I had Ned Clayton Cinemag 1254s for a while and it was pretty close to my Hashimoto HM-7s. The 1254s are a couple of steps down from Bob's SKY.
Now I'm running some James Audio SUTs that I got for half the price of the Hashimotos and I'd be hard pressed to find a significant difference.
I think over the $500 range for SUTs and the diminishing returns start. I go for gain and how it fits with my phono stage; you don't want to overload it. You can also try to match the cart load, but I don't really pay attention to all that.
Hum is a matter of placement and sometimes cables for me.
There's a good thread on SHF on SUTs under a $1000.
Hard to believe that Rodgers doesn't use some better SUTs or maybe proprietary ones, then again my Modwright uses inexpensive Lundahls mainly for the low gain and to hold costs down.
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@theflattire this is super useful information. As I said, I'm using some crappy found interconnects to go from the SUT to the phono. I have some better shielded low capacitance cables coming soon. Maybe those will solve the hum problem. Seems like Ned Clayton is on vacation based on his eBay profile so I'll check back after the holidays. Wondering about those James audio SUTs though. I found some straight transformers online but not mounted in a box. They don't appear to be octal but likely a couple different set of turns so more connections. Did someone make a box for you or did you find one already put together?
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They came mounted in a chassis; the listing said it was a custom job for an audio shop.
Didn't like the long wires so decided to re-do the chassis.
I decided to wire up all three taps, 3, 24, and 40ohm so I put them in a box I made with stuff I had around.
Here it is before the other RCAs came in.
James Audio was supposed to have workers from the former Tango or Tamura companies and DIY folks liked their trannies.
I saw the ones in Italy with four taps; that might make a good project.
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@rmdmoore A VAS Cartridge as you are investing in, is a bespoke built Cartridge. It is being produced by an individual who's reputation is recognised for both Cart' Overhauls and Scratch Built Cart's across the Globe.
Taking time for selecting the SUT or Head Amp to support it in use will be a worthwhile experience.
Adding to your considerations for a preparation, the general consensus is to keep connecting cables between the SUT / Head Amp and Phon', as short as possible.
As you have made known, the PA 2 has a inbuilt SUT used in combination with Tubes.
My experiences had with both owned and loaned SUT's and Head Amps is that the SUT can create a range of effects to impact on the perception of the Tone being produced. The SUT depending on model in use, can be perceived as creating an increase in Richness, ranging from a subtle influence, through to a very noticeable Bloated bottom end of the frequency range.
I have less experiences with Head Amp Models, and from what I have experienced, I am able to describe the effect of the Head Amp as being much more transparent as a influence in a comparison to a SUT. A Head Amp's influence in relation to certain SUT's could be described as the Anti Thesis of such models of SUT.
All the above is based on my experiencing a variety of Models/Designs in the home system.
The Company Sculpture A has a range of SUT's, that are offered with a broad range of winding ratio's. I have been demo'd a few Sculpture A SUT's in a system I am very familiar with and one that shares similarities to my own.
On the day of the Demo's a Sculpture A Copper and Silver Winding SUT was loaned for the experience. The Copper Winding was a perfect match for a 0.2mv Cart', which is the resident Cart's output.
The impact this SUT had on the system in comparison to the resident SUT was quite something, the transformation of the sonic has been notable and well worth making known to others.
The Silver Winding SUT was more aligned as a match to a 0.5mv Cart', but was still able to off something quite special and as well notable for what it could present.
I am left with two questions, as new to me electronic encounters had been had.
1, How much does the Cart' matching offer to create such an impressive demo'. In general this will be the suggestion that will be off the most importance
2, How much does the use of a Nano Crystalline Core Metal add to the impressive sonic produced. As it is not a commonly experienced material in use, it is difficult to tie this one down.
The overall outcome is that, Sculpture A SUT's are devices on my short list to be a home trial.
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Ortofon makes great SUTs at very reasonable prices. Most SUTs are severely overpriced. If you are good with a soldering iron. Sowter Transformers of England makes first class naked transformers which can be mounted in their own chassis or better yet inside a phono stage or preamp ( no interconnects!)
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I got my 1254's as apart of a Group Buy during COVID. The report was these were Hand Wound Versions due to the workforce being very limited. I got these for approx' $300 shipped to the door. The final build was approx' £400 inclusive of Pure Copper Low Eddy RCA's used on the chassis.
