Help building an old(?) FX it seems it's called minisynth

[alex frias]

It's a bad played sample recorded direct to the board, then to the A/D converter. No amp simulator/modeler/emulator was used, just a bit of software reverberation.
The neck pickup was used, a humbucking one (DiMarzio PAF Pro)
Firstly It's the sound of the distorted original octave (volume knob 1), full volume on guitar, then half way backed off. Then the other sounds (knobs 2 and 3 individualy).
At last the combination of the 3 octaves, same mix volume to the three sounds. 

http://rapidshare.com/files/41370927/MiniSynthyM3.mp3.html

[theehman]

I think I'd like to build one of these to try on my bass.  American Semiconductor has these SAJ110 chips for $12.93 but they want like $19 shipping and handling.  Anybody want to go in together to split the shipping and get some of these?

[oskar]

Sounds well. 
The "lo-fi gameboy style sound" comes from the circuit tracking overtones as well (I assume from
my own humble experiment with increased filtering).

But those chips again... they are way too expensive.
If I redraw it for a modern IC instead, would anyone use it?  Does it absolutely have to be the SAJ110?

[slacker]

Sounds well. 
The "lo-fi gameboy style sound" comes from the circuit tracking overtones as well (I assume from
my own humble experiment with increased filtering).

Yeah the octave jumping and weirdness is because there's too many overtones in the signal driving the chip, so it can't lock on to the fundamental properly. Doesn't sound too bad though, in my experience conditioning the signal is the hardest part, that's the bit that took me longest to get right when designing the Slacktave.

But those chips again... they are way too expensive.
Does it absolutely have to be the SAJ110?

After listening to the soundclip, if you used a CD4024 it would sound exactly the same. The only difference would be if the SAJ110 had any sort of filtering built in to help improve tracking, then the CD4024 might not track as well. Apart from the pinouts being different you could just drop one straight in instead of the SAJ110. A CD4040 would also work just as well.

[oskar]

After listening to the soundclip, if you used a CD4024 it would sound exactly the same. The only difference would be if the SAJ110 had any sort of filtering built in to help improve tracking, then the CD4024 might not track as well. Apart from the pinouts being different you could just drop one straight in instead of the SAJ110. A CD4040 would also work just as well.

No, hardly. In electric organs from those dark years the main brain was a frequency generating chip (Electric Projects For Musicians use one in a project i think)
which gives out the frequencies of the top scale. Each of these clocks are then divided down by a chip like the SAJ110. Just dividing, no filters, go CMOS.   

[slacker]

In that case the CMOS chips would work exactly the same then, and they're a fraction of the price

[oskar]

Allthough I don't think they come in red     
If you haven't tried the XOR-ringmodulator yet I think you should. The KORG MS20 synth use it and among analog freaks
it's on manys top 10-list. It use a 4011 quad NAND chip hooked up as an XOR-gate (am I officially a geek now?) 

oskar

[theehman]

Sounds well. 
The "lo-fi gameboy style sound" comes from the circuit tracking overtones as well (I assume from
my own humble experiment with increased filtering).

But those chips again... they are way too expensive.
If I redraw it for a modern IC instead, would anyone use it?  Does it absolutely have to be the SAJ110?

Redraw it!

[alex frias]

Some 4024, 4013, etc. I don't think it will sound any different with them.
But you must agree, nothing like a Red IC...
The Rocktave really shows a better tracking, a good answer and soon I will build one.
But I love the quasi-stability of this thing. i don't know why exactly it seems better than the BlueBox.
I had not enough time to check the circuit presented here comparing it to the real thing, but at first look it seemed pretty close to the diagram.
My eyes are not that good these days, so I couldn't recognize the transistors in it, but soon I will. Better glasses, I hope...
Maybe using a filter I saw and built (in GGG, I think) in order to use it on my GreenRinger. It is that kind of lowpass with a very strong angle at the cutoff freq.
The kind you see before and after BBD IC`s and A/D-D/A converters in order to filter out aliasing and clock noise. Lots of dB by octave.
Another experimentation is to try som MOD's suggested by Craig Anderton's Guitar Player Magazine's article you find at the Rocktave PDF doc pointed earlier in this topic.

So many projects, so little time...

[slacker]

If you haven't tried the XOR-ringmodulator yet I think you should. The KORG MS20 synth use it and among analog freaks
it's on manys top 10-list. It use a 4011 quad NAND chip hooked up as an XOR-gate (am I officially a geek now?) 

You mean this? http://www.analog-synth.de/synths/ringmod/digital_ringmodulator.htm I'll have to give it a try.

[alex frias]

It looks promising...

A very easy way to get more options is put a GreenRinger in parallel with it.
Or even in series, after the original octave distorted sound, assuming it will mix its output with the other octaves from the CMOS.

[oskar]

This very one. Another funktion is frequency doubling. I've seen it both in CMOS Cookbook and here... (somewhere in the middle)
http://www.geocities.com/tpe123/folkurban/fuzz/snippets.html
You can offcourse go fancy and use something like four outputs from a 4024 and drive the gates from an XOR-package with
an LFO or... whatever, driving the free inputs...
The funniest thing I haven't tried out yet (with a guitar) would be driving a digital noisesource, semirandom noise. I've done it on a modular and it really
is so much fun and if you have a short series like 32 bits it becomes audible as a dirty tone.

[alex frias]

Well, if you modulate a signal with itself, you can get a pretty simulation of doubling octave....

I'm building the 4024 mod just to experiment with my BlueBox alternative version. Following the Craig Anderton notes. I will soon report the results.

The possibilities of using the 4024 output as a source for a "tracking ringmodulator"  looks interesting too.

Only a note: On my MiniSynthy the transistors are BC109's.

[oskar]

some info on saj110


I'm going to paint all my IC's from now on...   

saj110 datasheet... low res.
http://www.largonet.net/midiboutique/downloads/documents/saj110lq.pdf

pinout


saj110 is compatible with saj210 !!!

ps. the original drawing use input 3 and outputs 11 and 12. It would be a good idea to ground the
unused inputs: 2,4,5 and 6!

[alex frias]

And the winer is...

It´s perfect, Oskar!

[Paul Perry (Frostwave)]

Well, if you modulate a signal with itself, you can get a pretty simulation of doubling octave....

That's true for a sine wave.
But if you try to do it with a square wave.....
Which has interesting implications for an up-octave device following a distortion...

[oskar]

XOR-octave
http://www.geocities.com/tpe123/folkurban/fuzz/dof.gif
I haven't built this precise one but the main thing with the XOR is that it's output changes state when one of the inputs do and thus works
like a frequency adder. I have built an xor-ringmodulator with a quad-pack with each gate being triggered by an LFO/oscillator
on one of the inputs and the remaining gate being triggered by.... This one

For a practical working unit you can't have all gates switching state at the same time. You'ld either add som filtering like the Digital Octaver
Fuzz or even better... you phase-shift the LFO-signal (cmos 4018 cirquit) to each of the XOR-inputs...     
The frequencies out would be signal in + LFO,signal in +2 x LFO... etc.
I honestly don't remember the precise sound of it.     

And off course you could do something like this...

Has any of you tried a 4046 for frequency doubling? Actually I think it's the way to go for a stable squarewave cirquit.

oskar

[loss1234]

has anyone figured out the original pinout so it could be transferred to 4024? really i just need to know where in the original schematic the clock, +v, gnd, and outs came from. if you look at the saj datasheet, its so low res that its impossible to read the pin numbers.

looking at the original schematic, it looks like clock is either 3 or 1 or 7? and the outs are 12 or 11?

any one do this with a 4024 and have luck??

thanks