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Luxman L-100U Recap

dshoaf said:
What's the plan for the actual replacement sequence? I'd suggest the electrolytics be swapped first. Then listen to it for a bit. Next, swap out one transistor in each channel on a board. Start with the output end of the board and work backwards through the signal chain alternating between swapping out one device on both channels then listening.

I did this with 2 McIntosh C28s and MX-110s. It really helped me understand the impact of the various parts on the performance improvements. The other thing it did was to allow me to catch mistakes or unintentional failures due to the rework itself.

I'd have to have had to chase mistakes like that after a wholesale swapout.

Cheers,

David
Click to expand...
I also like this Plan....Since the L-100U boards are easy to access...Using the WIMA's MKP10 requires around 125-150hrs burn in (I use these in Turners. Pre-Amps and Fresh they sound restricted and dynamics are limited...give them the time and they sound neutral, smooth with transparency and well balanced)...Yeh..I Like these!!!

1st: Recap All Electrolytic's and replace Big Cans then burn in 100hrs. That will take care of PB-647 Power Supply Board, PB-639 Tone Amp, PB-645 Winker
2nd: PB-649 Power Board - Film and Diode replacement
3rd: PB-640 Flat Amp - Transistor replacement
4th: PB-638 Touch Mute/Filter - Transistor replacement
5th: PB-636 Equalizer Board - Film, Transistor and Diode replacement

With the amount of time for the Films to Burn-In...About a Week for each board with Films.

Going to put a Mouser order in...Stay Tune...

Blue Shadow said:
I like this. It almost sounds like hot swapping the transistors as you are listening. That would be nice. The heck with blind tests, hot swap test the new standard in recapping/transistor upgrades and diode replacements. Probably let the value of those high speed components be heard.


For those that don't know better this is not something to try. It will destroy your unit and possible kill the tech doing the swaps. Don't work on live electrical gear. Do I even need to say this? Really?
Click to expand...
Alway's looking to improve testing techniques and to listen what others are doing...
 
Since I am waiting for the parts....

2 Questions:

Pic 1.The Idle and Zero Adjustments...Do I remove the steel bar then take measurements?
Pic 2. Power Supply Board...VR901/VR902...I do not see anything in the SM on adjustments?

Also, there is no thermal paste for the Outputs...I will install New MICA's and paste.
 

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I have been going thru the 2 sites on there recap/upgrades. On PB-647 Power Supply Board seems to get BEAT UP. R919, R922 and R933 need attention. Relay cleaned or Replaced.

http://www.sorscha.org/Content/html/Specials/luxman-L100/html/L100-1.html

https://picasaweb.google.com/vbkolsen/LuxmanL100Renovation#

So a couple of additions to the list:

PB-647: Replace R919 and R920 with Ohmicone 330ohm/2W Wirewound Resistor Cement Filled Ceramic
R933 replaced with Ohmite 560ohm/1/2W Little Demon Carbon Resistor
Replace 2 Trimmer Resistors with Bourns 10kOhm

PB-649: Replace 4 Trimmers Resistors with Vishay (2)1kOhm and (2)4.7kOhm
 
I thought I would play along. I dug my amp out of storage and opened it up. It seems to work fine, although it does take 12-15s for the relay to click (and the blinker doesn't work). I have previously adjusted the offset and bias.

I get ~ +/- 62V on the C7-10 connectors, and that value doesn't really change much if I adjust VR901 or VR902. I also notice my board is missing a few parts in this region: C903(4), R905(6), D905(6), R907(8).

From your last picture it seems your amp has these parts. However, the amp in the link that I provided is missing the parts, just like mine.

Hmmmmmm. I don't know enough about circuits to determine the effect of removing those parts, or what the VR's should be adjusting. As it is, I can't adjust mine down to +/- 58V on the C7-10 connectors. Is your amp still functional? Can you measure your voltages on C7-10 and see what you have and if they can be adjusted?

Steve.
 
SteveP said:
I get ~ +/- 62V on the C7-10 connectors, and that value doesn't really change much if I adjust VR901 or VR902. I also notice my board is missing a few parts in this region: C903(4), R905(6), D905(6), R907(8).

From your last picture it seems your amp has these parts. However, the amp in the link that I provided is missing the parts, just like mine.

Hmmmmmm. I don't know enough about circuits to determine the effect of removing those parts, or what the VR's should be adjusting. As it is, I can't adjust mine down to +/- 58V on the C7-10 connectors. Is your amp still functional? Can you measure your voltages on C7-10 and see what you have and if they can be adjusted?

Steve.
Click to expand...


There are some that do know how to figure out the need for these parts, but they need to read a schematic. If you post the part of the schematic in question in a brand new thread (better to get real tech eyes on the topic) you might get an answer. Lots of helpful folks on AK.

