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Re: LA500 opto comp leveling amp BUILD THREAD 500/51X

Posted: Tue Feb 24, 2015 7:25 am
by Lud
Hi Joe, actually i have spoken prematurely. The comp works excepted that the threshold doesn't work on a small section : between the eighth and the seventh lines, the sound is not processed. Do you have an idea of what it could be? Maybe a bad soldering point? And also the link mode does not work anymore but i won't be surprised this is due to the non working meter.

Cheers. Lud.

Re: LA500 opto comp leveling amp BUILD THREAD 500/51X

Posted: Sat Feb 28, 2015 4:12 am
by PatrickFromDavis
I had the wires to the LED on the meter backwards. The relay would not make a sound, and the light did not come one. However, I could set the VU, Gain Reduction, and Span points while it was in this state. The make up would show on the meter and it appeared for all practical purposes like it was running. But without the relay working, the audio was bypassed at all times. I used a spare piece of wire to jump across the two terminals of the LED on the meter, and the relay came to life. At that point I decided that if I had burnt up the LED it wouldn't matter if I swapped the leads. But just to be sure, I found the 1.8K ohm resistor and measured it to make sure I hadn't made a stupid mistake when stuffing the board. It was correct, so I unsoldered the two wires and swapped their positions. It worked, and everything functioned as it should! The calibration was still correct for the VU, but the GR and VU were not matched so that is something to take care of later. I thought I would write down my findings just in case someone else has what seems to be a functioning module except no signal or the audio is permanently bypassed. Fun kit, well put together.
Patrick

Re: LA500 opto comp leveling amp BUILD THREAD 500/51X

Posted: Mon Mar 02, 2015 4:21 pm
by Joe Malone
PatrickFromDavis wrote:I had the wires to the LED on the meter backwards. The relay would not make a sound, and the light did not come one. However, I could set the VU, Gain Reduction, and Span points while it was in this state. The make up would show on the meter and it appeared for all practical purposes like it was running. But without the relay working, the audio was bypassed at all times. I used a spare piece of wire to jump across the two terminals of the LED on the meter, and the relay came to life. At that point I decided that if I had burnt up the LED it wouldn't matter if I swapped the leads. But just to be sure, I found the 1.8K ohm resistor and measured it to make sure I hadn't made a stupid mistake when stuffing the board. It was correct, so I unsoldered the two wires and swapped their positions. It worked, and everything functioned as it should! The calibration was still correct for the VU, but the GR and VU were not matched so that is something to take care of later. I thought I would write down my findings just in case someone else has what seems to be a functioning module except no signal or the audio is permanently bypassed. Fun kit, well put together.
Patrick


Thanks Patrick. Yes it is safe to try the led wires on the meter both ways around. One way will work and one won't. Great to hear you like the kit :D 8)

Re: LA500 opto comp leveling amp BUILD THREAD 500/51X

Posted: Mon Mar 02, 2015 4:26 pm
by Joe Malone
Lud wrote:Hi Joe, actually i have spoken prematurely. The comp works excepted that the threshold doesn't work on a small section : between the eighth and the seventh lines, the sound is not processed. Do you have an idea of what it could be? Maybe a bad soldering point? And also the link mode does not work anymore but i won't be surprised this is due to the non working meter.

Cheers. Lud.


HI Lud not sure if this problem has been solved or not? Never seen this before. Shouldn't be the threshold pot as it is 2 pots in parallel so very unlikely to fail.

Only think I would think of is the pot wired wrong or the wires not twisted or too long so you are getting oscillation.

Re: LA500 opto comp leveling amp BUILD THREAD 500/51X

Posted: Mon May 18, 2015 8:42 am
by kevinrontel
Hi Joe,

I'm trying to calibrate my LA500, but, since I don't own an extension cable, I have to deal with my version of trial and error and lots of plugging in and unplugging of the unit from my lunchbox, which is consuming quite of bit of my day. Can you provide some rough starting points at which to set the three variable resistors for the VU meter? I'm hoping that'll at least get me off to a good start.

Thanks!

Re: LA500 opto comp leveling amp BUILD THREAD 500/51X

Posted: Mon May 18, 2015 9:38 am
by Joe Malone
kevinrontel wrote:Hi Joe,

I'm trying to calibrate my LA500, but, since I don't own an extension cable, I have to deal with my version of trial and error and lots of plugging in and unplugging of the unit from my lunchbox, which is consuming quite of bit of my day. Can you provide some rough starting points at which to set the three variable resistors for the VU meter? I'm hoping that'll at least get me off to a good start.

Thanks!


The trim pots come set to half way which is the best start points for alignment. There is no way to second guess the trimpot settings. It is easy to align in a rack if you follow the below info.

