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SUT shootout

Over the past six weeks I have had the chance to finish a SUT "shootout". I thought I would post my impressions.

My system config for the shoot-out consisted of the following:

TT: Nottingham 294
Tonearm: SME 312S
Cartridge: Koetsu Rosewood Signature Platinum & Benz Ebony
Preamp: Shindo Masetto
Amp: Atma-sphere S30 and Tube Audio Lab 300B
Speaker: Hawthorne Trio (Biamped Open Baffle Speaker)

Music listened to covered multiple genres (rock, jazz, classical) in both 33 and 45 rpm formats. Because of the different turn ratios of the products I used a SPL meter and tried to listen with volume at roughly 80-85db.

My subjective ranking is as follows:

1. Hashimoto HM-7
2. Auditorium 23 "Hommage"
3. Hashimoto HM-3
4. Modified EAR-834P (Upgraded parts and tubes)
5. Sowter
6. MC from Shindo Masetto (Lundahl based transformer)
7. Cinemag
8. Altec (DIY)

The good news is that all of the above are extremely musical. There were no poor performers. I think most people would be happy with any of these products on their own. It was only in direct comparison where some of the differences became apparent.

The top three (Auditorium Hommage and both Hashimoto's) were a notch above the rest because they had both huge soundstages and the ability to dig deep into the music in regards to detail. The Hashmito HM-7 and Auditorium further distinquished themselves from the HM-3 by being more nuanced and textured. The Koetsu's warm tone came across better with these top 2. The tone using the HM-3 was more neutral in character. In comparing the HM-7 to the Hommage, I felt the HM-7 had a slightly better ability to separate instruments in complex musical arrangements and had a slightly lower noise floor.

The EAR and Sowter were very good at showcasing detail and texture but the soundstage was smaller than the top 3.

The internal SUT from the Shindo preamp had the most unique sound of the group and was the toughest to grade. It had the lowest noise floor and really shined in certain types of music (intimate vocals or small scale jazz/chamber music). However, the soundstage of the Masetto (Lundahl) was the smallest of all the products and when it came to larger scale music (symphonies especially) it had a harder time separating instruments.

The Cinemag and Altec were, not suprisingly, extremely similar considering their common heritage. The soundstage was larger than the Shindo, Sowter and EAR but smaller than the Hashimoto's and Hommage. Where I felt they came up a little short was in the area of musical detail. Of these two products, I placed the Cinemag higher because I thought it was slightly quieter.

It is interesting to note that the pricing of the products ranged from a low of approximately $350 (Cinemag based SUT) to a high of roughly $5000 (Hommage). My "winner" (HM-7) is priced at approx $1600 for a finished product.

Finally, I am aware that the performance of the products in question may differ substantially with other cartridges and systems so my ranking is a subjective opinion within the paramaters of my system, room and musical tastes. None-the-less, I had a fun time doing it.
sibelius
doak
199 posts
 
Amen to the previous posts targeting the importance of the load a SUT is presenting to the cartridge in front of it. I recently acquired a K & K Premium SUT using Lundahl LL1931. It has solder sockets that allow relatively easy use of parallel resistors to precisely adjust the loading for the cartridge being used.

I was able to compare the K & K to the internal transformers on my EAR 834P (heavily modified but retains the stock transformers). After confirming that the EAR presents loading of about 125 ohms to the cartridge I made the adjustment to the K & K to present a similar load. Kevin Carter provides an .XLS spreadsheet file to be used for this purpose. What I found is that with similar loading of 125 ohms (EAR) and 122 ohms (K & K)to the my audio Technica AT33PTG the frequency balances were nearly identical. Yes, there was some difference in the sound of the two SUT, though nothing of the magnitude that I heard with dissimilar loading.

What the load matching allows, to paraphrase what others have stated, is the ability to compare "apples to apples."
Otherwise one is introducing an uncontrolled and unaccounted for variable into the "experiment."

almarg's avatar
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almarg
9,670 posts
 
To perform a meaningful shootout would first require identifying the optimal primary and secondary side load for each SUT/cartridge combination. Balancing even one such combination is a work of several hours, at least. It's also not inexpensive, since multiple sets of high quality resistors are required. I've done this for one SUT and two cartridges. It required $1,000 worth of resistors, which I've still got lying about if anyone wants to repeat it. It's not a task for the fainthearted.

Optimizing sixteen cartridge/SUT combos would take weeks (and many more resistors than I've got). Only after optimizing each combo could we begin meaningful A/B comparisons.
A question for Doug, Dertonearm, and the other experts who have responded above, which I'll introduce by saying that I have no experience with SUTs (or with MCs either, for that matter).

