Would it be possible to replace some, or even better, all the 2.2uF film capacitors in this layout with polarized electrolytic caps? Can you guys help me figure out which ones can be replaced and what their orientation should be ?
definitely would not replace them with electrolytics or tantalum caps. tantalum caps are notoriously a pain in the ass and can explode if they receive the wrong polarity. electrolytics would be a pain in the ass due to size. just grab some 2.2uf multilayer ceramic caps. they're small, non-microphonic, and non-polarized.
Most of them are coupling caps, and this is a dual-rail circuit, which means there will be no DC offset across the coupling caps. That's why those caps are specified as bipolar. The only way to use polar caps would be to modify the circuit to single-rail supply or modify the layout to accept caps in series.
Are you sure about that ? I'm only asking because people on the freestompboxes thread about this preamp seem to think polarized capacitors can be used as long as I respect the polarity (anode to +15v and cathode to -15v).
people on the freestompboxes thread about this preamp seem to think polarized capacitors can be used as long as I respect the polarity (anode to +15v and cathode to -15v).
There are no nonpolar caps in this schematic that connect between +15V and -15V.
The advice on FSB was general advice for replacing nonpolar caps. It's mostly accurate, but the part you mentioned requires there to be DC offset scross the cap. In this case, you don't have DC offset, so you can't use this method. Those caps are specified nonpolar for this reason.
You can do 2 inputs, 1 for each board, and have an A/B/Y switch pedal to go between the different option. You could also simply add a 3rd input jack that connects to both boards so you have 3 separate inputs, 1 for each option.
How about using the switching method used below ? The "I/O" jack would be my input, A would go to board #1 instead of a jack, B would go to board #2 instead of a jack, then both board go into the daughter board mixer.
The idea is that I can select either channel with my foot, as well as both at the same time with only one input jack.