freestompboxes.org

bajaman wrote:
members/bajaman/Baja/Baja%20Optical%20Limiter%20rev2

Hi there

A couple of small improvements you could try:

If you use two separate resistors to the two LEDs from the op-amp output, you prevent problems caused by differences in characteristics of the LEDs. It's also worth using 1 uF electrolytics, rather than the expensive non-polarised capacitors. I know that the non-pol types are "better" for the audiophools, but if you put the electrolytics with the positive side going to the FET and the positive side to the op-amp, you won't hear the difference, and will save some space and cost!

Hope this helps!

C.

f you put the electrolytics with the positive side going to the FET and the positive side to the op-amp,

Shouldn't one of these be "negative "??

Alf

fosnal1950 wrote:

f you put the electrolytics with the positive side going to the FET and the positive side to the op-amp,

Shouldn't one of these be "negative "??

Alf

Nope - the positive end of the electrolytic should be towards the op-amp in each case.

While i was using the LED envelope thing for other effect i have noticed that playing on higher strings has a stronger effect than the lower end.
I just put a cap (1n) on the opamp loop to compensate, and now it seems to have a more balanced response

I'm thinking of building one of these, but not sure whether to build this second one or the first one?
I haven't read through the whole thread (sorry! ) - but what are peoples' thoughts? what are the differences other than the obvious board layout?

I'm going to do the 2nd one. Think ill get the same color plastic case too.

does the fizzy noise keep at a constant volume regardless of output volume pot? if so it may be the opamp on the sidechain is clipping and putting noise on the power lines.

ok - stooopid question...

Whats the difference between on compressor and limiter?

Yours... confused...

RyUK

ok, i wanna report back because i also had problems with this one. The fizzy distortion rifing on top of the sound...i solved it by going up on the 560ohms resistor to ground on the feedback loop of the opamp. apparently i got rail distortion, maybe because i coulnd't get the right optocoupler, and use an ldr with a led. The only drawback is that i used a true bypass and the tone changed when pedal on...it makes ait a bit thinner or brighter...

any ideas on how to add "attack" or "release" controls?

hi, just wanted to check with someone about the pcb layout - it seems like the tip ring and sleeve are all connected at the input jack...this can't be right, can it? I don't have these fancy looking jacks so ...just wanted to check before i start. Bajaman?

ashtronaut wrote:it seems like the tip ring and sleeve are all connected at the input jack...this can't be right, can it?

Those are "switching" jacks. In that way the input effect is grounded if the input jack is not inserted

thanks yugi,
hmmm... so if i don't have 'switching' jacks, can i just wire in a normal jack?

ashtronaut wrote:thanks yugi,
hmmm... so if i don't have 'switching' jacks, can i just wire in a normal jack?

Of course!

Could I add a jack for a tuner at the point of the circuit that is labeled as "bypass output to footswitch"?
The tuner would always stay switched on. Would that influence the limiter circuit in any way?

hi rosebud11
that should work okay
cheers
bajaman

thanx for the quick reply - my soldering iron is still hot ))

would anyone recommend this for acoustic guitar? does it have a fast attack or can the attack be adjusted?

This would probably sound awesome on acoustic guitar. I've always liked Limiters over Compressors for Acoustic and Bass.

Is there any mod that makes this limiter bass-specific?