Boss CE1 king of chorus no chorus

[cniers13]

Hello! I have a Boss CE1 clone, king of chorus V2 board. I get bypass tone and preamp gain but no chorus sound. I've poked around with an audio probe around the TDA1022 chip and haven't gotten any vibrato/chorus. The chip was from small bear. D2 is omitted because of the DC/DC converter I chose. Any help would be great!

 

[cniers13]

 

[jwin615]

That TDA looks less than convincing.
Is there output at pins 8 and 12?
Is the LFO functional?
What opamp did you use for IC4? Not all opamps play nicely as an LFOs.
Ask anyone who tried to use a 072 where an 062 was called for.

 

[cniers13]

That TDA looks less than convincing.
Is there output at pins 8 and 12?
Is the LFO functional?
What opamp did you use for IC4? Not all opamps play nicely as an LFOs.
Ask anyone who tried to use a 072 where an 062 was called for.

I can hear ticking off the 1458 and on some of the TDA1022 pins. Let me fire up the probe again and test again. The chorus vibrato switch works and the rate changes the LED. I could try swapping the 1458 and 072

 

[cniers13]

That TDA looks less than convincing.
Is there output at pins 8 and 12?
Is the LFO functional?
What opamp did you use for IC4? Not all opamps play nicely as an LFOs.
Ask anyone who tried to use a 072 where an 062 was called for.

pin 8 and pin 12 I hear a chriping sound that is aligning with the rate LED

 

[cniers13]

my dc/dc is around 11V which matches the build doc. I have verified all components are correct. Wiring and soldering joints look good, not really sure what else would be causing it. I swapped the LM1458 for a MC 1458 and no change

 

[cniers13]

I swapped all the ICs minus the 1022. Not having any luck so far. The clock seems to be working but no chorus sound

 

[jwin615]

Do you have an oscope to verify the LFO is functional. What min/max clock speeds are you getting?
Also, is the internal trimmer to the right of the left footswitch jumpered out?

 

[cniers13]

Do you have an oscope to verify the LFO is functional. What min/max clock speeds are you getting?
Also, is the internal trimmer to the right of the left footswitch jumpered out?

no scope on hand, the jumper is for an optional chorus depth. I have a jumper between pins 2 and 3 per build docs

 

[cniers13]

For the 1022 I had these voltages (DC):
1 -5.2
4 -5.6
5 -3.1
8 -5.4
9 -11
13 -10.8
12 - 5.8
Everything else is 0 or in the mV range.

For IC1 and 2 i had -11 at pin 4 and 9.5/10 at pin 8

 

[ICTRock]

now I remember why I never built this ... friggen chip is $50
might need to pif this problem out of the pile

 

[cniers13]

now I remember why I never built this ... friggen chip is $50

yes! thats why I am hoping its not a bad chip

 

[jwin615]

You're using a +-15 converter?
Does you DMM have a frequency count/Hz function?

 

[cniers13]

I have the recom RP-1215D. And yes DMM has frequency function

 

[jwin615]

Pin 9 should be closer to -15
Try measuring the frequency at pins 1 and 4
Should be somewhere between 5k and 500k, depending on settings, square wave between 0v and -15v
May be good to check you meters max readable frequency and turn the rate/speed down on the pedal.

 

[cniers13]

Should I try the pedal at 12V?

 

[cniers13]

Mine can measure up to 50khz let me see what I get

 

[cniers13]

I don't seem to be getting anything. OL between pin 1 and 4 on the 1022

 

[cniers13]

Upon some further investigation I have the RP not RD model. The RP is 1w not 2w. should be the same voltage though?

 

[cniers13]

Running at 12dc I can get -15 on pin 9