electro-music.com   Dedicated to experimental electro-acoustic
and electronic music
 
    Front Page  |  Articles  |  Radio
 |  Media  |  Forum  |  Wiki  |  Links  |  Store
Forum with support of Syndicator RSS
 FAQFAQ   CalendarCalendar   SearchSearch   MemberlistMemberlist   UsergroupsUsergroups   LinksLinks
 RegisterRegister   ProfileProfile   Log in to check your private messagesLog in to check your private messages   Log inLog in  Chat RoomChat Room 
Live streaming at radio.electro-music.com

  host / artist show at your time
<on air> Rob Adventures in Sound
Please visit the chat
 Forum index » DIY Hardware and Software » PAIA Equipment
PAIA Wind and Surf Synthesizer
Post new topic   Reply to topic
Page 1 of 2 [32 Posts]
View unread posts
View new posts in the last week
Mark the topic unread :: View previous topic :: View next topic
Goto page: 1, 2 Next
Author Message
Dan Lavin



Joined: Nov 09, 2006
Posts: 620
Location: Spring Lake, Mi, USA
Audio files: 21

PostPosted: Mon Jan 16, 2012 7:37 pm    Post subject: PAIA Wind and Surf Synthesizer
Subject description: Having fun with analog noise!
Reply with quote  Mark this post and the followings unread

I just finished creating a John Simonton "Wind" using the manual found at PAIATalk. The circuit is so simple, it's best built on perfboard. It's a nice short weekend project. Really cheap too! No chips, just transistors and diodes for semiconductors.

I've mounted it in my homebrew FracRac cabinet with it's sister (brother?) product, the PAIA Surf Synthesizer. This was my very first Synth DIY project built the summer of 1977. This is about my 3rd restoration of it.
The surf synth has the mods suggested in a reader letter from 1972 with the exception of not reversing the filter diode D1. That just leaves the silly thing wide open with no control.

Both units use panel mounted pots instead of trim pots and have a volume pot for mixing.

the audio sample I recorded uses both units set to the extreme.....so it's like a wind storm at the beach. You can obviously dial everything back so it could be a pleasant day at the beach, but that's just not as fun!


DSCN3562.JPG
 Description:
Here's my homebrew panels in my homebrew case! (hick!)
 Filesize:  394.81 KB
 Viewed:  128 Time(s)
This image has been reduced to fit the page. Click on it to enlarge.

DSCN3562.JPG



WindyDayAtBeach.mp3
 Description:
Very minimal knob twiddling. I prefer the analog wind and surf over my more 'realistic' sample-based GM/XG units even though those probably sound more realistic.

Download
 Filename:  WindyDayAtBeach.mp3
 Filesize:  1.07 MB
 Downloaded:  318 Time(s)


_________________
Synth DIY since 1977!
Back to top
View user's profile Send private message
inlifeindeath



Joined: Apr 02, 2010
Posts: 315
Location: Albuquerque, NM

PostPosted: Tue Jan 17, 2012 12:13 am    Post subject: Reply with quote  Mark this post and the followings unread

nice! can you share the schem?
_________________
http://www.youtube.com/user/borisandfef
Back to top
View user's profile Send private message Visit poster's website
richardc64



Joined: Jun 01, 2006
Posts: 614
Location: NYC
Audio files: 25

PostPosted: Tue Jan 17, 2012 5:48 am    Post subject: Reply with quote  Mark this post and the followings unread

Nice work, as usual. It's great to see the Oldies but Goodies recreated -- then think about ways to update them! Wink

It appears the Wind synth knobs are also "oldies."

_________________
"I am endeavoring, ma'am, to create a mnemonic memory circuit... using stone
knives and bearskins." -- Spock to Edith Keeler
Back to top
View user's profile Send private message Visit poster's website
pinkspikyhairman



Joined: Jan 17, 2012
Posts: 3
Location: London, UK

PostPosted: Tue Jan 17, 2012 5:52 am    Post subject: The link to the manual... Reply with quote  Mark this post and the followings unread

http://www.paia.com/talk/viewtopic.php?f=6&t=197
Back to top
View user's profile Send private message
Dan Lavin



Joined: Nov 09, 2006
Posts: 620
Location: Spring Lake, Mi, USA
Audio files: 21

PostPosted: Tue Jan 17, 2012 6:33 am    Post subject: Reply with quote  Mark this post and the followings unread

Thanks Pinky for the schematic link.

