Fred's Toob amp(s) build.
- Thread starter WOPL Sniffer
- Start date
Well, I finally am taking a day off. I had a visit from Skip (Skipshot here on the site) and his friend Brian. They came through Hereford from Wyoming and stopped by and then we drank a shitload of beer so THAT day was not productive (for stereo work anyway). Then I fought with my Test Station which is a AP Portable 1 Plus Access and it turns out, there is NOTHING wrong with it. Day 2 wasted. So, I had to figure out what the hell was going on with the first tube amp which several days of burn in was unnecessary since the brand new tube set Fred bought, has a bad actor in there (Maybe more). The amp came up flawlessly after tweaking in the Bias and the Blue Lights shined brightly indicating all was good so I went back to the bench and finished the second amp. I was soldering, and i heard a little pop..... The fuse went on the amp I was burning in and after I went into town to fetch some Slow-Blows, I got the first amp back up and running and I noticed it ran about 50 degrees hotter that the second amp, measured in the exact same spots with my Laser Thermometer so I flipped it back on it's side, grabbed the meter and checked the Power Transformer, Output of 520 AC, which is perfect. Then proceeded to check the output of the rectifier which rectifies the 520 AC, to high voltage DC for use in other parts in the amp. PROGNOSIS, bad rectifier. I hope it didn't take a preamp tube or output tube with it. Fred, in his infinite wisdom, sent some Solid State rectifiers with the new tubes so I Installed it and got all my voltages back (both AC and DC). Tomorrow, I'll get it back on the AP and give it a good checkout. I went through both amps verifying every connection and THAT took some time. Damn Russian tubes. So, down one rectifier, but, they seem to like the solid state rectifiers as far as longevity so, I'll check the second amp and see what it's doing tomorrow along with the first amp, (he also sent 2 "Shorties) which are also solid state rectifiers so I'll check the operation of the amps with the shorties in each amp after I verify they are direct replacements. The "Tall" solid state rectifier works great( I got only one on hand) but will look silly with one amp tall, and one amp short so 'll check them and go with the shorties for esthetic reasons.
They are beauties though
They are beauties though
Went back to check my order. You are correct! The two shorties (Weber WS1) have no delay when voltage comes up. The WS1T has a thermistor that delays voltage rise similar to a tube rectifier. The autobias board does the same so the WS1T is unnecessary. Two shorties are fine with me. The tall rectifier is a WZ68 which is not recommended in audio amps, although it works fine.
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