Led-meter for the S S L comp...??

[dukasound]

Noone can explain about led gain reduction meter on LA-4 or similar ccircuit :?
Duka

 

[dukasound]

My observations :roll:
For showing 0db on LA-2A or LA-4A in G.R. on meter comes 1,23V.
When compressor rise than voltage drop.
It can be start to build led meter but with exchanging compressor circuit.
Duka

 

[hejsan]

[quote author="Steven V"]Hi folks,

I have made a led meter which works with the SSL G4000 clone. The voltage coming from the SSL circuit needs indeed to be inverted, so I used a TL071 opamp to do this.

If someone is interested in the design and/or schematic, just give me a shout and I will make it available.[/quote]

Yes please! If there is one place where I prefer leds to needles it's to show gain reduction.

Does it drop in at the same point as the analog meter?

Cheers,
hejsan

 

[veermaster]

Hi Steven,
thanks for sharing your knowledge but somehow those links don´t work (at least on my machine)...
Cheers, Emre

 

[hejsan]

Hi, Steven. I'm unable to open the files you posted.

I think .sch and .brd are not really very standardized files, so if you could save it as a .pdf or .gif it would be great.

Alternatively you can make a printscreen and paste that into some paint program.

Cheers,
hejsan

 

[Guest]

I can't open them either.

I tried Photoshop, Paint Shop Pro, ThumbsPlus, Microsoft Picture and Fax viewer and MSPaint ...can't open them with anything I have.

What program are these generated from?

 

[Sammas]

Hi Steven!

I think most members of this forum have become attuned to schematics and PCB layouts being posted in generic formats like .PDF, .Gif & .Jpg. Hence the confusion. Im sure they certianly appreciate your effects.


:thumb: Nice work

 

[Sammas]

Hi Steven!

I think most members of this forum have become attuned to schematics and PCB layouts being posted in generic formats like .PDF, .Gif & .Jpg. Hence the confusion. Im sure they certianly appreciate your effects.


:thumb: Nice work

 

[hejsan]

Thanks Steven!

-hejsan

 

[Sammas]

Hi Steven, just looking over your schematic...

I think you have the +v & -v labels mixed up on JP1.

 

[Guest]

Sorry Steven, I thought I had read through, but I missed the part about Eagle software.

Thanks for the PDF's, that's a much better way for me to look at things.
(Portable Document Format)

 

[glbaudio]

If you say: does it drop in in place of the analog meter? (sorry, I'm not a native English speaker)

The answer on this question is yes; you can just use this meter in place of an analog one. However, you do have to remove (or not mount) the 2k resistor on the GSSL main board in order to get the meter to work properly.

I have uploaded the source files: the .sch (schematic) file and the .brd (board layout) file on my webspace. Sorry for the messy schematic, but it's the board which will concern most people I think.

You are free to use and alter this board and/or schematic for your own use, as long as you don't going to make money of it.

Some more infos about the meter:
This circuit is based upon the LM3914 bargraph LED driver, with the design of the circuit directly from the datasheet. I added a straight-from-the-book inverter based upon the TL071 opamp (made by Texas Instruments and ST Microelectronics, amongst others probably) to invert the voltage coming from the GSSL main board.

There is a jumper on the board which lets you choose between dot-mode and bar mode. Place the jumper if you want the meter to work in bar mode. If you don't place the jumper the meter will work in dot mode. You can of course change the board layout so that te meter always works in bar mode if you like.

The meter displays gain reduction in steps of 2dB for each led, with 20dB displayed if the top led is lit. The lowest led is just connected via a resistor to the supply voltage and is thus always lit. This led acts as my 0dB led and also as an indication that the SSL clone is turned on.

If you can, you should apply 2V DC (e.g. from a linear power supply) to the input of the meter and turn the pot just until the top led lights. The meter will then be calibrated. If you do not have access to such a power supply, trim the pot to 1,133k. You can use any value of pot which is bigger than 1,133k because only two terminals of the pot are connected. I have used a 2,2k pot.

The meter is designed to work with the -15V and +15V which are available from the GSSL main board. The meter will also work with lower supply voltages, altough one would probably have to change the resistor values in order to work properly. Refer to the LM3914/LM3915 datasheet.

The board has been tested with an LM3914 @ +-15V DC supply voltage andit seems there aren't any errors (the board works perfectly). However, if you do find any, please let me know and I will correct them.

Just remember to get the 2k resistor on the main board out, and connect the input of the meter to the output of the opamp on the main board (you can use the hole of the 2k resistor which you have just got rid of for this). Gnd goes to gnd, -15V to -15V, +15V to +15V. It's all pretty obvious I guess.

Regards,
Steven

all your files appears to be offline...is possible to have back them?
Tnx in advance

 

[beatnik]

If you say: does it drop in in place of the analog meter? (sorry, I'm not a native English speaker)

The answer on this question is yes; you can just use this meter in place of an analog one. However, you do have to remove (or not mount) the 2k resistor on the GSSL main board in order to get the meter to work properly.

I have uploaded the source files: the .sch (schematic) file and the .brd (board layout) file on my webspace. Sorry for the messy schematic, but it's the board which will concern most people I think.

You are free to use and alter this board and/or schematic for your own use, as long as you don't going to make money of it.

Some more infos about the meter:
This circuit is based upon the LM3914 bargraph LED driver, with the design of the circuit directly from the datasheet. I added a straight-from-the-book inverter based upon the TL071 opamp (made by Texas Instruments and ST Microelectronics, amongst others probably) to invert the voltage coming from the GSSL main board.

There is a jumper on the board which lets you choose between dot-mode and bar mode. Place the jumper if you want the meter to work in bar mode. If you don't place the jumper the meter will work in dot mode. You can of course change the board layout so that te meter always works in bar mode if you like.

The meter displays gain reduction in steps of 2dB for each led, with 20dB displayed if the top led is lit. The lowest led is just connected via a resistor to the supply voltage and is thus always lit. This led acts as my 0dB led and also as an indication that the SSL clone is turned on.

If you can, you should apply 2V DC (e.g. from a linear power supply) to the input of the meter and turn the pot just until the top led lights. The meter will then be calibrated. If you do not have access to such a power supply, trim the pot to 1,133k. You can use any value of pot which is bigger than 1,133k because only two terminals of the pot are connected. I have used a 2,2k pot.

The meter is designed to work with the -15V and +15V which are available from the GSSL main board. The meter will also work with lower supply voltages, altough one would probably have to change the resistor values in order to work properly. Refer to the LM3914/LM3915 datasheet.

The board has been tested with an LM3914 @ +-15V DC supply voltage andit seems there aren't any errors (the board works perfectly). However, if you do find any, please let me know and I will correct them.

Just remember to get the 2k resistor on the main board out, and connect the input of the meter to the output of the opamp on the main board (you can use the hole of the 2k resistor which you have just got rid of for this). Gnd goes to gnd, -15V to -15V, +15V to +15V. It's all pretty obvious I guess.

Regards,
Steven

all your files appears to be offline...is possible to have back them?
Tnx in advance