Empty your lunchbox and put the comp in the first slot so you have lot so empty space to the right of the module then with a small jeweler / glasses screwdriver with a piece or plastic tube or heat shrink over the end to stop it slipping off the pot screw. Also write the name of each pot on the outside with a permanent pen so you know what each pot is. This way you can align the module same as if you had an extension cable.

Re: LA500 opto comp leveling amp BUILD THREAD 500/51X

Posted: Fri May 22, 2015 4:59 pm
by manerka
Hello Everyone,
This is my first experience with this kind of electronic DIY. First, I enjoyed building this baby, even if I knew that I would probably have to need somme help at some moment...And I think it is time to do so :-/
Time to set up the compressor :
I put the power on and the VU meter is lighting ; good. But here is the frustration. I am unable to find the 1,23 v. The needle of the VU meter don't move, there is no audio signal out, and when testing the output xlr with a multimeter (as mentionned in the procedure, with the 1Khz tone in), the multimeter still indicate 0 V.
Any thoughts about this issue ?
If the compressor sounds as good as it looks, it will be awesome.

Re: LA500 opto comp leveling amp BUILD THREAD 500/51X

Posted: Tue May 26, 2015 1:23 pm
by Joe Malone
manerka wrote:Hello Everyone,
This is my first experience with this kind of electronic DIY. First, I enjoyed building this baby, even if I knew that I would probably have to need some help at some moment...And I think it is time to do so :-/
Time to set up the compressor :
I put the power on and the VU meter is lighting ; good. But here is the frustration. I am unable to find the 1,23 v. The needle of the VU meter don't move, there is no audio signal out, and when testing the output xlr with a multimeter (as mentioned in the procedure, with the 1Khz tone in), the multimeter still indicate 0 V.
Any thoughts about this issue ?
If the compressor sounds as good as it looks, it will be awesome.


Email me some clear in focus photos of the compressor assembled for now from different angles so I can see the tops of the PCB's and parts to check your build over for mistakes.

Re: LA500 opto comp leveling amp BUILD THREAD 500/51X

Posted: Wed Jun 03, 2015 8:08 am
by kevinrontel
Joe Malone wrote:
kevinrontel wrote:Hi Joe,

I'm trying to calibrate my LA500, but, since I don't own an extension cable, I have to deal with my version of trial and error and lots of plugging in and unplugging of the unit from my lunchbox, which is consuming quite of bit of my day. Can you provide some rough starting points at which to set the three variable resistors for the VU meter? I'm hoping that'll at least get me off to a good start.

Thanks!


The trim pots come set to half way which is the best start points for alignment. There is no way to second guess the trimpot settings. It is easy to align in a rack if you follow the below info.

Empty your lunchbox and put the comp in the first slot so you have lot so empty space to the right of the module then with a small jeweler / glasses screwdriver with a piece or plastic tube or heat shrink over the end to stop it slipping off the pot screw. Also write the name of each pot on the outside with a permanent pen so you know what each pot is. This way you can align the module same as if you had an extension cable.


Excellent advice, Joe. It inspired me to pull out my two-slot 500HR box. With the the top off, it'll be a cinch to adjust the pots.

Many days later...

I finally found time to calibrate the comp and it works perfectly. Thanks, again.

Re: LA500 opto comp leveling amp BUILD THREAD 500/51X

Posted: Wed Jun 03, 2015 2:01 pm
by Joe Malone
kevinrontel wrote:
Joe Malone wrote:
kevinrontel wrote:Hi Joe,

I'm trying to calibrate my LA500, but, since I don't own an extension cable, I have to deal with my version of trial and error and lots of plugging in and unplugging of the unit from my lunchbox, which is consuming quite of bit of my day. Can you provide some rough starting points at which to set the three variable resistors for the VU meter? I'm hoping that'll at least get me off to a good start.

Thanks!


The trim pots come set to half way which is the best start points for alignment. There is no way to second guess the trimpot settings. It is easy to align in a rack if you follow the below info.

Empty your lunchbox and put the comp in the first slot so you have lot so empty space to the right of the module then with a small jeweler / glasses screwdriver with a piece or plastic tube or heat shrink over the end to stop it slipping off the pot screw. Also write the name of each pot on the outside with a permanent pen so you know what each pot is. This way you can align the module same as if you had an extension cable.


Excellent advice, Joe. It inspired me to pull out my two-slot 500HR box. With the the top off, it'll be a cinch to adjust the pots.


