Built my first 1590G today. This pedal sounds damn nice all the way through gain sweep. I had to use a B1M for the bass instead of the listed A1M since SmallBear was out of stock on the A1M.
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Show posts MenuQuote from: alanp on May 12, 2013, 05:47:01 PM
Yep, that's the one! Keefe kindly etched the boards for me, and Electricstorm provided the 1550G drill pattern as well (making life much easier in both cases.)
Same boards for v1.2 and v1.3, difference is in the stomp switching, plus the Rate LED
Quote from: stecykmi on March 29, 2013, 09:07:22 PM
do you get signal at R18/C17?
Quote from: stecykmi on March 27, 2013, 05:34:31 AM
try and narrow down where the signal is being lost. to see if it's being lost before or after the 2nd delay stage, probe pin3 and pin4 of IC4 (the output of the mn3005). try adjusting the bias to see if you can get signal.
No signal no matter where bias is set.
if you _do_ get signal, the signal is likely being lost in the filter section based around Q3 and Q4. if you _don't_ get signal, check pin7 (the input) of IC4 for signal.
No signal on pin7.
if there is no signal at pin7, probe around R24/R23/C20.
No signal on any of these 3.
if there is signal at pin7, it may not be biased properly (check the voltage at pin7), or your chip may be bad.
Voltage is reading 1.135...
can you confirm both chips are good? try swapping them and check the output pins again.
I've swapped them, they both seem to exhibit the same symptoms.
Quote from: madbean on March 27, 2013, 02:08:03 PM
You should be reading 0v on pin5 of the two BBDs. When you set the jumpers, it connects both of those pins directly to the ground trace.
I checked again and I am reading .008 on pin 5 of both chips.
You can run the ABDX on 9v no problem, and considering you have signal up to the input of the first BBD...well, something is just not right there.
I would spot check some other ground points on the PCB, including the GND pad itself to take some voltage readings. If you are not reading 0v in any spot, then it is a wiring issue. If you read 0v in some spots and not others, then we might need some pics.
I get zero on the ground points when checking against the ground lugs on the switch. Am I checking at the right points? This is the first debug I've done. Also, I have the power jack wired with two wires coming from the ground lug, one is going to the - spot on the board and the other going to one of the ground lugs on the switch.