Sunnbobb
Journeyman
I picked up a PL400 that looked pretty mint. I noticed the outputs had been changed to banana plug compatible jacks, and assumed there had been some work done to the unit. When I finally got to inspect it closely, i was kinda amazed. I've built around 10 of these so far, and every one had some previous work, some good, some bad. What I found in this one was nothing I'd ever seen.
First off, it had a nicely mounted on/off switch and power light, properly snubbed. it also had a quality microswitch to turn the meter lights on and off.
But that was nothing compared to what was inside. Not only had the boards been rebuilt, but this thing was sporting 4, yes 4, extra filter caps. It also is fitted with DTS402 transistors, something I had never seen.
I checked the fuses and hey were fine, the main fuse having been replaced with a 10A rather than the standard 8A.
I ran it up on the dim bulb and it fired up perfectly. After checking for anything weird, I went ahead and measured the DC offset. .28 mv on one channel and .30 on the other. The bias was also spot on. The main filer caps are running 9V, and the four add on caps running right around 35V on average.
All the work done on the inside was very professional. I bought this planning to drop an extra WOPL board and Audio speaker relay that I have, but honestly. I might just leave it alone.
I think I'll hook it up to the osc and see what sort of power this might be putting out.
Anyone ever see something like this?
First off, it had a nicely mounted on/off switch and power light, properly snubbed. it also had a quality microswitch to turn the meter lights on and off.
But that was nothing compared to what was inside. Not only had the boards been rebuilt, but this thing was sporting 4, yes 4, extra filter caps. It also is fitted with DTS402 transistors, something I had never seen.
I checked the fuses and hey were fine, the main fuse having been replaced with a 10A rather than the standard 8A.
I ran it up on the dim bulb and it fired up perfectly. After checking for anything weird, I went ahead and measured the DC offset. .28 mv on one channel and .30 on the other. The bias was also spot on. The main filer caps are running 9V, and the four add on caps running right around 35V on average.
All the work done on the inside was very professional. I bought this planning to drop an extra WOPL board and Audio speaker relay that I have, but honestly. I might just leave it alone.
I think I'll hook it up to the osc and see what sort of power this might be putting out.
Anyone ever see something like this?
