I've finally built my Odr-s using this layout , it's verified and sounds great with my tele
verified_ODR-S.png I used bc550c , 2n5457 and lm4562 ic.It's got no noise and heaps of output.I decided to use a 1590bb as I couldn't fit it all in a 125b .Good luck if anyone decides to build it. IMG_0044.JPG IMG_0049.JPG
first, thanks for posting this, but I was redrawing your vero layout for myself and found an error on your layout. according to the schematic, the last 200K output resistor goes to ground and on your layout it is shorted out so it's missing one cut. I also counted 32 cuts on yours but there actually should be 33 with the correction. hope this helps............
so without the correction notes, it should look like this:
once i'm done trying to shrink it a little, i'll post my vero of it.
thanks heaps John , when I'm done working this week I'll change my board and see what difference it makes to the pedal , and I'm interested to see how much smaller you can get yours as it was my first big vero attempt.
nice work John , I've fixed my board and it refined the tone a bit better , I also experimented with 3904 vs 550c vs mpsa18 and j201 vs 5457 and found that mpsa18 provided the most useable gain range and 5457 sounded better than the j201. I also put pairs of 4148 instead of singles for a bit more output. It's a fairly smooth drive with good sustain but with my gear and compared to my paisley , black 65 and fetto it sounds a bit too compressed for my taste.
I'm going to build this one today and by taking the 1K resistor off of the board and putting it between lugs 2&3 on the drive pot , I managed to shrink it down to 21x21 so it'll be 1590B friendly. hopefully i'll have my 21x21 layout verified later today.
I'd be interested to hear your opinion of this one JohnK, compared to the odr-1 [which I'm going to build myself soon], my odr-s sounds great but the gain ramps up pretty quick , but I've read that the odr-1 does a better job of the lower gain sounds.
I just finished testing my 21x21 layout tonight and it works perfectly, however, yes, I find it to be too compressed and dirty. it even has a little distortion with the drive set at minimum and there was also some fizziness in the background of the clean signal. I fixed both of those problems on mine by substituting 3 resistor values.
here's a pic of my built up and tested circuit:
IMO, the 2K7 resistor coupling the buffer to pin 3 of the first 4558 was too low of a value, clipping the front end of the opamp. I replaced that one with a 10K and it removed the ugly distortion on the clean signal.
first, I tired two green leds in the first set of clipping diodes, but it actually sounded worse, and the diodes never really lit up, so, to give it less overall gain in order to be almost perfectly clean with the drive set fully CCW, I doubled the values of the two frequency gain resistors (the 1K connected to the 68n to a 2K and the 1K8 connected to the 2u2 to a 3K6). finally, instead of using a huge 470u filter cap, I used two 220u's in parallel to fit the board better. here's my final, and verified layout: