la-light..it never ends...

[Johan]

..with VU-meter...might not folow perfectly, but the -20db point is accurate...

http://aronnelson.com/gallery/johan/la_light_vu_version

johan

[smashinator]

Nice!

[Jaicen_solo]

That looks really good. If you could re-draw the schematic a little cleaner, i'll have a go at knocking up a PCB for this one too.
Did you check out my orignal PCB Johan??

[Johan]

That looks really good. If you could re-draw the schematic a little cleaner, i'll have a go at knocking up a PCB for this one too.
Did you check out my orignal PCB Johan??

.oh..thank's Jaicen..never saw your pcb...allways buillt on stripboards...if you klick on the picture it should come up in full format. I think it should be clear enough

johan

[Jaicen_solo]

Johan, do you have any sound samples of your LA-Lite working?
Does it colour the sound in a similar way to the original?? I love the fatness they can add!
Also, have you ever thought of emulating the Urei 1176?? I'd quite like to build a workalike stompbox version of that!
Would be nice to have them both in a single enclosure, to toggle between transparent/coloured compression.

EDIT: I just looked at the schem again, this time a little larger thanks 
Looks like the gain reduction section is the same, but I'm wondering why you're using a lamp now, as opposed to an LED?? I also see you've removed the low frequency side-chain compensation, is that a result of using the incandescent lamp? I think I can just add that vU meter to my existing layout by adding another op-amp. Excellent!

[Johan]

Johan, do you have any sound samples of your LA-Lite working?
Does it colour the sound in a similar way to the original?? I love the fatness they can add!
Also, have you ever thought of emulating the Urei 1176?? I'd quite like to build a workalike stompbox version of that!
Would be nice to have them both in a single enclosure, to toggle between transparent/coloured compression.

EDIT: I just looked at the schem again, this time a little larger thanks 
Looks like the gain reduction section is the same, but I'm wondering why you're using a lamp now, as opposed to an LED?? I also see you've removed the low frequency side-chain compensation, is that a result of using the incandescent lamp? I think I can just add that vU meter to my existing layout by adding another op-amp. Excellent!

sorry, no soundsamples..I never had a chanse to compare, so I really cant say... the real one uses electroluminence panels and the usualy dont work at all under 100Hz and doesnt reach their full lightstrength until around 400Hz. that said, I dont know how well the El-lum. in LA2a works at low frequencys. with the filter in the earlier versions you can just dial it in until it sounds right. the only reason I didnt use the filter on this one was that I simply wanted it flat.
the reason I used a small lightbulb this time was this...with some, not all but a few of all the LEDs out there, there will be distortion in lower frequencys ( 0-150Hz )simply becouse the on/off action is too abrupt and the lag in the LDR isnt slow enough to eat it up ( with the bassfilter it isnt a problem but I wanted this one to be flat..)..I dont want it to be part-specific..if it says LED, I want any LED to work, not just "THAT particular one"...you can use bias to get around this as in the "WHAT"-compressor, but it gets tricky to get it right if you're not using completely sealed vactrol-type optocouplers..I use LDR and lighhtsource, so I small lightbulb seemed easier..and Im returning to the bassfilter...
If you have a spare opamp section on your earlier pcb, there is no reason you couldnt use that to drive the meter..

about the 1176..if you sit down and stare at the schematic for a while, and then break it up in buildingblocks..attenuator, gain recovery, sidechain..it's actually quite simular to the LA2 in builld-up..the attenuator sits at the same possition, but use a FET instead of LDR, the sidechain has attack and release and picks up the signal at the same position as the revoveryamp... its quite simmilar ..the attack/release is quite easy to implement, the only "hard" part would be to get the FET to work right...but that might not be so hard either..

johan

..and by the way..the sidechain is a never-ending "work in progress"..right now Im working on using a LM386 driving a 6/230volt transformer ( driving the 6volt and connect the 230v to the lightpanel) and using a REAL electroluminencepanel...9volt pedal with REAL electroluminence/LDR action..

[Jaicen_solo]

..and by the way..the sidechain is a never-ending "work in progress"..right now Im working on using a LM386 driving a 6/230volt transformer ( driving the 6volt and connect the 230v to the lightpanel) and using a REAL electroluminencepanel...9volt pedal with REAL electroluminence/LDR action..

HAHA, sounds awesome! I'm guessing that things' gonna eat batteries! I don't think that's somewhere i'd really like to go!
I was thinking of adding a sidechain input, to drive the comp with a source other than what's being processed. Think that would be useful. I'm going to build a pair of LA-Lights into a rackmount with a pair of VU's, just to be uber showy
As for the urei, I have been staring at the schem for quite some time, but i'm not really understanding it any better! I guess if I read up on my FET theory it would be easy enough to work out. I'll let you know how I get on anyway.
By the way, I found a source for small vU meters, RS components. 200mA meters for £5, not bad 

[Coriolis]

Jaicen_ solo: Where can I find that pcb for the LA-light? I can't seem to find anything by you in the layout-gallery...?
Do you have a website or...?

Regards, Christian.

[Coriolis]

Bump...?