometimes said to have. It doesn't seem like you had the latter impression with your pair at home either.

I have a good sounding room, with a nice combo of live and damped surfaces. The 121s sounded superb, and the imaging was just about as precise as any good speaker I've owned, but with more realistic dimensionality. With most speakers sonic images of voices and instruments tend to have a sort of flattened quality - they can appear in distinct spots in the soundstage, with differences in distance among them, but it's sort of like the depth stops behind the sonic image, like they are pasted on a background. With the omni-MBLs, there was an added sense of air/dimension that extended behind the images, making them seem more round, more dimensional. I have a recording of me playing my acoustic guitar recorded in a room in my house. When I'd play it on the MBLs the sonic impression of that guitar just appearing "in the room" playing was almost uncanny.

As well, the way their omni-design energized a room made them sound more "live" from outside the room too. I'd play a recording I made of my son practicing saxophone and on the MBLs from outside the room it just sounded real. I fooled a few people using that recording that my son was practicing sax in that room

 

[Purité Audio]

Only good for parties, in my humble opinion, if I was going for Omni I would get the Beolab 90’s where you can switch it off.
Keith

 

[MattHooper]

I've met and talked with JVS. He is not a machine, and has an excellent instinct for grift. One of his businesses is using whistling as therapy- i.e., you pay him to whistle at you to achieve healing.

Say what you will, he knows what his audience wants to hear.

I'm not as cynical about the intentions of reviewers. I've known too many of them, and by and large they are excitable audiophiles like the people they are writing for. They tend to be believers in most of what they write.

That said, though I do find some value in some subjective reviews, I've long since given up on JVS's stuff. Doesn't hold any value for me.

 

[SIY]

I'm not as cynical about the intentions of reviewers.

I don't lump all reviewers together. I'm happy to praise the good ones, happy to excoriate the bad ones, and even happier to get paid for doing it myself.

 

[Kal Rubinson]

I don't lump all reviewers together.

Good because that is not permissible these days.

 

[SIY]

Good because that is not permissible these days.

Depends. Some animals are more equal than others.

 

[MRC01]

Pricey pre-amp, and you can get transparent sound from the much cheaper Benchmark. But perhaps this crowd it might be interesting to see the measurements and comment from John Atkinson in recent Stereophile Review of the MBL N11 Pre-amp ...

As impressive as it measures, one of the engineering design decisions leaves me scratching my head. Input impedance of only 2.3 kOhm for unbalanced analog inputs? Why? Yet the input impedance of its other unbalanced analog input is 50 kOhm. That's more what I'd expect, why so different from the other? Why the inconsistency?

Anyway, for the price I'd expect a reference quality DAC and headphone outputs to be built in. And ... to be polite ... I'll just say it looks ridiculous. Too blingy. Form should follow and serve function, "tools not toys".

 

[Vasr]

I have spent a lot of time at the homes of Reference Line customers, and I know their taste, how they've constructed their living rooms, and the sound they prefer. The typical Noble Line customer has a different living room and different taste.

Who does he hang out with? The Sopranos? Or is it the Russian oligarchs?

 

[Dialectic]

Who does he hang out with? The Sopranos? Or is it the Russian oligarchs?

On the basis of my audio travels, I'd have to guess that most Reference Line customers are in East Asia.

 

[John Atkinson]

Some of those tests are strange:

View attachment 70881

10 millivolts? Why 10 millivolts?

I wanted to use a very low input signal level applied to the preamp to be certain that the analyzer's noisefloor would be below that of the preamp.

John Atkinson
Technical Editor, Stereophile

 

[PierreV]

Free healing here

 

[John Atkinson]

Free healing here

Here's another:

John Atkinson
Technical Editor, Stereophile

 

[CDMC]

Here's another:

John Atkinson
Technical Editor, Stereophile

The people standing around that clear out after he starts say it all.

 

[MZKM]

Here's another:

John Atkinson
Technical Editor, Stereophile

If no one has seen his performance of While My Guitar Gently Weeps, it’s impressive:

 

[MRC01]

Resistors and switches. Also the value of the resistors. The VCR of the resistors. Two resistors at a time or more? Input impedance, output impedance? These affect noise, distortion. If there's ground connected there may be ground related issues.

That's true, so quantifying the differences is key to the comparison.

Consider a typical preamp having an analog pot in front of a fixed gain ratio. Suppose it has a SNR of 120 dB at 2 V full output. Turn it down to 50 mV, that's 32 dB quieter and its SNR typically drops by 32 dB, so the 50 mV SNR is 120 - 32 = 88 dB.

Now take that preamp's full volume into a 10k passive with 32 dB of attenuation. This means R1 and R2 are 9750 and 250 respectively, so output impedance is 1 / ((1 / 250) + (1 / (9750 + 100))) = 244 ohms, assuming the preamp's output impedance is 100 ohms. Thermal noise at 244 ohms is 2.81e-7 V (at room temp and 20k bandwidth). At -32 dB the output is 2.5% of the input. So voltage across R2 for a 2 V source is 50 mV. Thus the SNR is: 20 * log(2.81e-7 / 0.05) = -105 dB

By my calculations, at 50 mV the passive is 17 dB quieter than a high quality preamp of conventional design.

 

[Ron Texas]

Did I miss something? Most (that does not mean everybody) people today run a DAC right into their amplifier. There aren't many amps that a balanced DAC with 4v output will not drive to the max.