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Schiit Skoll Balanced Phono Stage Review

Rate this phono stage:

  • 1. Poor (headless panther)

    Votes: 6 4.1%
  • 2. Not terrible (postman panther)

    Votes: 9 6.2%
  • 3. Fine (happy panther)

    Votes: 79 54.1%
  • 4. Great (golfing panther)

    Votes: 52 35.6%

  • Total voters
    146

amirm

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This is a review and detailed measurements of the Schiit Skoll balanced phono preamplifier. It was sent to me by the company and costs US $399.
Schiit SKOLL Phono preamp stage balanced moving coil moving magnet review.jpg

Touch controls select everything from loading of the input (resistance and capacitance) to input type (RCA or XLR), gain and filtering. A remote control is supposed to come with to let you do this remotely but my box had none in it. Back panel shows what is unusual about this phono stage:
Schiit SKOLL Phono preamp stage balanced moving coil moving magnet back panel XLR loading review.jpg

XLRs for input and output! Love that as in this day and age, most systems also have computer connectivity for streaming and that is just asking for ground loop. So even if you don't need it in a phono stage, it is a very good idea from system perspective.

Power is provided through a hefty AC transformer which provides dual voltages (24 and 5 volts nominally).

Company's marketing message is around a discrete implementation (as opposed to IC op-amps) and that enabling high voltage operation/high headroom. We will test for that.

Note that there is no explicit Moving Coil/Moving Magnet setting. You select a gain from 40 dB to 70 in 10 dB increments. For my testing I used 40 dB to represent MM and 60 dB for MC. I performed all my testing with XLR input and output. I did briefly test with RCA out but that lowers the gain. Performance roughly remained the same though.

Schiit SKOLL Phono Preamp Measurements
Let's start with our usual dashboard with 5 mv input and 40 dB gain:
Schiit SKOLL Phono preamp stage balanced MM measurement.png


I was impressed by almost total lack of mains noise and no reason to mess with any grounding as I always have to with other phono stages! Indeed grounding the unit or not made no difference at all. This is why you want balanced I/O.

Distortion is below -100 dB so SINAD is dominated by noise, ranking Skoll near the top of the class:
Best phono stage review.png


We can confirm that with SNR measurement:
Schiit SKOLL Phono preamp stage balanced MM SNR measurement.png


The phono stages at the top of the chart eek out another 5 or 6 dB of noise performance, mostly at higher frequencies.

Performances drops fair bit with 60 dB gain but that is to be expected:
Schiit SKOLL Phono preamp stage balanced MC measurement.png


RIAA EQ implementation is very good:
Schiit SKOLL Phono preamp stage balanced MM frequency response measurement.png


I like having high pass filter but like to see it not eat into audible band so much with sharper response.

Distortion by itself (no noise) is far lower than the LP/cartridge:
Schiit SKOLL Phono preamp stage balanced THD vs Frequency measurement.png


Let's test for headroom at 1 kHz:
Schiit SKOLL Phono preamp stage balanced THD vs Input Level measurement.png


Clipping point is well above average which is nice. That is offset by gradual rise in distortion however. Competing solutions haver a downward graph and then they suddenly shoot up.

Sweeping frequencies, I was pleased that performance was maintained up to 10 kHz:
Schiit SKOLL Phono preamp stage balanced THD vs Level vs Frequency measurement.png


Conclusions
The Skoll is a very flexible phono stage and I love the fact that it has balanced I/O which sharply reduced mains noise in my testing. Its discrete implementation allows higher operating voltages than some IC based solutions. Alas, distortion rises with level, likely courtesy of "zero feedback gain stages" as the company states. RIAA implementation is very good and I like the inclusion of high pass filtering. Better measured performance is available elsewhere but whether the LP format needs it, is another story.

I am going to recommend Schiit SKOLL phono stage.

Manufacturer Specifications:

Gain: 40db
THD: <0.006%, ref 4V RMS balanced, 2V RMS SE
SNR: >102dB, A-weighted, ref 4V RMS balanced, 2V RMS SE
Crosstalk: -100dB, 20-20kHz
Sensitivity: 2.85mV for 300mV output at 1kHz

Gain: 50dB
THD: <0.02%, ref 4V RMS balanced, 2V RMS SE
SNR: >90dB, A-weighted, ref 4V RMS,2V RMS SE
Crosstalk: -98dB, 20-20kHz
Sensitivity: 0.78mV for 300mV output at 1kHz

Gain: 60dB
THD: <0.03%, ref 4V RMS balanced, 2V RMS SE
SNR: >85dB, A-weighted, ref 4V RMS balanced, 2V RMS SE
Crosstalk: -95dB, 20-20kHz
Sensitivity: 0.34mV for 300mV output at 1kHz

Gain: 70dB
THD: <0.06%, ref 4V RMS balanced, 2V RMS SE
SNR: >70dB, A-weighted, ref 4V RMS
Crosstalk: -84dB, 20-20kHz
Sensitivity: 0.09mV for 300mV output at 1kHz

