Sutherland KC Vibe MK2 Phono Stage Review

[amirm]

This is a review and detailed measurements of the Sutherland KC Vibe MK2 phono preamplifier. It is on kind loan from a member and costs US $999:

The box is quite substantial and deep despite the fact that power supply is switching and external:

Where do you think the power supply plugs in? You would never guess. It is through a hole underneath! I suspect that optimized the circuit layout together with disjointed inputs and outputs.

The power supply is rated at 48 volts so hopefully that translates into good bit of headroom.

Gain and loading is programmable but sadly through jumpers inside the box:

I went with the recommended 45 dB gain for the measurements.

Sutherland KC Vibe MK2 Measurements
Let's start with our usual dashboard:

Very nice to see no distortion spikes which is my target. Noise is controlled enough to almost land it at the top of our chart:

Most important measurement in a phono stage is frequency response and the Sutherland essentially nails it:

My hopes however for good headroom were dashed:

Not only do we have a low input level saturation at 1 kHz of just 26 millivolts, it keeps getting worse with increasing frequency (this aspect is typical). Here is what it corresponds to on the output side:

So we can't even get to 5 volts out. Why?

Back to distortion (ignore noise), it is very low:

Conclusions
I like the nice RIAA implementation and exceedingly low distortion and noise for a phone stage. What I don't like is the low clipping point which means ticks and pops will be more audible. If this had not been the case, the Sutherland would be almost perfect.

Given the good performance in a few areas, I am going to put the Sutherland on my recommended list. It is pricey though and similar performance can be had for much less money.

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As always, questions, comments, recommendations, etc. are welcome.

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[dougi]

That was disappointing, given the 48V power supply, in terms of headroom.

 

[oscar_dziki]

I literally had to google what this device does

 

[Awsmone]

Is the not a common problem of phono stages , the headroom: especially in mc?

 

[DSJR]

Input overload is vitally important for obvious reasons, but why should a RCA equipped stage be required to give 4V output? Most amps with RCA inputs seem to have plenty of gain, don't they?

I do appreciate the input overload can be equated to output levels too as regards gain levels internally from input to output, but hoprfully SIY or another engineer can clarify for me?

Price is mad-high though, bearing in mind the basic casework I feel.

 

[AudioSceptic]

Input overload is vitally important for obvious reasons, but why should a RCA equipped stage be required to give 4V output? Most amps with RCA inputs seem to have plenty of gain, don't they?

I do appreciate the input overload can be equated to output levels too as regards gain levels internally from input to output, but hoprfully SIY or another engineer can clarify for me?

Price is mad-high though, bearing in mind the basic casework I feel.

It looks like a DIY case, doesn't it, nothing like $1k's worth? It seems that Sutherland has a high rep in the USA, and some of these are seriously expensive <https://sutherlandengineering.com/product_type/current-products/>.

 

[Casper]

Interesting company. I never heard of them but I'd like to see reviews of the products higher up in their lineup. The Vibe MK2 is their entry level product. Their top of the line model is only $4000--which for this type of product is reasonable if it performs significantly better. The styling is a little simplistic but their products are made the USA so they need to cut costs somehow. I like the aesthetic of their higher end products.

If their "Insight" model toped the review chart, I wouldn't mind putting down $1400 to get that level of performance.

 

[sarumbear]

Is the not a common problem of phono stages , the headroom: especially in mc?

Headroom is THE most important specification in a phone amplifier. I personally wouldn't touch this unit with a barge-poll.

SINAD is important but if a phono amplifier cannot handle ticks (spikes), which are the norm of record playback, how can it be recommended? This amplifier has at best 10dB headroom in the most important tick/spike frequency range. You will hear every tick, loud an clear.

 

[pseudoid]

A question that I had never contemplated; even during the decades of building my very large library of LPs.
I think that most cartridges are inherently balanced pick-up.
Yet, even the higher-end phono pre-amp stages (as well as most turntables) do not appear to offer XLR/Balanced inputs and/or outputs!

Oh, Yes! My question is a simple "Why?"
Note: I gave up my LP library/hardware a decade ago, after realizing that my CD library had gotten double the size of the LP library. Finally, I gave up physical media altogether.

 

[sergeauckland]

Headroom is THE most important specification in a phone amplifier. I personally wouldn't touch this unit with a barge-poll.

SINAD is important but if a phono amplifier cannot handle ticks (spikes), which are the norm of record playback, how can it be recommended? This amplifier has at best 10dB headroom in the most important tick/spike frequency range. You will hear every tick, loud an clear.

Exactly this. Any phono stage needs at least 20dB of headroom at 1kHz. Shure measured commercially available LPs way back when, and found that some hot LPs were cut with velocities of up to 70cm/sec. This is 14x or 23dB above the nominal 5cm/sec recorded velocity, and that's modulation, not scratches which can go higher still. This means that a nominal 40dB gain phono stage with a cartridge of nominal 5mV @ 5cm/sec recorded velocity has to be able to output at least 5V on peaks, and ideally a good few dBs more, so I expect a phono stage to output around 8V (+20dBu) without clipping.

Yes, RIAA accuracy and low noise are important, but they're trivially easy to get right, overload margin seems to escape modern designers. My own phono stages, made in the mid 1980s, can output 9.5 V (+22dBu) before clipping.

S.

 

[GWolfman]

Input overload is vitally important for obvious reasons, but why should a RCA equipped stage be required to give 4V output? Most amps with RCA inputs seem to have plenty of gain, don't they?

