Anyhow, I have this breadboarded but am not getting white noise sound from Q6-C. In fact no sound. In hz i get random frequencies the most common being 3.3hz (ish). I have swapped in and out transistors etc but to no avail.
9v in (8.9 at test)
Here is the leg readings.
Q2: C = 8.9v. B = 0.56v. E = ground
Q5: C = N/C. B = ground. E = 8.11v
Q6: C = 8.15v. B = 0.56v. E = ground
And here is the schematic.
The collector voltage of Q2 looks suspicious - it is at the supply potential, and the presence of R9 should drop the observed collector voltage down a bit. Check all connections, then Q2 and if it is OK, try reducing R10 to turn Q2 on a bit further. Aim for the same collector voltage as Q6.
White noise sounds like a gentle hiss, with a perceived (but not real) pitch of a few KHz - where the ear is most sensitive.