Mike: Did you paste the wrong link in your post?
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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!
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I just found the info on my preamp's internal SUTs. 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)?
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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.
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Yeah I lean toward copper not silver, though I am sure there are always exceptions. I cant drop $2400 though so need to either find a used standalone sut or replace the suts in my preamp.
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I sent an email to David Berning to see if he would potentially advise.
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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.
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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.
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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.
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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.
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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.
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Again my ignorance raises its head, but would the ideal windng ratio for the non-platinum be different? I believe the impedances are the same but the output is .4mv for mine, not .3mv (platinum). I imagine the answer is yes as long as there would be "enough" overall gain?
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After after all our exchanges, which I appreciate so much, I decided an experiment might be useful. So I am buying a used Intact Audio 1:20 copper SUT to just try and see how different it sounds from my internal 1:8-ish Jensens in my Berning pre. I will report back this weekend.
Stu
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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?
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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.
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Reporting back on the effect of adding Dave slagle's 1:20 Copper SUT to my Berning pre and Koetsu Rosewood Signature. In short, everything is back. The gorgeous tonal balance and graceful top end of the Bernng remain, but now all the Dynamics have been restored and the engagement and involvement is stunning. the difference is not subtle. it's as if every component of system were upgraded.
am I am I right that this huge difference can be attributed to some sort of better loading match between the Transformer and the cartridge? and maybe it is aided by the additional gain but not primarily driven by that?
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There was definitely some luck involved but it offsets all the times I have been unlucky with equipment failures, red herring issues, ghosts, phantoms, and just pure stupidity! All the fun of music and audiophilia.
I would like to understand why this sounds so good, but I can live with not knowing in this case and just enjoy the music. It is a real luxury to have all you guys willing to share knowledge. Thanks to all.
Stu
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