Plus 2A/B External Tape Input

[spider]

The black models.

The tape player does actually work reasonably well however I am thinking a little bit of creatively and preventative medicine as such. Not wanting an external 'modern' device at the moment. My TCM939 does a sterling job despite its age now (and difficulty in finding the belt but that's another story)


The guide I saw for this suggested the "input" connection to the negative side of C200 , although I've not studied (yet) the circuit diagram would not attaching said input lead to the tape player to main PCB connection be a bit safer ?

I did look at how this was done "on the other side" aka CPC machines and their method seems to be attaching said lead to one of two places on the tape PCB or (!) attaching to the actual RW head itself via its leads. I suppose similar would work on the speccy too but that's not really what I had in mind. I looked because I wondered how they did it that's all.

Just after any input (no pun intended) / thoughts on this and where others have connected.

I suppose I'm thinking if an accidental short on the input lead would with this "mod" cause damage, concerned if its connected straight into the asic or such.

I did think about those 'in car' tape adaptors too but the internal mod is neater because the socket is already stereo and one track cut underneath the socket and an insulated screened (ideally) piece of wire and you're at the same as the plus3.

Thoughts appreciated!

[Guesser]

I would add a second capacitor on the negative side of C200 so that it's not (DC) connected to either side.

Either way, it's miles from the gate array, you're injecting a tape signal into the input circuitry that was designed to receive an external tape signal on the +3.

[Ast A. Moore]

I seem to recall that it depends on the amplitude of the input signal. Connecting it to the positive side of C200 will simply mimic the +3 schematic, so is probably the kosher way to do it. I remember that on my +2B that really gave me poor performance with the modern-day sound sources (read: computers/phones). Wiring it to the negative side of C200 gave me very (and I mean very) reliable results.

I don’t remember off the top of my head, but I think there’s a couple more DC-removing caps in the signal chain before it reaches the gate array. (I could be making things up, though.)

[Guesser]

if you connect it on the negative side of C200 with no blocking capacitor of its own you're putting your audio output directly across D202 to ground. Whether or not that matters at all depends on what the output circuit is of course.