TREMMY TREMOLO

[bluebunny]

rght, i'm a happy bunny (but not blue )

Did someone call??   

Another great little project, Rob - thanks.  My "list" is getting too long!  I've only just boxed up your *first* reverb... 

[samhay]

^i'm all for lowering noise....diagram?
The first of the op-amp buffers here: http://www.muzique.com/lab/buffers.htm

This will make the effect inverting - I think we have had this discussion before in another epic thread.

[deadastronaut]

^ cheers sam, yes we have had this discussion before.. (but i have the memory of a zx81)

which leads me to think...yeah i know , could be dangerous

isn't there a bog standard go to 'in phase'  no tone loss, no volume loss, in and out opamp buffer setup that could be used for everything like this ...?

it seems were using variations on the same thing whether it be reverb, delay, ...so surely there is a 'standard' in/out config...hmmmmmm...


....................

ok, the first opamp buffer setup....i'll try it, cheers sam.

[deadastronaut]

ok , heres the latest... it works fine, just a slight tonal difference between bypass and on....slightly brighter when on, but i am being a bit anal as usual...

i'm guessing a cap on IC1B in parallel with R14 is in order...ive tried from 22pf to 1nf  but can't quite nail it  (testing with trem depth fully off)

[samhay]

Your input impedance is now 1M - was 470k - so perhaps you can hear that? Perhaps see what happens if you make R7 470k.
You can probably do away with C7.

[deadastronaut]

cheers sam, yep that seems better...

its weird with tremolo's, they tend to have a 'perceived' vol drop with distortion...which isn't at all really,


but on clean the trem is slightly brighter than bypass...

[deadastronaut]

i was thinking i might use a 25k trimmer for R16, ...

or maybe more sense would be using a pot...for the 'perceived vol change over speed changes...especially when fast choppy....

however in the UK we mainly have  just 22k's,  unless i use a 47k and stick a limiting resistor in front  hmmmmm...


edit:

is there a better way using transistors rather than led/ldr as the leds seem pretty noisey?

[samhay]

^i was thinking i might use a 25k trimmer for R16, ... or maybe more sense would be using a pot...
That might be a nice feature - at the moment, you can never quite get to unity gain.

^however in the UK we mainly have  just 22k's,  unless i use a 47k and stick a limiting resistor in front  hmmmmm...
I don't follow

^edit: is there a better way using transistors rather than led/ldr as the leds seem pretty noisey?
That's a whole other kettle of fish.

Have you tried playing with different types of LEDs or a proper vactrol?

[deadastronaut]

Haven't got a proper vactrol...ill mess with leds though, yeah seems it needs a pot for R16...

[deadastronaut]

ok, messed around with various leds..

turns out super blue is the quietest...(the red/yellow diffused screamed when guitar was turned down with distortion)

so i have a super blue, and super green with ldr...at the moment.


i found a 5.6k in series with a 10k pot where R16 is has enough kick....

[deadastronaut]

ok, i think i'm there with this, i ended up using a red diffused for the indicator, and super green for ldr. seems to be behaving quite nicely now,

any other suggestions before i knock this up..?

why can't i post youtube links in between the brackets anymore?...hmmmm.

[deadastronaut]

well ive been tinkering again,

i'm still getting an annoying screech from the leds when using a distortion,...especially with the guitar vol down....hmmmm...

ive tried caps on the second opamp to no avail...

everything is lovely when clean, but distortion not so....is this the same issue for ALL diy tremolo's?....

and how can it be overcome?.

[micromegas]

https://www.youtube.com/watch?v=a9b3UI60lFc&list=UUGP0eO8ADt0H9FY5UcHTf8A


why can't i post youtube links in between the brackets anymore?...hmmmm.

You have to take out the 's' from https

[deadastronaut]

ahhh cheers micro, i never used too...but i will now.  

done. thanks

[deadastronaut]

if i use red diffused leds i dont get the cut of choppynes on square wave...

so i'll try 2 super blues in series instead...

[samhay]

Clip sounds good.

^i'm still getting an annoying screech from the leds when using a distortion,...especially with the guitar vol down....hmmmm...
What kind of distortion (discrete or op-amp)? Your LFO may be throwing quite a lot of noise onto the signal ground, which you are hearing elsewhere.

[deadastronaut]

cheers man, yeah sounds great,

i'm using the X ROCK distortion from the xfuzz thread, 2 tranny type..

xrock on bread - tremolo on bread..


i just made led/ldr with blue, and a blue in series, back to being choppy again..

[deadastronaut]

upon messing with this more...

i find i can get depth with a 1k trimmer...no problemo

but when i try an actual 1k lin pot, to test 'real life' range of depth  it will not kick in the trem.(no adjustment at all) ....if i put a 4.7k it kicks in...hmmm..(with even less range obviously...

i know the pots i'm trying are fine...

any way to get a good range with a 4.7k pot instead?..

[duck_arse]

when is a 1k pot not a 1k pot, or, I know I'm fine, but how are you?

did you measure all the pins to all the other pins, while rotating the shaft? one of your two 1k pots ain't the full quid.

[deadastronaut]

 

i got it going now i had to raise the 470r going to 9v to 2.2k, or no joy..

even so the pot still has no depth effect for half its travel....hmmmm