Help needed, Lanzar opti 2500 - diyAudio
Go Back   Home > Forums > General Interest > Car Audio

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 18th January 2009, 07:34 AM   #1
Leif is offline Leif  Finland
diyAudio Member
 
Join Date: Nov 2004
Location: Finland
Default Help needed, Lanzar opti 2500

Hello everyone,
I have now an broken old Lanzar opti 2500 on my workbench and it seems like the preamp is broken. The amp section in it self works.
All inputs and gain&bassboost works, but when i increase volume distorssion accrue. In mono mode a very week and highly distorssion signal comes out from the amp.
I measured that the op-amps (U1-U4) gets a voltage of 28V.
So i wonder where the problem could be.

thanks!

-Leif-
  Reply With Quote
Old 18th January 2009, 07:48 AM   #2
diyAudio Member
 
Join Date: Nov 2003
Location: Louisiana
Does the rail voltage remain constant when you try to drive it to high power?

With no RCAs plugged in, do you read ~0 ohms between the RCA shield and the non-bridging speaker terminals?

Do you have an oscilloscope?
  Reply With Quote
Old 18th January 2009, 08:20 AM   #3
Leif is offline Leif  Finland
diyAudio Member
 
Join Date: Nov 2004
Location: Finland
Hi,
The rail voltage is in idle about 92V and when i push it higher rail voltage variate between 70 - 110V.

With no RCA connected there is about ~0 ohms between rca gnd and non-bridging speaker terminals.

I have not got a oscilloscope at home right now, but tomorrow i can borrow one from work.
  Reply With Quote
Old 18th January 2009, 08:39 AM   #4
diyAudio Member
 
Join Date: Nov 2003
Location: Louisiana
Assuming that this is essentially the same as the 50c, Q1 and Q3 are the muting transistors. With the black meter probe on the RCA shield, what DC voltage do you read on the 3rd leg of Q1 and Q3?
  Reply With Quote
Old 18th January 2009, 08:45 AM   #5
Leif is offline Leif  Finland
diyAudio Member
 
Join Date: Nov 2004
Location: Finland
Both Q1 and Q3 has -14.5VDC on leg 3
  Reply With Quote
Old 18th January 2009, 08:59 AM   #6
diyAudio Member
 
Join Date: Nov 2003
Location: Louisiana
That's OK.

Transistors Q4 and Q5 are the input to the power amplifier's differential amp. If the signal is clean there, the problem is in the power amplifier. If it's not clean there, the problem is before the power amp. Check the signal at the output pins of each of the op-amps to see where it becomes distorted.
  Reply With Quote
Old 18th January 2009, 09:08 AM   #7
Leif is offline Leif  Finland
diyAudio Member
 
Join Date: Nov 2004
Location: Finland
ok, thanks for now.
I have to borrow a oscilloscope from work to check that, but it has to wait to tomorrow.
  Reply With Quote
Old 18th January 2009, 10:10 AM   #8
Leif is offline Leif  Finland
diyAudio Member
 
Join Date: Nov 2004
Location: Finland
ok, a new problem after bending Q4... DC in speaker outputs...

Q4 and the other transistors do not have any short circuits, but in the speaker right channel output is -13VDC and in the left +13VDC.
Rail voltage is now about 107V

My DC power supply is set to 12.2VDC

So wtf just happend?
  Reply With Quote
Old 18th January 2009, 11:30 AM   #9
PQatPIT is offline PQatPIT  Finland
diyAudio Member
 
Join Date: Nov 2008
Ha! Another Finland guy with broken Opti2500.

I have a similar one, with power supply down. Some resistors burned black and just wanted to know their values, otherwise it seems to be ok. Those resistors route power supply fets their pwm signal. Bought it like that as a project, just haven't had time to repair.

When I was young I drooled for one and I just couldn't keep my hands of of it . Maybe we should join forces here? Email pq (at) pitsop.fi.
  Reply With Quote
Old 18th January 2009, 12:17 PM   #10
Leif is offline Leif  Finland
diyAudio Member
 
Join Date: Nov 2004
Location: Finland
Alright,
IŽd just e-mail you PQ, but your e-mail address seems to bee wrong... even with the @

I wonder how many of those amps is sold here in finland? They were quite expensive...

What components are you interested to know?
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Users manual to a lanzar opti 6200 Flames_Pastorn Car Audio 15 30th August 2012 10:26 PM
Needs specs for old lanzar opti 100 MatthewS Car Audio 3 16th April 2009 12:00 AM
lanzar optidrive 2500 abortion amc32 Car Audio 4 20th April 2008 08:41 PM
DC on the speaker outputs, Lanzar Opti 100 Mike1008 Car Audio 10 1st June 2006 04:05 AM
Amplifier Lanzar opti drive 2200 Urosch Chip Amps 1 27th September 2004 11:36 PM


New To Site? Need Help?

All times are GMT. The time now is 03:01 AM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright ©1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2