anybody seen this attack decay schem/layout??? uhh?

[breather-resistor]

ok so check it out here: http://members.shaw.ca/roma/

Ok so I tried to build this on a breadboard and I tried a couple different configurations.  Regardless, it passes dry signal only.  So my question is that doesn't the connection between Q1 and Q4 totally eliminate the effect by just bypassing the input straight to the output?  There is a description written there on how it works but its not entirely that clear...

does anyone else see how this works or if there are any errors?

thanks
breather

P.S. for ease of breadboarding I omitted the optional preamp so my circuit starts at Q1.

[GREEN FUZ]

What is it you`re building? The link just goes to the home page.


edit:`salright I found it.

[breather-resistor]

Oh, sorry. 

Because of the pages construction the url is the same...

ok from the home page click on projects, then click on guitar effects, thec click on attack decay...

sorry for the run around but theres no way to link directly.

breather

[slacker]

To save everyone searching here's a direct link http://members.shaw.ca/roma/attack.html. The site uses frames so to get the direct link to the page you have to right click on it and select "Frames/Show only this frame" that's in firefox/seamonkey I guess IE has a similar function.

I don't know exactly how it works, or if it works but I think Q1 and Q4 act as voltage controlled resistors, when the resistance of these goes low the volume will go down and when it goes high the volume will go back up. These are controlled by Q2 and Q3 via the switch. The pots and C1 and C2 set the speed at which the resistance of Q1 and Q4 changes.
I'm not sure but the circuit might need VR1 in place to work.
You can check that the circuit is doing anything by measuring the resistance from Q1 and Q4s collectors to ground, this should change when you open the switch.

[breather-resistor]

this should change when you open the switch.

you mean the switch that shorts to the ground right? not the bypass?

aynone else have any ideas?

breather

[slacker]

Yeah the switch that shorts to ground. I think when this is closed you're supposed to get no sound and when you open it the volume is supposed to swell up and then down again. 

[R.G.]

My impression of several of the circuits at this web site is that they are... um ... questionable.

[alanlan]

My impression of several of the circuits at this web site is that they are... um ... questionable.

In what way? please explain.

[GREEN FUZ]

I believe some of the circuits on Laurier`s site have been attempted in the past with less than successful results. Not saying none of them work but I don`t get the impression he`s actually made them himself. An unverified circuit is..just that. Handy perhaps, maybe not so Dandy.

On the other hand if you were to try it and it worked and then posted the results I`m sure some people would benefit.

[breather-resistor]

On the other hand if you were to try it and it worked and then posted the results I`m sure some people would benefit.

I agree, I think we should start with the attack decay circuit and see if theres any way it can work.  Maybe it only needs a tweak.
After thinking about it the circuit could work in theory and I certainly admire the simplicity of it.  In playing with it on the breadboard it seems like it isn't too far from success.  As I said earlier, it passes dry signal to the output.  But, when I happened to unplug the 10uf electrolytic (c2) as I plugged it back in I heard a swell of noise as the capacitor charged and it seemed pretty appropriate based on what the effect is supposed to do... maybe this is naive but it seemed like a good sign to me... 

Any ideas, I verified my wiring several times and tested each part to make sure it was golden.  It seems strange to me that laurier would talk about how it sounded and worked if the circuit stuff had never worked...  It makes me think that its a mistake in the schematic/layout...

any more ideas on how it could work???

[The Tone God]

His switching systems have errors that have been posted about many times before. A couple of his other circuits have been built but are considered by many to be "less then spectacular".

Being that the site has been around for so long it has gotten high rankings with most search engines despite the problems with the circuits. The unfortunate part is he does not seem to maintain anything with his site. It as if he just posted it and never came back to it.

Andrew

[Dan N]

I like his style!



Not enough schematics have little heads on them.

[oldrocker]

I have never built anything from that website although I've been tempted.  I haven't heard a lot of good things about those circuits but thought I might be able to work with them experimentally and get something out of them.  I just don't have the time as of late.  But the circuit ideas are really cool.  I would like to see a verified circuit design of these types.

[alex frias]

It's really scaring the little head...
But, at least for me, the Attack/Decay is a worthless build.

[nordine]

On the other hand if you were to try it and it worked and then posted the results I`m sure some people would benefit.

I agree, I think we should start with the attack decay circuit and see if theres any way it can work.  Maybe it only needs a tweak.

any more ideas on how it could work???

i remember -and this is from when i began DIYing circuits, far before breadboard era- that this was the first circuit i soldered... it went directly to stripboard.. and, having pretty newbie skills in that time, i obviously, built it bad, HOWEVER... IT WORKED! ... now, it worked pretty slow ..a rise from 0 to unity in 4 seconds i think... but it did nonetheless ..then i thought, what can i do with an attack/decay of 4sec... so throwed it away

sad story, but.. has a learning behind... the circuit HAS potential

[GREEN FUZ]

IT WORKED!

Interesting. It might just need some tweaking to make it useful.