"Nice Mixer"

[Freq Band]

Ray's "Nice Mixer"
http://www.musicfromouterspace.com/analogsynth/STEREOMIXER2006/STEREOMIXER2006.php


Look at board #2 schematic
....stereo line input 1
versus
stereo line input 2

....R62 and R66 in "line #1" say 150k
but
R69 and R73 in "line #2" say 47k

Is this a mistake ?
or does it serve a purpose ?
They are also shown this way in the parts layout.

thanks,
=FB=

[Pehr]

I have not seen this!
It must be a mistake, right?
Perhaps you should email Ray and ask?

EDIT: It should prob be 150k since the effect return inputs also use 150k.

[Pehr]

I couldn't wait

[factus10]

I'm glad I haven't done up the panel for mine yet (I have 2 of these boards). I've already soldered those resistors but that's reasonably easy to change

good catch!

[Freq Band]

Thanks !

I am gutting an old PAIA "9402 Sub Mixer", and using Ray's circuit to re-gut it. Building it point-to-point, using perf board. (sorry Ray, I'll buy some other stuff soon.)

The original owner DIY'ed it, and I thought I could improve on the old PAIA circuit (using a single NE5532) and redo the psu....plus add some effects channels.

Pics soon.

=FB=

[Freq Band]

Another confusion....

This mixer uses inverting opamps.

The mono channels have an inverting input buffer (opamp), and is sent to the the inverting output opamp.

But the Stereo inputs have no buffer.....which means they go directly to the inverting output opamp(s).

Will the stereo outputs be inverted, by passing through just the inverting opamp, at the output ?

Can someone clarify this for me?

=FB=

[Pehr]

You're right. Puzzling... I'll have a look with the scope...

[Pehr]

I've also noted that the strereo-and mono-channels have different gain. The mono ones have 10 and for stereo it's 2. I'll prob change my mono channels by replacing the 470k feedback resistors with 100k ones.

I'm also going to add a main vol out.

[Pehr]

I would also like the effect send pots to work like my behringer mixer. That is when they're at max it means the signal is wet and at min dry. Not dry/mixed.

[Freq Band]

I'm searching the web for a method for a "proper" wet/dry control.

I know it's out there....
So far, I found this:
This is a balanced design, but I'm trying to understand the theory/wiring idea)


(EDIT link not working)

=FB=

[Pehr]

'The page cannot be found'

I believe it can be solved with a circuit much like the panning, but I'm not sure...

[Freq Band]

(EDIT link not working to prodigy-pro.com)
(credit and copyright - Keith Andrews, 2005)

If this link doesn't work, I'll PM it to you.

=FB=

[Pehr]

Great link! Thanks!

[Freq Band]

Trying this again, so other people know what circuit we're referring to.
I was granted permission to post this by the designer.... Keith Andrews.

http://img.photobucket.com/albums/v379/SSLtech/Crush.gif

=FB=