[masi76gc]

Any experiences/recommendations for a step-up transformer to use with my AT-OC9?  I have two phono stages: Michael Yee Audio PFE-1 (predecessor to the Musical Surroundings Phenomena) and Pro-ject Tube Box SE.  While both of these phono stages are supposed to be capable of working with low output MC cartridges such as AT-OC9, I find that the bass lacks weight and punch.  I assume part of this is due to the natural character of the cartridge, but I am thinking that a well-matched step-up transformer between the AT-OC9 and one of my two phono stages just might do the trick.

[GBB]

I assume part of this is due to the natural character of the cartridge, but I am thinking that a well-matched step-up transformer between the AT-OC9 and one of my two phono stages just might do the trick.

While I really like step up transformers, I'd also suggest that you experiment with loading if you haven't done so already.  MC cartridges are very sensitive to loading and their character can change a lot.  Based on your description of the sound, I'd try the cartridge with much lower resistance loading and see if that helps.  Probably 100 ohms or lower if your phono stages can do that.

If you still think you want to try a step up, then you need to define your budget and also if you're willing to get raw transformers and DIY the box and connectors.  You'll get different answers depending on where you want to play.

---Gary

[masi76gc]

GBB, Thanks for the comments.  Yes, I have already tried different load as the MYA PFE-1 unit allows that quite easily.  I have tried adjusting load impedance from about 20 ohms to 200 ohms and noticed that lower load impedance makes the bass even leaner while higher load impedance makes the treble less clean sounding.  I use 80 ohms for the AT-OC9.

I have not yet considered DIY, but I am capable with the soldering iron.  I see many links to DIY transformers via Google, but is there any that you know to be particularly useful?  Tx.

[macrojack]

I have a Cotter MK 2L transformer and a Stan Klyne SK2A step-up that I'm not using. Contact me if either of these might be of interest. Both are rare and well regarded, if not classic, pieces.

[GBB]

I have not yet considered DIY, but I am capable with the soldering iron.  I see many links to DIY transformers via Google, but is there any that you know to be particularly useful?  Tx.

You can get vintage mic. transformers on ebay and they can sound quite good.  See for example:
http://members.myactv.net/~je2a3/mic-mcstep-up.htm
I've tried the Altec 15095 and they are good although people on the web seem to prefer the Altec 4722.  Right now I'm using some S&B TX-103 step ups, which are no longer being sold to DIYers, and they are a clear step up in performance but also a lot more expensive.  You can get a pair of Altecs for around $150 or $200 while the list on the S&B was closer to $600 a pair.

I've also read good thing about the Cinemag CMQEE-3440a which is actually a bit cheaper than the Altecs.
http://www.cinemag.biz/mic_input/mic_input.html

And Lundahl transformers have a good reputation and you can buy a complete kit from K&K audio:
http://www.kandkaudio.com/phonostage.html

As usual, I have no connection with any of these vendors.

---Gary

[marknoir]

Second GBB on his post. TX103s are the best currently available, or unavailable - depends how you look at it. I have a spare set, but not sure you need to go that high for an OC-9 (Hagtech version, $650). I would get a pair of Lundahl 9206s from K & K, naked $138 / pair shipped, $151 with a board, $275 complete kit. You have to burn them in to get the right sound. Their are evenly balanced, warmish. TX103s are more open, brighter. I remember having an Audio Technica transformer which at some time was sold as a package deal with OC-9 (many ys ago). You can find it used for about $50, but that may be too low in quality.

[jimdgoulding]

Hi.  I'd at least ask Macrojack (that's not what his wife calls him) what he wants for his Klyne.  After all, he said he's not using it (maybe that means somethin good).  Maybe you are way ahead of me, you probably are, but have you experimented with your verticle tracking angle?

[NealH]

Yea, be sure you have the VTA set properly because it will make a difference.  Also, that Mitchell Cotter was a stellar step up device in it's day - and probably still is.   Some products have never been knocked off the podium and this is probably one of them.  It's been many years since I heard one but, I remember really liking it.  You might want to consider it.