Quote:
It appears the Wind synth knobs are also "oldies."

Yeah, Richard. I'm sure they're at least 20 years old....probably 30.
I wanted to use the same knobs as I had on the Surf unit, but the price for a 100 ohm d-shaft, (for the filter Q), were unreasonable for this project.

_________________
Synth DIY since 1977!
Back to top
View user's profile Send private message
pinkspikyhairman



Joined: Jan 17, 2012
Posts: 3
Location: London, UK

PostPosted: Tue Jan 17, 2012 6:53 am    Post subject: Reply with quote  Mark this post and the followings unread

I was curious to see the schematic. It was easy to find on PAIAtalk. I can see that Q7 is the noise source, buffered by Q8, into a twin-T filter built around Q9, but I don't quite understand the prupose of D1 and why there are 3 multivibrators also feeding in to the filter at D1.

Do you have a sample without the surf module playing so I can hear what it does on its own?

I could breadboard it, but I have a lot of other projects in the 'todo' pile before I get to this one! Surprised)

Thanks
Back to top
View user's profile Send private message
Dan Lavin



Joined: Nov 09, 2006
Posts: 620
Location: Spring Lake, Mi, USA
Audio files: 21

PostPosted: Tue Jan 17, 2012 8:51 am    Post subject: Reply with quote  Mark this post and the followings unread

D1 acts like a voltage controlled resistor. John Simonton used this technique a number of times.

The 3 multivibrators create a pseudo random CV to the filter. The output wave are ramped squares /---\ but their periods are of varying length so you get different intensities instead of a steady triangle wave modulation which sounds very artificial.

I'll run a surf sample when I get a chance. I was planning on running one channel with surf and one channel with wind so you could separate the two, but I must've forgot to pan the inputs of my mixer before recording.

_________________
Synth DIY since 1977!
Back to top
View user's profile Send private message
Dan Lavin



Joined: Nov 09, 2006
Posts: 620
Location: Spring Lake, Mi, USA
Audio files: 21

PostPosted: Tue Jan 17, 2012 5:08 pm    Post subject: Reply with quote  Mark this post and the followings unread

Here's a softer surf-only sample. I would call this "medium" intensity. I may have touched the filter knob once or twice, but this is mostly as-is.


NiceSurf.mp3
 Description:
someone pass me a margarita?

Download
 Filename:  NiceSurf.mp3
 Filesize:  554.82 KB
 Downloaded:  264 Time(s)


_________________
Synth DIY since 1977!
Back to top
View user's profile Send private message
pinkspikyhairman



Joined: Jan 17, 2012
Posts: 3
Location: London, UK

PostPosted: Wed Jan 18, 2012 1:57 am    Post subject: Reply with quote  Mark this post and the followings unread

Thanks for the sample.

My digital electronics is fairly good, but analog is still a bit of a black art, particularly semiconductor characteristics. Having read the manual now, I understand that the voltage is effectively changing the diode impedance. I had never seen a VCF done this way before. Its a lot simpler than other designs, so I will definately have to get round to breadboarding it Surprised)
Back to top
View user's profile Send private message
v-un-v
Janitor
Janitor


Joined: May 16, 2005
Posts: 8932
Location: Birmingham, England, UK
Audio files: 11
G2 patch files: 1

PostPosted: Wed Jan 18, 2012 3:26 am    Post subject: Reply with quote  Mark this post and the followings unread

Cue JMJ! Wink
_________________
ACHTUNG!
ALLES TURISTEN UND NONTEKNISCHEN LOOKENPEEPERS!
DAS KOMPUTERMASCHINE IST NICHT FÜR DER GEFINGERPOKEN UND MITTENGRABEN! ODERWISE IST EASY TO SCHNAPPEN DER SPRINGENWERK, BLOWENFUSEN UND POPPENCORKEN MIT SPITZENSPARKSEN.
IST NICHT FÜR GEWERKEN BEI DUMMKOPFEN. DER RUBBERNECKEN SIGHTSEEREN KEEPEN DAS COTTONPICKEN HÄNDER IN DAS POCKETS MUSS.
ZO RELAXEN UND WATSCHEN DER BLINKENLICHTEN.
Back to top
View user's profile Send private message Send e-mail
Dan Lavin



Joined: Nov 09, 2006
Posts: 620
Location: Spring Lake, Mi, USA
Audio files: 21

PostPosted: Wed Jan 18, 2012 7:52 am    Post subject: Reply with quote  Mark this post and the followings unread

Quote:
I understand that the voltage is effectively changing the diode impedance. I had never seen a VCF done this way before. Its a lot simpler than other designs, so I will definately have to get round to breadboarding it )


You may also want to check out JS's other more modular synth based filters using the diode technique:
http://www.paia.com/talk/viewtopic.php?f=6&t=60
Check out the Band Pass Filter and the Low Pass Filter. I believe Thomas Henry mentioned the Low Pass Filter thumps with fast envelope times. Well, there's always a trade off with simple circuits.

