OPTO "Grinder"

[dirtyhanfri]

Looks Nice

I've been looking to build a new La-IV, but I'll give a try to this one.

Will we see a GRINDER G Bus Compressor or something like that?

 

[Gustav]

Will we see a GRINDER G Bus Compressor or something like that?

Nope!

And good luck with the build

Gustav

 

[tirsbak]

Hey guys, I'm making a stereo version of this project. I thought I would share some pictures

 

[razd14]

Do you still use both channels controls in stereo mode, or do one channel control both?

cool pictures

 

[gyraf]

Stereo LINK - exactly like when linking two la4's or 1176's. Synchronizes GR, nothing else.

 

[elskardio]

Hi tirsbak,
do you have audio clips of your Opto Grinder?
Thanks

 

[razd14]

Thanks for the info Jakob

 

[tirsbak]

Hi tirsbak,
do you have audio clips of your Opto Grinder?
Thanks

Not at the moment - right now i'm doing the calibration. But it sounds great! the stereo calibration is just a little difficult

 

[mrkrawn]

Hi guys i will start this compressor  in few days.
I don't know how to wire valtec vtlc2
Can you post a pic to help me please.
Thanks

 

[Gustav]

Hi guys i will start this compressor  in few days.
I don't know how to wire valtec vtlc2
Can you post a pic to help me please.
Thanks

Hi MrKrawn.

The markings for opto coupler are on the silk screen of the PCB. +/- on the opto side, and three legs for the resistors on the other.

If you are using two singles, just put them in series and combine a leg on the resistor side.

Gustav

 

[mrkrawn]

Thanks Gustav for your help

 

[melomane]

great project! I almost finished mine! I would put pictures when it's done

 

[dipfrik]

Hey Gustav,

i just finished my build and all voltages are ok. (psu-ic's etc.)
I didn't insert the IC's for the voltages tests but the BD140 gets instantly insanely hot after a few seconds when i power on the device so i stopped here.

Any idea?

Thanks, Sven

 

[dipfrik]

Oha…something smoking and burned too

Sven

 

[Gustav]

insert ICs (actually the one nearest to the area will do) to solve this problem.

Either you test with no ICs and no trafo, or with ICs and trafo, or the transistor will be abused..

Gustav

 

[dipfrik]

Ok, but in general the idea of checking voltages before inserting the IC's is not a bad one or?

I will do that later and give you an update.

Thanks, Sven

 

[Gustav]

Ok, but in general the idea of checking voltages before inserting the IC's is not a bad one or?

I will do that later and give you an update.

Thanks, Sven

In general, I should think so. I did the same as you on one occasion building a unit for someone, which is how I learned of the problem. I never happened to have the trafo in/IC out combo going while I was making the first few units.

You only need to place the IC driving the transistor to avoid it (TL072?)

Gustav

 

[dipfrik]

..piece of cake! Everything fine now after inserting the IC's and i think i didn't blow the resitor and transistor last night
The unit is cold i can hear (if needed) a lot of compression.

3 more questions now:

1) I couldn't find any information about the calibration routine?
2) again problems with the meter. *g It works ok'ish when in GR-Mode and what is the 2nd one? Output VU-metering? If so, the needle moves a little bit around <-20db on the meter. …sorry too many different meters here a regular SIFAM does the job very well.
3) what are the ratio values on the 5 positions of the Lorlin Switch from A1/C1 to A5/C5

Thanks, Sven

 

[Gustav]

..piece of cake! Everything fine now after inserting the IC's and i think i didn't blow the resitor and transistor last night
The unit is cold i can hear (if needed) a lot of compression.

3 more questions now:

1) I couldn't find any information about the calibration routine?
2) again problems with the meter. *g It works ok'ish when in GR-Mode and what is the 2nd one? Output VU-metering? If so, the needle moves a little bit around <-20db on the meter. …sorry too many different meters here a regular SIFAM does the job very well.
3) what are the ratio values on the 5 positions of the Lorlin Switch from A1/C1 to A5/C5

Thanks, Sven

google -> LA4A manual for info

Or for cheating, if you aren't running a stereo unit.

https://pcbgrinder.com/download/OPTO_GRINDER/OPTO-CAL.pdf

Gustav

 

[dipfrik]

Thanks, i will cheat

Sven