Where to insert the step up transformer

Hi Cucurello,
are we still value added, not loosing you?
I hope it'd still of some use to other folks.

Almarg asked:
>> What is "reasonable" after the capacitance on the secondary side is multiplied by a factor of 1000 or so would be dependent on those cartridge parameters. <<

I give an example: 10nF is a pretty reasonable C to be used with a 'lively' MC as most Lyras, and even an Orpheus --- but NOT with a Ortofon Windfeld.
Take this C load and leave it in, when using an SUT it will become 10nF -> 10mF and it 'kills' the treble stone dead.

So that is beyond reasonable in deed. But you can see what happens if you use a capacitive IC from trannie to phono input...

Now as to the resonance frequency. As the MAIN factor needs you to know the correct inductance of the cart ---- Ortofon, and I asked them in person, never even measures it!
Also, there is the SUT --- Ortofon? Don't know, so to be practical we have to experiment.

Depending on the SUT it MAY want some damping too. In this case you'd hear some 'papery chirp' in the treble...

If so, secondary loading will be the first best thing to try.
Bearing in mind that any parallel secondary loading is reflected / by the winding ratio squared as seen by the cart and as mentioned.
Example: 30dB = 1:31.6 ratio, 47k ohm phono input with 18k ohm secondary load = 13 ohm the cart will see on primary, intead of 47 ohm. (You know the maths)

If this makes everything too dull somehow, we consider primary loading to get an impedance match. I used ~ 2.5 x DC coil resistance MC 10 = 3 ohms according http://www.cartridgedb.com/results_2.asp
so somewhere around 10 ohm, i.e. a 13 ohm resistor in case of a 30dB SUT with 'natural impedance' of 47 ohm.

OK, now we are in this territory when I said earlier Cucurello needs more information than he'd care for :-)

The last thing, is getting any resonance of the SUT combined cart sorted, by putting an RC of suitable size on secondary to shunt any resonances around >20kHz...

If Cucurello has a T10, that came with the MC 10 none of this aught to any issue at all, and that's the good news :-)

Axel

Dear Cucurello, if the MC output is very low and the phonoamp is far away, do amplify the signal as early as possible and use a low capacitance phono cable. To keep solder joints and connectors to the minimum possible, I would however - whenever possible - integrate the transformer into the phono-input section (especially so as most step-up transformers do furthermore benefit from the additional shielding of the preamps cabinet and the input of the phono/RIAA-preamp can easily adjusted (with tubes.... sometimes with JFets too) to perfectly match teh secondary of the transformer.
Cheers,
D.

Hi,
as Dertonarm said, THE BEST is to have the trannie right inside the phono-pre ---- unfortunately most often there's not enough space unless you want to dismantle the trannie.
Of course that would give you the least capacitance issues with the out-put connection, and presumably including very good screening.

DerTonarm knows his FR products, and if you look at e.g. an FR XF-1 you know what I mean with regard to space needed.

Cheers,
Axel
PS: I now use an MM and have none of that issue either :-)

Hey Gregm, Axlewahl, Almarg, & Dertonarm
Thanks for your input.
But I gotta tell you it did not work.

Not the cartridge/transformer hookup, I have not tried that yet.
What I mean is that no matter how hard you try you'ze guys won't scare me away with a barrage of opinion

I have read every word of it.
Understood some and probably misunderstood as much again.
I really appreciate the energy you are all putting into this.

Here are some reactions/replies
- The cartridge & transformes ARE a manufacturer's match
- The transformers are passive "in-line" devices
- It will require a 4'cable to go from TT to MM Phono input

Gregm's suggestion to try both ways appeals to me as I am most comfortable with the "aural" comparison.

I will be biased toward Dertonarm's advice.
It just seems to make sense that the signal should be amplified before travelling the distance.
Shielding however is something that I'd not considered.
Do you guys/gals think these transformers and the cable run ought to be shielded?
If so. With what material?

That's it for now.

Thanks again to all

Cucurello

Hi Cucurello
maybe you want to have a look into the thread: "Clearaudio Stradivari " http://forum.audiogon.com/cgi-bin/fr.pl?eanlg&1245164397

I put some stuff on trannie loading and such, it may fill in some of what you are pondering about.

Also, note that Daniel's advise to have the trannie inside the phono-pre gives you an indication where it's at --- in fact it plain contradicts the notion to have the tone-arm cable to be shorter in lieu of a longer trannie to phono-pre, a proposition that I do not think to be the better one, but as always YMMV.

Good luck,
Axel