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You could probably do an additional mod via a switch to go between tails and true bypass. However, the downside to that is you would not be able to use the SPDT for bypass which is the big advantage here (i.e. much more silent switching). But, I think a combo of a DPDT and 3PDT would get you there.

I have a couple technical questions:
-What keeps the delay line seeing 4.5v so that there isn't a DC offset when it's switched on? Or alternatively, why isn't that an issue in this setup? (This was a problem I ran into when I did tails on the Multiplex.)

For number 1) I'd say it is because of the bias output of the first PT2399 (which is about 2.6v, IIRC). So, while there may be some offset it isn't large enough to impact the switching on and off. It just seems to work. Granted, I have not done a full battery of tests across multiple delay builds. Since I'm doing the build tutorial on the SDX this week, I'll give it another shot to say definitively if there are any issues. So far, none that I have found.

2) I made it 100n only to save space on the layout. I have not found much difference at all using 100n vs. 1uF (for guitar) in that spot. If you were using it for bass, it might be better to go up to 470n. I can always adjust the layout if desired...just not sure that it is necessary.

Yup, he's right. Gate is the the bottom lead, not the middle. The pinout is DSG with the transistor facing left.

Please feel free to discuss Valentine's day and/or workbenches, but DO NOT post links to adult sites here. I should think that goes without explaining.

I've done this...a couple of times. It sounds pretty cool. There's actually a "Zero Point" Sub-mini thread around here somewhere.

Here: http://www.madbeanpedals.com/forum/index.php?topic=4008.0

That's not a bad idea at all.

Let me think on that. Maybe we could do a submission thread on the first of each month for the previous month. And a little prize. Just a running build-off competition, even.

Thanks for bringing this up. I'll discuss it with the mods.

If it is a delay, I will build it. So, yeah.

Ooh cool! Never built the Cheese myself. Very sweet little layout.

Whatcho got goin on in that there Relay Bypass? Hmm?

The relay bypass is a wider board I made for Jack Orman's AMZ true-bypass relay controller so it could sit on top of the switch right at the front. It's a shame that I've got lots of those little green PCBs he makes for it left over. I'd buy just the PIC chips, but you have to buy 100 at a time.

Ahh gotcha. I have one of his board/controller sets. I need to find a good project to use it on.

Ooh cool! Never built the Cheese myself. Very sweet little layout.

Whatcho got goin on in that there Relay Bypass? Hmm?

$1.02 for the TC1044SCPA at Mouser. Just sayin'.

http://www.mouser.com/ProductDetail/Microchip/TC1044SCPA/?qs=%2fha2pyFadujneYfXSx2MlxxJDFFMj5iGawG%252bbwP%252bc28%3d

Okay, yeah it must be the ICL one that has the S designation. But, also the TC1044 one that I use too.

It's been quite a while since I've had one of the MAX ones since they are the more expensive...or used to be. I will amend the doc.

I'll add one more bit:

When I first took the leap from building whatever clone designs I liked to trying out my own ideas about five years ago, I spent lots and lots of time drawing out schematics by hand. I would do this to get an understanding of how to put the circuits together properly. Thing is, most of time I was taking the "intellectual" approach, i.e. I would construct filters based on how I knew the math worked, what the frequency response was supposed to be, etc. etc. And, they all sounded terrible! Just god-awful.

That's when I realized that I was neglecting the second component to design too much: the listening and ear training part. IOW, putting in time on the breadboard, or just building something and socketing the hell out of it so you can quickly swap out components and listen to the results is probably the single best thing you can do to gain instant progress. It is more important than being clever on your schematics and/or layouts (the thing that is the most fun for me).

One thing I did not mention in the doc: I highly suggest using the SPDT over a 3PDT. Not only because you only need one set of switches, but also because the mechanical noise of toggling the SPDT is greatly reduced. It is a much quieter switch and that is quite important when toggling a delay on and off.

Yes, that's the T0-92---same as the regular transistor casings we use. I have some of those as well.

While you could possibly use it in the circuit, it will not fit on the board. You would have to mount it off board somewhere and insulate it from the enclosure. This is a TO-220 style case and what you need is a TO-92 style case.

Jim, this is actually incorrect. The RR is made for a T0-220 style regulator mounted flat. This is assuming you are not also using the "SAG" trimmer.

The 7815CV is generally what I use for a T0-220 type regulator. The T0-92 style is fine, too. It just depends on what you are powering and what the current requirements are.