The Hashimoto SUT built to a very similar Spec' was short of £500
Both prices are in keeping with the monies the OP is considering, It is not known if a from scratch build is something they would consider.
My encounters with Pure Copper Low Eddy RCA's in use, is generating the notion making the use of such connectors is a must for any DIY Builds or Upgrade Works undertaken.
To get the full benefits, Cables used with the Chassis Mount Low Eddy RCA's are noticeably better when terminated with Low Eddy RCA's as well.
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Can you boil down your questions to two or three sentences ?
The only thing I’m sure of is DON’T replace a 12AX7 with a 12AU7.
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SUT (they are tricky, I got help here, did research, scratched my head, learned this).
Consider selected and future MC cartridges when choosing a SUT (or phono stage with MC):
You need to know both the cartridge’s signal strength AND it's coil's impedance to know what range of xFactor (enough but not too much gain) and that xFactor’s resultant impedance (that will be shown to the MM Phono Input).
Thus you want a SUT with several options of gain (xFactors) AND each of those xFactors give a RESULTANT impedance that will go to the Phono Stage's MM input (separate or in a Preamp).
Some equipment has independent options for gain and for impedance, they usually cost more, but are needed for some MC cartridges with signal strength/coil combos that need that separate adjustability. Best flexibility for unknown future cartridges.
…………………………………
FORMULAS
GAIN = xFactor = +____db.
xFactor squared = _____?
RESULTANT Impedance ‘shown’ to MM Phono Input _____?
47,000 (common MM phono stage is 47K) divided by xFactor squared ____ = impedance shown to the MM phono input (check your equipment’s MM Phono Input impedance, some not 47k)
The guidance for impedance shown to 47,000k is cartridge coil impedance __ x10.
……………………………………
example: for current and future MC cartridges (including my friend’s cartridges we listen to here): I chose Vintage Fidelity Research FRT-4 to get PASS and 4 optional xFactors and their resultant impedance
Some/this SUT’s face numbers are confusing, I had to find the specs to know what the face settings meant: how much gain/resultant impedance shown.
PASS (for MM or High Output MC) bypasses transformers, unchanged signal to MM input
Face 3 ohm = xFactor 35.84 (+31db). 35.84 sq = 1,284. 47k/1,284 = 37 ohms shown to MM input
Face 10 ohm = xFactor 20.68 (+26db). 20.68 sq = 428. 47k/428 = 110 ohms shown to MM input
Face 30 ohm = xFactor 18.27 (+25db). 18.27 sq = 333. 47k/333 = 141 ohms shown to MM input
Face 100 ohm = xFactor 10.55 (+20db). 10.55 sq = 111. 47k/111 = 423 ohms shown to MM input
Luckily for me, it also has 3 tonearm inputs, front selectable.
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this shows it (ding in face panel) (price a bit low due to that)
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Entre ET-100 is similar (black or silver)
Other SUTs with flexibility can be found
IF you or anyone wanted a New MM/MC Phono Stage with Options, Project makes several among other companies
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Simple right? It is, AFTER you have the chart of answers!
SUT Info Charts I gathered
Chart 2: Cartridge Column: my AT33PTG/II cartridge’s 0.3 mv signal strength and 10 ohm coil impedance is shown just change it to your cartridge’s numbers
When Considering a SUT or it’s setting: I start with Impedance shown to MM Phono Input, then check which xFactor ____? gives that result. Enough or Too Much gain?
The Bottom of Chart 2, Right Column: select the impedance ____ ? you want shown to the MM Input (guidance: cartridges coil impedance x10)
then go left, see if the Gain in DB of that xFactor is ENOUGH or TOO MUCH.
........................
Note: Calculated Signal Strength: Allow for a bit of loss, I just guess a little lower
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Ortofon T30 SUT
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You could do worse than ask Steve Leung whether his VAS transformer would suit your cartridges. I have the MkI version (there is now a MkII) and I have four low output cartridges feeding it through a switch (LP-S, Ruby 3 mono conversion, Ortofon Kontrapunkt C and a Soundsmith Sussurro MkII ES - the last is a low output MI cartridge). I'm very happy with it, even if I don't begin to understand how to calculate whether it is the "right" SUT for any of them.
