shake, rattle and roll

[rvin28]

Hi All,
I've not posted for a long time and I realised yesterday it had been 2 years since I had last used my class 5 (sometimes work can do this!!!). What a saddo I must be.

I'd previously replaced the Marshall EL84 with a NOS Mullard 'Blackburn' tube and the ECC83s with some Ei ones that I had available its just sounds awesome. Yesterday, I replaced the Ei's with some old Brimar 12ax7's and it has really warmed the overall tone and I wouldn't part with it at any cost now.

However, mine is suffering from the dreaded rattles I really think that this down to the thinness of the chassis. In replacing the valves yesterday, I had forgotten that if the two chassis screws are removed from the back panel that the speaker magnet is strong enough to attract the chassis to it. It cannot be right the chassis can flex to that amount?

Has anyone tried making the chassis into more of a ridged stronger 'box'.

Thanks

Rob

[ClassicRock88]

Well the usual questions apply. Specifically is it a Mark I, Mark II, etc. Does it have the 3 piece or 1 piece back? Also is it prior to or after the chassis design change? Basically you might just need a rubber washer between the chassis and the speaker, or the chassis and the cabinet.

[Rockman195]

When I get home from work I can post pictures of the chassis reinforcement I did. It sounds like you have a mark 1 otherwise it would have a rubber stopper on the chassis that rests against the speaker. I've heard that the stopper can cause rattles though, so I removed mine. The chassis will not be affected by the magnet because there are still screws holding it snuggly to the back piece top and bottom.