Advice on SUT for Koetsu Rosewood - EAR MC-4, Slagle/EMIA, other
Montaldo, I would get two of these,
https://www.sleevecityusa.com/Antistatic-Record-Cleaning-Arm-p/tac-01.htm and wire them directly into your preamp. There is no way you can do better at near the price. These are truly giant killers. Mike |
Dear @montaldo : I can see that along your other thread you want a SUT and a Sota Cosmos TT and is fine with me. Now, tubes are not a favorite electronics for me but Berning is a good design and Jensen transformers are good ( many phono stages and SUTs use Jensen. ). Adding a SUT means adding additional input/output connectors and the IC cable and the cartridge signal must pass for all these additional links where at each link that cartridge signal is degraded and lost quality level and music information. If I were you ( that I'm not. ) my first move will be to rewire internally the Jelco tonearm along a change of headshell better quality wires and my second step could be change the Koetsu cartridge and maybe better IC system cables. All these before other " moves ". I assume that you are looking for a better system/room quality level performance. If after " my advise " you still want the Cosmos then go a head but not before. Well, that's me and only an opinion. Regards and enjoy the MUSIC NOT DISTORTIONS, R. |
Yes Montaldo, Excuse me. Not sure what happened. Here is the right one.
https://www.sowter.co.uk/specs/1480.php This is the version that is specifically meant for your cartridge which has an impedance of 5 ohms. Notice the Bandwidth is higher. I have put these in ARC PH 3s for extremely low output cartridges and the results have been excellent. Any of the great cartridges will work with them, Air Tight, Lyra low output, Ortofon Anna etc. Wiring is simple. Just put a dab of silicone anywhere you have some real estate inside. Press the transformer into it and let it sit over night. You could add a soldering terminal to make the connections but you could also do wire to wire connections covering them with heat shrink tubing which would work just as well. Mike |
Mike: It never occurred to me until I read your post but maybe I could replace the Jensen Transformers in my preamp. or maybe you are suggesting just adding these if there is room? I don't understand this stuff well enough to do it myself but I have a local tech who could help. I will look at the link you sent and greatly appreciate the idea. Since the preamp has stepups could I simply upgrade the transformers? This would be amazing because I could buy the best available and make sure they are tailored to Koetsu Rosewood. Are the ones you suggested the best your know of the best for the Koetsu, in your opinion? Raul: thanks so much for your thoughts, but I am a tube guy until I die. I have listened to plenty of tube vs. Solid-state components over 35 years and theoretical arguments just don't sway me any more... I like the way tubes present music and I am not necessarily looking to reproduce what the engineer intended, but rather to create the feeling in me that the musician intended. (An admittedly intuitive endeavor!). For these reasons I love my Koetsu Rosewood signature and have no plans to change that one! But I totally respect your superior knowledge of the technology and appreciate that you took time to suggest things for me! |
I like Luxman toroidal silver SUTs AD8000 from the 70's, they are great, 3 different SUTs made to cover all cartridges, i'm using TYPE-8025 and 8030, to chose one you need to know your cartridge impedance (not output). There are many more amazing SUTs from the 70's/80's and all of them are normally much better priced compared to new SUTs. |
Raul I was only reacting to your suggestion of getting rid of my koetsu cartridge and your comment about tubes to the other poster. I think our respective objectives in this Pursuit might be very different. but again I really appreciate you taking time to offer suggestions! Keeping the burning preamp and changing out its step-up Transformers might be a great route for me. I know from trying the Hashimoto step-ups that there is quite a bit of Dynamics missing that I might contribute to a possible mismatch between my cartridge output and the Transformer windings. if you think I am missing something here please let me know. |
Talk to Dave. I have his lcr and Avc stuff. You are a tube guy and obviously know what real music sounds like. Have him build it you can swap out load resistors. Then you can find tune any carts you have or will get in the future. Also the copper , for you , might be a better fit than silver. General rule silver little more detail , copper more body. Enjoy the ride Tom |
I have loading plugs and settled on exactly 100hz after listening, coincidentally. So 64 dB is enough, eh? Hmm. Could it simply be that the Jensens are not nearly as dynamic as the hashimoto hm-7 suts? The difference was not subtle. Also, my previous preamp, a Thor TA-1000, was more dynamic with my previous phono stage, a Joule OPS-1 with the same Jupiter copper/wax caps that are in my Bernng pre. But I liked the smooth top end of the Berning and it posed less of a bass problem in my room. |
David Berning responded to my email and corrected one small thing ... that the Jensen sut windings in my preamp are 8 to 1 ratio. But he also seemed to think there should be no mismatch between the koetsu Rosewood and these Transformers. So I'm not sure why I heard such drastic Dynamic differences between the Jensens and the Hashimoto hm7 Transformers.I feel like I still need to try something so at this point I am considering trying a used EAR mc4 or MC3 because they have choices of multiple windings to try in the same unit. I used to own at ear 834p and I do like the house sound. if anyone knows where I might find one please let me know. There is also an Intact Audio (Dave Slagle) copper sut for sale now, but I dont know anythng about those other than the good reputation. If anyone has comments about that unit please let me know. It is a 1:20 winding and Dave Slagle told me that while is not a perfect match for the koetsu, it would probably do fine. |
