Build Your Own Clone Message Board

I've seen a few other posts with seemingly similar issues...title says it all. When engaged, pedal has way low output, and the volume pot doesn't do anything.

One thing I did notice– the 101 resister included in the kit was a 101r (Brown/Black/Black/Black/Brown). The kit calls for a 1 - 100 Ohm/101 (Black/Brown/Black/Black/Brown). I removed the resistor and jumped it for the time being– didn't actually make an impact. Acknowledging this could be the issue and I emailed BYOC for a replacement. Double decked all of the resistors and the rest look fine to me...but ive been wrong before. Need another set of eyes on this!

See pics below.

Re: that resistor, it's a misprint on the color band coding in the instructions. You had the correct resistor.

I don't see anything out of place, so that's to the good. First thing I'd recommend is to work through THIS PROCESS, since it often solves problems like what you're describing. If still no joy, try getting a set of DC voltage readings on the pins of the IC and report them here.

_________________
“My favorite programming language is SOLDER” - Bob Pease (RIP)

My Website * My Musical Gear * My DIY Pedals: Pg.1 - Pg.2

I resoldered all joints and added the resistor back in. All issues still persist, with one change....The volume pot does have a sweep now, but fully counterclockwise there is still a bit of signal. Imaging that sound should fully cut out, but if someone could confirm that'd be great.

Can you or someone provide the DC pin voltage for the IC? Seems like the next place to troubleshoot...

*Edit* happy to take my readings.....I have this old radioshack multimeter ( https://hdkorean.com/hd-%ec%83%9d%ed%99 ... nt&uid=202 ). What setting should i put it on? (I tried DCV and got all blanks)

Which DCV? You'll want DCV20 for this application.

_________________
Scott

My band, Austin Hollow

Yeah, turning the Level full CCW should completely kill the output.


Pin 8 should be at your power source voltage (nominally +9V), pin 4 should be 0V (grounded), and all six other pins should be right around 1/2 of your power source voltage (nominally +4.5V).


To measure the DC voltage level on the IC pins, set your multimeter to the DC voltage mode, indicated by a solid line above a dotted one. Use the 20VDC range setting if it's not an auto-ranging meter. Your power source needs to be connected and there needs to be a cable in the input jack. If the pedal is assembled into the metal enclosure, put the black probe into one of the corner screw bosses of the enclosure--this is your ground connection. If the "guts" are out of the enclosure, use the sleeve tab of the input jack for the ground connection. Then touch the red probe to each point that you want to measure. See image below for the numbering of the pins.

_________________
“My favorite programming language is SOLDER” - Bob Pease (RIP)

My Website * My Musical Gear * My DIY Pedals: Pg.1 - Pg.2

Readings below....no idea if these are good or not (im guessing NOT)
1. 4.34
2. 4.34
3. 4.34
4. -
5. 4.26
6. 4.98
7. 4.39
8. 8.7

Also to leave nothing to chance... here are the capacitors I put in (text i added in red is what was on the body). I also had another I didn't use– it said .153 on the body and was a white square (unlike the rest, which were more rounded and red)

Those voltages are perfect. Can you please take voltages of the two transistors now?

_________________
*patience is a virtue*

Please do not PM me. email is prefered. keith@buildyourownclone.com

Your cap positions are also correct.

While you're checking the transistor voltages, could you also measure the three lug connections for the Vol pot (VR3) and the bottom lead of resistor R7? See labeled PCB diagram below.

_________________
“My favorite programming language is SOLDER” - Bob Pease (RIP)

My Website * My Musical Gear * My DIY Pedals: Pg.1 - Pg.2

Sorry for the delay– will take these measurements asap. To confirm to things quickly...
1. what setting on the multimeter dial should I use?
2. Do I measure this with both probes to the leg im measuring?

Do it exactly the same way that you took the IC pin voltages: meter set on 20V, black probe to ground and red probe on the test point.

_________________
“My favorite programming language is SOLDER” - Bob Pease (RIP)

My Website * My Musical Gear * My DIY Pedals: Pg.1 - Pg.2

OK, here goes....

Q1
-left leg: 8.7
-Middle leg: 1.84
-Right leg: 2.94

Q2
-left leg: 2.94
-Middle leg: 1.84
-Right leg: 2.94

VR3
-Left Lug: 3.92
-Middle Lug: 0
-Right Lug: 4.32

R7: 4.32

You should recheck those results. The transistor values don't look too bad, though it appears that you missed the collector on Q2, which should be ~8.7V based on your Q1 results, and it also looks like you may have switched the base and emitter values (base/middle leg should be higher than the emitter).

