can this Danelectro delay be improved?

[Dimitree]

I'd like to know if the first stage of this Danelectro PB&J delay can be improved..mainly the dry signal path.
I already did true bypass to this pedal, but I wish it could retain more fidelity in the dry signal when the effect is on.

Also, why did they supply the opamp with 5V and not 9V? so that it clip the signal at around 5V and hit the delay chip with a lower signal?

https://experimentalistsanonymous.com/diy/Schematics/Delay%20Echo%20and%20Samplers/Danelectro%20PBJ%20DJ-17.PDF

[antonis]

I'd like to know if the first stage of this Danelectro PB&J delay can be improved..

On what improvent you refer on..??
(gain, impedance, filtering or what..??)

[ElectricDruid]

Also, why did they supply the opamp with 5V and not 9V? so that it clip the signal at around 5V and hit the delay chip with a lower signal?

Because the delay chip is running on 5V, so it can't handle a higher signal level anyway - hence, there's no *benefit* to running the op-amp at 9V. And maybe the op-amp clipping sounds better than the delay chip, who knows?

In terms of sorting out the dry path, there's a fair bit of tone shaping going on - C105 and C106 in the input amp, C108 and C109 in the output mixer. I haven't worked out what response those capacitors give, but that would be my first step: Either do the sums, or put the input and output op-amp stages into a sim and have a look at the frequency responses.

If it turns out those are limiting the frequency response significantly, then some "improvements" might be possible, but be aware that they probably come with other costs. For example, if they limited the high end of the signal, it might well be because the delay chip doesn't handle the top end well and the distortion goes up if you feed it to the delay.

HTH