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Good point on asking Steve Leung, there @Dogberry. I also would not underestimate the N Clayton builds- I needed something not spendy for my vintage system based on old Quads and was using a VAS Franken-Denon cartridge Steve put together. Clayton may be taking a few days off for the holidays- but offers blue Cinemags, as well as vintage transformers. There is also a guy on SHF who custom builds some old stock Altec Peerless- he used to work at Altec and had a stash.
I remember first looking at SUTs years ago when I was still running an ARC SP-10 --it had gain, but the preamp was notorious for microphony. At the time, I was trying to find the elusive Expressive Technologies unit- no go.
I use an Allnic phono with built in SUTs on my main system- readily adjustable with the turn of a knob. I like that feature-there are differences in sound based on the settings. My dumbed down approach is to look at the internal impedance of the cartridge and multiply by 10 for the load seen by the cartridge. The secondary (or output) from the SUT will be 47k.
On the cables, I do use the high end spread in the main system, but on the vintage system, use Analysis Plus -- well made, cost effective, and suitable for a system of that period.
Good hunting.
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What has always boggled my mind is that SUT manufacturers so rarely publish the turns ratio(s) of their products. Which would make it very simple indeed to at least begin to match a SUT to a particular cartridge. Instead, and especially in the golden era of vinyl, most SUTs were given a value in ohms (see Elliot’s compendium above). Typically, the value in ohms is meant to indicate the recommended internal impedance of the cartridge to which you want to match the SUT. For example a "3 ohm" SUT is meant to be used with cartridges having an internal impedance close to 3 ohms (probably 2 to 5 ohms cartridges would work). It also means that the turns ratio of that cartridge is such that when mated to that group of cartridges will result in an acceptable ratio between the internal R of the cartridge and the input impedance that will be seen by the cartridge when using that SUT hooked up to the standard MM stage with a 47K ohm input impedance.
The turns ratio is equal to the voltage step-up ratio. A SUT with a turns ratio of 1:10 will increase the output signal V of the cartridge by 10-fold. Etc. The resulting impedance seen by the cartridge will be equal to the input Z of the phono stage (47K ohms) divided by the square of the turns ratio (100, in this case). So the cartridge sees 470 ohms (47,000/100). Since you want the ratio of the internal R of the cartridge to be about 1/10 of the input impedance of the phono, you can see that any cartridge with an internal R of less than 47 can drive a 1:10 SUT. Nothing explodes if you break the rule of thumb. The actual loss of gain and high frequency response that occurs when the match gives you a ratio less than 1:10 is on a continuum, losses get gradually worse as the ratio approaches 1:1. At a ratio of 1:1, 50% of cartridge output goes to ground instead of driving the phono stage, and there is audible loss of HF response, due to input capacitance.
Back to our "3 ohm" SUT. A theoretical cartridge with an internal R of 3 ohms can drive a net 30 ohm load before you cross the line of the 1/10 rule of thumb. In order to create a 30 ohm load, you just have to work the formula for the load seen by the cartridge backward. I calculate 1:40. A cartridge with a 3 ohm internal R can drive a SUT with a step-ratio (voltage gain) of 1:40 into a 47K load, if you want to rigidly obey the 1/10 rule of thumb.
By the way also, an ideal SUT or any transformer does not have an impedance per se. Transformers merely reflect the impedances from secondaries to primary windings, or vice-versa. I wondered that Elliot mentioned there are SUTs that let you choose both voltage gain and impedance. That can only be done if the SUT has built in resistors typically across the secondary, which would be in parallel with the standard 47K load.
Whart, you wrote, "My dumbed down approach is to look at the internal impedance of the cartridge and multiply by 10 for the load seen by the cartridge. The secondary (or output) from the SUT will be 47k." In your first sentence, I suppose you mean that you multiply by 10 to determine the (minimum) load that should be seen by the cartridge. I agree. In your second sentence, you may be confusing others. The secondary is connected to a 47K standard load at the input of an MM stage. The SUT acts on that impedance to reduce it as seen by the cartridge, in proportion to the square of the turns ratio of the cartridge. I am guessing you know this but there is a semantic disconnect in what you wrote. I point it out only so others will not be confused.
