Does anyone have experience matching an Icon PS1 MKII with a Soundsmith Zephyr MIMC Star?


I own Soundsmith Zephyr MIMC Star LO cartridge. I am looking to purchase an Icon PS1 MKII phono pre. The PS1 uses a passive 10:1 SUT with a fixed 100 ohm impedance for the MC input. The Soundsmith Zephyr MIMC Star cartridge requires a minimum 470 ohm load. Music Direct is telling me that I should be fine. But I would be interested in hearing from someone who has experience with this actual combination. Thanks.

flash56

An update.

I take back what I said about Soundsmith. Peter Lebermann quickly responded. He said that he would supply me with a stand alone SUT for the Zephyr MIMC for a very reasonable price of $500. I have taken him up on his offer. So that problem is solved.

I am currently using an old Sonic Frontiers SFP-1. Which is a tube phono pre that uses a FET MC step-up pre. I am going to use the SUT with it through the MM inputs. And see what a SUT sounds like. Maybe I will like it, and maybe I won't. But I am intrigued enough that I want to find out. The Sonic Frontiers is getting old. The company no longer exists. And I have yet to be able to find a schematic for it. If anyone should know where I might find one. Please pass that information along, If you would be so kind.

As far as Icon Audio is concerned. Now that I will have a stand-alone SUT that matches the Zephyr. I would consider purchasing the Icon PS2 MM phono pre. But the fact that they have not yet bothered to reply to my very valid questions concerning the PS1 MKII causes me hesitation about doing business with them.

@flash56,

Parts Connection Parts Connexion services Sonic Frontiers components and does improvement mods on some.  I am quite sure they could refresh your SFP-1.  

Thanks Antinn! I will definitely check into it. It would be nice to have it refurbished. It is a good preamp. Much like the design of the Manley Chinook but without the loading resistors and capacitors being installed into dip switches. There are posts in which to solder the needed resistive or capacitance loads. It uses the same 6922s for the gain stage. It differs from the Chinook by using12AT7As for the output stage.

I want to apologize again to Soundsmith. I was just frustrated and had hoped for some guidance. I should not have taken my frustration out on them. It is really Icon that deserved all of my frustration, not Soundsmith.

In fact, it was Peter Ledermann who told me, in the first place, that if I could get a schematic from Icon that he would be happy to look at it and tell me if the circuit   allowed for a simple modification. That is what started my whole quest with Icon. Only to be told half-truths. Saying that there was no schematic simply because all that the MC circuit consisted of was a simple 1:10 transformer. They knew that I was looking to alter it to fit my needs. And when I had managed to educate myself enough, thanks to this forum and other publications, to question them on the 100Ω impedance. Simply because the math didn't play out, if it was, indeed, only a simple 1:10 transformer. And requested for a second time to be given a schematic of the MC section. That request has resulted in silence. Not even giving me a response at all. Or so it would seem. Quite possibly they are working on a response. And I will receive one eventually. If I do. I will let you know what that response is.

I feel good that Peter is doing the SUT. He will make sure that it is done correctly. As he states. Not all 1:10 transformers are necessarily a good match. The impedance of the transformer windings come into play. That can differ by the construction. How tightly together they are wound. The core. All of which can make a difference in the impedance. He designed the cartridge. And I have absolute confidence that the SUT will do the job correctly.

Thanks, one more time, for everyone's feedback and advice.

Another update.

Icon finally responded today. I said that I would post the response. So here it is. Just to put things in prospective, I am going to post my question also. David at Icon had said that it was strange that there was no mention of SUTs on the SS site. And speculated that the cartridges were designed for MC head-amps only. Antinn had been kind enough to post the link.

Question:

Hi David,

I have discovered a link on the Soundsmith site about SUTs that might be useful.  Transformer use with Soundsmith MI/Fixed coil designs | Soundsmith (sound-smith.com)
 
May I ask how the 100 Ω input impedance is being calculated? You stated a ratio of 1:10, with a required output load of ≈ 47KΩ. 47,000 ÷ 10^2 = 470. That would reflect a 470Ω input impedance. Which would be sufficient. 
By the calculations. An output load of 10KΩ would be required to achieve a 100Ω reflected load. Either that, or a stepup ratio of 1:21.67. 
Forgive me, but I am learning on the fly here. Many on the Audiogon Forum are suspecting a resistor across the secondary. Is that the case? If so, it could be removed. If I could just get the schematic for the MC SUT circuit. The manufacturer of the cartridge will be able to tell me if we can make it work. Thank you.
 
Reply:

Hi again

Regret time does not allow for anything more than a quick reply.

In my experience, providing the MC load is high enough, the effect on FR is minimal. (see Ortofon recommended loads). Which we recommend amongst others.

I recommend you follow the designers recommendations.

Regards

Icon Audio (UK) Ltd

Included were two PDFs of Ortofon Cartridges and SUTs.

Is it just me? Or did the response seem like it was a response to a totally different question? That response wasn't even artful at dodging answering any question  that I had ask. I would have had more respect if he had said. "Look, we aren't going to tell you, and we aren't going to send a schematic. So get that through your head and stop bugging me."

What amazes me is that I was going to a lot of effort in order to be able to purchase Icon's product. And they plainly didn't care. I still fail to see what they think is so ground breaking that they won't reveal it. As Lewm states. It would be a simple thing to buy it, open it up, and see what was going on. PTP wiring no less. Put the lid back on it and return it. This isn't a particle collider. A gifted middle school student could reverse engineer the entire pre as a weekend project. Unfortunately I'm not that gifted. But, you get my point. Now that I am going the stand-alone SUT route. I would have considered the Icon PS2 MM. But not if this is the mindset of the company. If I purchase a piece of gear. I expect to have access to the schematic for it. Enough of Icon.

Dover you are certainly correct. Just out of curiosity I loaded the Zephyr just a few ohms < 470Ω. It sounded god awful!

And for a third time. Thank you Antinn for the Erhard Audio link. I was on the phone with Peter Ledermann today. I had ask if he could make me a 1:8 instead. Because the Zephyr really comes alive in my system with a 700Ω load. Unfortunately he couldn't. He understood my reasons. I mentioned that I had been looking at the Erhard site. He knew them. He said that they make great stuff and that I should go with them. They are reasonably priced. And they have exactly what I am looking for.

So if it turns out that I like the way a SUT sounds. I will be on the hunt for a good sounding quality tube MM pre that doesn't break my bank account. I am open  to any suggestions.

Thanks Everybody.