_________________
Synth DIY since 1977!
Back to top
View user's profile Send private message
richardc64



Joined: Jun 01, 2006
Posts: 614
Location: NYC
Audio files: 25

PostPosted: Wed Jan 18, 2012 8:54 am    Post subject: Reply with quote  Mark this post and the followings unread

A significant quirk of the 2720-3L Lowpass VCF diode-CV is that, unlike the band-pass, higher voltage causes a lower cut-off. (That's why in Thomas Henry's old ADV-Snare the envelope gets inverted.)

In the SurfSynth the operation is turned around in a way I don't fully understand, and in any case, since the CV is constantly changing, which way is up and which is down is irrelevant.

_________________
"I am endeavoring, ma'am, to create a mnemonic memory circuit... using stone
knives and bearskins." -- Spock to Edith Keeler
Back to top
View user's profile Send private message Visit poster's website
PickNick



Joined: Oct 16, 2009
Posts: 82
Location: BP

PostPosted: Sun Jan 29, 2012 4:26 pm    Post subject: Reply with quote  Mark this post and the followings unread

another one:
http://www.epanorama.net/sff/Audio/Circuits/Sound_Effects_and_Synthesizers/Surf%20synthesizer.pdf

_________________
Allow theex.nl
Back to top
View user's profile Send private message
Dan Lavin



Joined: Nov 09, 2006
Posts: 620
Location: Spring Lake, Mi, USA
Audio files: 21

PostPosted: Sun Jan 29, 2012 6:56 pm    Post subject: Reply with quote  Mark this post and the followings unread

Quote:
another one:

Actually it's the same. John Simonton was PAIA. He would typically release a product to Popular Electronics or Radio-Electronics here in North America, then sell the kit to readers of those magazines as well as his own catalog.

The mods at the very end of that article I did implement with the exception of reversing the diode. I still like to maintain filter control.

John did do a redesign in the August 1992 issue of Electronics Now called the Surfman which replaces the two-transistor VCO design with 74HC14-based oscillators. I haven't built that one, so I can't really compare the two.

_________________
Synth DIY since 1977!
Back to top
View user's profile Send private message
-minus-



Joined: Oct 26, 2008
Posts: 761

Audio files: 13

PostPosted: Thu Oct 25, 2012 5:35 pm    Post subject: Reply with quote  Mark this post and the followings unread

Nice one. I always wondered what this sounds like. Cool
Back to top
View user's profile Send private message
donpachi



Joined: Jul 16, 2009
Posts: 60
Location: Marburg
Audio files: 2

PostPosted: Sat Nov 24, 2012 6:55 am    Post subject: Reply with quote  Mark this post and the followings unread

Inspired by this thread, I built John Simonton's Surfman (no legacy transistors needed), schematic was found here:

http://www.theprojectasylum.com/electronicsprojects/surfman/surfman.html

Running on 9 V with a 40106 IC and into 63 ohm headphones, this circuit sounds really nice, quite like Dan Lavin's sample.

However, I need to connect a real speaker, so I put a 100 ohm resistor to ground on the output of the Surfman schematic, then a 2 kohm series resistor into a 50 kohm trimmer as a volume control for an LM386-based amplifier (schematic from the datasheet, gain of 20, no input cap) into an 8 ohm speaker. There is sound, but only on a narrow window of the trimmer setting. The highest volume I'm getting is okayish, but not great.
Most of the range results in (almost) no sound or high-pitched regular farting sounds. Raising the LM386's gain to 200 does not help at all, neither does bridging the 120 ohm output resistor from the Surfman schematic.

