Step up transformers, good, bad or maybe?

[MartinT]

Hi Ron, yes you need the MM board as the SUT is expecting a standard 47k input to work with. A line input wouldn't work at all, far too low sensitivity and it wouldn't have the essential RIAA compensation curve for vinyl.

[Pete]

Gents,

A very timely thread!!

I just picked up a Conrad Johnson Premier 15 MkII phono stage with CJD teflon caps upgrade


Now this phono stage has 53 db gain, as opposed to my Modwright SWP9.0SE phono stage which as 68db from the MC stage. I am using a Zyx cart with 0.34mv output.

So the CJ and the Modwright faced off today, with a good friend of mine adding his fine tuned ears to the evaluations.

The CJ proved the superior phono stage which I thought was no small feat compared to the Modwright. The CJ had more dynamic bass that is better defined and not slightly bloated like the Modwright. The mids are more fleshed out and the highs are more resolving, just a more transparent and natural presentation. The Mod sounded a bit CDish or solid stateish if that makes sense?

In the end we both agreed the CJ had the better presentation.

As with all things audio there are seldom all positives.

Now one advantage for the Modwright is that it has a lower noise floor. At matched listening levels the Modwright had no discernible hiss, while the CJ has some low level hiss which can be heard. Not too objectionable, unless you go for fairly loud listening levels, at which point the hiss becomes distracting on quiet passages.

I plan to put in some better tubes, and this may help somewhat, but ultimately I have been looking into step-up transformers for the CJ, which is essentially an MM phono stage, albeit an incredibly good sounding one.

I'm sure there are insanely priced SUTs, but I was looking into the Bobsdevices SUTs like others here. I had seen some reviews from Jerry Siegel on 10audio, and was intrigued. He had the same CJ phono stage and realized the virtual elimination of hiss and a positive sonic benefit from the higher signal levels going into the CJ.

Has anyone heard the Sowter transformers, or the Altecs that Bob sells?
How about other transformers and how they compare to Bobsdevices?

Cheers,
Pete

[jonners]

Has anyone heard the Sowter transformers, or the Altecs that Bob sells?
How about other transformers and how they compare to Bobsdevices?

Cheers,
Pete

I use Altec 15095 transformers and I like them a lot. They are not from Bob's Devices, though - I bought the transformers and wired them up in a box myself. The 15095s are actually line transformers used in reverse, and they can probably still be bought more cheaply than the 4722 microphone transformers.
A pair of the latter currently on US eBay are nearly £200, and that's just the bare transformers.
The only other transformers I've tried were Newcomb, which are also sometimes sold by Bob's Devices. They sounded soft and rolled off at the top compared to the Altecs.

[MartinT]

Pete - Bob will be able to tell you which transformers best match the Zyx. He is very friendly and helpful.

[Marco]

Hi Ron,

Sorry I missed this before...

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.

If they're serious, they will have dedicated SUTs for each of their MC cartridges!

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.

The boards in Naim preamps are actually very good, especially since their performance will have benefited from the Avondale mods, so unless you have around £800 to spend on something like a Whest TWO (which works superbly well with Naim equipment), I'd leave things as they are.

The internal phono boards have the advantage of being hard-wired to the preamp circuit, at the closest point to the signal, and thus the subsequent sonic benefits of that, together with the removal of the external cables required when an off-board phono stage is used.

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?

Nope - it's not a problem. I had the top model MM version, a Kora 3T Limited Edition, on an extended loan for some months, and compared it to the valve MM phono stage in my Croft, using my then A23 (103) SUT and DL-103SA with both.

I have to say that the Kora was superb, and one of the best solid-state phono stages I've heard.

It didn't sound thin and grainy, like some SS phono stages can sound, due to its use of FETs, which are a bit like the transistor equivalent of valves, and with the A23 SUT/DL-103, it produced an effortlessly musical sound full of insight and involvement.

Ultimately, though, I preferred my Croft's built-in MM valve phono stage, as it has particular strengths, musically, which are quite unique. Anyone who's heard a Croft phono stage will know what I mean.

I'd say at just under £800, in terms of SPPV, the Kora 3T Limited MM is a superb bit of kit, and in conjunction with a good SUT, would likely be an improvement on what you've got, although I'd advise you audition it against an active MC stage like the Whest TWO in order to hear which product/approach offers the best sound (and synergy) in your system.

DC's your man, as he has both in stock

Marco.