As you can see (a photographer I ain't), the PCB used is Veroboard. I wanted a tidy build so the long connector goes to all the controls on the front panel (that and the three pin to the disc pot).
I made a few changes; All 20k changed to 18k, all 200k to 220k.
I used 2 TL084 quad opamps, an LM358, TL7660 ( - volts), LM555 (CMOS 555 for low batt alarm) and a 74HC4024. The 4024 will go soon when I decide the sound I want. I added decouplers to all ICs and (later) found that screened cable for the disc pot (and earthing the pot case) was a good thing to do, even thought the wires are only 4" long.
It was all pretty straight-forward. Bit tight aruond second TL084. I only used these chips because I have a pile in my boxes - as I said, my top limit was $20.00 or £15.00 in real money, or what, 1000 Euros in Monoploy money ?
If you use that cheap vero (it isn't Vero) from Ebay be warned : it is so easy to make spiders across the tracks because it does not have the same 'void' as Vero. Always run a blade along the gaps when you are done and brush off with IPA.
The caps are all cheap (well what else) ceramic discs and work fine.Reulator is OTT, but hey, it was cheap.
Nothing much more to say about the board really - I did not have the right switches in the bin so I have used a DPDT for Disc/metal. An SPST biased for Retune and a SPST for Auto. also added a volume control (the correct way - put in series with the cans is a bit of a waste of time).
Current consumption with a loud sound, is 37mA - I did have a fault (track spider) that puoshed it up to 44mA - but it still worked. When I fixed the fault the current was back to 37mA again and it did work better. I also added a 20M across the auto switch.
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