Short update

For nearly half a year, I couldn’t work on any electronics projects due to a renovation. Now that everything is back to normal, I can finally pick up work again!

In the mean time, my projects list only grew, of course…

My old tube amp (a philips AG9014) crapped out, an old signal generator has some issues (the sine wave wasn’t a sine wave anymore), the tube tester still isn’t finished and I had to do some other small repairs (cracked phone screen, a few broken guitar cables, etc.). That doesn’t even include any of my own circuits!

The old tube amp turned out to be an easy fix:A while ago, a tube went bad and took out a few resistors due to a wrong fuse. After replacing the resistors and tubes, the power tubes kept red plating. The schematic is easy to find online, but is quite hard to read. After a lot tests and inspections I finally noticed two trim pots hidden behind the power tube sockets inside the enclosure. Of course, these were for bias adjustment and after some trail and error I found a reasonable bais point. They’re probably running a bit cold, but close enough for rock ‘n roll ;). There are still some issues with the phono preamp and (probably) some of the pots, but it’s working again!

I’m currently running the fx-loop send of my guitar amp (Blackstar ht5-r) into the AG9014, which gives me a lot more headroom and really nice crunch at higher volumes. I’m really happy with the end result, especially considering that this is the amp that got me into both diy electronics and tube stuff.

Up next is finishing the tube tester, so I can test the tubes in the signal generator and hopefully find out which one is faulty. After that, I’ll probably go back to experimenting with strange tube preamps again :).

My wish list is a lot longer of course:

-Midi/arduino something

-trying something with diy analogue synth modules

-fixing/recapping another old tube amp (a philips AG9015)

-Some utillities, such as an A/B/Y, stereo to dual mono and back, etc…


With some luck, I’ll post a bit more frequently over the coming months :).


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