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Luxman L110 dc offset adjustment

sx-70

sx-70

Well-Known Member
I’m doing a little research for the benefit of the tech prior to taking the L110 in for a minor tune up. As many know the service manual for the L110 that is floating around is incomplete and difficult to read. The L100 service manual (complete but still lacking detail) shows the following pic and I found a post on vinyl engine on the subject:

https://www.vinylengine.com/turntable_forum/viewtopic.php?t=56194

This post mentions having to desolder a wire in order to make the adjustments. I would really appreciate if a L110 owner could confirm this procedure and hopefully provide more specific information about which wire. I read through a L110 thread by @xratedpez and would really be grateful for his or anyone’s input. Thank you so much in advance!

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one and only bump...

Any advice or info I can pass along would be so helpful, thank you!
 
are you working with Blaine on this one?

I'm not a tech.

A tech should have a good idea of where those connections are and with the amp module in front of them would be able to determine what part of the circuit is opened for the measurement. Commonly that would be the emitter current, frequently measured as a voltage across the emitter resistors. But if that location is not available, then measuring the current where a fuse might have been or opening a circuit to get the amps flowing would be a way to get the answer.

Knowing that an amp is biased in A/B instead of class A would clue a tech to how much bias current would be needed. Maybe not the exact 61.23mA but a more general 60-65 and something that the amp would not care about the difference. Additionally, a sine wave can be evaluated to see if the notch is sufficiently reduced to indicate enough bias is being applied to provide good sonic performace.

I don't know what output transistors are used in the L-100 vs. the L-110 but there may be a difference in desired bias based on this. Again something a tech would have more insight. If they have the L-110 in front of them they can see the transistors used and the manual for the L-100 however poor probably lists the transistors used for its outputs.

It is unfortunate that some of the nicest sounding, best looking vintage gear has such horrible manuals.
 
Blaine is well aware of this L110 but I've tortured him enough - believe he referred to it as a hanger queen! He got it out of protection without a legible service manual and it sounds amazing to boot (L110 > 5L-15 head to head). I was hoping to bring it to a shop that is blocks from my place that has done a few small things on other gear and done a decent job.
 
sx-70 said:
Blaine is well aware of this L110 but I've tortured him enough - believe he referred to it as a hanger queen! He got it out of protection without a legible service manual and it sounds amazing to boot (L110 > 5L-15 head to head). I was hoping to bring it to a shop that is blocks from my place that has done a few small things on other gear and done a decent job.
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Hi I am working on one of these nightmares, missing critical voltages on the service manual, would you have them ? For example power supply board PB1138
 
lazio2000 said:
Hi I am working on one of these nightmares, missing critical voltages on the service manual, would you have them ? For example power supply board PB1138
Click to expand...
Sorry - just seeing this. I don't have the critical voltages or other technical information unfortunately.

My L110 is back on the shelf - think the speaker relay is acting up.
 
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