[jimdgoulding]

I'd use Bob's Devices, the one that cost around $375, or the K&K that costs around the same.  If I needed to, that is.  We love our moving coils don't we.   I believe the K&K uses Lundahls tho I dunno which ones.

[Halcro]

A phono preamp is basically a RIAA filter. And it is MM. 47k.
What makes a phono preamp a MC phono? well the gain stage of course!
What you choose for your gain stage is your choice...or not, if you have built in MC gain stage then you usually use that! Of course.
But you could use the MM section and stepup with stepup transformers.

That is the gist of this thread. Those of us that have forgone the gain stages in our phono pre's or are using MM stages with stepups.

Of course it is inconvenient to use stepups when our preamps have it all built in, but hey, we spin vinyl, if we wanted convenoence we would do digital. Right? I am sure there are those that understand what I am talking about..

Remember all our gear is built to a price point, every cap, resistor, inductor, choke, wire, was a cost consideration at some point in the design. The usual markup is 5X, so a preamp that costs 5K usually costs about 1K to build, a 5k phono preamp with built in stepups is not going to have expensive stepups. That is not to say they are not good, but when you go simple you can really tailor your sound.

Mike Fremer uses a very expensive phono preamp that is just MM. And he uses great stepups. The results can be mind blowing.
The quality of the transformer varies, and so do the results.

I have an expensive phono/pre with both MM and LOMC inputs and agree with you that a good passive SUT can sound better than an active additional amplification stage.
I use a Kondo KSL Sf-Z SUT for my MIT-1, FR-7f, ZYX Universe, Dynavector XV-1s and Denon D103R......and agree with all the points you make 

[neobop]

Hi Halcro,
Welcome to Vinyl Circle.   Elison on Asylum said that SUTs have a lot of capacitance at the output.  Do you use any special cables with yours?

Nice to see you here.
neo

[bacobits1]

I had always stayed away from step-ups because I had the gain for low output MC's and thought it sounded fine.
But have been blown away at what my measly OC9MKII and Cinmag 3440A sounds like not to mention my Phono has got to be 12 years old.

I had been experimenting with the pair of cables coming off of the Trannies to the phono pre. I use WyWires throughout and they cannot be used because they are not shielded.
Very sensitive to sound changes in construction and materials on these interconnects.
Settled on using a 1/2 meter of Neotech NEI3005 and these worked the best. I don't know the measurements here.
Went through Diamond Back, Sidewinder, Old Aperture cables , Belden 1694A, were second best (.85 /ft !!) go figure. These being all shielded and some at 75 ohms coax various materials.

Ellison is using some old Grado interconnects he re-terminated. I spoke to him inquiring what he was using.
I bet with a change of cable he could get it better.

[neobop]

Interesting aspect here.  I don't use a SUT so I haven't thought about it much.  You're increasing the voltage by transforming current to voltage.  A SUT works by connecting coils (inductors) together.  Since you're plugging into a MM input, that inductance and capacitance become a property of the signal just like a MM cart has inductance and the capacitance load interacts with it. 

I would think the inductance from a SUT would depend on the turns ratio mostly, but I don't know how much inductance we're talking about.  I suspect it could be substantial.
neo

[WireNut]

If I bought a Dynavector 10x5 cart with 2.5mV would I need an SUT?
My Vista MM phono stage has around 45-55db gain. 
I currently use a Goldring MM cart with 6.5mV output and it gets pretty loud at around 10-11:00 on the preamp dial. Loud enough for the cops to come knocking.


 

[neobop]

If I bought a Dynavector 10x5 cart with 2.5mV would I need an SUT?
My Vista MM phono stage has around 45-55db gain. 
I currently use a Goldring MM cart with 6.5mV output and it gets pretty loud at around 10-11:00 on the preamp dial. Loud enough for the cops to come knocking.

No SUT with a HOMC.  It's designed to go into a regular MM input.  That Goldring has a hefty output.  Most MM have between about 3.5 to 5mV.  To get it that loud with the Dynavector you'd probably be around 3:00 on the volume control (guess).  That should work out well cause at "normal" levels you'd be around 10 - 11:00, the sweet spot on the dial.  Unless of course you normally listen at levels that bring the cops?   
You might want to change the load with the 10X 5.  Not sure what people like with that cart.
neo

[neobop]

I was looking around on the net to find out how much inductance on the signal, coming out of a SUT.  Seems like I found out everything but that.

Anyhoo, I did find a great article on selecting and optimizing a SUT.  Anyone contemplating getting, or anyone using one should read this:
http://www.rothwellaudioproducts.co.uk/html/mc_step-up_transformers_explai.html

neo

[bacobits1]

Rothwell was banned from VE for promoting his products in his posts.
The page is good info but he is a manufacturer promoting stepups, he had a lot to say about my Vista at one time. You never knock someone else's product.
Ahhh such is the internet. 

[SCompRacer]

I built one for a friend, he wanted 'inny' versus outside mounted transformers. He had an extra housing so I built one for myself. I used CineMag blues in his, and fell into a great deal on a pair of used reds for mine.  I use mine with a Denon 103R and AT33PTG/II. Prior to the AT cartridge I had a Dynavector 17D3.

[YoungDave]

I used a pair of SUTs from Bent Audio for several years.  As I recall, they were Stevens and Billington transformers in Bent cases.  They were wonderful with the 3 different LOMC carts I had then and a Sutherland PhD phono stage.  The PhD had plenty of gain but the SUTs improved it, so I ran the PhD at a reduced gain level.  Very nice setup.  Well, the upgrade bug bit, of course, and I sold the Bent SUTs and the PhD and got a Manley Steelhead.  Had it for a number of years now and will keep it indefinitely.  Note:  it has SUTs built-in. 

