Rod Elliot Guitar Vibrato Unit

[lonewolf]

Has anyone built this device?
the signal passes thru but has no modulation
I have double checked the circuit,and everything is correct
I substituted 2N5457 for 2N5459.. and TL072 instead of the 1458 IC's
any Ideas

[petemoore]

any Ideas
  Vibrato is pitch control, that's a tricky one, but in this case 'vibrato' probably refers to the circuit Rod Elliot'ed.
   Don't know that I've looked at it and definitely don't recall what the scheamtic might have looked like.

[PRR]

> Don't know that I've looked at it and definitely don't recall what the scheamtic might have looked like.

Yes, if help is wanted it is good manners to link to the article.

Bi-polar supply?

Voltage at opamp outputs (pins 1 and 7)?

In particular, U2B pin 7 should be wobbling around zero. If it is stuck, report voltages at U2B inputs pins 5 and 6.

[lonewolf]

Mammoth  does not supply pinouts for their transistors ,so I crossed to a NTE # and the two are reversed..found that out after more investigation..I flipped the BC549 around and then it worked....

[lonewolf]

this is a versatile circuit..by using the effect control it varies the sound from a tremolo to vibrato effect
I socketed R17 to experiment with the speed and added a DPDT switch with a 10K resistor on one side and a 150K on the other so I can slow down the rate or speed it up to where it sounds like a ring modulator...3 different sounds in one box