Can you build any electronics yourself? A SUT is probably the easiest thing to do. Then you could try alot of different sut's on the cheap. Lundal and cinemags also have multiple windings for various ratios. They all sound different so you can play to voice it to your system. Dave's intact unit is probably great with the midrange. He built stack 57 quads with custom amps. Need I say more about Jazz/blues reproduction. The numbers do not tell alot of the story when it comes to real music. You have to experiment. From your original post you showed you are not looking for HI FI, just real music. Enjoy the ride Tom |
I have a few Koetsu Platinums, and I know for sure I prefer them with higher ratios/gains to bring out the dynamics - 30x SUT or an active stage with 69dB or more seems to be ideal. I know this is higher than the usual recommendations. I wouldn't even bother trying an 8x SUT. I’m actually currently using the HM-7 with my Blue Lace and love it, but I kind of get what you say about its "larger than life" presentation. I prefer it slightly to my EAR MC-3 (I use it on the 30x / 4 ohm tap), but I really like that SUT too. You might end up preferring the EAR, but it’s not much more laid back in the treble if you’re looking for that. The Koetsu SUT might be more your style as it’s more laid back overall, but they’re hard to find, and currently I do prefer the more dynamic presentation of the HM-7 and EAR. |
Montaldo, it looks like you are facing a trial and error situation. Trying to audition all this stuff is virtually impossible. If it is a higher step up ratio you are looking for the Sowter 9990 unit is 1:20 for 1-15 ohms. They cost about $100 and you will need two of them. Not crazy money at all. The risk is that you might overload your phono stage. If so, you could just put a resistor in series with the secondary. But if you have used a 1:20 transformer and there were no problems you should be all set. I prefer the transformer be internal. I think there is less noise and you don't have to mess with interconnects and two more connections in line. |
Tom: I am a pretty handy guy with most things except Electronics. I'm just terrible at soldering. But I have a local Tech who is great. Good to know that Dave units tend to be good in the mid-range because that's my highest priority. Mijostyn: yes I expect this will be some trial and error. When people talk about overloading the preamp is it possible to actually do it damage, or is the overload more a sonic artifact that is not helpful? I only tried the Hashimoto for about an hour in my system and I'm not sure if it was set for 15x or 30x. I certainly didn't hear anything negative in terms of an overload. |
Dear @montaldo : """
I think our respective objectives in this Pursuit might be very different. """ Could be you are rigth. My overall room/system target ( main target. ) is that what I listening through it be stay nearer to the recording. Then my quest is to acieve that target that puts me nearer to what the recording microphones pick-up that puts me nearer to the " real music " ( it's imposible to mimic live music experience in any room/system. ). For that can happen the room/system must be a very high resolution one and at the same time with very low distortion levels at each singhle link in the room/system audio chain. That is true HiFi, not what refferd Tom. Now, in " paper " those Jensen are very good transformers and for many years Jensen was and is a reference in audio, several high end manufacturers use it: https://www.av-iq.com/avcat/ctl1642/index.cfm?manufacturer=jensen-transformers&product=jt-347-axt I know that numbers does not say all but are important. Hashimoto as other transformers are good too but in the case of the Hashimoto and due the way of thinking of the manufacturer amybe just maybe what you are listening trhough it more than a real an better " dynamic " characteristics against the Jensen in your Berning been only a different kind of distortions not only because the SUT but because the additional IC cables and connectors. I think that way because you said the differences for the better is not a tiny one but something important. In the other side, through the years you owned the Berning and after the burn-in time the quality level performance of that unit changed in any way? Because could be too that through the time something " degraded " the Jensen performance as " cold " wire solder down there ( with so many wires. ) or even one de-soldered. It's imposible to figure out what is happening in your room/system because no one here already had your experiences betwwen the Berning and the external SUT. Btw, @mulveling the KRSP ( that I owned. ) is way different to the Koetsu OP model. The KRSP output level is 0.2mv and the OP is 0.4mv. As a fact both models only shares the Koetsu name because the quality level performance is way different in favor of the KRSP. R. |
I have only owned the berning preamp I have only owned the berning preamp for 2 months so this is not a change that happened over time. I I think I may have mentioned that my time with the Hashimoto sut was very limited but the impression of dynamics differencess was pretty stark. the interconnects I used with the sut were the exact same that I using the rest of my system, so well every interconnect adds some sort of flavor or distortion, I don't see it dition of one more as possibly creating the difference I was hearing. |
