[justubes]

I hoping to squeeze out the  most performace of the v2.1 .

Some Suggestions sought on the best opamps to roll that control the ldr light intensity, would this improve sonic performance of just the accuracy of controlling the intensity of each ldr?

[tortugaranger]

I hoping to squeeze out the  most performace of the v2.1 .

Some Suggestions sought on the best opamps to roll that control the ldr light intensity, would this improve sonic performance of just the accuracy of controlling the intensity of each ldr?

In my opinion the use of a compatible precision quad op amp with high PSRR that can operate on single sided supply of 9-12 V  can improve overall autocal accuracy which seems to have greatest impact on sound quality so far. The autocal op amp is the one on the underside of the board. So far I've not found a substitute op amp for the 2 topside quad opamps that run on single sided 5 V power. I would also think that running the unit off a 12 volt battery would yield the best results.

[justubes]

We shall wait for updates from you in future developments.

Would adding some good caps to the ldr improve performance?

[Wingfield]

Would adding some good caps to the ldr improve performance?

If you're looking for sonic improvements from upgraded caps in the signal path, there aren't any caps in the signal path.

E.

[justubes]

I mean a cap for the + rail to each ldr

[tortugaranger]

I mean a cap for the + rail to each ldr

There are 0.1uF bypass caps on the voltage signal that drives the LDRs coming out of the op amps. Upstream of the op amps there's a low pass filter with a cutoff somewhere down around a few hertz. However there are no bypass caps on the power supply to the op amps. These op amps are not handling AC, just DC. I've not tested benefits of bypassing op amps PS which is SOP when using them in the audio signal path. To do this you'd have to solder pins across the mid (4th) pin on each side of the op amps.