If there is not any member response, suggest you telephone the factory since their customer service includes being able to talk to someone knowledgeable about upgrade options when it is an older used amp.
Tube rolling is always one way to upgrade.
Consider Herbiesaudiolab.com tube dampers.
Also, check out his footers for another bargain upgrade idea, although I ended up preferring the Mapleshaderecords.com elaborate three part more expensive approach for my Cary amp.
Between these two extremes stands Dan Sherbrook of edenSound (802)635-7410 who sells giant "Bear Paw" brass cones seated into "Paw Print" Myrtlewood mini-bases for excellent sounding support upgrade at moderate cost. I use these under other tube and solid state amps.
What tubes are currently installed?
My original upgrade set of NOS vintage tubes for an SLA-70Sig still going strong, possibly because the two 5V4G rectifier tubes are designed to slowly warm up, avoiding turn-on surge to other tubes.
Consequently, I still have multiple unused backup tubes since I mistakenly stocked up (when a tube newbie) in advance of need.
Tube rolling is always one way to upgrade.
Consider Herbiesaudiolab.com tube dampers.
Also, check out his footers for another bargain upgrade idea, although I ended up preferring the Mapleshaderecords.com elaborate three part more expensive approach for my Cary amp.
Between these two extremes stands Dan Sherbrook of edenSound (802)635-7410 who sells giant "Bear Paw" brass cones seated into "Paw Print" Myrtlewood mini-bases for excellent sounding support upgrade at moderate cost. I use these under other tube and solid state amps.
What tubes are currently installed?
My original upgrade set of NOS vintage tubes for an SLA-70Sig still going strong, possibly because the two 5V4G rectifier tubes are designed to slowly warm up, avoiding turn-on surge to other tubes.
Consequently, I still have multiple unused backup tubes since I mistakenly stocked up (when a tube newbie) in advance of need.