[onform]

Hello

I would like to include an led ring around the volume control of an amp to denote the position of the knob as i dont want markings on the face plate and I was wondering if anyone has done this already on their own build. being a bit of a beginer I am asking for the help of some of you very experienced people on here on how to achieve this.

Any help would be much appreciated.

 

[adamus]

sounds hard!!!

Couple of routes, could crate a the led ring from some perspex (maybe sand it to diffuse the leds). Then use a card ring or something to block the light (think semi circle attached to the shaft).

Other route is build a VU meter to light up the leds as volume increases. I dontknow how you could do this without introducing crap into the signal though.

 

[onform]

the volume control is a 24 way stepped attenuator so i was thinking of 24 led's with seperate switch wafer?? directing the power to the relevant one??

 

[Sovkiller]

I think that if you not want markings, to place nothing will look even better, leave those toys solutions for low fi equipment, use the look of Perreaux, simple, professional, sleek and period...just for example:

 

[onform]

This is what i would like to achieve..

what do you think??

 

[adamus]

ok, you could use an unudes proportion of the stepped attenutaor, but you would need a 3 or 4 channel. and a lot of patience.

 

[onform]

Would anyone be able to help me with a schematic or wiring diagram?? for this. 24 led's rswww.com |* LB 3333-Q1S2-35, OSRAM Opto Semiconductors, HYPER 3 MM LED, blue, LB 3333-Q1S2-35, 654-2601

 

[onform]

i,m intending on using a stepped attenuator with an extra wafer to swith between power for each led. will i have to make my own pcb??

 

[synaesthetic]

I think it would be a lot simpler and less of a hassle to just do a "light ring" around the pot like Ferrari has done on his builds, and use a notched piece of metal to only let a "line" of light out, aligned with the pot's current position.

 

[guzzler]

You'll pay a lot of extra cash for the extra board on a stepped attenuator, and I would think you'll have to get a 4 channel balanced one as 3 channel is not common at all. If you want the discrete LED look you'll have to be a bit more creative. How about a small microprocessor with onboard DAC and attach a conventional potentiometer to the shaft of the stepped attenuator if you can? Or, a set of discrete contacts inside the box on the shaft would also work but would involve a bit of manufacturing on your part...

What was the point of the link you posted? They're just normal LEDs as far as I could see.

 

[kipman725]

Cheap volume pot > Micro controller (with ADC) > Digital volume control
Then just use the micros spare outputs and some demultiplexer IC's to drive the LEDS. Modern digital volume controls are very low distortion if applied correctly. The whole thing could be built for less than a 4 channel stepped attenuator and would be far more awsome.

 

[onform]

wow.. that does indeed sound quite awsome..but a little over my head. any links/info on how i might achieve this?? please guys remember i'm no electronic engineer.. what i lack in knowledge i make up for in blind enthusiasm

 

[Chris4891]

this suggestion is kind of a takeoff of what other people have already mentioned.. short of having some circuitry that only lights up one light at a time or spending the money on the additional board for the stepped attenuator, you can either allow only a discrete portion of the light through or what i propose, which would be to only have one led to begin with.

haven't worked with the stepped attenuators myself, but i would imagine this could work for any pot that has a relatively long shaft. provided you have access to the shaft behind the front panel, you could simply attach a shaft collar or the like onto the shaft and then mount a single led into it that would rotate with the shaft.

the only problem id have with this is that the transition between the discrete volume levels would be less cool than with the other steps.. youd see the led moving between positions. i personally would prefer the look of one led turning off and the next one turning on immediately as it clicked into position.

anyway.. it's just a thought. there would still be a few details to work out, like how to get the light through the panel (tiny pieces of translucent plastic plugs pressed into through holes?)

 

[MASantos]

There was a member who ordered special made SA with an extra waffer to switch the leds on and off, but I can't find his posts or photos. I remember that the SA weren't cheap., but the final result was awesome.