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4 lines from the bottom of my post I wrote “in proportion to the square of the turns ratio of the cartridge “. I of course meant “in proportion to the square of the turns ratio of the SUT”.
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Thanks for all the input.
@lewm I know subbing 12au7 for 12ax7 seems off but the amp is designed to take 12au7, 12av7, or 12ax7. Each has increasing gain but also increasing noise so if I can get more gain out of the transformer then maybe I can use a quieter lower gain tube.
@dogberry I had asked Steve what I should get and he was kind of elusive. I named a bunch of different things including an Entre, and an FRT thinking to myself that this isn't technology that's changed a lot so maybe an older high quality adjustable one would be good. He said "they're too old". He told me to not get a bobs devices. I'm wondering if he was trying to lead me to to his own one that I had somehow not realized he makes. Also, what switch are you using? I think that the higher gain SUT might sound better enough that I'd want to use it for both cartridges. I did text Steve and ask him if his SUT would be a good choice but I'm yet to hear back as it's Christmas.
Overall, it seems to me that with a 6ohm internal impedance what I want is an SUT with more turns, probably 30 or 40, to better match the cartridge. I think that will produce more gain that what I need with the 12ax7 so going back to 12au7 and letting the transofrmer do more of the work is gonna be the answer.
Thanks, everyone. This has been incredibly informative. Any addition thoughts are appreciated.
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@rmdmoore I use a SoluPeak 4-way switch from Amazon. I can’t tell the difference with it in circuit, or connecting the tonearm directly. If you want to just run two carts, there is a Rek-o-Kut switch that also seems very quiet. I have a couple of them from previous iterations of tonearm numbers, which seem to grow and grow! I’d recommend the 4-way, though, as it lets you add two more! The cartridges have internal impedances of 38, 38, 10 and 5Ω. I don’t know what the turns ratio of the VAS transformer is, and you’re correct, Steve doesn’t push it. Basically, he said your ears will tell you if it’s right. If you can get him to reveal the turns ratio, please let us know.
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Might as well ask this audience... What phono cables are you using? I don't want to go crazy. Found some on eBay that look fair, low capacitance with good shielding.
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My Phono system already sounded great, with ’regular’ phono cables.
When I bought my long tonearm, the Russian maker almost insisted I use this Ortofon
That TT, I had been using a basic cable from Amazon while waiting.
I heard ZERO difference, I used two ’upscale’ din cables that came with my other two tonearms. Plugged
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Audioquest Fire w DBS to keep the dialectric formed…more important on the tonearm cable…. in my opinion But any AQ interconnects w DBS used should be on your list.
OP your wife is a saint…. just saying…..
when selecting said, choose one with a ending result of YES on the turns ratio…..
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Don't get too caught up on loading. I don't unless there is a huge mismatch.
MC carts don't generally react to capacitance so I don't worry about that either.
I use DH Labs Pro Studio cable hard wired on my VPI terminated with AECO RCAs on the other side.
Thinking about going to solid silver.
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@lewm- no disagreement w/ your clarification of my wordage. Thanks.
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@tomic601 you are correct sir. My wife is an absolute saint. She mostlybsupoorts my hobby and doesn't ask too many questions. She even used the turntable sometimes!
@elliottbnewcombjr was that TT set up with a SUT? I'm definitely getting more hum with the SUT and I'm attributing some of that to one of the cables in usong being crappy and picking up a lot of hum. Could be placement of the SUT but when I picked it up and moved it around it didnt seem to change much.
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Yes, I posted a photo of the SUT I use above: Fidelity Research FRT-4
Zero Noise at any setting, or arm selection.
My friend had some hum, Steve at VAS diagnosed it, the Grado cartridge that came with the Vintage JVC Turntable was the cause. He said MANY Grado's Hum. My Grado Mono (using PASS thru the SUT does not hum here.
My friend changed to a different cartridge on a spare similar headshell, nothing else, hum gone.
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One of the advantages of a SUT with multiple tonearm inputs, is you do not change the output cable or which preamp's input, it sends any selected arm out to preamp or phono stage.
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Something wrong with the numbers
0.2 mv into 10x transformer is only 2mv signal out, that's too low for some/many phono inputs. Would cause volume controls near max, perhaps the volume control/circuit is noisy when raised so much.
