step up transformer for clearaudio


I have a clearaudio concerto cart with a balance phono stage. It is a dedicated mc only phono stage. Is it safe for me to use a step up transformer without overloading the phono stage? I have tried the ortofon verto with great results but i dont want to continue using it unless im sure it is safe from overloading.
csr827
I use a Bob's Devices SUT ahead of a Blue Circle 707 with both set to high gain with no problems using Denon 304 and 103.
Dear Csr827: You say that own a dedicated MC phono stage: why do you want to pass the cartridge signal for and additional stage ( SUT ) when any additional stage can add distortions/noise/colorations degrading the cartridge signal? is something wrong with your MC phono stage?

Regards and enjoy the music,
Raul.
With the low setting of the Verto (24db) and the 0.8mV output of your cart, I dare say you are pushing the envelope by inputting ~ 12mV into your phono-pre.

A ~normal overload spec for a 60db MC phono-pre is seldom >10mV, after which there would occur some overload.

Your phono-pre might be of slightly higher spec. and this is why it may still work and sound good.
If you go into over-load you would start to hear some distortion.
If you never hear any distortion and like the cart with SUT --- don't worry, be happy, I say.
Axel
Thanks for your responses. I was really about to change my phono preamp to a tron seven which would set me back around 4k dollars. My clearaudio is okay but i find that it lacks weight in the bass and mids as when i auditioned the tron seven. The tron with its built in sut sounded a lot better than the clears...more weight i would say. This is why i heeded a friends advice to try a step up which i did and so far has improved the sound of the clear. Im really ignorant with regards to specs thats why im quite worried that will it have a long term negative effect if i continue using it. So far i have not heard any distortions what so ever.. if i am overloading my clears, would i hear it immediately or it would slowly ruin the clear if i continue using the step up? thanks
My system did not "NEED" the step up but sounds better with it. This has been discussed in the review of it in TEN AUDIO and in recent discussions of SUTs in STEREOPHILE. Theoretically Rauliruegas is correct, I avoided SUTs for years. But we don't listen to theories. The discussions in STEREOPHILE I mentioned include how the writer finally tried a combination that "OBVIOUSLY" would not work and it was the best he had tried. Also he (Rauliruegas) prefers MM so he doesn't need one. It you were having overload I believe it would be obvious to you.
Csr827,

A friend of mine has a Tron phonostage. The design does not afford the user any options on loading, gain, or anything else and the designer insists that the tubes provided are the "best" for that particular design.

While I thought that the phonostage was okay for the money, it performed MUCH better with different tubes in it. I am sure the right combination is really system/personal preference dependent, but, don't take the designer's word for what is best. Do some experimentation on your own. In this particular system, the Amperex bugle boy 12AX7s (I believe) sounded the best.

We did not do any experiments with loading, but I suppose you could do that also. I have a phonostage with a SUT built in, and I optimized its performance by changing the loading of the primary of the transformer. If you don't know how to do this, I am sure you can find someone who can help.

I personally like the sound of preamps with SUTs, but, matching to particular cartridges is an added complication that can make things a hit or miss affair. Perhaps more work, but the result can be very rewarding.
I am quite a supporter for SUT, but only for LOMC.
A SUT suits the chain the better the lower the output of the MC and its source impedance (and the resulting source inductance).
You may try a 1:4 step up with 8 to 12dB gain.
This might work well and tell you a few things about your MC. But the question is - as Axel pointed out - whether your phono stage can handle the input.
Always keep in mind, that the SUT and the cartridge are a team. You need to match the right "teammates" - otherwise the "best" SUT will sound terrible with the "best" MC if their technical parameters aren't matching.
Dertonarm,

I agree that a SUT is a good approach to dealing with low output moving coils. Such cartridges need an additional stage of amplification and any form of active amplification adds noise whereas an SUT does not add noise.
How would i know the overload spec of my clearaudio phono stage? All i know is that it has a 58db gain and input impedance of 5oo ohms/270 pf . Max output is 12v(1hz). Please help if you know the computations to my phono stage overload spec. . Also if im overloading it, will it be obvious immediately or will i hear the distortions with repeated use of the step up? Thanks
Hi Csr827, it will be obvious audible if you overload the input. The sound will be unbearable thin, distorted and somehow "breathless" (in a most negative sense of the word) and it will be obvious that something is entirely "wrong".

Get the manufacturer contacted and ask him about the maximum allowed input voltage in the phono input.
He should know the answer within 5 seconds, as this is one of the key parameters of any phono stage worth the name.

