http://www.tonepad.com/project.asp?id=27 (http://www.tonepad.com/project.asp?id=27)
hi, so i made this delay pedal a while ago. it didnt work but i figured it out that opamp was bad and replaced. and it worked!
today i went to play it but all of sudden again!, it doesn't work. bypass is fine but when pedal is on, there is no sound. I went through debugging and checked connections etc. but seems like parts are bad maybe?
i measured the voltage throughout I noticed pin #3 of IC PT2399 is zero and pin #4 of IC TL072 is also zero.
what does this mean???
please help me!!
im so frustrated as it was working...
I would also like some help on this. I have 2 rebote 2.5's that have been subjected to ac power(not by me) and no longer work. They both power up but no sound when engaged.
check the schematic. Pin 3 of the PT2399 is connected to GND, 0V reading is ok. Same goes for pin 4 of the TL072.
AC could mean trouble. Post voltages on all IC's.
Hi, thank you so much for reply!!
Here are the voltages on ICs
IC 1 Delay Chip
1 --5
2 --2.5
3 --0
4 --0
5 --2.3
6 --2.5
7 --0.6
8 --1
9 --2.5
10 --2.5
11 --2.5
12 --2.5
13 --2.5
14 --2.5
15 --2.5
16 --2.5
IC2 Op Amp
1 --4.6
2 --4.56
3 --4.62
4 --0
5 --3.46
6 --4.4
7 --4.4
8 --9
i heard that pin 5 on op amp should be higher. if op amp is not working properly, this is really strange since i replaced it before because it wasnt working and after i put a new op amp, it was working for a while but all of sudden, no sound when on.
so if i have to replace op amp, this will be second time in really short period of usage. maybe i have something else wrong?
thanx!!!!
Voltages look ok.
Do you get a sound out of Pin 14 of the PT2399?
Quote from: Auke Haarsma on September 25, 2008, 11:23:10 AM
Voltages look ok.
Do you get a sound out of Pin 14 of the PT2399?
sorry. what do you mean by that? do I just tap it plugeed it literally to get a sound?
you could use an audiopobe (check geofex.com).
I just 'plug in' there. If you can visualize with an oscilliscope that's easier ofcourse. But not everyone is so lucky to have a scope at hand ;)
Quote from: Auke Haarsma on September 25, 2008, 11:47:56 AM
you could use an audiopobe (check geofex.com).
I just 'plug in' there. If you can visualize with an oscilliscope that's easier ofcourse. But not everyone is so lucky to have a scope at hand ;)
ohh ic
thanx for suggestion. i have to order parts now. just curious is there any other way as well?
thanx
no need to order anything. Just connect a wire to a jack. Connect to other side of the wire to whatever you wanna listen to (in this case pin 14).
Quote from: Auke Haarsma on September 25, 2008, 12:13:44 PM
no need to order anything. Just connect a wire to a jack. Connect to other side of the wire to whatever you wanna listen to (in this case pin 14).
thank you auke.
so plug in 1/4" cable input and 1/4' cable to amp and input cable touch that pin 14 to hear noise through amp?
Almost ;)
2 cables:
1) Guitar -> Jackcable -> Input of Rebote.
2) Amp -> jackcable -> jackbus (connect sleeve to ground). Tip of jackbus to a wire. That wire you can use to listen to the signal anywhere you plug it in.
Quote from: Auke Haarsma on September 25, 2008, 12:38:32 PM
Almost ;)
2 cables:
1) Guitar -> Jackcable -> Input of Rebote.
2) Amp -> jackcable -> jackbus (connect sleeve to ground). Tip of jackbus to a wire. That wire you can use to listen to the signal anywhere you plug it in.
:icon_redface:sorry auke. i sound dumb but jackcable means ordinary 1/4" guitar cable?
jackbus?
thanx
No need to say sorry, I should have been more precise!
jackcable is indeed your normal guitar cable.
jackbus is something like this:
(http://www.newtone-online.nl/catalog/images/cd63mo.jpg)
or
(http://www.newtone-online.nl/catalog/images/cd63msppm.jpg)
Hi, Auke. thank you.
I just tested the sound. I get sound from any pins of Dealy IC.
??
You get sound?
Or do you not get sound?
I get sound.
You should only get sound on Pin 16,15,14 of the PT2399.
I suspect something went wrong with the audioprobe.
Quote from: Auke Haarsma on September 25, 2008, 02:56:00 PM
You should only get sound on Pin 16,15,14 of the PT2399.
I suspect something went wrong with the audioprobe.
oops :icon_redface: you were right.
i got sound from 14 15 but not 16.
and those sound i got was delay lay lay lay>>>>>
exciting!!
seems like almost there??
yeah seems like the PT2399 is working ok.
Now follow the signal to the Repeats and Level pot. Still good sound?
Hi!
so I followed the signal and found a place where cuts off the delay sound and i resoldered it.
and it works!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! :) :) :) :) :) :) :) :) :) :)
thank you so so so so so so much!!!!!!
Auke!!! thank you so much!!!
now i want to make more pedals or mod this one. yes!!! thank you!!!
Awesome! You found and fixed it yourself, good job!
You have got the two basics of debugging now:
-measure the voltages
-follow the audiopath
Both can show you where something is wrong.
Enjoy the delay! :icon_mrgreen: