Can anyone help with my new basic looper design?

[RaceDriver205]

Ive run into some issues with this looper I am designing.
I have built it and programmed it, but the first thing ive noticed, is that the straight guitar signal does not pass through.
Can anyone see why this is?

Thanks for your help all

[slacker]

I think the ANA IN pin is referenced to ground so you need to decouple it from U3 otherwise it's going to mess up the biasing.

[danngreen]

I'm curious why you have such a large attenuator at the beginning? i.e. R5 is 1M, R6 is 33k ==> gain of 0.033! Is that to not overload the ANA-IN pin? When you gain it back up with R7/R9 (3.3k/100k), you'll be introducing noise. Noise can be a plus or a problem, depending on what you're doing!

[RaceDriver205]

I think the ANA IN pin is referenced to ground so you need to decouple it from U3 otherwise it's going to mess up the biasing

Aye, I guess Ill put a capacitor between in and the resistor instead of a direct connection

Is that to not overload the ANA-IN pin?

Thats right. ANA-In has a low peak voltage. This design really does have its emphasis on simplicity, so 1 TL072 was the aim.

[RaceDriver205]

OK, playing a capacitor from pin 1 of U2 to R7 instead fixed that.
More importantly, the looper doesn't work!

I am hoping someone who has knowledge in the workings of this chip and microcontrollers (that'd be Andrew  ), would be able to point out what im doing wrong. The code is fairly simple, and the indicator LED shows that the code running right. But the ISD IC is not responding.
When I get this finished, Ill be glad to share the designs for the simplest/smallest DIY looper ever!

reset:
   ;PB4 - Play Switch
   ;PB3 - Indicator
   ;PB2 - Address control and P/R
   ;PB1 - Record Switch
   ;PB0 - /CE pin
   ldi   temp, 0b00000101
   out   ddrb, temp
   ldi temp, 0b00000001
   out portb, temp

main:
   sbic pinb, 4
   rjmp play
   sbic pinb, 1
   rjmp record
   rjmp main

play:
   ldi temp, 0b00000101 ;setup for play
   out portb, temp
   sbi ddrb, 3 ; turn on indicator
   sbi portb, 3
   cbi portb, 0 ; play
   rcall delay    ;debounce
   rcall waitclear ;pause until button released

a:
   sbis pinb, 4 ; wait until play pressed again
   rjmp a
   sbi portb, 0
   cbi ddrb, 3
   rcall delay
   rcall waitclear
   rjmp main

record:
   ldi temp, 0b00000001 ;setup for record
   out portb, temp
   sbi ddrb, 3 ; turn on indicator
   cbi portb, 3
   cbi portb, 0 ; record
   rcall delay    ;debounce
   rcall waitclear ;pause until button released

b:
   sbis pinb, 1 ; wait until record pressed again
   rjmp b
   sbi portb, 0
   cbi ddrb, 3
   rcall delay
   rcall waitclear
   rjmp main

Thanks all. I hope im not asking too much 

[RaceDriver205]

No one?

I fixed one error (which didn't solve it), which was that PB2 connects to A8 and A9 - not A7 and A8.