I do appreciate the input overload can be equated to output levels too as regards gain levels internally from input to output, but hoprfully SIY or another engineer can clarify for me?

Price is mad-high though, bearing in mind the basic casework I feel.

I agree and would appreciate it if someone could chime in. I've never dabbled into the vinyl realm so this sort of idea is relatively new to me.

 

[sergeauckland]

A question that I had never contemplated; even during the decades of building my very large library of LPs.
I think that most cartridges are inherently balanced pick-up.
Yet, even the higher-end phono pre-amp stages (as well as most turntables) do not appear to offer XLR/Balanced inputs and/or outputs!

Oh, Yes! My question is a simple "Why?"
Note: I gave up my LP library/hardware a decade ago, after realizing that my CD library had gotten double the size of the LP library. Finally, I gave up physical media altogether.

MC cartridges are inherently balanced, MM cartridges less so, as the (fixed) coils are much larger and therefore the capacitance to the screening can is different on the two legs of each channel. Also, in many cartridges, the screening can is grounded to the -ve side of one channel, so further upsetting the balance. Nevertheless, there would still be some benefit to balanced inputs on phono stages, especially for MC cartridges, yet that's rarely provided, whilst high-level line inputs (which hardly need balancing in a domestic environment) are far more frequent. Go figure that one...marketing?

S.

 

[sarumbear]

…Nevertheless, there would still be some benefit to balanced inputs on phono stages, especially for MC cartridges, yet that's rarely provided, whilst high-level line inputs (which hardly need balancing in a domestic environment) are far more frequent. Go figure that one...marketing?

That and also tone-arm and turntable manufacturers must make changes as well. That puts this in a chicken-and-egg situation.

 

[DonR]

Adding performance tires to a Model T in the jet age.

 

[AaronJ]

The lack of headroom is a real shame. I have been contemplating a Sutherland for a while now. Sutherland has been around for a very long time using basically the same circuit. The more expensive units contain better and more sophisticated parts that likely lead to even better distortion and RIAA measurements. But I suspect the overload figures are an inherent flaw in the design. If you have invested heavily into pristine vinyl there may be no better unit than a Sutherland. Unfortunately for those of us with a library full of VG and VG+ copies we may not see the benefit of such clean performance.

 

[AudioSceptic]

Exactly this. Any phono stage needs at least 20dB of headroom at 1kHz. Shure measured commercially available LPs way back when, and found that some hot LPs were cut with velocities of up to 70cm/sec. This is 14x or 23dB above the nominal 5cm/sec recorded velocity, and that's modulation, not scratches which can go higher still. This means that a nominal 40dB gain phono stage with a cartridge of nominal 5mV @ 5cm/sec recorded velocity has to be able to output at least 5V on peaks, and ideally a good few dBs more, so I expect a phono stage to output around 8V (+20dBu) without clipping.

Yes, RIAA accuracy and low noise are important, but they're trivially easy to get right, overload margin seems to escape modern designers. My own phono stages, made in the mid 1980s, can output 9.5 V (+22dBu) before clipping.

S.

I wondered how my Pro-Ject Phono Box S2 Ultra compared on this. The Hi-Fi World measurements by Noel Keywood say 9.5 V, not bad for a budget product, and I paid even less used. https://www.henleyaudio.co.uk/shop/product/viewfile?FileId=4933&ProductId=999

 

[sarumbear]

I wondered how my Pro-Ject Phono Box S2 Ultra compared on this. The Hi-Fi World measurements by Noel Keywood say 9.5 V, not bad for a budget product, and I paid even less used. https://www.henleyaudio.co.uk/shop/product/viewfile?FileId=4933&ProductId=999

The Hi-Fi article says 95mV for 43dB gain with a circuit fed with 18VDC. What is the point of the tested unit using 48VDC, the engineer in me asks, if 10dB or more headroom can be achieved while fed by 18VDC?

 

[LTig]

Not only do we have a low input level saturation at 1 kHz of just 26 millivolts, it keeps getting worse with increasing frequency (this aspect is typical).

Why is that typical? I'd rather expect that the headroom increases with frequency because the gain factor decreases accordingly. A RIAA deemphasis circuit has 20 dB more gain at 20 Hz compared to 1 kHz, and 20 dB less gain at 20 kHz.

Phono preamps using passive RIAA circuits do not profit from this gain characteristic and suffer from less headroom than would be possible which is the main reason why one should keep clear of those.

 

[AudioSceptic]

The Hi-Fi article says 95mV for 43dB gain with a circuit fed with 18VDC. What is the point of the tested unit using 48VDC, the engineer in me asks, if 10dB or more headroom can be achieved while fed by 18VDC?

I didn't spot that until now. It makes no sense, does it? It can't be simple incompetence...or can it? I mean, it costs about 4x the price of the Pro-Ject.

 

[sarumbear]

I didn't spot that until now. It makes no sense, does it? It can't be simple incompetence...or can it? I mean, it costs over about 4x the price of the Pro-Ject.

Engineering requires you to understand the system and the environment the device you are designing will work in. Or, there must exist comprehensive specifications. Unfortunately, the latter doesn’t exist and the former is lost within futile beliefs and opportunistic marketing,

We only measure audio equipments as we see fit. We don’t check them against specs. We compare one against other. Normally, devices are tested against spec.

That is the problem of the industry. There’s nothing any one person can do to change that.