Simple Tremolo

newfish · March 13, 2008, 05:32:30 AM

Would anyone be interested in a *very* simple optical tremolo?

I've been messing around with a 555, because I have a few lying around - and have half-built a simple Optical Trem.

So far, there's a very low parts count (less than 10), with a single control for 'Speed'.

May well be suitable for beginners looking at building a trem, without the complexities of larger circuits - or for experienced builders with 10 minutes to spare...

I'll have a stripboard layout by the weekend, depending how much time I can spend on this.

Stellan · March 13, 2008, 05:41:11 AM

I would be very interested in a layout for a trem as simple as possible.
Maybe you could post some soundclips too

aledjack · March 13, 2008, 05:57:11 AM

the tremolo is always a good efx and a new project is alwais welcome!!

You have drawn a schem?

newfish · March 13, 2008, 06:17:27 AM

Not as yet - it's still on my Breadbord.

I'm aiming to get soundclips, schematics and layout posted this weekend (other 'stuff' pending...)

Thanks for your interest.

nokaster · March 13, 2008, 07:24:37 AM

looking forward to this!!!!

greigoroth · March 13, 2008, 08:08:55 AM

Cool!

If you can be bothered, see how the trem takes to both clean and distorted sounds, if not... keep at it, it is a great idea!

Quote from: newfish on March 13, 2008, 06:17:27 AM
Not as yet - it's still on my Breadbord.

I'm aiming to get soundclips, schematics and layout posted this weekend (other 'stuff' pending...)

Thanks for your interest.

ItZaLLgOOd · March 13, 2008, 09:08:24 AM

I would also be interested. So far I have mainly been working on distorting the signal and I would like to start messing around with other things.

Boogdish · March 13, 2008, 10:04:50 AM

you should definately post it. It could also make a good building block for those of us who're just starting to expirement with making our own designs.

Dragonfly · March 13, 2008, 10:44:42 AM

I'm definitely interested in seeing it !

Any "ticking" issues ? Thats a very common problem with 555 trems...

newfish · March 14, 2008, 05:27:17 AM

Ticking? Yes, unfortunately.

Not massive amounts until you turn the amp's O/D on - then you can really hear it.

I've used the 555 to drive an LED, coupled to a LDR - using the LDR to control the guitar's volume.

There are no physical connections between the timer circuit, and the LDR - not even grounds.

Granted, the circuit is still on a breadboard with *no* shielding whatsoever - which will be addressed on the final build.

Apart from the ticking, it's a very useable, decent tremolo.

Am I missing smething here?

** I realise this question would be easier to answer if I'd posted a schematic - but I'm at work at the mo... **

** <smacks forehead> D'oh! Maybe I should use a decoupling cap... It might *just* help **

smallbearelec · March 15, 2008, 12:58:22 AM

One tweak that is usually helpful with 555-based trems is adding an R-C to the output of the chip to "soften" the modulating waveform. See the schem of the Tremulous Bear on smallbearelec.com for one idea.

Regards
SD

Paul Perry (Frostwave) · March 15, 2008, 05:03:44 AM

And remembering to use a cmos 7555, not an 'ordinary' 555.

newfish · March 16, 2008, 07:47:48 PM

Almost there.

Been away this weekend, so haven't touched anything musical or electronic...

*Did* work on a layout for a couple of hours tonight - and while it works, it's not perfect...

Watch this space - it's about 95% done.

newfish · March 17, 2008, 08:52:09 AM

Through more blind luck than maths, I'm using a 7555 - although I'll sub for a '555' tonight to see what the fuss is about.

Thanks to Smallbear for the R-C tip - will be doing that tonight.

I have a layout, but due to me running out of board it's *very* cramped.
I've had to be particularly ingenious (if not *cunning*) to make it fit.

...and I've learned loads.

Will be sure to post schems, layouts and soundclips once it's not ticking anymore...

newfish · March 26, 2008, 05:38:16 AM

...for those still interested in this build, it's done.

Not yet boxed, but tested and working (as of about midnight last night).

Minimal parts count (12 I think) - will post layout this evening and (hopefully) record some sound clips.

Would not have reached this stage without Frostwave's '7555 vs. 555' advice, or Mr.Smallbear's R/C advice, so thanks very much guys.

ItZaLLgOOd · March 26, 2008, 09:17:24 AM

I've been looking foward to this one.

culturejam · March 26, 2008, 11:47:42 AM

Sounds like a great project. Can't wait to see the schem and layout.

newfish · March 26, 2008, 08:03:43 PM

Right - layout now available at...

http://www.iansnape.co.uk/images/Tremolo_Layout_260308.png

No sound clips as yet - needs boxing up to stop ambient light creeping in (I've tried copious amounts of electrical tape. Only way to use it without the box is with the lights off...)

Schematic to follow shortly.

Single control for 'speed' - doesn't get much simpler than that.
The numbers posted for C2 and C3 are the numbers marked on the capacitors. For those of you building from grab-packs (me too!), I thought this would make it easier to identify which components to use.

Light Dependant Resistor is one I was given amongst other bits and pieces.

D1 value not too critical - I happened to have a 1N4148 to hand.

Any comments gratefully received.

Cheers!

GREEN FUZ · March 26, 2008, 08:23:25 PM

Straightforward enough, except for D2.

What is it, exactly?

DWBH · March 26, 2008, 08:37:49 PM

It's an LED but I don't think it's represented as it should. The anode isn't connected to anything.

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Simple Tremolo