I've recently upgraded my stereo arrangement with a nice walnut media cabinet. I'm probably being paranoid, but should I put something between my Dynaco st70 amp and the cabinet? The amp puts off a decent amount of heat. I really don't want to damage the surface. Thanks in advance. Ryan
Underneath the amp? Probably not, but to be over precautionary go to Menards or similar and get a small marble or granite slab for a few bucks to put under it. Or even a piece of glass. I have not had my ST70 in use for years and don't really remember the heat output, but I was never concerned with it.
From memory of my Dyna 70 (and Mark 3 and 4) days. They do run hot, most tube amps do. But that heat is traveling upwards. The bottom part of the chassis, especially if it still has feet never grows alarmingly hot. It's the output tubes and power transformers (especially on the stock underspec'd Dyna 70!) that get the hottest. I currently have a Eico ST70 sitting on cork flooring - no discernable heat damage when I pull the amp out for servicing.
Excessive amounts of heat, on and off over months and years, is never a good thing for good woodwork and even the toughest finishes. IMO, find a rigid slab of something (e.g., marble, wood, etc.), put some felt/non-marring feet on it, position on the media cabinet and use it to support the Dynaco.
I'd be less concerned about the furniture and more concerned about heat build up affecting the amp itself-- heat kills electronics. Tube amps need good ventilation. I don't know what your set up is, or how much flexibility you have with the cabinet, but I'd consider something like cutting out the back wall where the amp is shelved, and installing some fans- to draw off heat. I used various components AC Infinity to do that -- not their "plop the fan unit on top" style, but specific fans, a temp probe and a controller. All told, it might cost you $150 from them plus a little labor. I also make sure any component that generates heat is on a platform or surface that is heat resistant-- those vary but you don't necessarily need "audiophile approved" material.
Thanks for all the replies! Just to be clear (I should've been more earlier), the amp is sitting on top of the cabinet and NOT inside/enclosed. Again, sorry for the confusion. Thanks, Ryan
The underside of a Dynaco ST-70 does not get very hot, but there are some ventilation slots on the bottom cover which must not be blocked.
I ran a Dyna 70 on top of a clear coated pine cabinet for many years. I never had a problem with heat transferring from the bottom of the amp to the top of the cabinet. I just made sure there was plenty of ventilation all around the sides and above the amp. Boy that was a nice amp!
How much space is there between the amp and any wood above it? I'm running two Dyna/VTA 70s in a wood cabinet. There's a few inches above the tubes, and I leave the doors open when it's on...no issues after quite a few years.
Thanks everyone for the replies. I just going to run it on top of the cabinet. Amp has factory feet, and plenty of space around it. Thanks again Ryan