My rather limited abilities in circuit analysis make me figure that this is probably an impedance matching problem. I arrived at the values I mentioned by putting together pieces of information gathered at various online places and from trial and error; however, preferably I would like to understand how to calculate component values. Any pointers where to learn about impedance matching for beginners? My search engine skills are obviously not up to it, and consulting The Art of Electronics did not make me any smarter.
Back to top
View user's profile Send private message
elmegil



Joined: Mar 20, 2012
Posts: 1504
Location: Chicago
Audio files: 14

PostPosted: Sat Nov 24, 2012 7:41 am    Post subject: Reply with quote  Mark this post and the followings unread

What's the voltage output of the basic circuit without the 100 ohm going to ground? That's important to determine how much gain you can get out of this.

I'm going to swag a bit here, if someone with more experience comes along, listen to them before you listen to me Smile

So that output stage is an op amp. Very commonly, for the circuits I've worked on around here, the output resistor is 1K rather than 120 ohms, so you might try simply swapping that out for a 1K and see if you get better results.

Putting a 100 ohm to ground with the 120 ohm circuit cuts your output level by half. That certainly could cause output level problems. Don't use it with the 1K or you'll cut your signal by 90% (roughly). You might also try simply omitting that 100 ohm resistor and seeing if you get better results.

The output stage looks like it already has a volume control, is there a reason why you wanted to add one to the LM386 stage? You could use it as a simple fixed-gain amplifier and still control the volume from the original circuit.

I would try using the 1K, no resistor to ground, straight into the LM386 circuit from the datasheet listed as gain == 20, except I'd run the 1k directly into pin 3 rather than through the additional volume control. if that didn't work, I'd go back to using the 10k volume control as well.

The gain is fixed at 20, so that volume output I mentioned before is important. If the level is higher than 400mV you will likely get clipping (with a 9V supply) at which point we'd have to go back to the drawing board.... And if the level is below 50mV you'll likely need to use a higher gain setting for the amp with a resistor and a cap between pins 1 & 8.
Back to top
View user's profile Send private message
donpachi



Joined: Jul 16, 2009
Posts: 60
Location: Marburg
Audio files: 2

PostPosted: Sat Nov 24, 2012 12:04 pm    Post subject: Reply with quote  Mark this post and the followings unread

Thank you, elmegil! This already helps a lot.

elmegil wrote:
What's the voltage output of the basic circuit without the 100 ohm going to ground? That's important to determine how much gain you can get out of this.


I'm going to measure this, have to power up the oscilloscope.


elmegil wrote:

I'm going to swag a bit here, if someone with more experience comes along, listen to them before you listen to me Smile

So that output stage is an op amp. Very commonly, for the circuits I've worked on around here, the output resistor is 1K rather than 120 ohms, so you might try simply swapping that out for a 1K and see if you get better results.


That didn't change anything. In fact, 120, 1 k, or 2 kohms do not change the level of the signal in an audible way.

elmegil wrote:

Putting a 100 ohm to ground with the 120 ohm circuit cuts your output level by half. That certainly could cause output level problems. Don't use it with the 1K or you'll cut your signal by 90% (roughly). You might also try simply omitting that 100 ohm resistor and seeing if you get better results.


Great! Now the volume level is adequate Cool

elmegil wrote:

The output stage looks like it already has a volume control, is there a reason why you wanted to add one to the LM386 stage? You could use it as a simple fixed-gain amplifier and still control the volume from the original circuit.

I would try using the 1K, no resistor to ground, straight into the LM386 circuit from the datasheet listed as gain == 20, except I'd run the 1k directly into pin 3 rather than through the additional volume control. if that didn't work, I'd go back to using the 10k volume control as well.


Did that. For some reason I need the trimmer. Set correctly, everything is kind of fine. Next to the good setting is farty motorboating, farther away the signal is lost. Anyway, the problem is a lot smaller - yet I'll try to understand this trimmer issue.

Thanks again, elmegil!
Back to top
View user's profile Send private message
elmegil



Joined: Mar 20, 2012
Posts: 1504
Location: Chicago
Audio files: 14

PostPosted: Sat Nov 24, 2012 1:33 pm    Post subject: Reply with quote  Mark this post and the followings unread

You're quite welcome Smile
Back to top
View user's profile Send private message
Danno Gee Ray



Joined: Sep 25, 2005
Posts: 1343
Location: Telford, PA USA

PostPosted: Sat Nov 24, 2012 1:37 pm    Post subject: Reply with quote  Mark this post and the followings unread

Dan,

Is there any way that modern general purpose transistors can be substituted for those specified?

Or, are the specified transistors still readily available through normal sources?

