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 1 
 on: June 14, 2019, 05:30:24 PM 
Started by mmoore5553 - Last post by mikekvan
I would check all the ribbon cables and make sure they are seated and not damaged. Also make sure all the chips are solidly in their holders. It just takes one pin not making contact!

Capacitors are always a problem on gear this old I would put all new ones in starting with the power supply. Check for a blown fuse.

If everything is working but the sound is aweful you may need to reset the programs with the tape function and a wav file.

 2 
 on: June 14, 2019, 05:25:52 PM 
Started by Circuitbenders - Last post by mikekvan
I made a video that might be helpful for tuning the Korg Poly-61

https://www.youtube.com/watch?v=oG_I3-Ztu0Y

 3 
 on: June 12, 2019, 11:55:37 AM 
Started by pinsoir - Last post by Namtip
Believe that some people have different ideas

 4 
 on: June 12, 2019, 11:55:02 AM 
Started by Mikemodual - Last post by Namtip
It is a matter of debate.

 5 
 on: June 11, 2019, 02:08:39 PM 
Started by Mikemodual - Last post by Mikemodual
Thanks Sam! It worked like a charm! I decided to go with a 3MHZ crystal with three legs (same as the SA-1 22MHZ) and wire them to a DPDT switch:)

 6 
 on: June 11, 2019, 01:41:50 AM 
Started by ELHeath - Last post by MrSoul
Hi,

Sorry to dig up this post, but I'm on the same project and there are really few people who have made these kinds of modifications.

After watching this video (https://www.youtube.com/watch?v=DTus8kwXA8U) and working on the Service Manual (https://elektrotanya.com/panasonic_sa-pm21e.pdf/download.html), we can see that it is possible to solder a jack on the tuner circuit: TUNER_LCH(5), TUNER_RCH(7), and PORTSEL(1) (which seems to be in bridge with TUNER_GDN(10)) for ground.

I deduce that it is possible to solder a jack on the k7 audio circuit: PB_LCH(6), PB_RCH(8), but for the ground, 9VGND(19), or VREF-(11)+AGND(10)?
Or on the CD drive: CD_L(17),CD_R (15) and D_GDN(12)?

You think I'm right?

 7 
 on: June 08, 2019, 04:20:06 AM 
Started by Blindjoedeath - Last post by Blindjoedeath
Hi, im relatively new to circuit bending. I was wondering if anyone can provide any advice/info about using a 555 in monostable mode as a lfo trigger as a circuit bend.

Many thanks

 8 
 on: June 04, 2019, 11:47:29 PM 
Started by untune - Last post by daneelolivaw
Hi general calisti,
Have you tried with the same lfo, but converting the output voltage to a variable resistor? If you build a vactrol (LDR+LED together) the output goes to flash the LED which in turns will vary the amount of resistance in the LDR and this gives you a controlled variable resistor that you can hookup in parallele or in series to the pitch potentiometer!

I have a Memoplay too, and canít wait to bend it (as soon as I have some time).

Best,
Sam

 9 
 on: June 04, 2019, 11:38:37 PM 
Started by Mikemodual - Last post by daneelolivaw
Hi Mike!

Usually what I do (and I did it on a sa-1) is to wire a dpdt switch in order to use both clocks. The central pin (is pin the right name?) of the switch goes to the IC on the Casio, the other two ends to the ltc1799 and the original crystal. Now, I canít exactly remember if the xtal in the sa-1 was a three legs or a two legs one. Usually only one pin is the one ne where to connect the incoming clock signal.
The other pole of the switch I use it in order to power on the ltc1799 at the same time I switch to its clock,in order not to drain batteries too quickly. Which the Casio sa-1, when I switch between the two clocks, it crashes. So, you either start it with the internal crystal or the Lyceum oscillator on. With other keyboards usually you need to power them on with the original xtal and then switch to the one you installed. Anyway, this is my experience..

Hope this helps mate, itís quite here...

Best

Sam

 10 
 on: June 04, 2019, 02:47:36 PM 
Started by Mikemodual - Last post by Mikemodual
Thanks! Iīll give it a go! Fingers crossed:)

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