Wouldn't it be possible to accelerate the lengthy optimization process, which Doug has done a good job of describing, by using an oscilloscope and appropriate test record to optimize pulse response?

What would be required, I believe, is a test record that provided an riaa pre-emphasized square wave, say with a fundamental frequency of 1kHz, and whose risetime and falltime correspond to spectral components extending some distance into the ultrasonic region. Given that input signal, it seems to me that by using the scope to monitor the resulting phono stage or preamp output, and by substituting resistors until overshoot, ringing, etc. are reasonably optimized, it should be possible to get into the right ballpark much more quickly than by trial and error resistor substitution and listening. Further optimization by listening would then presumably be a relatively rapid process.

I'll add, though, that I am not aware of any test record that would seem to be suitable for this purpose. The Analog Productions test LP, for instance, and others that I have or have encountered, typically just provide sinusoidal waveforms, pink noise, etc.

Thanks! Best regards,

-- Al
gadfly's avatar
gadfly
194 posts
 
Impedance match was the main factor in choosing the CineMags for me. Using the DL103 w 40ohms, the Cinemag makes a close match at about 37ohms.

I have a switch to toggle between 37 and 150 but the 37 seems a more colorul and settled setting which also drops the level of hum in my system.

Phono preamp in use is the Hagerman Cornet2.

With this SUT and preamp I can really tell the difference between wood bodies, stylus'n and cantilevers. So for me there is enough detail in that sense.
dougdeacon
3,338 posts
 
Al, a few quibbles (it's what I do!)...

No normal cutting lathe could cut a square wave and no playback rig could trace one. You certainly wouldn't find me trying with my $4K cartridge! A square wave would be useful but perhaps it's not essential, though I have zero experience with oscilloscopes.

I believe RIAA pre-emphasis or its lack would be irrelevant. An SUT's function is to amplify voltages across all frequencies. To the extent ringing could be detected with sinusoidal waveforms, it should be detectable regardless of the incoming voltage (amplitude) at any particular frequency. Most SUT's operate before the RIAA de-emphasis anyway.

Quibbles aside, that method might well work. It would take me a while at first, since I haven't a clue how to operate a 'scope, but it might indeed be a quicker path into the right ballpark. Signal analyzer software instead of a 'scope might work too.

I stopped using SUTs several years ago, so further developments are up to you!
almarg's avatar
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almarg
9,670 posts
 
Thanks, Doug. A couple of clarifications to my previous post, which are relevant to your "quibbles" :)

By "square wave" I did not mean to refer to something that is truly square, with edges that are nearly vertical, or that even approach being nearly vertical. My reference to "risetime and falltime corresponding to spectral components extending some distance into the ultrasonic region" means that the edges of the waveform would rise and fall in a controlled, somewhat gradual manner. Since risetime and falltime have an inverse relationship to bandwidth, if those parameters were set so as to correspond to a bandwidth of say 30 or 40kHz, and if the amplitude of the signal were small, I would not expect tracking to be much more difficult than for a high frequency low level sine wave.

The point to riaa pre-emphasis would be to make the waveform that is monitored on the scope, at the output of the phono stage or preamp, more readily interpretable by the user, given that the user would be monitoring at a point downstream from riaa de-emphasis. Monitoring the signal at the phono stage input, prior to riaa de-emphasis, may be problematic due to the low signal level, and possibly also due to the effect of probe capacitance on the signal being put out by the SUT.

I vaguely recall that such test records were available way back when, from Shure among others, but I have no knowledge of any that may be available now.

Scopes are very easy to use, btw, following some brief familiarization, and, as you are probably aware, are potentially useful for optimizing some tonearm settings as well.

Basically, as I see it, the process of optimizing SUT/cartridge loading is attempting to accomplish two things:

1)Minimizing resonant peaks in frequency response, and/or shifting the frequencies at which they occur so as to make them inaudible; and minimizing overshoot, ringing, time dispersive phase shifts, etc.

2)To the extent that those kinds of effects cannot be eliminated, making them as synergistic as possible with the sonic characteristics of the rest of the system.

It seems to me that all of the effects that come into play in item 1 would be reflected in the response of the system to a "square wave" with suitably chosen rise and fall times. And a methodology like that could conceivably facilitate item 2 as well, with the waveform characteristics providing clues as to what to listen for and what type of material to listen with.
Further developments are up to you!
I'll keep it in mind. But if my Grace F9E Ruby performs as expected when I get it back from Soundsmith, I may not venture into mc's for a considerable number of years. :-)

Best regards,
-- Al
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