[sonata149]

I scratch-built the Coronet with 12AX7s feeding a 6SN7 CF and the sound is very nice.  However I feel it might be overloading the rest of my amplification. Above a certain point, the Coronet seems to loose control and I have to lower the volume slightly. This does not happen on CD where I can increase the volume without losing on the sound (distortion-wise).

It is driving a pre-amp with 26dB of gain, which in turn drives a pair of SE-KT66/paralleled 6SL7 (a la JE Labs).

Has anyone with similar amplifier specs experienced this problem.  How best can I reduce the gain on my Coronet? On one of the first 2 stages (12ax7) or on the CF valve?

[hagtech]

That is a lot of gain for a linestage.  Although it is probably irrelevant.  If the CD sounds ok at high volume, then the CORNET should too.  But I'm thinking the problem isn't electrical.  Perhaps you are experiencing acoustical feedback?  Maybe through the turntable, maybe microphonics of the tubes.

Have you looked into chassis or tube damping?  Maybe some experiments with TT setup might lead to interesting results.  Maybe the dust cover needs to be down.  It could be something simple like that.

jh