LA500 opto comp leveling amp BUILD THREAD 500/51X

Support for JLM Audio Kits

Moderator: Joe Malone

User avatar
Joe Malone
Site Admin
Posts: 1572
Joined: Wed Jan 24, 2007 11:35 pm
Location: Brisbane, Australia
Contact:

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

Postby Joe Malone » Tue Oct 24, 2017 5:44 pm

kante1603 wrote:
G-Sun wrote:Hi!

My meter-light died.
How may I replace it?


Hello G-sun,

the squared and the round part can be detached.Take care when doing that,gently tear them apart.No brutal force please,or you might damage the meter or bend the needle.
Then gently tear apart the white inlay.
After that you can reach the led.Take care while unsoldering and soldering a new one in,also watch polarity.

Have attached a pic,hope that helps.

Meter opened.JPG

Best regards,

Udo.


Thanks Udo

Do just as Udo said :-)
Joe :-)
JLM Audio
Capturing Audio without Injury

G-Sun
Posts: 39
Joined: Mon Dec 12, 2011 3:48 am
Location: Norway
Contact:

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

Postby G-Sun » Wed Oct 25, 2017 5:05 pm

kante1603 wrote:
G-Sun wrote:Hi!

My meter-light died.
How may I replace it?


Hello G-sun,

the squared and the round part can be detached.Take care when doing that,gently tear them apart.No brutal force please,or you might damage the meter or bend the needle.
Then gently tear apart the white inlay.
After that you can reach the led.Take care while unsoldering and soldering a new one in,also watch polarity.

Thanks a lot Udo!
Tried to use my LA500 today, but turns out it's more than the light.
Seems like meter is moving correct GR/Level, but it's not compressing and the Gain-pot is not doing anything.
Any pointers to the cause of the problem?

User avatar
Joe Malone
Site Admin
Posts: 1572
Joined: Wed Jan 24, 2007 11:35 pm
Location: Brisbane, Australia
Contact:

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

Postby Joe Malone » Wed Oct 25, 2017 5:13 pm

G-Sun wrote:
kante1603 wrote:
G-Sun wrote:Hi!

My meter-light died.
How may I replace it?


Hello G-sun,

the squared and the round part can be detached.Take care when doing that,gently tear them apart.No brutal force please,or you might damage the meter or bend the needle.
Then gently tear apart the white inlay.
After that you can reach the led.Take care while unsoldering and soldering a new one in,also watch polarity.

Thanks a lot Udo!
Tried to use my LA500 today, but turns out it's more than the light.
Seems like meter is moving correct GR/Level, but it's not compressing and the Gain-pot is not doing anything.
Any pointers to the cause of the problem?


Email me some clear in focus photos of your build so I can check it over. And answer all of the below questions.

Does the meter light? If NO link over the outside 2 terminals on the meter with a piece of wire to bypass the led and check if the comp is now working except for light not going. (If the led is blown the comp will never come out of bypass mode otherwise.)

Does threshold turn the level down ? Does GR meter show reduction?

Does makeup turn the level up?
Joe :-)

JLM Audio

Capturing Audio without Injury

G-Sun
Posts: 39
Joined: Mon Dec 12, 2011 3:48 am
Location: Norway
Contact:

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

Postby G-Sun » Fri Oct 27, 2017 11:57 pm

Joe Malone wrote:Email me some clear in focus photos of your build so I can check it over. And answer all of the below questions.

The unit has worked perfect for some 3 years.
Please tell me if you need the pictures after reading this post.

Does the meter light? If NO link over the outside 2 terminals on the meter with a piece of wire to bypass the led and check if the comp is now working except for light not going. (If the led is blown the comp will never come out of bypass mode otherwise.)

There is no light.
Does threshold turn the level down ? Does GR meter show reduction?

No, there is no audio GR, but the meters show GR.

Does makeup turn the level up?

No

Your explanation that the unit does not come out of bypass-state, caused by the VU-led, makes very much sense.
Meters is showing GR, and VU-out is reacting to GR and MakupGain.

If you don't tell me other-wise, I'll just test with bypassing led, and then change led.
What's the specs for a replacement led?

Very helpful answer :)

User avatar
Joe Malone
Site Admin
Posts: 1572
Joined: Wed Jan 24, 2007 11:35 pm
Location: Brisbane, Australia
Contact:

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

Postby Joe Malone » Sat Oct 28, 2017 8:13 am

G-Sun wrote:
If you don't tell me other-wise, I'll just test with bypassing led, and then change led.
What's the specs for a replacement led?

