Oh dear god......

When I saw this I wasn't sure what to make of it. I was pretty sure that whatever happened it was not repaired to code and it was not going to look nice under the hood. Furthermore some 1970's air conditioner is missing a power cord.

This transformer is HORRIFIC!!!!!

The amp itself though is pretty cool, this particular one is a rare breed of B-15-N. You can tell from the 5U4 rectifier..

Opening the back cover we see the electrolytic quad cap that will need to be replaced followed by the removal of all of the tubes for testing. This is the LAST project to exclusively use the Century tube tester for testing as i transition in the Hickok 6000 this month.

Since my Hickock 6000 was not ready, I did go down to cornerstone and borrow theirs, also providing for some comedy relief. This was brought about by my inability to test the 6SL7 tubes on the century. and also because my Hickok is also ready.

After testing, the amp was simply to disgusting to work on so I had to stop and clean it, and vacuum it.... and re-clean it.... and then disassemble it. Hey, theres a treasure map inside under a layer of dirt!

This map tells us that the quad cap is actually wrong! the first of many wrong things in the amp. Jesus!!!! Look at the power cable, its not even soldered. Its tied in!

Theres also a soldered in fuse just hanging in-line, no rhyme or reason... no mount either, bet its high voltage that can short onto other connections.

Impressively, cathode bias is tied to the humdinger circuit.... cool!

This is the time to Deoxit everything.... I don't like this part, but it is necessary.....

The replacement monstrosity that was installed in the cabinet was drilled through. Whoever did this should find a new line of work. So i decided to remove EVERYTHING that didn't belong in the amp.

Starting with that nasty transformer.....

The schematic mentions a thermistor, which this device is missing. This is a curiosity but many of these actually did not come with them. It was not so important with tube rectifiers as it was with solid state. With new CAPS its even less important.

Due to mental health issues I decided to measure ESR for all of the coupling caps. But then common sense prevailed and I moved testing to the IT-11

Hey that 7.5k resistor is 1.5K.... Hmmm looks like components on the supply side were swapped to accommodate the Abrams tank that was powering this unit previously.

Im running out of tape.... time to flip this beta cartridge to side 2.

свернуть