10x is only +20db.
do you mean SUT xFactor 10 combined with the MM Phono gain will be 70db?
If something is great, but it hums, it ain't great.
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I have and had several SUT - and there is difference- not sure why -
I had an inexpensive Denon AU-300LC- that was thin sounding...
I use now an E.A.R MC 3 (there is a newer model MC4) which is great. Also a Dynavector SUP-200 which is still in a box but apparently also good. but I can attest firmly to the E.A.R. . the Phono is in a nu-vista Preamp with mm Phono.
Cartridge is MC Ortofon Kontrapunkt b
YMMV of course - but this is my experience
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mdmoore, I advised against replacing a 12AX7 with a 12AU7 first and foremost because those two tubes are electrically very different from one another. Upon further thought, I do seem to recall that there is something out there where the manufacturer officially OKs such a tube swap. I can conceive of doing it if there is some sort of switch that changes the load resistor and other parameters, when the user makes such a drastic change in tube types. Is that so, in the case of your unit? Do I recall correctly that you have a Bellari? The second reason I reacted so negatively is that I and many other hobbyists do not much like the sound of a 12AU7, when it is used for gain, typically in a linestage. Using a 12AU7 in a phono gain stage seems impossible; you would get very little phono gain, nowhere near even the 40db typically associated with MM stages. So, to sum up, the 12AU7 would be current starved in a 12AX7 socket, would result in very inadequate gain even for an MM cartridge, and would sound bad even if changes were made to the circuit so the 12AU7 would run properly. Better candidates would be 5751 (check me on the numerical designation of this tube, which is a standard replacement for 12AX7 when users want slightly less gain), 12AT7 (which also would run better if the circuit for a 12AX7 was slightly modified), and those are your best bet. There are some others in the 12A?7 series, e.g., 12AY7 and 12AV7 that might work, especially 12AY7, but the circuit really ought to be re-worked for such swaps.
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@rmdmoore When using a SUT there is a possibility Hum can occur.
One cause of this can be using a RCA Connection that does not have a good bite.
The most simple method to try to remove/ substantially reduce a Hum, is to move the SUT around in relation to the Phon' and TT. Typically a movement away from both will start to create a change to the level being heard.
As short Cables are recommended between SUT > Phon' the movement of the SUT with a short cable may not be enough to have an effective control.
It has been a very long time since I done this, but in the past have also had good success using a very small gauge earth wire to bridge across connectors on the SUT. From recollection the Bridging has been done in line and not across channels.
As for Cable selection, for quite some time now I have been an advocate of a Cable using PC Triple C wire for the Signal Path. My recommendation for RCA Connectors are outlined in a earlier post.
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@elliottbnewcombjr you got it. The total gain with the inbuilt SUT and 12ax7s in P
place is 70db. My understanding is that if I place a 1:10 SUT on the MM input it will have the same.
@lewm I appreciate what you're saying and in truth, yes, I agree with not liking 12au7s in my line stage. I had a Rogue RP-7 and did a lot of tube rolling and in the end just didn't like it that much. I switched over to linestages with 6sn7 and I love them. You should check out the design of the Rogers PA-2 which is my phono stage. As I said, different tubes in one of the gain stages is how you adjust the gain of the unit. It's a pretty cool design. When I had a Hana ML cart, 12au7 were great, when I had the cadenza black, 12av7 worked well, with the current cart I need all the gain so 12ax7.
@pindac I did move it around some and the hum didn't change much. Maybe the issue is more that the crappy RCAs have loosely goosey connectors that hum some. I ordered some new cables that should have better connectors and shielding so we'll see.
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There are folks on here making blatant statements about diminishing returns of an SUT. Being an owner of some of the finer SUT's (EMIA Ag, Cotter Mk2L, Tango Silver), I can tell you definitely that not all SUT's are equal. The statements being made are of those that have systems that do not have the ability to differentiate a silver SUT vs copper or are basing it on their hunch. Don't underestimate the qualities of a higher end SUT, unless you have tried it and your system can handle it.
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I would check the specs of your phono Stage’s Sensitivity.
My McIntosh mx110z for instance, the MM Phono Input’s sensitivity is 3mv.
