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Projects => Tech Help - Projects Page => Topic started by: SuperBaz on January 27, 2019, 11:50:16 PM

Title: Total Recall issue - can't calibrate <sorted>
Post by: SuperBaz on January 27, 2019, 11:50:16 PM
Hi there. Having successfully built a Total Recall, I have attempted another. In this case it's actually a rack mounted, dual mono or stereo linkable version for studio use, ie. 2 boards.
I'm getting high pitch squeal and very distorted sound when calibrating IC6. No clean delay.
Voltages are good at the regulator. I've measured all voltages on IC1 through 9 and there is only one notable difference (same on both boards) - IC2 pin 7 is -12.23 rather than -4.71. On IC5, pins 5,6 and 7 are a little low (-5.95). Other than that, all is as it should be.
Given that I have a working version, I have tested the NE570 and CD4047 in it and they are ok.

Any suggestions? Please note that though I've built lots of pedals, and some studio compressors, I have no knowledge of electronics. I can follow instructions though!
Thanks in advance.
Bevan
Title: Re: Total Recall issue - can't calibrate
Post by: Scruffie on January 27, 2019, 11:54:44 PM
Check ye R10 & 11 values (and R9 while you're at it too).
Title: Re: Total Recall issue - can't calibrate
Post by: SuperBaz on January 28, 2019, 01:34:52 AM
Blimey that was quick, and accurate too. As you've no doubt guessed, I have put 6K8 in those three positions. I shall replace and see what happens!
Back soon.
Thanks!
Title: Re: Total Recall issue - can't calibrate
Post by: SuperBaz on January 29, 2019, 02:54:25 AM
Success!
Thanks Scruffie, much obliged.
I shall post a pic once the faceplate is lazered.
Bevan