Switchback Delay with just 1 repeat

[guidoilieff]

I made this delay https://www.dropbox.com/s/2jmuajeei6bdew6/Switchback%20Delay%20Build%20Doc.pdf?dl=0


It just makes 1 repeat  almost 1 second later. Repeats and delay pots dont work.


I replaced R2 from 360k with 330k. Could that be the thing that makes the effect have only 1 repeat? I cant find 360k in my country.


Thanks

[vigilante397]

http://www.diystompboxes.com/smfforum/index.php?topic=29816.0

I would love to help, but if multiple pots aren't responding that means you likely have multiple errors. Follow the directions in that link and we'll see what we can do to help

[thermionix]

330K+33K=360K+<1%.

[guidoilieff]

http://www.diystompboxes.com/smfforum/index.php?topic=29816.0

I would love to help, but if multiple pots aren't responding that means you likely have multiple errors. Follow the directions in that link and we'll see what we can do to help

I dont know what the deal is with 4.33 volts


v 8.97


Q1
1 = 8.67
2 = 0
3 = 5.06


IC1  tl072

P1 4.33
P2 4.33
P3 4.32
p4 0
p5 4.32
p6 4.33
p7 4.33
p8 8.67


IC2  pt2399

P1 5.6      vcc
P2 2.52   ref
P3 0      agnd
p4 0      dgnd
p5 3.10   clk_o
p6 2.52   vco
p7 0.57   cc1
p8 2.53   cc0
p9 2.52   op1 out
p10 2.53  op1 in
p11 2.53  op2 out
p12 2.52  op2 in
p13 2.53  lpf2 in
p14 2.51  lpf2 out
p15 2.52  lpf1 out
p16 2.53  lpf1 in


D1 1n1407

A (anode, the non-band end) = 9.1
K (cathode, the banded end) = 8.71

[thermionix]

I dont know what the deal is with 4.33 volts

Vref

[guidoilieff]

I dont know what the deal is with 4.33 volts

Vref

2.53v too?

[thermionix]

I don't know anything about PT2399s.  Usually Vref is approximately half the Vcc (9v), so 4.33 sounds right.

[bluebunny]

2.53v too?

Yep.  It's half the 5V-ish supply to the PT2399.

[anotherjim]

A fixed long delay and no repeats - seems like the delay and repeats pots aren't working. Could they just be bad pots?

[guidoilieff]

A fixed long delay and no repeats - seems like the delay and repeats pots aren't working. Could they just be bad pots?

The mix pot in the circuit goes from 1k to 11k and drops again to 1k. I removed it from the pcb and its ok, from 0k to 50k.

[nocentelli]

A fixed long delay and no repeats - seems like the delay and repeats pots aren't working. Could they just be bad pots?

The mix pot in the circuit goes from 1k to 11k and drops again to 1k. I removed it from the pcb and its ok, from 0k to 50k.

Sounds like you had the lugs mixed up

[guidoilieff]

A fixed long delay and no repeats - seems like the delay and repeats pots aren't working. Could they just be bad pots?

The mix pot in the circuit goes from 1k to 11k and drops again to 1k. I removed it from the pcb and its ok, from 0k to 50k.

Sounds like you had the lugs mixed up

the pots are board mounted

[nocentelli]

Ok. What effect doe the mix pot have on the sound when in circuit?

[guidoilieff]

Ok. What effect doe the mix pot have on the sound when in circuit?

Its the only pot that works! haha

It blends the dry signal with the 1 repeat.

[anotherjim]

Are all the pot legs actually connected via the copper traces to the rest of the circuit - continuity test. It's very easy with thin copper cladding for the pot leg to break the copper pad away from the trace and be hard to see with the eye.