Signal Strength:
My cartridge’s output is 0.3mv. I use xFactor 18.27, thus signal strength to Phono MM input is 5.4mv. A bit of loss, guessing: perhaps 5.2mv, at least 5.0
Your cartridge 0.2mv x10 is only 2mv out to MM Phono input. I think too low, and perhaps the source of hum. A bit of loss, you might be getting only 1.8mv.
To find out, you could borrow a friend's SUT or Phono Stage with a higher xFactor, or order one from a source like amazon, with 30 day returns, try, keep or return.
Even if you don’t prefer it’s sound, it will tell you something about you existing x10’s involvement in the hum.
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I prefer a stronger signal than mx110z’s 3mv minimum, keeps preamps volume centered, and closer to my MM cartridge’s 5mv output.
Switching arms/cartridges, the volume is not that different. I change volume remotely via my Integrated Amp’s Volume, thus preamp’s volume never moves, except when I often swish it full left/full right a few times, to keep the internal contacts fresh, it’s a Vintage control. I also use contact cleaner on all the controls once per year to prevent noise.
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Another Chart I had found: Cartridge Specs and Recommended Impedance Load. (you need to increase your monitor's zoom to read these).
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There seems to be a lot of markup in some SUT's. Why not buy bare transformers and put them in a box yourself? More control, more satisfaction, less money.
Sowter makes good ones. Lundahl makes several grades from good to great. I've used both. The Lundahl 1931Ag is quite unforgiving. Why not email Lundahl and ask? They are very nice people, and helpful too. So with Sowter.
Good luck!
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And it might not matter if we carefully calculate the effective loading on the cartridge:
At the end of it all, if it sounds pleasing to you, it is good and you might as well be happy.
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Another thing - the higher the gain, the higher the distortion. Just something to keep in mind; don't buy more than you need.
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Dogberry, The information contained in the referenced thread from Steve Hoffman Forum echoes precisely what Atma-sphere and Jonathan Carr (two authoritative sources) have been writing on this forum for years, loading an MC (at any resistive value above some multiple of 10 or greater of the iinternal R of the cartridge) should make very little to no difference in frequency response. Yet, there are an endless number of posts stating otherwise. I suggest to anyone interested in this topic to search these archives for their words. Even below a load equal to 10X the internal R of the cartridge, where you start to get significant loss of gain, due to shunting of the cartridge output to ground, the gain penalty is very gradual as you go down from 10X to 1X (cartridge internal R = load R), where 50% is lost to ground but also there is a potential loss of HF response due to capacitance at the interface, and almost all phono stages have at least some input capacitance. The input Z does affect the phono stage in ways described by Atma-sphere.
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@dogberry In a earlier post on in this thread, I make it known how impressive the Sculpture A SUT has been as a Copper Winding and produced as an ideal match for a 0.2mv Cart'.
In the same session a Silver Winding SUT from Sculpture A that was not the ideal match, was also used on the same 0.2mv Cart', which proved to be equally impressive for different reasons for how it produced a sonic.
From all of my experiences had using SUT's, these are the most attractive I have from recollection.
Using ones ears to assess whether the interface is an attraction or not, really does seem to be the method.
I have had SUT's demo'd that are ideal matches for the Cart' in use, where there is noticeable overbearing perception of Bass Weight being produced, as well as a unattractive Looseness of the Bass Notes. Certainly not my flavour of choice.
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@elliottbnewcombjr the Bellari SUT I have now to play with has 1:30 as well and when I switch to that the hum does not go away. I really think it's cable related but can't prove that until I get more cables.
@pindac you did mention the sculpture A prior. What turns ratio did you use for a 0.2mv cart?
@terry9 I've looked at that option a little bit. There are even some premade boxes to put SUTs in online. You can buy kits from lundahl's US importer and I've thought about that as well vs getting a Rothwell from the UK with decent lundahl units in it.
Again, thanks everyone for all the input. Super helpful.
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@rmdmoore I would have to get it confirmed by the individual who loaned the SUT's for the Demo's but do believe the Sculpture A with a Copper Winding was 1:26 Ratio.
The nano crystalline core is not too commonly seen on audio, and it is this material, that certainly seems responsible for a proportion of the standout impression made.
Lundhal are offering this Core Type on some of their designs for a Tranx.
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@pindac I'm chatting with an eBay builder about building one with lundahl 1941s. The core is listed as amorphous. Is that what you're talking about?