My system is a Koetsu Rosewood Signature (.4mv), Jelco 850M on a Sota Star Sapphire, Berning all-tube bespoke capacitance coupled preamp (46 dB gain on the MM stage, Jensen transformers on the moving coil stage), Quicksilver v4 monos, Verity Audio Pafisals.Jensens are some of the very best SUTs made anywhere at any price. They are Jensen JT-347-AXT Step Up transformers (1:12 ratio configured). Given these and overall MC gain of only 64dB, does this explain my lack of dynamics with the Koetsu Rosewood Signature (.4mv)?@montaldo -And that is one of the best that Jensen makes. Now there are some things you should know about when you use an SUT and this applies to all of them: SUTs need to be loaded correctly in order to perform correctly. Not to go into it with too much depth but transformers have an input side (primary) and output side (secondary). If they are not loaded at all, the inter-winding capacitance comes into play and the transformer will not have proper bandwidth- it will look like a flattened bell curve. If the transformer is loaded too heavily, the output will be rolled off! The cartridge itself doesn’t need any load if an SUT is employed! IOW **never** attempt to load the cartridge if a Step Up Transformer is in use!! Instead, you load the output of the transformer, and the correct loading values change depending on which cartridge you are using. Again, this applies to all SUTs. BTW cartridge loading is a different topic but in a nutshell for this conversation the impedance of the cartridge is what is requiring the loading of the SUT to change depending on the cartridge. Now in the case of Jensen, they’ve sorted out what the correct loading values for most cartridges actually are (including the Rosewood Signature). If you contact them they can advise you on the proper loading the JT347. You’ll have to talk to David about how to install the loading in the preamp. Seriously, the Jensen is excellent! But to unlock its performance you **have** to pay attention to proper loading, and this will be true no matter what transformer you use!! |
Thank you Atmasphere! the Berning preamp has loading plugs for the moving coil section but if I understand what you're saying correctly those are for the INPUT side whereas you think the Jensen transformers themselves may need loading on the output side. Is that correct? If so it sounds like I should contact Jensen and ask what kind of loading should be added to mate with the koetsu Rosewood signature. Since the consensus is that the Jensen Transformers are excellent and the 8:1 winding is not a huge mismatch, this output loading is a hypothesis that might explain what I was hearing with the Hashimoto transformers. So maybe the Hashimoto simply had a better loading match and weren't necessarily superior sounding. Maybe is a road to fixing this. |
I like to add as little gain as possible. My phono/pre has a LOT of headroom, right on the edge of using no boost at all (accomplished with multiple devices in parallel). For many records, that is sufficient. For some, the Lundahl is useful, and easily the best I’ve tried (includes Koetsu’s own, Hashimoto, and Sowter; but not Jensen). The 1931AG adds the least gain. That would be my suggestion for a KRS. The fine fellows at K&K Audio (no affiliation, just a satisfied customer) are very good guides - talk to them about your system. So is Mr. Lundahl, a gentleman of the first water. If you can’t afford the silver, I’ll bet the 1931 with copper windings would be better than anything else you could buy - but remember, SUT’s don’t wear out. You only buy them once. |
montaldo, You can try contacting Isao Asakua of Hashimoto, he can help you in getting the right transformers for your application. Isao Asakura, support@obsinc.us. I was going to go with Hashimoto SUT’s myself until I found a pair of MU Audio SUTs, they have Stevens and Billington transformers inside. The Hashimoto are excellent, definatly superior to the Jensen’s, and the MU audio are better still. If you have to add loading its going to drop your gain and degrade the sound. Better to avoid that if possible. If you have a good tech, he can install the Hashimoto’s in your phono pre if there is space and you are good to go. |
Thank you Atmasphere! the Berning preamp has loading plugs for the moving coil section but if I understand what you're saying correctly those are for the INPUT side whereas you think the Jensen transformers themselves may need loading on the output side. Is that correct?I can't speak to the Berning as I'm not familiar with its innards but to the last question, any and all SUTs should be loaded on the output side and the cartridge should never be loaded at all since the SUT is doing all the loading via its ability to transform impedance. So when its loaded correctly (with the cartridge at its input) there is simply no need to load the cartridge. As an additional note, cartridge loading is for the benefit of the preamp not the cartridge. If the preamp has good RFI immunity no cartridge loading will be needed. When the SUT is used, it blocks RFI generated by the cartridge inductance and tonearm cable capacitance, so no need for cartridge loading. Clear as mud? An additional note: the amount of gain you ask of a transformer also degrades its performance. So the least amount of gain you get from it will always be the best. Also, if you use a different turns ratio the correct loading will change. Until you are able to sort out this loading issue, its quite pointless to compare transformers!!! Some transformers are designed to be fairly well loaded when presented with a 47K load and a nominal cartridge resistance, others are not (IMO Jensens fall into the latter category; they assume that you are going to pay attention and get the loading right). In a nutshell you would then be comparing apples to oranges. Any SUT comparison needs to have the SUTs on an even playing field; both need to be properly loading which will not be the same values! The transformer manufacturer should **always** be able to to supply you with the correct loading values (which will usually be a combination of a resistor and capacitor). |