Very helpful answer :)


Yes first try a wire across the outside terminals of the meter to bypass the led and see if the comp works without led just to check all the wiring is ok.

Led is white clear 5mm about 800 to 1000mcd. We have the LED as spare part on our website if you are trying to match other LA500 meter lights exactly. Open the meter as Udo showed to check led hasn't broken off one of the mounting posts if comp has been working so long. If still soldered in place replace led. New led must go in same way around Anode & Cathode and face the top of the meter. In LA500 you can unclip back of meter without removing wires or meter from the metal frame.
Joe :-)

JLM Audio

Capturing Audio without Injury

G-Sun
Posts: 39
Joined: Mon Dec 12, 2011 3:48 am
Location: Norway
Contact:

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

Postby G-Sun » Sun Oct 29, 2017 7:05 pm

Joe Malone wrote:Yes first try a wire across the outside terminals of the meter to bypass the led and see if the comp works without led just to check all the wiring is ok.

Led is white clear 5mm about 800 to 1000mcd. We have the LED as spare part on our website if you are trying to match other LA500 meter lights exactly. Open the meter as Udo showed to check led hasn't broken off one of the mounting posts if comp has been working so long. If still soldered in place replace led. New led must go in same way around Anode & Cathode and face the top of the meter. In LA500 you can unclip back of meter without removing wires or meter from the metal frame.

Thanks a will!
Was hitting the replacement led in your shop until 20aud for shipping :)
I'll have a look another place

G-Sun
Posts: 39
Joined: Mon Dec 12, 2011 3:48 am
Location: Norway
Contact:

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

Postby G-Sun » Tue Oct 31, 2017 7:22 pm

Now, look here:

IMG_20171031_101626965.jpg


Seems like we've found the course.
Remember when soldering that this spot seemed a little weak :)

Fixed. Working perfect again. Thank you!
You do not have the required permissions to view the files attached to this post.

kante1603
Posts: 85
Joined: Wed Jan 20, 2010 6:12 pm

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

Postby kante1603 » Tue Oct 31, 2017 10:22 pm

G-Sun wrote:Now, look here
Seems like we've found the course.
Remember when soldering that this spot seemed a little weak :)

Fixed. Working perfect again. Thank you!

Looks like an LA500A to me,not LA500.
Wrong thread......?

User avatar
Joe Malone
Site Admin
Posts: 1572
Joined: Wed Jan 24, 2007 11:35 pm
Location: Brisbane, Australia
Contact:

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

Postby Joe Malone » Thu Nov 02, 2017 1:45 pm

Cool great to hear it was a simple solder joint to fix :-)

This is a LA500A not LA500 so I will move it over to the LA500A build thread
Joe :-)

JLM Audio

Capturing Audio without Injury

studiomollan
Posts: 19
Joined: Mon Jan 21, 2013 9:11 pm

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

Postby studiomollan » Thu Sep 27, 2018 3:35 am

Hi,
If you were to try and fit an original T4B module in here, where would it go? I just replaced a drip t4b for a kenetek in a diy LA2a and it made such a huge difference. Im not saying the la500 sounds bat the way it is, i love mine, but would be fun to hear the difference.
/
Emil

User avatar
Joe Malone
Site Admin
Posts: 1572
Joined: Wed Jan 24, 2007 11:35 pm
Location: Brisbane, Australia
Contact:

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

Postby Joe Malone » Thu Sep 27, 2018 10:04 am

studiomollan wrote:Hi,
If you were to try and fit an original T4B module in here, where would it go? I just replaced a drip t4b for a kenetek in a diy LA2a and it made such a huge difference. Im not saying the la500 sounds bat the way it is, i love mine, but would be fun to hear the difference.
/
Emil


The LA500 cannot run a luminescent cell as they need 40vac to 200vac to light. So T4B will never work in LA500.
Joe :-)

JLM Audio

Capturing Audio without Injury

studiomollan
Posts: 19
Joined: Mon Jan 21, 2013 9:11 pm

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

Postby studiomollan » Fri Sep 28, 2018 12:00 am

Ok. then i know. Thanks joe!

Return to “JLM Audio Kits”

Who is online

Users browsing this forum: No registered users and 5 guests