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Not to make an already very confusing thread even more confusing, but Jensen make great step up transformers, too, at a reasonable price. And their staff of engineers are very knowledgeable and helpful to DIYers. Go for their top of the line, and you won't be sorry.
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Amorphous is not Crystalline.
The following is a bit of other forum talk on the subject.
"According to Per Lundahl, writing by email, "Choice of core material is a question of taste. Our top-of-the-line MC transformers are available with either our uncut amorphous strip core (like the LL1931) or with a conventional mu-metal lamination core (like the LL1933). As it has turned out, the amorphous-core transformer is most popular, but the mu-metal lamination transformer is still preferred by some audiophiles. In THD ... and linearity measurements, the mu-metal lamination version outperforms the amorphous core version, but in listening tests, the amorphous core usually wins."
"I asked Per to explain the metallurgical differences between mu-metal, amorphous cobalt, and nanocrystalline transformer cores."
"In true amorphous material, there should not be any crystal structure. Atoms are randomly oriented, and there is no repeated structure such as you find in most solid metals. To achieve this, the melted metal is cooled so rapidly that atoms get stuck in their random positions. ... This very rapid cooling requirement is the reason why amorphous metal is only available as thin film, about 1 mil (0.025 mm) thick.
"To achieve nanocrystalline material, special amorphous iron is carefully heat treated at very controlled temperatures. In this process, very small [nano]crystals are formed."
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I had a number of MC step-up. All of them sound completely different. Day and night difference.
I had:
1. Altec 15095
2. Altec 4722
3. Haufe T890 (the modern production, not the vintage one)
4. Jensen 44
5. Tamura TKS-83TWIN
6. Tamura MC20 (Sun Audio SAT-1000)
The worst are Jensen and Haufe. Really bad.
The best are Tamura.
Altecs are in the middle. Not bad.
If the load is too small (too high impedance) and sound is too bright you can solder the resistor (from 100K down to 15K) to the secondary of the step-up transformer. Smaller resistor - darker sound.
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@pindac I see now on the Erhard audio page the area that lists nano crystalline transformers but I don't see any that are marked as SUTs. Will have to give them a call
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Alex, your opinion is your opinion, but it is not helpful if you don't provide more information, like what turns ratio, what cartridge with what internal resistance and voltage output, and what phono stage with how much gain?
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I changed all my RCA interconnect cables to Locking Connectors. Mess with any cable, others do not get disturbed.
I got 2 sets of these video cables to make 3 pairs for audio, color coded ends, locking connectors, zero noise, great price. These are 12 ft long, I got 6 ft long, you just need to find the right length
these come various lengths, with Locking Connectors, many other choices. Remember, Amazon has easy returns if you find it is not the cable causing the hum.
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Hi @lewm ,
I used the original EAR 834 phonostage and then improved the DIY version based on the EAR 834 phonostage schematics that I built myself.
I used Ortofon Rondo Bronze with Altec 15095. Then I used Ortofon Jubilee with Altec 4722. After that I moved to EMT TSD15. I tried Altec 4722, Jensen 44 and Hauffe with EMT. Altec did not match the EMT cartridge well and Jensen and Haufe matched in terms of impedance and tonal balance was OK but sound transparency and dynamics were very bad. After that I bought Tamure 83 that sounded great with an extra load resistor. In the end I bought Tamura MC20 that was even better morey dynamic, deeper bass, bigger soundstage.
In my DIY 300B SET amp I use Hashimoto output and interstage transformers and they are great. I used James Audio transformers before that were really good, but Hashimoto gave more low level details. I think Hashimoto MC transformers should be good as well.
I heard from people that vintage Houfe transformers are magical. It is possible, but the new Haufe production is a total garbage. Jensen 44 is a bit better but Tamura is a different league.
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@rmdmoore As stated in a earlier post in this thread and in another thread very recently.
I am a user of Valve equipment who much prefers the end of a Valves produced Sonic that leans heavily towards transparent.
This has made me inquisitive and searching for items that assist with keeping the sonic where I prefer. As stated, I have been demo'd numerous SUT's across many years and state with full conviction in my system and in other systems, SUT's add Richness to the Sonic being produced.