Ralph, you would think the transformers would be designed for a 47K load which is pretty standard for MM phono stages. If not 47K how would you figure out what it was? Just a meter? Also why the capacitor. Wouldn't just a resistor do? I know you might have to change capacitive loading for a MM cartridge but why the transformer? Mike |
Mike the the formation so far has been confusing at best. You might be best served talking again to Dave at intact and call Kevin at K+K audio. The ratio of the step up is squared then divided into the 47,000 resistor. So 10 to 1 is 10x10=100 then 47,000÷100=470. So the cart is seeing a 470 ohm load. There are ways to parallel resistors to lower that value but not increase it. The cap is use if you want a zobel network. Some guys like others do not. If you really want total control with step up ratios and cart loading you need have your friend bypass the 47,000 and play with various resistors externally. Then when have what you want you could replace the 47k with the new value. If you sell the phono stage latter you could put back the 47k. Without total control of the step up and loading you never really know what your cart is capable of. And of course the transformers also have a sound of their own. Maybe Dave or Kevin will build you a sut box that you can plug in different resistors and easily change step up ratios. Then bypass the 47k in the phono stage and you are good to go. Enjoy the ride Tom |
Ralph, you would think the transformers would be designed for a 47K load which is pretty standard for MM phono stages. If not 47K how would you figure out what it was? Just a meter? Also why the capacitor. Wouldn't just a resistor do? I know you might have to change capacitive@mijostyn They are designed for 47K, but any transformer designer worth his salt knows that the transformer isn't going to work perfectly with that- and that it will also change depending on what cartridge is used. IOW they know that it has to be loaded correctly (if they don't, they are leaving performance on the table). The capacitance has to do with the fact that you will likely get a peak somewhere that might not show up from simple ringing of the transformer with a square wave. @montaldo If you don't get the transformer loaded correctly, you will hear differences but they won't tell you anything about which transformer is better! On top of that 20:1 is very different from 8:1. To get to the right loading values for the transformer you have to talk to the manufacturer of the transformer. The only way I know to do this empirically on the bench is to apply a square wave in series with the cartridge and look at the output of the transformer on an oscilloscope and vary its load to get a very slight amount of overshoot. The problem here is that the capacitance of the tone arm interconnect cable is a variable, as well as the capacitance of the cable at the output of the square wave generator, and you run the risk of damaging the cartridge by deguassing it. This is why I like working with Jensen, as they have demonstrated over and over again that they know and care what they are doing. Most SUT manufacturers can't tell you how the unit works with every cartridge out there. |
Ralph, I will ask Dave Slagle what he thinks about my setup and loading. The original sound tradition Hashimoto hm-7 I tried had an even higher winding ratio such as 1:30 I think. It sounded pretty amazing with 29dB gain. But it was a little too big and "in my face." This will be 26 dB on top of 46 dB of my linestage, which seems reasonable. As fas the loading issues I still don't understand all those variables so I will continue to listen to you guys and talk to Dave Slagle as well. |
@montaldo I have a diy SUT with Jensen AT 347 trannies. These can be wired for 8:1, 12:1 and 24:1 gain. I run a Dynavector XVT-1s at 24:1 into the MM of a Zesto Andros 1.2 phono pre. You might want to ask Berning if your trannies can be rewired to 12:1 which should be enough of your cart's output.. That being said, not sure what is the MM gain of your unit. If you go to the Jensen site, you can see the schematics for the three different gains. The loading will not have that much impact on gain but it definitely helps to experiment as it relates to the sonics. I used the zobel circuit that Jensen recommends for the 347 at the gain used. |
Barolobrain: Firat of all you may need to explain your username to me (expiring minds want to know). Second, I did not realize these Jensen Transformers had optional configurations. If I could have mine required to 1:12 or 1:24 that would be interesting to try. Is the procedure difficult or could any tech do it, with insrtructions from Jensen? |
Name came from a big night out when I lived in London and we were drinking Barolo wine. As long as the leads have not been cut too short it can be done. How easily is something you'll have to determine. Go to their web page and there are three docs, one each for 8:1, 12:1 and 24:1 ratios. There is also a doc for the zobel networks, dependent upon single ended or balanced configuration, step up ratio and internal impedance of cart to be used. I don't remember if that doc is on the website. Good luck. |
