OCC is just a marketing buzzword. The Ohno continuous cast process has nothing to do with the wire's electrical properties. It's only of use to those in the business of continuously casting fine wire and thin foils as it's a method of preventing blowouts in the casting process.
Sure, it has fewer grains, but I've not seen any evidence that grain boundaries have any effect on electrical conductivity.
What does have an effect on that are dislocations in the lattice, which will occur in OCC wire just as it will in ETP or HCOFC when the wire is bent or worked.
se
Right. Read his patents. The process has nothing to do with the wire's electrical properties.
OFHC had become too commonplace. So they had to come up with another acronym/buzzword.
se
Yet your Simplistic Salas RIAA MC may sound better than adding a transformer at the input of a MM one.
I got a brief listen to a friend's pair a while back. Wired for 150ohm input, with my DL-103R I thought they sounded quite nice. He seems to be happy with them, in situ with a Koetsu Black.
jeff
Depends. If you want the valves tone you go for my Valve Itch pre. Of course my 3XK363 input Low MC for 103R shows -105dB at 20Hz and -145dB at 20kHz noise bed when the Itch shows -80dB & -120dB with SUT. One slams and analyses better, the other is silkier. Noise bed differences and resolution impact grow pro Jfet as the speakers move from 90dB sens mark upwards never the less. Its also the SUT cost issue. And then again they are both open loop & passive filtering, you may prefer closed loop with OPAMPS in the consecutive stages and active Riaa for more sense of low THD and control tone.
I have measured my 103R for 19 Ohm Rs lately contrary to its 14 Ohm spec and I went to 220R load (nicer) its a hint to try reflecting to the primary if feasible. I have found its true compliance to be 14cu also.
Regards
Gee,
And I thought the interesting model was the CM-2436. A telephone line bridging transformer with 100K input impedance and able to take a DC blocking capacitor. You couldn't even tell it is there!
It seems if I want to go with the 2 Ohm Grados, it will be via trannies. The Cinemag site has a PayPal link but no prices, I presume you ask for a quote and then pay?
It would appear that we have run out of coherent input on input transformers. Thanks everyone, I learned a few things, I hope that the rest of you did as well.
In any case, transformers do have drawbacks that have to be balanced against potential improvements. Personally, I find that the playback environment that I normally use in my home listening conditions does NOT need the galvanic isolation of an input transformer, and I generally do not use it. However, some very special low output phono cartridges might work somewhat better with an input transformer, and tube preamps virtually need one for MC cartridges.
In designing an all-out phono stage, for just about every MC phono cartridge or MM cartridge available in the world today, I have added an OPTIONAL step-up transformer, just to have the best S/N possible. Normally, it will not be used, with most quality phono cartridges. It would just reduce the headroom of the input stage.
However, moving on with 2 stage phono preamp design:
One very good design approach for the first stage is a Voltage to Current converter, or TRANS-AMP design, rather than a standard OP-AMP design. This sort of design can be very simple, or relatively complex, depending on ultimate S/N, and open loop linearity. Usually, it is best to make this stage open loop in operation, in order to remove the need for a feedback resistor, and listening tests have shown me, at least, that it sounds better that way. While some distortion must, of course, be generated, it can be shown to be virtually measureless at working operating levels up to the maximum musical output of the phono cartridge, and still not clip in the presence of mis-tracking or clicks or pops. This is important to keep the arbitrary transients from 'blocking' the amplifiers. This requires a significant amount of 'headroom' and the 2 stage design helps this, in a big way. (more later)
In any case, transformers do have drawbacks that have to be balanced against potential improvements. Personally, I find that the playback environment that I normally use in my home listening conditions does NOT need the galvanic isolation of an input transformer, and I generally do not use it. However, some very special low output phono cartridges might work somewhat better with an input transformer, and tube preamps virtually need one for MC cartridges.
In designing an all-out phono stage, for just about every MC phono cartridge or MM cartridge available in the world today, I have added an OPTIONAL step-up transformer, just to have the best S/N possible. Normally, it will not be used, with most quality phono cartridges. It would just reduce the headroom of the input stage.
However, moving on with 2 stage phono preamp design:
One very good design approach for the first stage is a Voltage to Current converter, or TRANS-AMP design, rather than a standard OP-AMP design. This sort of design can be very simple, or relatively complex, depending on ultimate S/N, and open loop linearity. Usually, it is best to make this stage open loop in operation, in order to remove the need for a feedback resistor, and listening tests have shown me, at least, that it sounds better that way. While some distortion must, of course, be generated, it can be shown to be virtually measureless at working operating levels up to the maximum musical output of the phono cartridge, and still not clip in the presence of mis-tracking or clicks or pops. This is important to keep the arbitrary transients from 'blocking' the amplifiers. This requires a significant amount of 'headroom' and the 2 stage design helps this, in a big way. (more later)
Yeah, just call 'em up and talk to David. They only accept checks or PayPal and charge an extra 3% or so for PayPal transactions to cover the fees.
se
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