My synthesiser

[Dr.EM]

You people have been very helpful, helping to answer questions about this project, so I thought i'd say a little about it. It is now electronically finished, and I can say that it works perfectly. It won't however fit into the enclosure :wink: . Anyhow, here are the boards:

**broken link removed**

It features:
3 voltage controlled oscillators utilising 7555 timers and diode waveshapers which can generate square, saw, sine, tri sort of waves (not to scientific quality, but they sound right). One is set up as a sub oscillator, which is preset to a slightly uneven sine for bass. Another has a hard sync input.

An exact clone of the Minimoog voltage controlled filter

2 LFOs made using op-amps, generating triangle a square waves. One can be flicked into audio frequency for crazy modulation.

A passive ring modulator

A 3 signal mixer

And a board to deal with summing CV and triggering oscillators.

I do have an audio demo, if anyones interested, just PM me.

 

[bonxer]

Sweet mother of Radio Shack! Why so many small boards with wires going everywhere. I must admit I don't recall reading any of the previous posts about it, so perhaps there was an answer. But why not just have one big board for the processing unit, then some ribbon cable to connect the potentiometer knob boards?

 

[bonxer]

Can we have an MP3 demo or such of you playing some effects?

-- Updated: I just noticed he offers a sample through PM.

 

[Nigel Goodwin]

You people have been very helpful, helping to answer questions about this project, so I thought i'd say a little about it. It is now electronically finished, and I can say that it works perfectly. It won't however fit into the enclosure :wink: . Anyhow, here are the boards:

No disrespect! - but may I just say that looks horrible :lol:

May I make a SIMPLE! suggestion? - how about buying various colours of wire?. Having said that, back in about 1969, a friend and I rebuilt an old motor bike (I think it might have been a Norton?) - I had to make a wiring loop for it from scratch - and we only had black wire :lol: We were pennyless school kids - we couldn't afford to BUY anything!.

As for bonxer's query about the multiple boards?, an analogue synthesiser is essentially a modular device - and it makes GOOD sense to build it as seperate modules.

 

[Dr.EM]

The reason for the seperate boards is simply that to use stripboard as one big board, I would have to break hundreds of tracks to stop all the cicuits from joining to each other, if you get me. Also, yeah, its very modular, and it would help me find fualts if something failed.

I agree, it does look horrible, and i'm worried some of those wires are going to be a bit on the short side :x . I would do colour coding, but it would mean buying a lot of different cables, and the extra cost that entails. Don't worry, you won't see it when its in its case :lol:

 

[audioguru]

Hi Dr. EM,
Very nice! :lol: :lol: :lol:
I'm the Veroboard guy and I've made many projects with lotsa modules like yours cuz I kept adding circuits.
Like others have commented, I suggest using ribbon cable to wire everything together.

Here is a small project and ribbon cable made its wiring neat and tidy:

 

[Dr.EM]

Yeah, ribbon cable, thats an idea. Is it stranded? I used both stranded and bell type wire. Bell tends to break off sometimes though, so i'll try and stick with stranded in future.

 

[audioguru]

Hi Dr. EM,
Yeah, ribbon cable has many very fine strands for flexibility. You will wear out your fingers twisting them. I use a temperature-controlled soldering iron that doesn't melt nor shrink the soft insulation.
Also I recommend using real insulation strippers instead of the wire knickers that so many people use. :lol:

 

[Nigel Goodwin]

the wire knickers that so many people use.

Obviously this must have a different meaning in Canada :lol:

 

[audioguru]

OOOps, I meant, nickers. He, he. :lol: :lol:

 

[moody07747]

Sweet mother of Radio Shack! Why so many small boards with wires going everywhere.

that must be because hes like me

If I have the room, I cant help but space it all out

thats why when i built my circuit today (power regulator) i used a small board and forced myself to cram everything into a small package.

it turned out great in the end and im glad i went with the compact method.

 

[Dr.EM]

Yeah, I should have the additional case soon, so I can have fun trying to fit it inside them :shock:

I have once tried to make a very small project, but it didn't go too well. Think I just didn't measure properly, you know, internal measurements for enclosures being less than extrenal :lol:

BTW, how do you drill holes in veroboard? I tried, and the piece craked and shattered and was pretty useless. Do I need a special drill bit, or a pillar drill or something?

 

[Nigel Goodwin]

BTW, how do you drill holes in veroboard? I tried, and the piece craked and shattered and was pretty useless. Do I need a special drill bit, or a pillar drill or something?

It drills pretty easily, just take it carefully and slowly - and try not to drill too close to the edge.

 

[Dr.EM]

My mistake was drilling too close to the edge mostly I think. But, that was the largest piece of board I could get, and I knew i'd need it. Look at the filter, toward the right with the line of orange caps. It goes right to the edge, even on that size of board, so there was ne space for holes. The way I plan to assemble this it quite bizzarre. I basically plan to wrap the boards in something non conductive, then pack them in using lots of bubblewrap :lol:
Its all I can think, should do the job

 

[audioguru]

The cheap phenolic based Veroboard (beige colour) is very brittle and warps too. The epoxy-fiberglass based Veroboard (used to be dark blue, other makes are light grey) doesn't shatter, wears-out grill bits and saw blades quickly and is mechanically stable. It costs only a few pence more.

Phenolic has a distinctive smell, especially when it is being broken, cut or drilled. I guess the smell is from formaldehyde or another chemical evaporating and making it even more brittle over time.

The stripboard that RadioShack sells is phenolic based, has oversized holes and its copper seems to be very thin.

Smell? The Veroboard copy from Taiwan that I use now seems to be dung based. It doesn't cost any more for its unique smell and built-in warp. I just looked, its warp is gone.
:lol:

 

[Nigel Goodwin]

The cheap phenolic based Veroboard (beige colour) is very brittle and warps too. The epoxy-fiberglass based Veroboard (used to be dark blue, other makes are light grey) doesn't shatter, wears-out grill bits and saw blades quickly and is mechanically stable. It costs only a few pence more.

I've never seen fibreglass veroboard in the UK, it's all SRBP (Synthetic Resin Bonded Paper).

 

[moody07747]

Hay Dr.EM

you did a great job on this project and it sounds great

keep up the great work

 

[audioguru]

Yeah, really cool sounds. :lol:
The beat makes my computer speakers move towards me because they have ports on their back. :shock:
Yeah, I'm the audio guy and I haven't even connected the audio output of my new computer to my stereo only 2m or 3m away.

 

[Dr.EM]

Hi. Erm, I have'nt sent you the audio demo of this one yet, not sure which one your thinking of, this one is just a collection of sounds.

You should wire it up to your stereo, thats what I have done on my computer. It does work very well, but it sounds like you have some pretty decent computer speakers anyhow :lol:

BTW, also have an audio demo of that optical compressor prototype...

 

[audioguru]

Hi Dr. EM,
I know what! Post an MP3 of your latest sounds here, but change the file type ".mp3" to ".pdf". Then we can download it and change the file type back to ".mp3" and it will play.
That's what I do to keep my wifey from seeing my "good stuff". :lol: :lol: