Pete's First Clipper!

petesguitar1 · February 07, 2006, 07:56:26 PM

Hi folks, long time watcher and tinkerer here. I have built a blue clipper from www.tonepad.com and built it on a PCB I bought from the site. I have a problem (how often do you hear that!?!) I am very new to this game!

I have substituted the 200k (R1) and 240k(R2) resistors with 220k resistors. Unfortunately it's all I had.

The pinout of the IC TL071CP is as follows

1 Offset N1 8 NC
2 In - 7 Vcc+
3 In + 6 Out
4 Vcc - 5 Offset N2

When I have looked at the schematic it seems to all line up properly.

I have tested all of the solder joins for voltage, and I have discovered something which I thought was kind of strange. I have good voltages all the way up until C3 (4.7uF) and after this cap I have no voltage. Everything after it is zero. I have replaced this cap 3 times with 3 brand new caps and still nothing.

I am also wondeing about the trimmer it says to use.It says a 50k trimpot, just wondering how that would translate to a normal pot for adjustment outside the case.

Thanks heaps

Pete

Joecool85 · February 07, 2006, 08:04:21 PM

Caps kill the voltage, thats suppose to happen. Please, someone correct me if I'm wrong.

BrianJ · February 08, 2006, 12:49:58 AM

You are quite right, Joecool85. Capacitors do block Direct current. In fact, as I look at this schematic, that seems to be the only purpose of this cap. If you are getting sound in and out, petesguitar1 I think you hit the nail on the head. As for the pot, use what ever value the schematic says, and put it on the outside of the box with no worries. Use an audio taper pot with the wiper terminal going to the output jack. If your adventurous, you could replace the 150k feedback resistor with an audio taper 100k pot-wired as a reostat (wiper tied to one end)-in series with a 50k resistor and BOOF! You now have a gain control.

Congrats on you first pedal

petesguitar1 · February 08, 2006, 01:05:14 AM

Unfortunately for me, I have nothing, no sound at all. A little bit dis heartening!

petesguitar1 · February 08, 2006, 01:33:06 AM

Voltages

IC
-

1 - 0.11
2 - 2.77
3 - 2.42
4 - 0
5 - 0.11
6 - 2.57
7 - 5.22
8 - 0

Capacitors

C1 - 2.27 - 0
C2 - 2.52 - 0
C3 - 2.51 - 0
C4 - 0 - 0
C5 - 4.96 - 0

Resistors

R1 - 2.24 - 4.95
R2 - 2.24 - 0
R3 - 2.49 - 2.49
R4 - 2.49 - 2.49
R5 - 0 - 0
R6 - 0 - 0
R7 - (trimpot) 0,0,0

Diodes

0,0

I'm also getting no voltage on any of the jacks if that matters...I don't know!?!

Thanks for your help so far

valhalla · February 08, 2006, 03:59:38 AM

I just built this myself, i used the schematic from www.runoffgroove.com , as i cant open the PDF file on tonepad i cant see the schem you used. The schem i used has 2 - 22k resistors, apparently the 240k resistor and the 20k in some schematics is wrong. Anyway i hope you get this fixed as it sounds pretty good.

Steben · February 08, 2006, 04:12:36 AM

Are you feeding it with 9V? Pin 7 should be exactly the supply voltage. Pin 3 should be around the half (which is the case here).

petesguitar1 · February 08, 2006, 04:25:42 AM

I just checked my battery voltage, and it's down to about 7.2 Volts. Could this be the cause of no sound? Maybe not enough power? I know in the checklist it says to have a new battery with at least 8 Volts. I'll try again tomorrow. Thanks heaps for all your help. Can't wait to get this finished. I looked at the runoffgroove schem for the new clipper. My next step was to sub in different values for those resistors (apparently to avoid oscillation). Oh well, it's all good fun!

Joecool85 · February 08, 2006, 07:22:12 AM

That could definetly be the problem. Some pedals work fine with almost no voltage, but a lot of pedals require 8 or 8.5 volts minimum. I'd go grab a new 9volt, or a wallwart and see how that goes.

theundeadelvis · February 08, 2006, 11:42:32 AM

If you haven't already build yourself an audio probe. You wouldn't believe how often it will help you debug stompboxes!
http://www.diystompboxes.com/pedals/debug.html

petesguitar1 · February 08, 2006, 06:58:31 PM

Thanks heaps. I'm building a probe right now! What a fantastic idea!

petesguitar1 · February 08, 2006, 11:18:37 PM

You know that feeling when you've done something right! WOOOOHOOO! I know it's simple but I now have a very nice sounding Blue Clipper Clone pedal. It makes my TS-9 (Keeley) sing like a bird! Wow, I'm hooked!

Thankyou all!

Joecool85 · February 09, 2006, 08:47:16 AM

Was it just the battery?

petesguitar1 · February 09, 2006, 06:08:47 PM

It was actually my input jack. It was mounted a touch too close to the casing, so when I soldered the wires onto the jack, one was touching the casing, causing a short circuit hence nothing coming out. It was just systematic problem solving in the end. I'm almost finished my second one. I'm wondering about using LED's as diodes. Any thoughts?

Joecool85 · February 09, 2006, 09:34:34 PM

Not sure what it will do in the clipper, but in a bazzfuss LEDs make it sound really mean compared to the soft(er) sound of a 1n914.

petesguitar1 · February 10, 2006, 12:15:57 AM

I have built a second one, all the same specs but now I have really low output. It's there, but I havce to turn up my amp flat out to hear it!

Any ideas?!?

petesguitar1 · February 10, 2006, 02:09:05 AM

IC - faulty I'm guessing!

Ok, new question. My Keeley Modded Ibanez TS-9 works fine by itself, but when I try to plug my Blue Clipper in after it it shuts off. Pedal chain is

Guitar -----> TS-9 ------> Blue Clipper Clone -----> Amp

Any ideas!?!

Joecool85 · February 10, 2006, 07:43:41 AM

I would say one of them is positive ground and the other is negative.

petesguitar1 · February 11, 2006, 12:16:56 AM

Any way I can rectify this. As I said, I'm pretty new to the game!

petemoore · February 11, 2006, 01:41:36 AM

How is power supplied to these pedals?
That and more description...under what exact conditions do the pedals function and malfunction?

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Pete's First Clipper!