Muroidea no sound.

Travis

Active member
I built a Muroidea, try with some ICs and with some 2n5458... It's doesnt sound.

Some help please?

Thanks
 

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Which ICs have you tried? 4558 is a dual opamp and this build calls for a single. LM308 is the standard but people have had good results with TL071, OP07 etc.
 
Well ive always used either an op07 op amp or a TL71, both from tayda. The LM833 seems to be a dual op amp again, so make sure to check to see if you have any single channel op amps.
 
I replace with TL071 and new 2N5458 and nos it's sound but It makes Huge whistle when I turn gain more than 60% :(
 
With a TL071, snip out the 30pf cap from pins 1-8. I have had to add small buffer circuits to the front end of rats after running in to the same issues. Does turning the filter knob change the frequency of the oscillation?
 
With a TL071, snip out the 30pf cap from pins 1-8. I have had to add small buffer circuits to the front end of rats after running in to the same issues. Does turning the filter knob change the frequency of the oscillation?
Just the oscillation come Down when I turn gain less than 60-50%...
So I must remove 30pf?
 
hi all, I just built this same pedal and I'm having the whistle oscillation sound as well. I am using a TL071. I was troubleshooting and referenced the data sheets. I noticed the TL071 has a different pinout than the LM308. Pin 8 on the TL071 is not connected. the pin 5 on the LM308 is not connected. Initially i was not getting audio to pass until I used a jumper to get from the 30p cap to pin 5, connecting pin 1 to pin 5) and clipped pin 8 on the IC. I now have sound but I'm experiencing the same issue of the loud whistle. I tried removing the 30p cap and it doesn't change the whistle. I also replaced the A100k pot on the filter with an A25k (didnt have A50k on hand) and there is no change in the whistle.

I checked each component during install to make sure the values were correct. I have also checked the caps, diodes, IC and the JFET for proper orientation.

Any ideas what could be causing this?
 
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