Mr C wrote:Thanks Bob. I haven't short cycled it. And it's been on and off just a few times with all it's tubes. I went over some of the solder joints this morning, specially the quad cap and SCM. This morning my line voltage is 119.6. I have seen it a little over 121. most the time its in the 120 range. My speakers are rated at 89dB, they are Polk monitor 10s. I did have it turned up a little at the time. It had been on for about 2 hours and I had it on for about 2 hours earlier. I cant do anything till I get the tube. Any preference between the Weber SS rectifiers?
Either the Weber WS-1 (with thermistor) OR the Weber WZ68 will work fine in the ST-120. Note that if there is a problem with the amp itself, you can also blow either of the Weber's. What deepee99 has said is also good advice. If you can find a GZ33 or GZ37 tube rectifier, these are the best tube rectifiers that you can use in your amp. Unfortunately these are not made anymore and the remaining stock are priced in the $100 range.