External step-up transformer with Io or MP-1


I'm curious to know if anyone is using an external step-up transformer into their Aesthetix Io or Atma-Sphere MP-1.
Or, if they experiment with this.
exlibris
Not sure why you would want to do that as I think each of these has sufficient gain w/o an SUT.
I have tried an external stepup into the Io at its highest and second-highest attenuation. The results were not good - no synergy whatsoever. The Io is meant to be used as a fully active phonostage. If you want to use stepups, I'd look elsewhere.
I'm not sure I want to do this either. I had no intention of trying it until I read some very positive reviews of a few SUTs and talked to a few people who use them even though they too have sufficient gain in their phonostages.
It is an interesting idea and one I have recently done with an Io Signature and an ARC MCP-33. I just completed an update to the ARC. The Io, set to low gain, was used to verify the ARC component functioned correctly after the rework.

I can not report how a SU transformer might work here as the ARC is a tubed device. The ARC has an adjustable gain of 16, 20 and 24 db. Compared to the standalone Io set at 68db gain, the Io/MCP-33 combination gave up a little bit of bass; there was some added noise and hum most likely due to the mess of cabling ..... but ..... there was a little more treble energy and perceived extension which is no surprise as this is often typical of ARC products, new and old. And the Io is a little soft on top. Portrayal of space, decays and placement of musicians was first rate with either configuration.

Overall, the Io/MCP-33 combination is very musical but not a typical use of either product. And again, this was only done for the sake of validating the functionality of the MCP-33. The added cost with a Jade Hybrid IC and a Stealth Dream or Dream State PC for the MCP-33 makes this an expensive setup .... a very pleasing result ..... but ultimately bettered by the Io on its own.

John
I asked Ralph Karsten (of Atma-Sphere) the same question at CES, in reference to a Shelter 901. He said it is not necessary, as the MP-1 has enough gain. I listened to the 901 into the MP-1 all year, and it sounded fine, NO noise at all.

That said, two friends recently acquired Bent Silver Step-Ups, so I will borrow one to use between the 901 and the MP-1, and compare the results.
I realize that the Io, MP-1, and many, many other phonostages have enough gain to work with low-output MC cartridges.
I'm not concerned with what is technically possible or with what should sound better in theory; I'd like to know what people have found to sound best in practice. The Manley Steelhead, for instance, can amplify low-output MC cartridges through its MC input but many users prefer to use an SUT and the MM input of the Steelhead.
I'd like to know what people have found to sound best in practice.
Unfortunately, there is no general rule. Some Cartridges sound well without SUT AND are also good sounding when you connect it to such a unit.
And some wake up with it, some not and there is everything in between.
The main problem - IMHO - is to find a good SUT, most are colouring and degrading the Signal. The only one I can bear is the Kondo SFz.
Sometimes it's Magic.
Not always, but sometimes.
Sometimes it's Magic
What you're saying is that in rare instances, when perfectly matched with a particular cartridge, an SUT offers more benefits than just the reduction of noise.
This is what intrigues me.
Have you heard any of the offerings from Auditorium 23?
I've tried the MP-1 both ways- a few years ago some ex-partners of mine were real advocates of the SUT. My experience is that while you can get the overall setup to be quieter, ultimately you find that the phono is not as interesting as before- brighter, less bass impact, less transparent- in effect, more 'digital'. Ick.

So I went back to direct-in. What an improvement! The big deal seems to be making sure you actually have quiet tubes :)

After I got the company back, we introduced the MP-1 MkIII. One of the big improvements is in the phono; vastly improved constant current sources in the phono section cut noise, increased gain and reduced distortion. In effect, there is even less incentive to run a SUT than there was before. I've been using the ZYX Universe and also the Transfiguration Orpheus with no worries.
Thanks Ralph.

My experience is that while you can get the overall setup to be quieter, ultimately you find that the phono is not as interesting as before- brighter, less bass impact, less transparent

These traits are what I would expect to hear from an SUT and, as such, I was surprised to hear people taking about the 'magic' that some of them provide.
Given the choice, I think I would prefer analog though a really good transformer than listen to digital :)
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