Step up transformers, good, bad or maybe?

[JazzBones]

I've noticed that some folk use a Bob Devices SUT so I had a browse on his web site, nice looking units especial the wood plinth ones however I need educating where SUTs are concerned. I know what a step up transformer is but not really what its actual use is in this day of good MC/MM outboard/onboard phono amps. I believe they came into existence when users of valves with onboard MM inputs wanted to use MCs? What benefits do they bring? Also:

(a) Do they come before the seperate phono amp or after (I would imagine its after)?
(b) Where does arm cable earthing take place, I notice Bob's has a lift switch?
(c) Are these Step up transformers mains powered?
(d) If a pre or intergrated amp, such as Croft, has a MM input then a SUT would be mandatory if a MC is used?
(e) For users of SUTs what has been the improvement (or otherwise) of using these units?

Okay, I know I ask alot of questions but the purpose is to clarify my thinking and correct any misconceptions.

Thanks fellas

Ron

[jimmieg]

I have used a Denon AU300LC step up tranny with a DL103 cartridge and a Pro-ject Tube Box II phono stage. (I recently upgraded my phono stage and I no longer use this set up.) The Denon SUT was specifically designed for use with the DL103. I would run the Tube Box II in MM mode with the SUT transformer before the phono stage. The Denon SUT has a ground post for the ground wire from the turntable, and another ground wire to connect to the phono stage. It does not have a mains cable.

When using it I noticed the DL103 had just a little more presence, a little more soul. If I took the SUT out of the system and switched the Tube Box II to MC mode, it seemed to lack a little bit of life. I am by no means an expert on any of this, just sharing my personal experience. Regards, Jim

[JazzBones]

Thanks Jim for sharing your experience on the Denon SUT. They do appear to be a postive and well looking into a bit more.

Ron

[Vinyl-Tubes]

Hello Ron,

Here's my experience:

(a) They come before the MM phono input.
(b) I've tried both on the SUT and the MM phono pre - I use whichever works best.
(c) SUTs require no external power, just the signal connections.
(d) Yes, a SUT or Head Amp is required, unless you are using a high output MC cartridge that works with MM inputs.
(e) I have always used a SUT so I can't compare.

You may want to check out K&K Audio SUTs. Hope this helps. Best regards.

[JazzBones]

Much appreciate the info Gerard, its looking a positive for using a SUT

Ron

[The Grand Wazoo]

Don't mix up SUT's & head amps though. A head amp for a cartridge will need mains power.

P.S. It's about time that vinyl users claimed back the term head amp from those pesky ear-muff users who seem to have appropriated the term because they're too bloody lazy to type headphone.

[Ammonite Audio]

It is very good that we can discuss SUTs here on AoS without an electronics 'expert' chipping in that they are fundamentally inferior to a well-designed MC head amp. All I can say is that my Bob's Devices Cinemag SUT sounds way better than the MC input of my PS Audio GCPH, and paired with the MM only Paul Hynes Veron Concert is quite magnificent. So, the proof of the pudding is in the listening: if you get a SUT that will correctly load the cartridge, and is well designed and constructed, you are likely to have a most enjoyable listening experience. Marco will confirm this, as he uses (used?) the Auditorium A23 with the Denon 103. MartinT uses the same Bob's Devices SUT as me and is similarly pleased. All of us are content to ignore the theory and simply enjoy the music. It does help, though, to understand the maths to work out what the loading is - I don't have much of a clue but I think Martin does.

[Marco]

Don't mix up SUT's & head amps though. A head amp for a cartridge will need mains power.

Unless it's battery operated, Chris, like the Lentek

I'll comment more on SUTs, later... It's interesting, though, that the real enthusiasts seem to use SUTs (often, after having compared them with high quality active MC stages)

Marco.

[The Grand Wazoo]

Unless it's battery operated, like the Lentek

I'll comment more on SUTs, later

Marco.

Yes, of course, I should have said 'an external source of power'.

[JazzBones]

Thanks again for more info. Do you have to decide on the actual cartridge to be used so that the SUT works in harmony (no pun ) with one another? what happens at a later date if you change to a different make of cartridge? Looks like I will have to finalise on cartridge to be used first???

I'm getting there, I think

Ron