Thanks,

Dan
Back to top
View user's profile Send private message
Dan Lavin



Joined: Nov 09, 2006
Posts: 620
Location: Spring Lake, Mi, USA
Audio files: 21

PostPosted: Sat Nov 24, 2012 6:16 pm    Post subject: Reply with quote  Mark this post and the followings unread

Dan, actually yes. Although my Surf Synth restoration was the original trannys, I just used 2N3904's and 2N3906's for the Wind Synth. Should be able to do the same with the Surf Synth.
_________________
Synth DIY since 1977!
Back to top
View user's profile Send private message
Dan Lavin



Joined: Nov 09, 2006
Posts: 620
Location: Spring Lake, Mi, USA
Audio files: 21

PostPosted: Sat Nov 24, 2012 6:24 pm    Post subject: Reply with quote  Mark this post and the followings unread

Quote:
Inspired by this thread, I built John Simonton's Surfman (no legacy transistors needed), schematic was found here:


per my post above to Danno, the PAIA units are not exclusive to "legacy transistors." When JS created the things, those were really commons PNP and NPN's. General purpose NPN and PNP's will work just fine. No magic involved. Wink

_________________
Synth DIY since 1977!
Back to top
View user's profile Send private message
-minus-



Joined: Oct 26, 2008
Posts: 761

Audio files: 13

PostPosted: Sat Nov 24, 2012 7:20 pm    Post subject: Reply with quote  Mark this post and the followings unread

I had not seen that link donpachi. Thanks.

I played around with this circuit on breadboard for a while (the original one). I too wanted to eliminate the transistor oscillators so I used a 40106. The thing is, the 40106 did not achieve the same results as the transistors did. You don't need a scope to see this. I attached a LED to each transistor circuit and watched the pulses of light.

With the three transistor oscillators, they are not 50% duty cycle. I needed to change the pulse width to get the same result as the original. Without doing this, the waves did not crash as 'naturally as the transistor version. I'd be interested to hear a sample of what you have.

EDIT! Oh, I just see the resistors on the inverters. I suspect that would work. I used diodes.
Back to top
View user's profile Send private message
donpachi



Joined: Jul 16, 2009
Posts: 60
Location: Marburg
Audio files: 2

PostPosted: Sun Nov 25, 2012 10:44 am    Post subject: Reply with quote  Mark this post and the followings unread

Dan Lavin wrote:
Quote:
Inspired by this thread, I built John Simonton's Surfman (no legacy transistors needed), schematic was found here:


per my post above to Danno, the PAIA units are not exclusive to "legacy transistors." When JS created the things, those were really commons PNP and NPN's. General purpose NPN and PNP's will work just fine. No magic involved. Wink


Thanks Smile So I'll build it too since I am interested if the circuits really sound the same.

A recording I just did has more pronounced deep rumbling and howling compared to Dan's, this might be attributed to the mic's position, which was close to the membrane. On the other hand, a larger speaker (6" compared to 3") sounds even more bassy. The crashes can be heard in any case. I fiddled a bit with the frequency knob throughout.


surfman.mp3
 Description:
Sound sample of the Surfman recorded through an LM386 amp, 3" speaker, and SM 58 clone.

Download
 Filename:  surfman.mp3
 Filesize:  2.34 MB
 Downloaded:  178 Time(s)

Back to top
View user's profile Send private message
donpachi



Joined: Jul 16, 2009
Posts: 60
Location: Marburg
Audio files: 2

PostPosted: Sun Nov 25, 2012 10:56 am    Post subject: Reply with quote  Mark this post and the followings unread

Just thought "what the heck" and connected the Surfman to a preamp input of my soundcard with alligator clips. The frequency response should be a lot better this way.


surfman2.mp3
 Description:
Surfman straight into MOTU 828 (original schematic, signal was taken after 120 ohm output resistor).

Download
 Filename:  surfman2.mp3
 Filesize:  1.96 MB
 Downloaded:  196 Time(s)

Back to top
View user's profile Send private message
Display posts from previous:   
Post new topic   Reply to topic
Page 1 of 2 [32 Posts]
View unread posts
View new posts in the last week
Goto page: 1, 2 Next
Mark the topic unread :: View previous topic :: View next topic
 Forum index » DIY Hardware and Software » PAIA Equipment
Jump to:  

You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You can download files in this forum
e-m mkii

Please support our site. If you click through and buy from
our affiliate partners, we earn a small commission.


Forum with support of Syndicator RSS
Powered by phpBB © 2001, 2005 phpBB Group
Copyright © 2003 through 2009 by electro-music.com - Conditions Of Use