Build Your Own Clone Message Board

I finished the FET Preamp and am having volume issues. For one the volume knob seems to be reversed- as in clockwise the volume decreases, counterclockwise the volume increases. Also, at its loudest it’s slightly lower than my clean signal. The other controls seem to work as they should.

1) Check to make sure that the two IC's are properly oriented.

2) Swap their positions and see if that changes the way the pedal acts.

3) This process is very often effective in solving a variety of problems: viewtopic.php?f=9&t=52188

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

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

I’d gone through this message board and looked at most of FET issue posts and tried what worked for them to no avail. The IC’s are properly oriented and and I’ve tried swapping them. I’ve made sure my 470 ohm and my 470k resistors are all good. I’ve reflowed my solder, but didn’t hit the points under the treble knob so well because I didn’t want to bend it much but could try that tomorrow

I suspect the next step may be voltage readings on the ICs. Do you have a multimeter?

_________________
Scott

My band, Austin Hollow

I do

In that case, please take voltage readings on each of the 8 pins of both IC's and report the results here. Also, please pull the IC's (gently!) from their sockets and get voltage readings on the sockets themselves.

In case you're unfamiliar with how to do that, here's some guidance:

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 to the pedal 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.

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

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

I think I did this right

Top
1-0.3
3-18.4
4-0
5-0
6-9.2
7-0.1
8-19.8

Bottom
1-0.4
3-18.4
4-0
5-0
6-9.2
7-0.4
8-19.9

What kind of power supply are you using?

_________________
*patience is a virtue*

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

True Tone one spot. Not daisy chained to anything else.

You might be reading the voltages incorrectly. According to your readings, your power supply is producing 20VDC.

_________________
*patience is a virtue*

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

Entirely possible I’m reading it wrong, this is the first time I’ve taken my multimeter out of the box and I’m not sure I’m using it right. I’m using the Economy Digital Multimeter that I bought from BYOC. How should I have it set?

That's BYOC's video on the subject.

_________________
Scott

My band, Austin Hollow

See marked up image below. You want the 20V DC setting that I've marked with the arrow. If you don't have this exact meter, then look for the comparable scale markings on yours. The black probe goes to the COM port in the bottom-middle of the meter, and the red probe goes in the port to the right. Then follow the measurement instructions I provided above.

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

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

Suuuuper helpful video, thank you!

New readings I’m much more confident in

Top
1-0.23
3-8.84
4-0
5-0
6-4.64
7-0.16
8-9.47

Bottom

1-0.11
3-8.84
4-0
5-0
6-4.64
7-0.04
8-9.46

Based on the fact that your supply voltages (0V on 4 and 9V on and bias voltage (4.5V on 6) are good, yet no output on 1, 5, and 7, I'd say not just one, but both of your chips are bad. Please contact sales@buildyourownclone.com

_________________
*patience is a virtue*

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

Right on, just did, thank you! What should the output on 1, 5 and 7 be so I can check the new chips?

1 and 7 should be about 4.5V. I don't recall what 5 should be. -8.5V I think.

_________________
*patience is a virtue*

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

New chips came today. 100% resolved. Thanks everyone!