I have no idea how to figure that out. That and my Luxman that looks like yours and CJ's is just a preamp.
 
Looking over the (2) PB-635 Transistor Boards....Since I am Cleaning the Old grease and putting in New MICA's and paste....

I am going to replace the (4).33ohm 5W Cement Resistor, (2) 22ohm 1W Flame-proof and (4) 10ohm 1/4W

Replacement:

(2) 22ohm 1W 1% KIWAME Flameproof
(4) .33ohm 5W 1% Mills MRA
(4) 10ohm 1/2W 1% PRP PR9372 Audio
 

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If you leave the leads a bit longer on the solder side of one of the .33 ohm resistors per channel then you could measure the bias by measuring the voltage across that resistor and setting accordingly (it would save desoldering and resoldering that jumper bar every time you wanted to check the bias)
 
CohibaJoe said:
Checked a few threads.....

VD1221 replace with: (2) 1N4148 in series for each VD1221
2SC1345 replace with: KSC1845FTA

This Luxman is keeping me busy.....
Click to expand...


I'm replacing my 2SC1345's with KSC1845FTA's in my Luxman L-85V.

I noticed the KSC1845FTA's are running about 350 for HFE compared to 500+ for the original 2SC1345's. Is that enough of a difference in gain to worry about?
 
madtech said:
I'm replacing my 2SC1345's with KSC1845FTA's in my Luxman L-85V.

I noticed the KSC1845FTA's are running about 350 for HFE compared to 500+ for the original 2SC1345's. Is that enough of a difference in gain to worry about?
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I am re-checking this Transistor. I was looking at some Past thread here and the KSC1845FTA are recommended.

Looking at http://www.hilberink.nl on Luxman Mods....I have used this site for information on Luxman Mods...
They are using Fairchild BC550CTA for the replacement of Hitachi 2SC1345

***So am asking for a Part Check on what one of you may have used***

Going over the specs on KSC1845FTA and BC550CTA
 
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Blue Shadow said:
There are some that do know how to figure out the need for these parts, but they need to read a schematic. If you post the part of the schematic in question in a brand new thread (better to get real tech eyes on the topic) you might get an answer. Lots of helpful folks on AK.

I have no idea how to figure that out. That and my Luxman that looks like yours and CJ's is just a preamp.
Click to expand...

Done. See:

http://www.audiokarma.org/forums/showthread.php?p=7289698&posted=1#post7289698
 
So I'm guessing you saw the volume control cleaning I did to my C-1000 and Hans posted on his site? Easy to get in there and get the stepped volume control sounding new again.
 
Yeh I know....It's been awhile.

I was gathering some info for Sansui AU-517. Since I was ordering some parts from Parts Connexion...Needed to wait as shipping is higher due to Canada.

Parts will be here this week from PC and Mouser.

This one will be worth the wait!!!!!
 
I was curious where you had been yesterday while I was looking at AK. Seems you post often enough to keep us up to date but as you say it has been a while. At least we know you are back at the recap journey.
 
With Cohibajoe's permission I've decided to post a question in this thread.

I'm looking for new equivalents for the output transistors in the L100. Anyone who knows their stuff, please help out, and we'll have this thread as a great resource for parts.

Looking for equivalents for-

-2SC1079Y
-2SA679Y
-2SD287BQR
-2SB539BQR

Any help is greatly appreciated!
 
ficklecycler said:
With Cohibajoe's permission I've decided to post a question in this thread.

I'm looking for new equivalents for the output transistors in the L100. Anyone who knows their stuff, please help out, and we'll have this thread as a great resource for parts.

Looking for equivalents for-

-2SC1079Y
-2SA679Y
-2SD287BQR
-2SB539BQR

Any help is greatly appreciated!
Click to expand...
And the ones on the Power Supply Board:

2SA653
2SC1161
 
I finally got ALL my Parts in (Parts Connexion, Mouser was backed up 1 week due to the Snow/Ice storm 1 1/2 weeks ago). Also was putting my Parts list for Sansui AU-517 (next in-line) and this took abit to look at everything.

L-100U is not just getting a Recap...but Transistors, Diodes and Films replaced.

1st Up...PB-647 Power Supply Board
 
PB-647 Power Supply Board is done....Bourns Trimmer with be last after I test 1st.

I wound up replacing R901/902 22ohm/1W R919/920 330ohm/1W since there are Heat marks on the Board. Also, the caps were showing signs of wear from the heat it was giving off (Color code bars fading).

Look over the Relay...I am leaving this as is....Cannot see any carbon wear on the contacts. When I purchased the L100U...the seller only used this a few hours a week....And it shows.

Next, PB-649 Power Board
 

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