[TV MAN]

With my recent power amp work going on, I felt I needed a good solid preamp. Again, trying to keep costs down and function up. I've been using a couple of these lately as they do about everything I need to do. The subject at hand was my "test" amp and I'd been using it for several years. But is is sounding lackluster and drab. I did find part of it was my lousy cheap portable CD player, but even with a good rack CD player, it still sounded dull. So, it is time to see if I can liven it up back to where it should be! I ordered a handful of caps from AES and finally got it on the bench. 

It wasn't easy, but it wasn't bad either. The PC boards made it a lot easier to unsolder and replace the old caps. In my pictures, you will note I've replaced one transistor with a heat sink on it. That is Q4, the output transistor. They were originally a larger round thing with a heat sink, but they get weak and make static. I spent hours trying to track down the source of that static, resoldered, replaced resistors, scoped and finally tracked it down those transistors. After a little research, I found parts at: https://www.updatemydynaco.com/ This fixed the problem. Parts are very affordable and shipping is very prompt. He also has the complete recap kits too, but I ordered mine with other parts from AES. I did NOT replace the main filter can cap. I didn't see any issues with it at this point, and it's very easy to get to when that time comes. Ill let the pictures speak for themselves.


A few notes: I pulled the rear of the chassis, PC board brackets, power trans & filter can. I tried to pull the selector switch, but the knob screw was rather find if it's place, so I just pulled the rearmost wafer switch. Be careful if you follow suit. They're delicate, and there's a small fibre washer that's easy to miss. The rear PC board was fairly easy to flip up and get to the connections, the front one - not so easy, and is why I pulled all the previous. This allows you just enough room to flip things into a figure 8 and get to your solder joints, Take pictures and mark your - on your caps. I only replaced the electolytics, There's plenty of sources for schematics and service info on the 'net. I also replaced the output caps on the front panel (for headphones). The rest, I left alone. Just keep track of your washers, nuts and screws. There's no labeling on the PC boards either, so one piece at a time. Also, keep the soldering heat minimal because it is easy to lift the traces.

Tied my PC boards in a figure 8
   
All those old caps. They should have lasted more than 50 years!
   
Thought this was interesting.
   
And this.
   
Just trying to get the "bugs" worked out!