Recent content by sregor

How about the artichoke? Also, some flowers are edible.

IMHO most protect issues are actually symptoms of other issues. Voltage regulator/power supply being the most common, followed by amplifier failure. So, reengineering would be useful in those areas, not the protect circuit itself. My 2 cents

search "alcohol dispenser push down" Amazon or medical supplies. Also, can use nail polish remover or acetone dispenser.

Bad me for not looking more carefully at the back label. I was going by what was in the tp668 manual for the turntable.. And that may not be correct. FWIW 8VAC rectified and filtered would be about 12V DC. And will bet money it is a DC servo motor drive.

That turntable is part of a rack system. (Sanyo 660 system). Found the 0wners manual for a 668 system which uses the same power cord. (Edit - misinformatiion removed)

There used to be contact cleaners called blue stuff or blue spray. Some were ok, others left messy residues. So may be from that, but don't know how it would just be under heat sinks. Or maybe something spilled, and was cleaned up off the boards, but not where you can see easily? Also, oxidized...

Wood case? there were a few cases of funny noise due to too long screws which were affecting the jacks in the front panel.... just a shot.

Many companies glue components in place before wave soldering. Some of the early surface mount IC's you had to unsolder and lift up the leads, then twist to break the glue.

Oops. Just presumed larger tweeter was mid tweeter.

Those look like Celestion HF-1300 tweeters. They are no slouches IMO. Some people prefer them over the Coles. There are a few DM4's with those in them when searching. Oops - wrong tweeter.

worked for me - Windows 10 and Edge. Soon as I put developer in the search box, the switches came up.

+1 on cut the shrink off and see what's in there. Schematic says 3.6 volt NiCd. Length is about the same as 3 "N" size batteries. There are NiMH n size type batteries with about the same voltage as NiCd cells around. Quick search came up with this...

https://en.wikipedia.org/wiki/Mondegreen Mis-hearing of lyrics - like "lucy in disguise" Search of AK got 32 hits.

Going back to the original schematic, with the input coupling cap. Changing the second resistor (R8 and R10) to 510K (or 470K) will lower the low frequency cutoff by a factor of 10 - a smaller film cap will give the same or better low frequency limit. C2 and C4 could be 1uF or even 0.47 uF, and...

For lower level signal tracing, try a .01 cap into the mic inputs on an old cassette recorder. Bypass the record interlock or put a blank cassette in it, press play and pause - gives you a meter and a level controller for it. (Unless it's an Advent without mic input)