Tuner output circuit from Etherwave hotrodding manual

Great. Is that a 470nF cap in your drawing, or 470uF?

470nF is enough. Don't exaggerate. The other one is 100nF. Sorry for my unreadable scribble... 

I have, in the past, cobbeled together a work around where I take a headphone feed from the amp that my EW goes into and plug it into my auld Korg tuner (pictured somewhere here).

It seems to work although I'm not sure about latency etc etc etc.

As an aside - regarding Hotrodding, I'm thinking about going down the dark path to using the EW to control MIDI devices and was thinking of converting my EW to the Plus via the conversion kit: is this a good move?

I haven't tried the field upgrade kit... but that's a good idea. 

I think the problem with using the headphone out from your amp is that it won't have any signal when the volume is off, and the point of using a tuner is to know which note you're on when you first bring up your volume hand.

'I think the problem with using the headphone out from your amp is that it won't have any signal when the volume is off, and the point of using a tuner is to know which note you're on when you first bring up your volume hand.'Jason

Eh...aye...I can see the logic there...

(ok, it's late and I've had a beer...)

"I highly value Christopher's scientific mind and all the experiments he does, but here, he is completely off the rails."  - Thierry

I agree with both sentiments in this sentence.  The board consists of a SG3525 (high current PWM controller) with beefy output transistors, and only incidentally a LM358.  It's made for switching power supplies and small motor control and such, not audio.

Here some pictures which I just posted in a thread with a similar topic:

http://thereminworld.com/forums/T/32191?post=213781#213781