Thinking about buying a different tube preamp...

Spent today trying different things to lower the noise. Nothing helps. Sent an email to Dan at Modwright to see if he could help. If no suggestions help, I'll sent the unit to him to have it gone over to be sure it's operating correctly. If it is working as it should, I will go back to solid state and be done with the noise. I've had nothing but bad luck with tube preamps. Hoping for the best from Dan. The Modwright sounds real nice, other than the hiss, which is very audible.

Got to thinking about the hiss. Also thought about my previous preamp, the Jolida Music Envoy. To use it I had to attenuate the signal going to the amps so I inserted a passive volume control between them. Then I wondered what would happen if I did that set up with the Modwright. Would my hiss be reduced? Sure enough! I have to place my ear very near the drivers to hear any noise whatsoever. I can have the pvc turned up about half way with the Modwright around the 10 o'clock position and the music is very loud, but the hiss is gone. It sounds wonderful and I'm happy again. I think I've learned to leave well enough alone and keep things as they are. Time to enjoy the music.

Abuck,
Something seems very wrong here.

1) Good tube preamps (including the Modwright) don't normally making loud hiss

2) In many years in this hobby you're the first I've heard of inserting a PVC preamp between an active preamp and amp to try to eliminate noise. An extra box and extra cables should be helping.

Perhaps there's an impedance mismatch? what are the specs on the amp and pre in that regard. Maybe someone more technical than me can comment based on that additional info.
Don't give up, figure it out :-) Cheers,
Spencer

Talked with Dan at Modwright and he said some of the earlier models had a bit of tube rush.
The LS-100 has an output impedance of 300 ohms. The Classe monoblocks have an input impedance of 75K ohms. As far as using the pvc I'm happy with it. Just an added resistance between the components that doesn't add any unique traits of it's own.
When I had the Jolida Music Envoy in the system I had to attenuate the signal with the pvc because the signal was popping, causing the speaker drivers to extend to full excursion. Luckily nothing was damaged. Originally I didn't insert the pvc in this set-up, but when looking the system over, I glanced at the pvc sitting there and wondered...wouldn't hurt to try it back in the same configuration to see what would happen. Surprised me when it reduced the noise floor considerably.

I am surprised no one mentioned CAT SL-1, perhaps the most famous and long lived preamp with built in phono. It is also one of the few that can drive any SS amp due to it's 100 ohm output impedance. The latest and greatest incarnation is called Renaissance.

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