Step up transformers, good, bad or maybe?

[The Grand Wazoo]

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

Not really, there are two main variables - step up ratio & loading. The ratio is the thing that could possibly limit future choice of cartridge if you decide to go for something with an incredibly low output, but it's usually nothing a twist of the volume knob won't cure.
The loading is usually easy to vary to very fine degrees by adding a resistor of an appropriate value - some SUT's have a bit of choice here as standard.

[Reid Malenfant]

One advantage with SUTs that hasn't been mentioned is that you can run balanced wiring from the phono cartridge to the SUT & convert to a single ended output to your phono stage

At the miniscule voltages we are talking about with an MC cartridge running balanced is a big advantage as it naturally cancels out interference picked up by the cables themselves.

[JazzBones]

I'm beginning to absorb more info on SUTs now than at the beginning of this thread, thanks all, but there is still alot more I can learn. I take it that a MM input, either intergrated or outboard is used as opposed to a MC input and then comes the SUT? Of course using my MC of choice.

Ron

[The Grand Wazoo]

No - we're still not quite there!
Think of it like this. A MM cartridge is an electrical generator and it produces a teeny weeny amount of energy. You need a normal, bog standard MM phono stage to get this up to the same sort of level as a CD player, tuner etc. That phono stage may be built into a preamp or an integrated amp, or it may be a seperate unit.

A moving coil is another flavour of electrical generator, but it's not quite as efficient, so it needs a little extra boost to get it up to the same level as an MM cartridge. This is what the SUT / head amp / MC stage will do.

So with a moving coil cartridge and a MM phono stage, you have several choices:

• Plug your arm cable into the MM stage & turn it up........way up. This can give you too much noise and it will make you fall out with your neighbours the day you forget to turn it down before playing a CD
  
• Plug your arm cable into an SUT & then plug the SUT into your MM stage
  
• Plug your arm cable into a head amp then into the MM stage
  
• By-pass the MM stage & get a dedicated moving coil phono stage & plug your arm cable into that, then plug it into a spare input on your amp
  
• Chuck away your MC cartridge & stick with a very good MM straight into the MM phono stage

All of the above have their proponents and there is no 'best' way. I've done all of the above, and nowadays I waver between a Bent Audio Mu step up into an MM phono stage and an LFD moving coil phono amp into an aux input.

[MartinT]

Hi Ron

I have the luxury of connecting my low output MC cartridge either directly to my Whest phono amp, with suitable switch settings, or via my CineMags. Having compared them, there is no contest. The step-up correctly matches impedances to give the cartridge the correct loading and also drive the phono amp at a lower gain setting, giving less noise.

In real-world language, I find the step-up gives better dynamics and a more vivid and life-like sound with lower noise. I would not be easily persuaded to revert to direct input to the phono amp.

[Marco]

Hi Ron,

In my experience, SUTs work best when they've been designed from the ground up, along with a partnering MC cartridge, by the same manufacturer. You can get away with it though sometimes by mixing and matching, as Martin has done.

This allows the manufacturer not only to match the cartridge and SUT in an electrical sense (in terms of impedance and loading), but crucially in terms of voicing both in order that sonic synergy is achieved. That's the hard bit!

Denon, for example, have products which epitomise this approach, and it's one I would recommend.

It's all very well finding a transformer that matches a cartridge, electrically, but it may have a sonic signature that doesn't synergise well with the tonality of the cartridge (all transformers sound different, even those which measure the same), which is where experienced ears are needed in order to obtain a good match!

I believe that it took Keith Aschenbrenner in Germany years to find the optimal transformer (sonically) for the Denon DL-103 before he eventually came up with the A23, and I can well believe it.

There's an art to matching transformers with MC cartridges that goes beyond simply attending to the known electrical parameters, but if you get it right, vinyl replay will beguile you in a way that I've not heard yet from using an active MC stage

Marco.

[JazzBones]

..........

There's an art to matching transformers with MC cartridges that goes beyond simply attending to the known electrical parameters, but if you get it right, vinyl replay will beguile you in a way that I've not heard yet from using an active MC stage

Marco.

Thanks Marco and forum family, it looks like I've got some seriously serious learning ahead of me, but I guess everyone starts from the beginning
Out of sheer curiosity what happens when vinylists have two arms on their decks with differing pickup cartridges? This is a minor question and can be ignored if you wish.

At the moment my AT OC9II is connected to the onboard S board MC input of my Avondale modded NAC72. There is a better solution for better fidelity and I would welcome suggestions but not at stratospheric cost.

Alex N's ANT (sold by Hi Fi Sound) gets good kudos from HFW mag but I have not come across anyone using one yet... are they worth it, sorry if this last question puts you on uneasy street?

The arm that my AT is bolted to is an Ekos 1 which has been completely worked on by Johnny 7/ AO ie: Kondo silver wiring from cartidge tags to SME arm connection, continuos. Damping of the arm and an AO gold plated * decoupled counter weight. (* a moment of sheer indulgence on my part but it does look good ) The TT is the Tek1210 with TS HE PSU, Copper sub platter, Acro mat, Isnoe feet and the whole caboodle sits on a Townshend Audio Seismic sink (bellows and spring type), there is an old Mana glass shelf between Isonoe feet and the Seismic sink, overkill maybe but in the interest of perfection one must experiment With the latter I thought I would go beyond the surgical glass disc and sorbathane footers... now can you follow what I'm trying to do???

Ron

[MartinT]

Ron, it sounds as if you have everything set up for superb sound quality with the possible exception of the MC input to your NAC72. Since you have an AT-OC9 and the Bob's Devices CineMags are designed for it, I would suggest that this may be the route to go down. Can your NAC72 take MM inputs? You could be looking at a serious upgrade in sound with just one device introduction and a Mark Grant G1000HD cable between step-up and preamp.

[JazzBones]

Ron, it sounds as if you have everything set up for superb sound quality with the possible exception of the MC input to your NAC72. Since you have an AT-OC9 and the Bob's Devices CineMags are designed for it, I would suggest that this may be the route to go down. Can your NAC72 take MM inputs? You could be looking at a serious upgrade in sound with just one device introduction and a Mark Grant G1000HD cable between step-up and preamp.

Hi Martin, thanks for your words of encouragement. Yes, I do have Naim MM daughter boards that I can substitute for the MC ones. Would it be better to use the MM boards married to Bob's Devices SUT instead of the MC boards? On the other hand I could always put link wires which would make the vinyl input into just another line input and work from there.... hmmm, permutations are numerous. Incidently, one cartridge I've got my eye on and sticking loose change into a jar for is the gold Dynavetcor 17DR3, it has a very small/short cantiliver but many years ago Naim reckoned that one did not need to go beyond this one as it was real value for money, of course it cost less than today's asking price of £699.00p, any musings on the 17DR3 Martin?

Thanks again for your advice

Ron

[JazzBones]

Martin, since sending the preceding post I have got an education (further) on SUT, a must read for anyone who wants to learn more! I shall email Bob and give him details of my cartridge etc., also my pre-amp and then go with his suggestions... Bob looks like he has had alot of positive feedback, can't ask more than that. Luckily I have a set of MM inputs for my Avondale modded NAC72 thus saving me the expense of a MM head amp. Should be interesting with what Bob comes back with.

Ron