Denon 103, 103R, 301......Which one would you get?

FYI, the Lounge Audio Copla is not a step-up transformer; it is an amplifier, often called a "head amp". An SUT is a passive device - no power cord.
Correct, but I'm wondering if it's some kind of Freudian slip owing to the fact that the Copla is a transconductance amp, meaning that it inputs low impedance current and outputs high impedance voltage.....similar to a transformer. In fact, it could be called an 'active transformer'.

I've heard a couple of these types of headamps; the one in my Threshold SL-10 uses one, but a completely different variation of it that has a much, much lower input impedance. The Denon should do very well, based on my experience with the pairing.
 
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meaning that it inputs low impedance current and outputs high impedance voltage.....similar to a transformer. In fact, it could be called an 'active transformer'.

I believe this is the goal for all gain stages/buffers/drivers
 
I believe this is the goal for all gain stages/buffers/drivers
Voltage gain in the case of voltage amplifiers, usually have high impedance in (Zin) and low impedance out (Zout). This is the opposite of the transconductance amp. The voltage amp, because of it's high Zin, allows for any amount of shunt resistance to vary the load, which is one reason it's more commonly used. The Copla is unusual in that it provides a limited degree of loading by varying the current, and thus gain, through the transistor. The SL-10 has no such option, but instead uses series resistance to drop the input voltage....the gain itself is not variable.

It's a technical difference which affects the application and sonics, but yes, in effect it is still providing gain. Some consider it superior to a voltage amp, and it does have it's advantages.
 
Voltage gain in the case of voltage amplifiers, usually have high impedance in (Zin) and low impedance out (Zout). This is the opposite of the transconductance amp. The voltage amp, because of it's high Zin, allows for any amount of shunt resistance to vary the load, which is one reason it's more commonly used. The Copla is unusual in that it provides a limited degree of loading by varying the current, and thus gain, through the transistor. The SL-10 has no such option, but instead uses series resistance to drop the input voltage....the gain itself is not variable.

It's a technical difference which affects the application and sonics, but yes, in effect it is still providing gain. Some consider it superior to a voltage amp, and it does have it's advantages.
I'm going to have to read this more carefully later today. Thanks for educating, man :)
 
I'm going to have to read this more carefully later today. Thanks for educating, man :)
It might help if you search for 'transimpedance' instead of transconductance. Both terms are correct but transimpedance seems to return more favourable hits.

Here's a couple of links to get you started: the first is Marshall Leach's original paper outlining the circuit that is the inspiration for the Copla. The second is an MM/MC preamp kit that uses the exact same design, complete with the photocell power supply.

http://leachlegacy.ece.gatech.edu/headamp/

http://www.lcaudio.com/index.php?page=8
 
FYI, the Lounge Audio Copla is not a step-up transformer; it is an amplifier, often called a "head amp". An SUT is a passive device - no power cord.
Nobody said it was a stepup transformer. I said it was a step up and it is not just a step up amplifier, it also changes the cartridge loading.....
 
I lack the electrical knowledge about how the device works but I can say its worked nicely for my two MC carts. Still running in my DL301mk2 before swapping back the DL103.

I'm still not getting the same sense of magic/musicality from the DL301mk2 but it's proving to be a fantastic cart in all other areas.
 
You might also want to consider the ZU/DL-103 Mk II. A lot of guys really like it. Unfortunately, the price is now up to $459.
If you supply the 103 cart to ZU, the cost is 210.00. I had ZU mod mine, and it is outstanding! Mine ended up measuring at Grade 2! Sean at ZU told me only a small percentage end up at that spec. He said they measure and test them after they do the mods. The grades are determined by how Denon made them, ZU has no control over the final grade rating. He also said they have only had a few grade 2+'s since doing the mods. To me, this was a great improvement for the price.
 
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