Maximum Output: 20V RMS balanced, 10V RMS SE
Overload Margin: >20dB
RIAA Accuracy: +/- 0.15dB, 20-20kHz
Low Frequency Filter: switchable 2 pole at 15 Hz, fully passive, for balanced XLR outputs
Output Impedance: 10 ohms

Input Loading: 10, 50, 100, 150, and 47k ohms resistive, and 50, 100, 150, or 200pF capacitive, switched via remote or front-panel button

Topology: Equipoise™ balanced, differential, fully discrete zero feedback gain stages, passive RIAA, 0.1% thin-film resistors, and 1-2% film capacitors, switchable passive CR LF filter, microprocessor oversight and relay switching, remote control

Power Supply: “wall wart” style 24/6VAC transformer, dual-filtered, regulated +45V/-19V rails, plus 5V/3.3V supply for microprocessor and relays

Power Consumption: 7W
Size: 9 x 6 x 1.5”
Weight: 2 lb

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...and there's the answer to my question. Thanks for the review. Schitt is churning out new products at quite a clip lately.
 
Very nice product to be honest. Same size as the recent preamp?

I love that the loading can be changed on the remote. Nothing more annoying than getting comfy on your coach and realizing Brothers in Arms needs a couple more picofarads.
 
It's a bit odd way of providing the needed voltage by what looks like a DIN plug? (get flashbacks to old B&O stuff) -And a two voltage external trafo. -To avoid internal PSU and noise because they want a small case?
 
It's a bit odd way of providing the needed voltage by what looks like a DIN plug? (get flashbacks to old B&O stuff) -And a two voltage external trafo. -To avoid internal PSU and noise because they want a small case?
They use these with another product, the Vali 2++.

interesting. must have quite a large stock of them.

I don't mind the higher roll off frequency, but a sharper filter would be appreciated.
 
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XLRs for input and output! Love that as in this day and age, most systems also have computer connectivity for streaming and that is just asking for ground loop. So even if you don't need it in a phono stage, it is a very good idea from system perspective.

Phono cartridges are balanced by design and balanced input phono stages are a very worthwhile addition.
 
It's a bit odd way of providing the needed voltage by what looks like a DIN plug? (get flashbacks to old B&O stuff) -And a two voltage external trafo. -To avoid internal PSU and noise because they want a small case?

24V for the analog stages and 6V (likely 5V reg) for the digital (control) stages.

Put anything digital on the same supply as a high gain phono stage and you'll hear it.
 
How do FFTs in this case affect your noise measurements? When I superimpose my Luxman LXV-OT10 over the dashboard for MM, the noise looks nearly identical with the exception of the distortion (from the tube stage).

1697346900937.png
 
How does that work, I've never seen a turntable with anything but RCA out. Does the RCA in need testing?

Some people modify the wiring and some decks can have the RCAs isolated from one another and from earth/ground so they are already wired as balanced. Obviously any cartridges with an earth strap to the body needs that removing (many are designed to be removed/installed). But the advantage really applies to MC carts.
 
Hi,
Given the high results of Schiit for DAC and HP AMp and now for this, my wish would be for Shiit to release a digital all-in-one solution with Ethernet/Wi-Fi renderer + DAC + HP Amp. All that at the Schiit price range :)
Would be a nice competition for BluSound... And maybe something better, using open standards like UPnp and DLNA instead of proprietary stuff :-(
Regards.
 
So, now we have 2 preamps with balanced outputs at a decent price tag: ifi zen and schiit skoll. Schiit have better SINAD, but, (from what I remember) I think ifi have better RIAA and overload behavior.

Schiit have standard XLR connectors, capacitance options for MM and remote control ... I think it justifies the price difference... really tough decision.
 
There are only very few turntables that have balanced outputs as standard. I also consider this connection technology to be generally superfluous in the home hi-fi sector.
The new Thorens TD 1600 has it - to show an example - and there are a few others.
20200623_Thorens_TD_1600_NB_16_72.jpg
 
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Why are moving coil cartridges considered the "better" choice, when every pre-amp measurement I've seen show you sacrifice significant noise and distortion due to the extra gain needed in the pre-amp?
 
Why are moving coil cartridges considered the "better" choice, when every pre-amp measurement I've seen show you sacrifice significant noise and distortion due to the extra gain needed in the pre-amp?
The preamp matters very little when you realize the cartridge will always dominate with its own distortion and non linearity
 
The preamp matters very little when you realize the cartridge will always dominate with its own distortion and non linearity
So MC carts are significantly lower distortion?

And noise? Or do we just say that with the noise floor of the vinyl itself, that the electrical noise of the preamp is lost below that?
 
Back in the day, having a detachable stylus assembly as in most 'MM' types was regarded as a nono. MC designs often had/have a more substantial build and mounting arrangement with everything tied together and this was judged superior. My own rather elderly MC's here don't give handling noise as some of my 'MM*' types do in the tonearm I use. I gather MC types are brilliant at reproducing cutter ringing in the vinyl pressing at 40 - 50kHz or so (according to earlier 'Choice' tests)

* I put quote marks around MM due to the various generation systems under that broad umbrella.
 
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