Need help!About a simple circuit designed by myself

[Lee]

http://bbs.guitarchina.com/attachments/month_0508/peak%20indi_qwHHFrDpmy7i.jpg

There was really a long time that I haven`t been here``How`s All you going?  Brothers ~ this is the first one circuit that designed by my self `and ,I am sorry if you couldn`t view this pciture``Because im not good at using an html script to show it ,and I`m not good at English .If you can`t see the PIC~Tell me ` I will fix it .Erm~That little thing is what I `ve maded to use as an peak indicator``The LED indicate the input signal`s level .But the problem is that ``Although it works really good as an indicator,but it will made an very low dist sound out the output .I really  don`t know why~~I hope anybody could help me to solve it
And thank you first

[The Tone God]

Firstly, linkie no workie. Secondly whats the problem with the circuit, need more information ? Thirdly since when do circuits design themselves (selfdesigned) ? That would make life easier.

Andrew

[vanhansen]

Firstly, linkie no workie. Secondly whats the problem with the circuit, need more information ? Thirdly since when do circuits design themselves (selfdesigned) ? That would make life easier.

Andrew

That would be sweet.  Just a little magic words and it's done.  

Hocus pocus flipity flam, razamataz and alacazam.   :lol:

[Lee]

:oops:  The wrong word have been changed~I really feel my face is turning red`~  ~I just Edit the  Subject just now```and  ,... :lol:    Would you answer the question by using an simple word. I mean ,my english is too bad to understand   thank you alot ~!!!

[Lee]

Do You mean the link doesn`t work ?  I `ll check it

[Lee]

You r right ```it doesn`t work.  And ,,Could you tell me how to post the Img?? thank you very much

[Lee]

http://bbs.guitarchina.com/attachments/month_0508/peak%20indi_qwHHFrDpmy7i.jpg
Check this ~ This will work

[ninoman123]

What is point A?

[gez]

It's likely that the LED will always be on.

Helps if you tell us what you're trying to do.  

If you want the peak to be variable, try making the 100k a pot, connect the + input of the first op-amp to its wiper.  Probably won't need that much gain by the way.

[gez]

PS  I'm assuming the junction of the 100k and 1k isn't supposed to be connected to the + input (would help if you made it clearer).

Comparitor with variable threshold would be my choice.  Stick the LED and stop resistor at the output.

[Connoisseur of Distortion]

wouldn't the LED in the feedback loop cause the opamp to distort??

but then, i don't really know what the opamp is running into (point A?)...

[gez]

If I've understood correctly what you're trying to do, this is what I had in mind:



Replace the lower resistor of the bias divider with a trimpot of equal value to set the threshold.  Don't take the input too low (unless you use an amp that allows inputs to be pulled down to ground), maybe reduce the gain in the first op-amp.

Apologies if I've got the wrong end of the stick, but you didn't say much in your post!  

[Lee]

Thank you guys~~

I just want the circuit to have a shortest response time```Point A is unconnected
The LED shines by following the input signal`s level,the level turns high,the Led turns bright.the level turns low,the led turns dark.
The problem is``If the effect circuit is an clean booster,the indecator `s dist sound(sounds very low) will mix the clean sound out .And it seems that the signal  runs out through the ground```*_*

[Transmogrifox]

I thought your first idea was fine.  Gez's idea is a peak indicator--when the signal level gets above a certain threshold, the light turns on.

I think I understood your idea to be simply an intensity indicator.  The LED glows bright when the signal amplitude is high, the LED does not glow as bright when the signal amplitude is lower, and does not glow much at all when you're not playing at all.

There should not be much noticeable distortion unless you biased the 5088 too low (or too high) on the input.  Your "bias" should be around 4.5 to 5 Volts, and should be adequately decoupled, i.e. a big capacitor to ground.

I suspect your distortion problem has something more to do with whatever is in the "effect circuit" box that is mysterious to us all.  If the input impedance is low, you probably have it right there.  that would give you a distorted sound on the emitter follower transistor type buffer.

Maybe I have misunderstood what you're trying to accomplish.

[gez]

The problem is``If the effect circuit is an clean booster,the indecator `s dist sound(sounds very low) will mix the clean sound out .And it seems that the signal  runs out through the ground```*_*

Is this on a breadboard?  With the amount of gain you have in the first amp, its output is slamming from rail to rail for much of the time, hence the distortion, and with bad layout it's easy to get bleed-through.

Use separate ground paths for the indicator circuit and join everything at the -ve terminal.  If your project is on a breadboard, it's probably just your layout.