But please keep in mind, that the influence of a SUT is diminishing with increased source output of the MC. You already have a medium to high output MC. Don't expect even a well matched SUT to make a difference like night and day. What you will get is increased dynamic, punch and "inner gain" (in the sense of more power, as if you are running your car with the next more powerful engine..).
But these effects will be rather small.
Csr827,
+++ How would i know the overload spec of my clearaudio phono stage?+++

By looking up the spec. sheet, or if not in the spec. sheet asking the man that makes the stuff, no?

Greetings,
Axel
Dear Larry: +++++ " any form of active amplification adds noise whereas an SUT does not add noise. " +++++

IMHO your statement is a misunderstood. There is no perfect electronic devices ( pasive or active ). Any SUT has its own distortions ( colorations, noise, inaccuracies, etc, ) as an active amplification.
Which one makes lesser degradation to a cartridge signal?, this deppend on the design and the execution of that design and how you mate it to the cartridge.

So, IMHO your statement makes no sense or means that you don't understand almost nothing about. There is a lot of posts in this forum about SUT and active phono stage amplification, so I don't want to repeat what you can read anywhere in the forum.

Regards and enjoy the music,
Raul.
Raul said to Larryi, "So, IMHO your statement makes no sense or means that you don't understand almost nothing about."

The always tactful and all knowing Raul. Raul this is why I love you.

Bob
Raul,

Sure, SUTs distort. But, correctly implemented, an SUT does not introduce hiss or any such noise not correlated with the signal. Sure, "noise" can be introduced from imperfect shielding, but the act of converting current to voltage in the SUT itself (i.e., the "amplification" is noise free). That cannot be said of any form of active amplification (look it up in EE journals).

Solid state devices are low enough in terms of noise production that active amplification with solid state devices can also be, for all practical purposes, noise free. SUTs are used in tube phonostages because, in part, it is much harder to get noise-free high gain amplification using tubes.

Whether someone likes the sound of tubes or solid state or SUT or active amplification is a personal matter. There are plenty of designers (and purchasers) who will take the trade-off of SUT distortion and tube noise and distortion over the sound of solid state.

Yes, Raul, many of us are idiots. But, not everyone who disagrees with you -- on the superiority of solid state, on the superiority of moving magnet over moving coils, on the superiority of your own product over anything man or god has ever conceived -- is necessarily an idiot.

Dear Larry: +++++ " Whether someone likes the sound of tubes or solid state or SUT or active amplification is a personal matter. " +++++

I can't agree or say it better than you.

+++++ " But, not everyone who disagrees with you ... is necessarily an idiot. " ++++

I never say that and you know that I don't use that kind of word to refer to any human been, so please don't feel in that way. IMHO I think that what I posted is very clear: no perfect devices, if you think in other way then you have a misunderstood: that's all.

regards and enjoy the music,
raul.
Dear Larry, dear Raul,
I am using special bipolar Class A amplifiers, special FET SE-amplifiers, super regulated heater supply with L-power supply triode only preamplifier with SUT.
So we have most all kinds of active and passive amplification married happy together in my set-up.
Raul will certainly agree that the most advanced SUTs today do add as little coloration, distortion and phase shift to the music as the majority of the better solid-sate-amplifiers available today.

A good SUT is only a good SUT if it is the "right" SUT for the given cartridge.
And only then.
Dertonarm,

I agree with practically everything you have stated. Particularly, I agree with your implication that it is not the particular technology that matters so much as developing the right synergy.

On paper (meaning conventional measurement), I don't know if even the best SUTs will ever measure as well as solid state, but, to me, that hardly matters. I have heard plenty of setups with SUTs that sound terrific. My own phonostage uses a SUT at the front end, so I certainly have no issue with SUTs.
Im using a peerless 4722 with my stradivari which mathematically should overload the preamp input but with the tube pre's Ive tried it with it works great and sounds great. I have found that it overloads all the SS units Ive tried it with though.
Dear Dietrich: You and me knows exactly the differences between those gain approaches.
I don't want to talk about advantages or disadvantages on either. Like you I'm using what I think give me a neutral and accurate response that can/could put me near to the recording.

A controversy between different aproaches ( I'm just tired about ) is a endless one and like you like to say: useless.

Problem is that many people has poor know-how on the subject and poor know-how on music-sound reproduction. You know that every single " War " happened because " ignorance " subjects. You know too that there is no worst " deaf " that the one that does not want to hear. I never stop to learn and like to " hear " from you or any one else but sometimes like I posted: I'm just tired to go on in controversies.

regards and enjoy the music,
Raul.