JC3+ Anyone?
Have you checked out the Liberty B2B-1 ? Liberty B2B-1 Michael Fremer gave it a "Gruvy" Award on Analog Planet, just last week, makes me pretty happy. From its maker Peter |
Original JC3 was probably noisy (as well as being less than optimal) with many cartridges because it had outrageous amounts of gain. 68 dB on the MC input spec'd and it tested even higher than that in the Stereophile review. Parasound reduced the MC gain on the plus model to 64 dB to alleviate problems with overload which seemed to affect a number of users. 64 dB is still quite a bit of gain. Personally, I wouldn't pair a phono stage with that kind of gain with a cartridge like the Kleos which has a .5 mV output. Not a good matchup IMO. With a .5 mV Kleos I'd be looking at a phono stage with fixed gain around 56 dB or adjustable gain that could get you into that area. |
I had a Delos customer who had problems with the Parasound JC3 - the high gain gave too much signal output, which would occasionally overload the preamp. He solved the problems by building a fixed attenuator and inserting it between the JC3 and the preamp (there is a very interesting thread about this on the Steve Hoffman forums). In some systems 64dB may be too much gain for the standard output Kleos (especially if you have horns), but for most, it should be OK, and allows you the possibility to use the half-output Kleos SL version at a later date. I know from experience that 58dB will work, but 56dB may be getting close to the edge. Compatibility between phono cartridge output and phono stage gain depends very much on the gain of each component after that. The line preamp, power amp, and speakers (sensitivity). Regarding noise suppression, it is best to have as much of the total system gain as early as possible, and use less further downstream. IOW, combining a high gain phono stage, with a lower gain line preamp, power amp with even lower gain, and low-sensitivity speakers would be best if your primary goal is to minimize noise and hiss. kind regards, jonathan |
"Have you checked out the Liberty B2B-1" It was on my list. Only one XLR rules it out as I am not going to buy two. I do like your use of FETs. Been a fan of FETs for years. Had a Sony TA-1130 with MOSFET output devices. I also like the way the JC3+ has premium parts in the right places. " He solved the problems by building a fixed attenuator and inserting it between the JC3 and the preamp " I read that thread, one of the best forum threads ever. "half-output Kleos SL version at a later date" Always good to hear from my favorite cartridge designer. If I send my Kleos back to Japan can it be converted? It needs a complete checkup anyway. Just started seeing the SL version mentioned. Have you folks not done an official announcement? "Compatibility between phono cartridge output and phono stage gain depends very much on the gain of each component after that. The line preamp, power amp, and speakers (sensitivity)." I am testing the XLR inputs on the CDP-500. One of the many nice things about the GCPH is the switches on the back for gain and loading. It will do 66db and also has a rotary control for the output section on the front. Overload would be harshness on the loudest notes, right? I am not hearing that but I am hearing what sounds like tape compression. I played my original Telarc 1812 and the KLEOS managed to stay in the grove on the canons but the loudest orchestra sections sounded compressed. This was with the GCPH on 66 and the rotary all the way. So that's like better than 11, yeah? :-) BTW, as some might expect, the best tracking of the canons on that LP was via a Shure V15. I have a VxMR and I believe I had a V15III when I bought the 1812. Thanks Folks, Robert A. Ober |