In some cases it is a subtle underpinning of the Sonic, and at the other extreme, the sonic can be Bass Laden and very very loose in its shape and roll off.
My 'Gut Intuition' strongly leaves myself feeling the use of a Nano Crystalline Core has reduced the perception of Richness using a Copper Winding to the least I have detected it. Also the impact it had on the Cart' was quite something, the sense of effortless function and the projection of the sonic, had one feeling the system had gone through a very expensive upgrade. The system it was demo'd on has been via a Valve Phon' close to my own in use design, a Pre Amp' that shares very similar design to the Model I am having produced, EAR Valve Power Amp's and ESL Speakers. This system has similarities to my own inclusive of the ESL's.
As stated the Nano Crystalline Core with the Silver Winding that was not a ideal match for the Cart' in use, was equally impressive for other reasons. This had the most voluminous Sonic, extra pumps of Volume were seemingly added to the Soundstage. I am no stranger to this perception, but using older experiences and recollection this came at the expense of a undesirable colouration, one that is way beyond what I seek. The Structure A Silver Winding, offered all this Voluminous perception, as well as maybe being the most Transparent SUT ever heard.
Hence, this Brand is Shortlisted for Home Demo's.
It is good to see that other Companies have become aware of the value of adding the nano crystalline cores to their range and individuals like yourself have become interested in the notion of adding it to a SUT.
All SUT users, who prefer the Transparent End of the sonic that can be produced, will have to wait for patiently for the time when PC Triple C Wire Wound Tranx's are being made, to get to the next exciting level of sonic that can be created.
I'm hoping for Cart' Coils, Lead Out Pin's, Wand Wire (Already Achieved), SUT Windings to be produced in PC Triple C Wire. My World of interest in Audio will become a place with new enthusiasm to encounter such items.
Interconnects, Power Cable, Speaker Cable, Internal Speaker Wire and Internal Hook Up Wire are all uses for PC Triple C Wire that I have now experienced in use.
Internal Speaker Wire being the only device not able to be A/B compared as a Demo' to a Typical version.
PC Triple C Wire has proved as a result of Demo's to be the correct choice made as a Copper Wire.
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@elliottbnewcombjr I use WBT locking connectors, but they still need a wiggle or a jiggle every now and then to decrease resistance caused by accumulated crud. (I guess they might be gold plated but it is impure gold!)
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My question is where do I go from here? Bob's makes the sky 30 which is switchable from 1:15 to 1:30 which I like because I can play with the gain tubes in my preamp and potentially go to a quieter 12au7 than the 12ax7 that's currently in there. Will that be a real improvement?
@rmdmoore We've worked with SUTs a lot over the last 40 years. @lewm's suggestion of Jensen Transformers is an excellent one- they make some of the very best in the business at any price.
One thing you learn very quickly is that you want the least amount of step up possible so as to work with your cartridge. The more step up you go for, the more issues the transformer can introduce.
If you have 0.2mV you really only need 60-65 dB of gain if you have a regular line section in your preamp. So you should be using the MM input, not the LOMC input.
The other thing that is tricky about SUTs is loading. The loading does not affect the cartridge (other than measurably and audibly limiting its high frequency bandwidth; lewm already linked to the thread on the Steve Hoffman forum that shows what is really going on), but loading is critical for any SUT!
If the SUT is improperly loaded it will either 'ring' (distort, so adding brightness) or be rolled off if loaded too heavily. Jensen transformers has published a pdf file that shows the correct loading for their transformers when used with most known LOMC cartridges. Mot SUTs made for a specific cartridge are designed to be loaded at 47KOhms with 100pf of capacitive loading (which is about the capacitance of the tonearm cable 1 meter long); IOW they are designed to be plug and play.
But if you use a different cartridge with such an SUT the loading will be off and it won't sound right! That is one reason I like to work with Jensen since they did their homework, figured out the loading values and so their transformers work with almost any cartridge.
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@atmasphere Ralph, thanks so much for your input. Yes, the plan is to use the MM input and which has about 45-50db of gain with the current tube complement. I should really only need about another 20db which, if I understand correctly, would be a 1:10 transformer. That's what is in my unit on the MC side according to the designer. Seems like that's really all I need then. There are some good deals on recently discontinued Hafler SUTs that had Jensen transformers in them. Anybody have any experience with those?
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