The Nyquist Aliaser is just ring modulator?

[oldrocker]

After listening to sound samples of this effect I started building it and now I'm thinking this is only a ring modulator.  The sound samples I think had the envelope follower circuit added to it so it sounded like something else.  So I guess I thought it was more than that.  Is it strictly just a ring modulator?

[oldrocker]

Okay, finished the build and I can see it's much more that just ring modulation.  Some nice octave type sounds combined with the guitar signal.  It's also got a cool odd distortion at some settings.  Really bizare at times.  I tried a few different dual opamps like 4558, 5532, TL082 and 1458.  All have different characteristics to them.  It was hard to choose which one sounded best.  They all sounded good really.  I ended up using the 1458's just because I thought it sounded cool.  For fets I ended up using 5952's.  I haven't added the envelope follower mod yet.  Can I just use a Dr. Q before the Aliaser for the same effect or does it have to be added in the circuit?  All in all it's a fun sounding effect.  I'm going to bring the 10K trim for wave shaping to the outside of the enclosure to get more sound variation.

[John Lyons]

Randall  (by the way, I got those ICs, Thanks!)

Did you perf this?
How is the Bleed through with yours?

I'm cobbling up Biroids CMOS version now. Just need to order up those chips...

If you have a soundclip or two I'd love to hear it.

John

[oldrocker]

Hi John,  I'm glad you received the chips OK.  I received the ones you sent too hence the 4558 and 5532 I was able to try in the Aliaser.  That made it nice trying all those different dual opamps so thanks again.  I didn't want to waste the only two chips you sent me in this pedal and I have a few extra 1458's laying around and since they all sounded good why not use what I had most of.  Yes I did perf this and I used all 5952's for fets except for the first position where I used a J201.  It made it deeper and louder with more strange artifacts.  I'm not sure about the bleed through but I can hear a little high pitch whine way in the background especially while wearing headphones.  I'll send you some sounds clips.  Man this has some strange wild sounds in it.  Just up my alley.

[John Lyons]

The bleedthrough is the carrier frequency whine you mention, same thing... It seems that it's not too bad from what you decribe.
Anxious to hear the clips.

I'd really like to add some more noise maker and odd circuits to my soundclips page..

John

[slacker]

Can I just use a Dr. Q before the Aliaser for the same effect or does it have to be added in the circuit?  All in all it's a fun sounding effect.

You need to add the envelope follower to the circuit, like moosapotamus did. The envelope follower basically then changes the frequency of the aliaser in the same way that turning the trim pot does.
I've added an LFO to mine instead of an envelope follower and found that adding a 100k resistor between the centre lug of the 10k trim and the base of the transistor really improved the sweep.
If I ever get round to boxing it up I'll post some samples, it's pretty cool.

[oldrocker]

OK you got it John I'll make sound clips as soon as I can get it boxed.  Thanks Slacker now I can't resist trying out some type of automatic frequency adjuster.  I think I still have enough room on the board to add that in there.  That's the beauty of perf. 
Slacker I would like to hear the LFO circuit used in the Alaiser so sound clips would be awesome. 
A stompbox addicts work is never done.

[oldrocker]

I added the envelope follower to the circuit.  I also added the A D voltage supply separation too.  Sounds pretty good although maybe a little noisier but worth it.  Now I just need to box it up.  Below are some pics of the perf board.
http://www.logmonster.com/images/full/?pic=aliaser1_1170007440-422-14672.jpg
http://www.logmonster.com/images/full/?pic=aliaser4_1169985910-422-14673.jpg
http://www.logmonster.com/images/full/?pic=aliaser5_1169957698-422-14674.jpg

[oldrocker]

I've got a stupid question.  What is the CV input use for?

[moosapotamus]

...I would like to hear the LFO circuit used in the Alaiser so sound clips would be awesome. 

I've got a bunch of audio clips that I made posted here...
http://moosapotamus.net/IDEAS/nyquist/nyquist.htm

... there's one with with the LFO circuit, with me playing bass.

What is the CV input use for?

It's for inserting a control voltage to modualte the carrier frequency. You could use a foot pedal or any other control voltage source. For example, for that LFO clip that I made, all I did was connect the LFO output from my moogerfooger phaser into the CV input. I also have another clip posted where I plugged the output from a little analog sequencer into the CV input. Pretty cool.

~ Charlie

[oldrocker]

Thanks moosapotamus,  Hey the clips sounds very close to mine if not exact.  They sound great.  Okay I added the cv input also so I can try that too.  Pretty cool.  This ended up being more complex than I originally thought.  So now I have 5 knobs and three jacks.  It took me a few hours to add the envelope follower.  I used another 1458.  I'm not sure why but the TL082 didn't work in there.  I had to stop playing with it or my wife was going to kill me.  She says I'm building too many pedals.  IMPOSSABLE!!

[oldrocker]

Finished boxing up the Aliaser.  It works great.  I'm now working on sound clips.  Pics below.  A play on words for the name.
http://www.logmonster.com/images/full/?pic=Nyquist1_1170007735-422-14677.jpg
http://www.logmonster.com/images/full/?pic=Nyquist2_1170089100-422-14678.jpg
http://www.logmonster.com/images/full/?pic=Nyquist3_1170101937-422-14676.jpg

[moosapotamus]

Lookin' good. What about the guts?

~Charlie

[oldrocker]

The pics of the guts are 6 messages up.

[moosapotamus]

Ah, yes... saw the board pics. I meant inside the box.
whatever...

~ Charlie