mesmerizer - not so subtle mesmerizing (waveforms?)

[lcipher3]

Harmonic Mesmerizer Troubleshooting
Issue: seems to "work" but not very much range in "tremolo-ness" Seems like its a sort of on/off trem, no real useable range and not subtle at all. I an not a super experience trem user so I'm probably not describing it well

I have a scope (Analog Discovery Digilent) connected to base of Q5 and the base of Q6 - this is what I get::

At MAX RATE and DEPTH I'm getting about a 20Hz and +/-0.72V signal - nice looking sine waves​

180 deg out of phase between the two signals.​

Turning the DEPTH amplitude is smooth from the max to pretty much close to zero.​

Keeping DEPTH maxed, changing the RATE down (low) the Q5 base drops a bit to +/-0.65 and Q6 drops to +/-0.2V.​

Freq is slow (0.2 Hz or so)​

Is this what is should be doing ie less amplitude than Q5?​

Phase shifts a bit but they're still out of phase.​

Some other measurements (DC volts)

TRANSISTOR pin: 1/2/3
Q1: 10.6/1.75/0
Q2: 17.1/10.6/8.1
Q3: 10.6/1.9/0
Q4: 17.1/10.6/8.1
Q5: 1.2/1.2/ (varies)
Q5: 1.2/1.2/ (varies)

 

[lcipher3]

Anything else I can check? If I put a signal in (sine wave?) what should I see?

 

[lcipher3]

Is the design sensitive to the dual LED type?

 

[Robert]

I don't have one of these here to verify, but I don't see any reason the gate of Q5 and Q6 shouldn't be similar (but 180 degrees out of phase with each other).

 

[lcipher3]

I don't have one of these here to verify, but I don't see any reason the gate of Q5 and Q6 shouldn't be similar (but 180 degrees out of phase with each other).

So they should always be same amplitude 180 apart - across the RATE?

Thought so - it is at MAX rate but changes as the rate is decreased. Losing something in the signal to Q6. That gives me a starting point on what to look for.

Is the LED an essential part of the circuit or just a visual?