Thunder 1-RVT Questions: Speaker/Hiss/Tremolo

I've been restoring my fave Guild amp, the Thunder 1 RVT and have a few questions for other owners/users. So far I've replaced all electrolytics, re-soldered all connections, re-tubed and replaced speakers (WGS G12Q and G8C). It sounds great, except for the following:

1) Reverb Speaker frame connection: Originally I remember a wire connected to the reverb speaker frame. It is missing now and I don't remember what it was connected to or what it was for. Does any one know what it is connected to (speaker pos or neg)? Is it even necessary?

2) Hiss: The amp has an excessive/annoying amount of hiss. I also have a Thunder 1 and it has a lower (normal) level of hiss. Wondering if other owners have this issue or if there are any tips to reduce hiss (wiring, replace key resistors, etc)?

3) Tremolo: When I engage the tremolo there is a small volume drop and noticeble distortion when I dig into notes/chords. The distorion is not present when tremolo is turned off. I've noticed the same thing on my Thunder 1 and wonder if this is just inherent in the design or if its fixable. Does anyone else experience the same thing? or have any ideas for troubleshooting/fixing?

Mostly, I'd like to reduce the hiss...as I'd like to use it for recording.
Thanks for any info!!
- Aaron

1 - More than likely a ground connection. I'm working on an old Sano that had the same connection, though I can't explain why it was done. It still has the two speaker signal connections.

2 - High gain pre-amp tubes can induce hiss. Also, the plate resistors on the pre-amp tubes. I'd replace those with metal film, if it is indeed the source. Try a lesser gain tube as a first test.

3 - I haven't looked at your schematic, so I'm not sure what's going on with your Tremolo. I've not experienced that problem.

Jack

Thanks for the info, Jack! Anyone else have an RVT with the speaker frame connection? I replaced all the plate resistors and some dropping resistors without any significant drop in hiss level. May try replacing ceramic caps to see if there's any change. Still have the tremolo issue.
- Aaron