Happy B'day to me - MC Cart Suggestions

[scott wurcer]

Or maybe not balanced, who knows? Scott follows his own muse, who whispers in his ear constantly....

I'll start out with balanced JFET's either open or closed-loop. I found an open-loop two stage JFET preamp that I built 20yr. ago indistinguishable from an Adcom preamp (LT1115 based) that I borrowed. Admittedly not the best comparison but the only one I tried with everything else the same. It was basically a differential version of many I see here like Salas' simplistic.

The next experiment is with digital RIAA with and without an analog 75 usec time constant in front.

 

[scott wurcer]

To quote Ben Duncan , a British audio expert: ,,Very small direct current(2microampers) will offset the magnetic material BH curve from its linear region and we can expect an increase in distortion and related maladies, particularly when tracking high level passages,,.
Always is better to avoid any risk.

As was said only the offset current flows in the cart and many single ended DC coupled designs (a quick survey shows at least 1/2 of them) suffer full ib into the cart. I suspect if Mr. Duncan computed the actual distortion caused by 1uA DC flowing and compared it to the tracing distortion of the LP he would be surprised.

 

[Speedskater]

Did any of the Ben Duncan technical articles ever make it to the web?
He is/was a hippy poet with a day job in audio engineering, so sometimes he got of track.
But he was fun to read.

 

[kevinkr]

As was said only the offset current flows in the cart and many single ended DC coupled designs (a quick survey shows at least 1/2 of them) suffer full ib into the cart. I suspect if Mr. Duncan computed the actual distortion caused by 1uA DC flowing and compared it to the tracing distortion of the LP he would be surprised.

I suspect most people would be surprised..