All the VR3 pot values should be ~the same, so recheck those, too. Be sure that you're getting good contact with the probe against the solder joints when you take these readings.

R7 value looks good, and this value is what you should see on all of the VR3 lugs.

_________________
“My favorite programming language is SOLDER” - Bob Pease (RIP)

My Website * My Musical Gear * My DIY Pedals: Pg.1 - Pg.2

Thanks– im a bit confused on the first part of the response....can you clarify which legs are the base and emitter?

Also I redid the volume pot and got the following
-Left Lug: 3.92
-Middle Lug: 4.77 (was 0 before)
-Right Lug: 4.32

Sure. Since the two transistors are mounted in opposite orientations, the order of the legs is different as viewed. From left to right:

Q1 (lower transistor): collector, base, emitter

Q2 (upper transistor): emitter, base, collector

Both collectors are connected directly to the pedal power source, so you should be seeing ~8.7V there based upon the other readings you've posted.

Here's what I see for the transistors in my own LMOD. Note that I'm using a "hotter" power supply than you are:

Q1

C: 9.94
B: 3.28
E: 2.84

Q2

C: 9.94
B: 3.31
E: 2.87


The values should really be closer than that. On my own LMOD, those three lugs of VR3 differ by no more than 0.04V at any setting of the pot sweep, while yours differ by as much as 0.85V. This discrepancy leads me to believe that there might be something wrong with the connections/soldering around that pot. The PCB connections look OK in your photos, but I'd reflow them anyway, if you haven't already. A photo of the connections to the pot lugs might be useful.

One other thing I see is that you have a lot of excess wire on your connections, and that all has to be tucked between the PCB and the pots & jacks. That can lead to a lot of stress on some of the joints or even some shorting in some cases. So you may wish to redo that wiring if nothing else seems to be working. If you do, there's some detailed "how to" guidance here: viewtopic.php?f=9&t=52513

_________________
“My favorite programming language is SOLDER” - Bob Pease (RIP)

My Website * My Musical Gear * My DIY Pedals: Pg.1 - Pg.2

making progress.

I rewired the volume pot and also doused it in deoxit as I noticed it was being finnicky. I also trimmed some cable as it was making it hard to seal up the enclosure.

The transistors are now measuring correctly, matching where they should be.

For the volume pot– when turned full clockwise, lug 1 & 2 = 3.92, lug 3 = 4.31
When turned counter clockwise, lug 1 = 3.92, lug 2 & 3 = 4.31


I can't crank the pedal now (working from home with roommates)– but at low volumes sounds roughly like i think i should. WDYT? dont want to fix something that aint broke....

That sounds encouraging. Let us know how it sounds with the volume dialed up.

_________________
“My favorite programming language is SOLDER” - Bob Pease (RIP)

My Website * My Musical Gear * My DIY Pedals: Pg.1 - Pg.2

it sounds very good. I think what it's supposed to sound like. Probably will just keep as is.

It will bug me knowing that the voltages may be a bit off but, may have to live with it. What do you think?

and thank YOU for all of your help!

Assuming the pedal sounds good to you, I encourage you to put this and all similar thoughts into the dumpster in the back parking lot of your mind where they belong.

_________________
Scott

My band, Austin Hollow

I would echo exactly what Scott is saying. Voltages are not what is ultimately important, though they can be very useful in determining what's going on in the circuit. But your ears are the final judge. And the slight differences between our measured voltages are very possibly just a reflection of small differences between our components or the hotter power source I use.


You're most welcome.

_________________
“My favorite programming language is SOLDER” - Bob Pease (RIP)

My Website * My Musical Gear * My DIY Pedals: Pg.1 - Pg.2

Sorry, I actually meant specifically the voltages on the volume pot.

For the volume pot– when turned full clockwise, lug 1 & 2 = 3.92, lug 3 = 4.31
When turned counter clockwise, lug 1 = 3.92, lug 2 & 3 = 4.31


Does this still look off? Seeing a .4v difference, but it was mentioned a .04 difference was expected...

Close enough at this point, IMO. And the values appear to be reacting appropriately to the Vol pot settings. Unless you find that you don't like the sound, I wouldn't fool around with the pedal further.

_________________
“My favorite programming language is SOLDER” - Bob Pease (RIP)

My Website * My Musical Gear * My DIY Pedals: Pg.1 - Pg.2