Moral of the story:  SUTs work well for LOMC cartridges, at least, they do for me.  Much better than just increasing the gain of the phono stage.

Cheers

[Halcro]

Hi Halcro,
Welcome to Vinyl Circle.   Elison on Asylum said that SUTs have a lot of capacitance at the output.  Do you use any special cables with yours?

Nice to see you here.
neo

Thanks for the welcome Neo...
It took so long for a Moderator to clear my first Post that I stopped looking after 4 or 5 days....
I have no expertise in electronics like you and John....so I can't comment on the capacitance at the output....I only have read what J.Carr and Ralph Carsten have said, and I make sure I add the lowest possible capacitance I can into the Halcro DM-10 phonostage, and load the Resistance at 47K Ohms.

I use only 18" of Kondo Audionote pure silver interconnect from SUT to phonostage.....and as it is contiguous with the preamp....there are no further interconnect cables 





L

Kind Regards..

[S Clark]

If I bought a Dynavector 10x5 cart with 2.5mV would I need an SUT?
My Vista MM phono stage has around 45-55db gain. 
I currently use a Goldring MM cart with 6.5mV output and it gets pretty loud at around 10-11:00 on the preamp dial. Loud enough for the cops to come knocking.


 

I'm using that rig, but can't remember what Boris put in it.  Just drop him an email telling him  your cartridge and he'll tell you the optimum values.  He is very familiar with the 10x5.

[neobop]

Thanks for the welcome Neo...
It took so long for a Moderator to clear my first Post that I stopped looking after 4 or 5 days....
I have no expertise in electronics like you and John....so I can't comment on the capacitance at the output....I only have read what J.Carr and Ralph Carsten have said, and I make sure I add the lowest possible capacitance I can into the Halcro DM-10 phonostage, and load the Resistance at 47K Ohms.

I use only 18" of Kondo Audionote pure silver interconnect from SUT to phonostage.....and as it is contiguous with the preamp....there are no further interconnect cables 

Kind Regards..

Hi Halcro,
I'm not an EE like those other guys.  I just have a little experience and get over with BS.

You mean Ralph Karsten of Atma-Sphere?   He's the king of OTL amps.  It would be interesting to know what he says about SUTs.  Many tube preamps use them, but Ralph certainly knows the benefit of ditching transformers on the output.  I believe J. Carr prefers going straight into a high quality phono stage.  I think Lewm mentioned his Atma-Sphere preamp.   Isn't it hybrid with a FET initial gain stage, or is that Lew's modified version? 

You have the Audionote interconnects hard-wired into your MM phono input?   What do you do when you want to use a MM, have a female to male RCA adaptor?  Beautiful piece BTW.
neo

[Halcro]

Hi Neo,
You're right about both J. Carr and Ralph preferring active amplification to SUTs....
They simply recommend keeping capacitance low if you choose to use one 
The Kondo RCA cables are simply plugged into the phono input of the Halcro.
I simply unplug these when I change arms......I have six of them and five have MMs attached so the SUT must be detached in any case....
Regards

[WireNut]

How did you learn how to build a SUT and where do you get the transformers?
I'd like to learn how to build one.

I built one for a friend, he wanted 'inny' versus outside mounted transformers. He had an extra housing so I built one for myself. I used CineMag blues in his, and fell into a great deal on a pair of used reds for mine.  I use mine with a Denon 103R and AT33PTG/II. Prior to the AT cartridge I had a Dynavector 17D3.

[SCompRacer]

How did you learn how to build a SUT and where do you get the transformers?
I'd like to learn how to build one.

I researched forums and went with CineMag transformers. You can order them direct from CineMag. At first I followed their wiring schematic and then made some changes to the ground circuit.

http://cinemag.biz/phono/phono.php

You can spend from a little to a lot on transformers! You have to match your moving coil cartridge with a transformer. I used good quality sealed signal switches for the gain and ground lift.



EDIT: For what its worth I used these switches, CKN1032-ND, from Digikey.

http://www.digikey.com/product-search/en?KeyWords=CKN1032-ND&WT.z_header=search_go

[JackD201]

I have a Koetsu SUT that I use for my Koetsu Jade and a MYSonic Lab which I use for my MYSonic Ultra Eminent and TechDAS TDCOi cart.

I'm pretty much all SUT. My Lamm has built in Jensens and my Valvet Soulphono has 3 sets with different ratios. The SUTs are a german make (silver wound toroids).

[Muser]

SCompRacer:
I looked at your pointer to cinema, but you're pointer is only to the transformer.
What did you read to learn how to build your own step-up, if you don't mind sharing.
I have an mm stage in my YBA Alpha 1. The output of my Dynavector XX2MkII (0.28mV)
is almost inaudible, so I'm looking at the Cinemag. 
In advance, thanks for reading my note.
Larry

[SCompRacer]

Hi Larry. At first I wired it per Cinemags suggested way. Here is the direct link to cinemag pdf file. You can add a switch where they say to "Jumper if there is no separate turntable/pickup arm ground" (JP1).

http://cinemag.biz/phono/PDF/CMQEE-3440A-Moving-Coil.pdf

My friend complained of a hum in his system wired that way, so I revised the ground scheme. Friend B had a Bob's SUT that he let friend A try that didn't hum so we followed Bob's ground scheme. It looks like this.