Cool :-)

Re: LA500 opto comp leveling amp BUILD THREAD 500/51X

Posted: Sat Jun 27, 2015 1:37 am
by carlosguardia
Hi Joe,
I'm Carlos from Costa Rica. I bought an LA500 recently and just finished assembling it. It's my first time attempting to assemble an electronic device but I figured it couldn't be that hard. It did take me longer than I thought it would to get the hang of soldering the parts to the PCB, and I think I didn't do such a terrible job.
I installed the LA500 yesterday to my API Lunchbox and here's what happens: When I turn on the lunchbox, with the LA500 HPF Flat, the Meter at VU and the ratio at 3:1 the VU Meter turns on but no audio comes out. If I change the HPF settings or the Ratio Settings nothing happens, and the Thresh or Makeup are not doing anything either. Now when I switch the Meter to OFF or GR, the VU Meter switches off and sound comes out but it appears that the unit is bypassed as it's doing nothing to the sound regardless of what I do with the Thresh, Makeup, Ratio or HPF.

HELP!

Thank you very much and I'm very eager to start processing vocals and acoustic guitars through the LA500!

Best Regards from Costa Rica,

Carlos

Re: LA500 opto comp leveling amp BUILD THREAD 500/51X

Posted: Mon Jun 29, 2015 10:00 am
by Joe Malone
carlosguardia wrote:Hi Joe,
I'm Carlos from Costa Rica. I bought an LA500 recently and just finished assembling it. It's my first time attempting to assemble an electronic device but I figured it couldn't be that hard. It did take me longer than I thought it would to get the hang of soldering the parts to the PCB, and I think I didn't do such a terrible job.
I installed the LA500 yesterday to my API Lunchbox and here's what happens: When I turn on the lunchbox, with the LA500 HPF Flat, the Meter at VU and the ratio at 3:1 the VU Meter turns on but no audio comes out. If I change the HPF settings or the Ratio Settings nothing happens, and the Thresh or Makeup are not doing anything either. Now when I switch the Meter to OFF or GR, the VU Meter switches off and sound comes out but it appears that the unit is bypassed as it's doing nothing to the sound regardless of what I do with the Thresh, Makeup, Ratio or HPF.

HELP!

Thank you very much and I'm very eager to start processing vocals and acoustic guitars through the LA500!

Best Regards from Costa Rica,

Carlos


From your description the bypass relay is working but since GR is still in bypass then there is some soldering missing or not connected. Best to send me a few photos to my email of the assembled kit so I can see but best will be to pull each PCB out and send me clear in focus well lit photos of the top and bottom of the each PCB so I can spot shorts and missing solder joints.

Re: LA500 opto comp leveling amp BUILD THREAD 500/51X

Posted: Wed Aug 12, 2015 10:20 am
by CGMix
Hey Joe,

I have a pair of LA500s, powered by a Lindell six slot rack. Whenever I link the compressors, it links everything in the rack. I took all of my modules out, and placed the the 2 compressors in random slots. I put them in link mode and sure enough, they linked no matter what slot they were in. Is there something I need to do in my rack? Have you ever heard of this?

Re: LA500 opto comp leveling amp BUILD THREAD 500/51X

Posted: Thu Aug 13, 2015 9:44 am
by Joe Malone
CGMix wrote:Hey Joe,

I have a pair of LA500s, powered by a Lindell six slot rack. Whenever I link the compressors, it links everything in the rack. I took all of my modules out, and placed the the 2 compressors in random slots. I put them in link mode and sure enough, they linked no matter what slot they were in. Is there something I need to do in my rack? Have you ever heard of this?


Yes most racks like the Lindell come with all link jumpers fitted. Remove the link jumpers on the backplane of the rack leaving only the ones you need between stereo pairs of comps.

Re: LA500 opto comp leveling amp BUILD THREAD 500/51X

Posted: Tue Sep 29, 2015 11:35 am
by scissor
Hi Joe, my name is Greg.

I've just built my first LA500 and am experiencing a small problem. Like previous posters my comp works but appears to be suffering from the side chain oscillation problem. Voltage on audio out @ 1kHz is 1.23VAC. GR meter shows about -2dB (I'll let it warm up next time I re calibrate). If I have the input terminated with a muted mic pre, the comp ratio @ 3:1 and I wind up the threshold knob to about 2 o'clock the GR meter moves back to -20dB, then as I increase the threshold knob all the way clockwise the GR meter comes back to -10dB. This is only made worse with the two higher ratio settings and isn't affected at all by the side chain filter freq switch. During this process I can un mute the mic pre and monitor the audio going through the comp with headphones. Apart from the obvious attenuation, everything sounds fine.

As per your earlier advice, I've made sure the 3 wires to the threshold pot are twisted tightly and are as short as possible. I've been over both boards with a magnifying glass and cleaned them with Fluxclene.

How would you suggest I proceed from here?