@brd
Forum Replies Created
-
Posts
-
Put the wires from the 4 pin connector where ever they were when you posted that the boost switch made the volume, tone and overdrive work. That is now your on/off switch. If you have the other switch properly orientated then you should be able to swap the yellow and black wire on the stomp switch that the 3 pin connector goes to and all should be working fine. If you already have the switches labeled on the front graphics, just swap (move) the stomp switches, it looks like you have enough wire. I hope that helps.
I might be able to simplify if further. your boost is switched on and off by making a connection between either the yellow and red or yellow and black wires from the 3 pin connector. you can try to manually connect them to verify the boost is switching on and off and working as expected. If that’s good, then wire the stomp switch accordingly. yellow on a middle pole and red and black on the corresponding throws. use an ohm meter to verify you have it oriented correctly.
Sorry I didn’t think of it earlier, you could also try connecting the wet and dry sends to the amp. If you get sound, the problem is in the last half of the circuit then. Also be sure the Volume pots are fully clockwise when using the normal output jack, those are more like blend controls.
The box looks awesome BTW. I have one of my paramix’s in the same enclosure.
Johnnysmoke,
My first check whenever a pedal doesn’t make any noise, is the input and output cables, go direct guitar to amp through both cables. That verifies the guitar and cables and amp.
Try plugging the guitar into the returns then, If you get sound, then your problem is in the front half of the circuit.
Then check voltage (DC) on the board, at the 9v+ pad and a ground. if that is good then verify the bias voltage (VB) that would be at pins 3, 5, and 10 on the IC, that should usually be around half the supply voltage, 4.5 volts. while your there write down the voltage readings for the other pins. pin 4 should be 9v. pin 11 should be 0v. NOTE: the pin to the left of the dot on the IC is 1 and you count down and over then back up..
If nothing obvious is wrong ,at this pint I would break out the audio probe. I’m not one of the guru’s here.This is where they take over.
Remember those folks that build their pedals all neat and tidy, are artists, I’m not one of them, It doesn’t matter what it looks like, as long as it works..Post some pictures and the voltage measurements..
I ran out to my shop and grabbed my box of IC’s and my notes to see if I had any LM-1458’s, but sadly I have none in stock here.
Swapping IC’s is a very easy mod, I highly recommend trying it. The hardest part is not bending the legs prying them out of a socket. ( no I don’t have the tool )
I used all OPA-2134’s in my last Mule Kicker build, IMO the best sounding Klon I’ve built yet.
Have a look at this link http://www.geofex.com/article_folders/potsecrets/potscret.htm , I hope Barry doesn’t mind me posting that here. It’s a lot of information, but the section on pot tapers is helpful and also describes how to make your own custom tapers if you ever need that.
I think Bruce Lee once said “whatever works use it”. ( or something like that). So yeah, that’s the beauty of it, we can make them any way we want.
Best
BRD
The traces are the lines in the schematic connecting the components, they can be signal or power. They run traces on both sides because they can’t cross. They are not drawn like the schematic because that would waste space on the board. Hope that helps.
Sounds like what happens when you connect the power supply to an active pedal. You will get a pop and a delay before signal is passed. Check voltage on the board with the switch in bypass.
Go bright and crank up the fog machine, you’ll get a stage light show off of your pedal board. Best reason to use the bi-color led’s
Using the schematic and the readings that you have already supplied I think your Va, Vb, and Vc reading are fine.
Long explanation:
Va should be the same as your Q1 drain voltage, which was 7.4v. The expected value given by Barry was 7.27v. That is close enough.
Vb should be half of Va because of the voltage divider R29 and R30, which it is.
Vc should equal to your collector voltage on Q2 and Q3, which it is, and it is close enough to the expected voltage of 5.05v
What doesn’t look correct is your base voltage (middle pin) on Q2. Barry’s number is 3.75v you are at 1.48v.
Recheck that voltage measurement and be sure you have the Decay pot turned fully counter clockwise.
Also, Just using a little math, you have a diode D3 that should be dropping at least .25v so you should expect your voltage at pin 1 of IC2 to be at least .25v higher than your base voltage on Q2. Your readings are nearly identical, that doesn’t seem correct either.
Just to be sure, Are Q2 and Q3 BC550’s?
There is a small pass through next to R23, that is suspiciously close to pin 1 of IC2. Check your work there to see if you may have bridged that by accident.
Thanks for the tip, I wish I had that information a few years ago. However, talent and patience are the missing ingredients here. Below is a photo of my first and last pedals, clearly showing no improvement in my art or my ADHD.
Big O
I have been around this forum for a while, long enough to know you are one of the most prolific build posters here. Your graphics and finish are second to none. I can make them work but I can’t make them pretty. I built my “Omega” petal a while ago, but there is a breadboard on my desk now with some half baked idea that just might make it into a box. Hopefully something will inspire you again.
Ralf,
I would say the first version might work. I have the equivalent of Barry’s Tone TwEQ circuit installed in my semi-hollow guitar as a pre-amp for the piezo, although I’m using 2 jacks and a modified Paramix board to mix the signals on the floor. Note, my piezo pickup just doesn’t play well with some effects, so try it before you modify the guitar. Mojo is hard to predict.
Awesome project, good luck,
Elio,
Raising the values of the input and output caps will pass more bass frequencies, but c7 and c9 may also need to be adjusted too. You may need to experiment with values to find your sweet spot, so if you decide to try to adapt the pedal I suggest using sockets to spare the board from repeated de-soldering. No worries about letting the smoke out.
-Best
In regards to pin identification, short answers is yes, I think you have the pins numbered correctly in the picture. However flipping the board over requires too much extra thought for me, I use the legs of the IC for checking voltages. From the top of the board, number 1 is the pin to the left of the little indent on then count down then over and up the other side.
As far as the wiring for the jacks, there is a “T” printed on the board to identify the pad that is connected to the Tip on the jack.
Now as far as the signal. You should check for output from both the send and the out jack. remembering the gain and mix pots should only affect the signal at the out jack.
Best
