Dead End FX Dekadent - Capacitors?

[Meyatch]

https://drive.google.com/file/d/14GZfHa1M3ThQPYdIIEGSTHft33C3Eh2I/view

I was thinking of trying my hand at this decade pedal.  I was going through the parts list adding stuff to cart and I couldn't find one of the capacitors in ceramic, so I took a look at the board, and its labeled with a positive connection.  I then took a look through all the capacitors and a bunch of them are labeled with a positive connection.

In the parts list he's got one cap specifically labelled as electro.  Am I right that all these ones with the positive connection should also be electrolytic?

Is ceramic good for all the ones without a specific polarity?

Thanks
-mitch

[Kevin Mitchell]

Is ceramic good for all the ones without a specific polarity?

Hey, welcome to the forum!
The answer to this is no. Typically anything that is 1uF or higher is electrolytic unless specified otherwise, anything lower is assumed to be non-polarized, usually either ceramic or film or even a bipolar electrolytic.

The cap in question is a polarized electrolytic, everything below 1uF is ceramic or film and everything else 1uF or higher are also polarized electrolytic.

It would be ideal to have more information in the build doc's BOM but I suppose these docs are for folks who can easily hash out what's what, which sadly leaves some folks left to ask the forum 

Good luck with your build!

[antonis]

Welcome also.. 

Can't see any reason for 470nF cap (C15) to be a polarized electro..

[Kevin Mitchell]

Welcome also.. 

Can't see any reason for 470nF cap (C15) to be a polarized electro..

I agree but didn't want to dig into it without details to back it up. Figured if Dino called it out it was was for a reason.
My shot in the dark guess is form-factor. 470nF caps tend to be pretty big so maybe it was in the original design for space. Film caps are much smaller nowadays but the 470nF box-films are still pretty beefy. Even using ceramic wouldn't matter much unless you're *one of those guys*.

But! There could be an electrical reason and I hope someone can explain.

[digi2t]

Welcome!

That one 0.47uF (470nF) cap is an electro in the original schematic, and I always try to stay faithful to whatever the originals use, or called for in the schemos. You can sub in a film cap if you want for that one.

And yes, if the cap silkscreen outline on the board is round, and indicates a polarity, you should be using an electrolytic. It's extremely rare that we use axials.

[Meyatch]

Thanks for your help.

Some more questions:

I'm continuing adding parts to my cart, Q1 calls for MPSA18, which appears to be a 3 pin transistor, but there are 4 holes on the board.  Some light googling seems to indicate that the EBCE is so you can plug a 3 pin transistor in without having to cross wires.  Does that sound right?

I've been adding all my parts to a Tayda order, maybe there's nothing to be done, and I know nobody wants to source my parts for me, but they don't have TLP222A.  Is there any substitute for this?

PS: these questions it asks me everytime I want to post are biased against bass players...

[PRR]

..these questions it asks me everytime I want to post are biased against bass players...

Those stop after 3 or 4 postings; just trying to deter spam robots. (FWIW: often if you put the question in Google an answer is clear, and spam robots probably do that better than we humans.)

If you want to complain, write to Aron. I doubt he means to be mean to bassists, suggest better questions.

[Meyatch]

Is this suitable to substitute for the tlp222a?

https://www.taydaelectronics.com/tlp240ga-solid-state-relay-spst-mosfet-output-120ma-400v.html

[idy]

Yes, the four pin transistor outline on the board allows you to use any pinout transistor without twisting the legs around. Just make sure that you know the pinout of the one you have.

The relay, man that is a fancy bypass scheme with a PIC and everything. Tayda has the similar TLP240GA, but I would try to shop around for the original part. Unless someone can pipe in on the data sheet differences....The price you pay for choosing a complex build.
You could probably make it true bypass and save a lot of parts. And then if you really feel the need you could add the relay/PIC and supporting parts. But that's just a DIY hack talking.

[digi2t]

Thanks for your help.

Some more questions:

I'm continuing adding parts to my cart, Q1 calls for MPSA18, which appears to be a 3 pin transistor, but there are 4 holes on the board.  Some light googling seems to indicate that the EBCE is so you can plug a 3 pin transistor in without having to cross wires.  Does that sound right?

Yes.

I've been adding all my parts to a Tayda order, maybe there's nothing to be done, and I know nobody wants to source my parts for me, but they don't have TLP222A.  Is there any substitute for this?

TLP222G also works fine. Mouser, Digikey, Newark, Rapid, and maybe Banzai (not sure, check) are the go to places for stuff like that.

Insofar as the TLP240A is concerned (Tayda stock), we haven't tested it in this application, so we can't definitely say whether it is a suitable sub. Maybe I'll pick one up on my next order and give it a whirl.

The relay, man that is a fancy bypass scheme with a PIC and everything. Tayda has the similar TLP240GA, but I would try to shop around for the original part. Unless someone can pipe in on the data sheet differences....The price you pay for choosing a complex build.
You could probably make it true bypass and save a lot of parts. And then if you really feel the need you could add the relay/PIC and supporting parts. But that's just a DIY hack talking.

Yes, it's fancy... but it works quite nicely. Especially for circuits that are bypass POP prone. We don't take using it lightly, but when we have a pop issue with a particular build, then we apply it. It's still true bypass, but a much quieter one when switching.

Of course, everyone is more than welcome to work around it, and revert to a DIY direct to footswitch bypass setup. That's what schematics are for. We have a fond appreciation of DIY hacks.

And bass players too.

[Meyatch]

apparently the 222 is being discontinued by the manufacturer and the 240 is its replacement.

https://toshiba.semicon-storage.com/us/semiconductor/product/isolators-solid-state-relays/photorelay-mosfet-output/detail.TLP222A.html

[digi2t]

Thanks for that info. I guess I'll order a couple to test with then.