Was just testing ya. You passed.
KA-9100 Facelift
- Thread starter geode
- Start date
Well, I finally finished this amp last night. I did everything in my original checklist in post #1 except change out the resistors. They all measured well within spec with no signs of overheating. This amp must have lived an easy life since it had no signs of stress anywhere. In fact, I was surprised to see the Thermal Compound was still soft. I cleaned it off and replaced with new compound anyway. My brother-in-law and I set it up (temporarily) in the garage for a listening session. All I can say is "WOW!" This amp really does sound incredible. This is really my first Kenwood to own. I've had my share of Marantz, Sansui, Pioneer and others, but none sounded better than this one. The music sounds almost 3D. I've read many glowing reports as to how good it sounded and now I'm a believer. I want to say Thanks to my AK buddies who guided and suggested the proper way to handle this amp. So, Thanks EW and Sicman for your help. Also, this amp really is a bitch to work on, but go slow, ask questions, take lots of pictures, and don't do anything stupid and it will happen. I'll attach some pics of this beauty, but forgive my poor photography skills because she looks MUCH better than these pics.
and it will happen. I'll attach some pics of this beauty, but forgive my poor photography skills because she looks MUCH better than these pics.Attachments
Pol
New Member
Hi,
Here there's a novice trying to restore my 9100, just two questions..
Do you can tell me wich of these 78 is it?
https://www.digikey.com/products/en?keywords=1N4005
Do you know where to buy it?
We'll keep in touch,
POL
Here there's a novice trying to restore my 9100, just two questions..
Do you can tell me wich of these 78 is it?
https://www.digikey.com/products/en?keywords=1N4005
Do you know where to buy it?
We'll keep in touch,
POL
Last edited:
Got most parts from Mouser.
This trimmer https://www.mouser.com/ProductDetail/652-3299Y-1-501LF
These diodes are now obsolete but you can look at the datasheet and find a substitute https://www.mouser.com/ProductDetail/512-1N4005
Good luck.
Pol
New Member
Thanks for your help, it's very appreciated!!
Pol
New Member
At the moment from Mouser I'm ready to order these components:
x1
https://www.mouser.es/ProductDetail/512-KSC945CYTA
x1
https://www.mouser.es/ProductDetail/512-KSA1220AYS
x2
https://www.mouser.es/ProductDetail/512-KSC2690AYSTU
x1
https://www.mouser.es/ProductDetail/652-3299Y-1-501LF
I hope it will be right..
x1
https://www.mouser.es/ProductDetail/512-KSC945CYTA
x1
https://www.mouser.es/ProductDetail/512-KSA1220AYS
x2
https://www.mouser.es/ProductDetail/512-KSC2690AYSTU
x1
https://www.mouser.es/ProductDetail/652-3299Y-1-501LF
I hope it will be right..
Last edited:
Pol
New Member
Hi Geode,
I found the obsolete diode of Mouser on Digi-Key, this one ..isn't it?
https://www.digikey.com/product-detail/en/on-semiconductor/1N4005RLG/1N4005RLGOSCT-ND/1139657
please, tell me if it's the correct one..
POL
I found the obsolete diode of Mouser on Digi-Key, this one ..isn't it?
https://www.digikey.com/product-detail/en/on-semiconductor/1N4005RLG/1N4005RLGOSCT-ND/1139657
please, tell me if it's the correct one..
POL
THD
Active Member
I never use light bulbs, they will just burn out again, I use LEDS, BA9 Base with a little modification. 14vdc or 12 works just fine.I've been eyeing this beauty since I bought it. Cosmetically it is about an 8/10. It appears to be totally unmolested. Electronically it all seems to work excepting the channel drop out once in a while. I did a quick and dirty deoxit session with it that helped. I plan on keeping this amp in my small collection. So, the restoration begins. I've already pulled the faceplate and have all the control board (X11-1410-00) apart. The plan after reading all I can find on restoring the KA-9100 is listed below.
1) Light bulb or bulbs in meter burned out. Will contact dgwojo for them.
2) Changing all electrolytics capacitors. Will use Nichicon PW and PM everywhere, except the Control board. All the orange capacitors will be replaced with Elna Silmi II and the Nichicons in otherplaces. I'm also using Wima films for the 1 uF 50V caps.
3) The 4 big filter caps will be replaced with Nichicon Gold Tune solder lug 10000 uF 63V from Michael Percy.
The Boards:
Power Supply (X00-1870-11)
1. Recap electrolytics. I am increasing the voltage to the next available higher voltage.
2. replace DZK1 YZ-140 zener with TZX14B-TAP
3. replace DK1-5 W06B diodes with 1N4005
4. Replace relay with Omron MY4-02 DC 24
Diode Board (X00-1880-11)
1. Replace 4 big filter caps with Nichicon Gold Tune
2. Replace small electrolytics with Nichicon PM or PW
3. Replace DZ9 W06B with 1N4005
4. Replace DZ10-12 1S2076 with 1N4148
5. Question? Should the transistors be changed on this board. If so,
a. QZ1,3 2SC945 replace with KSC1845
b. QZ2 2SC1212A replace with KSC2690A
Power AMP (X07-1500-11)
1. Replace all carbon resistors with carbon film 1/2W. Not replacing Metal Film.
2. Recap small electrolytics with Nichicon PM or PW
3. Transistors
a. Q1-4 2SC1775 looking for suitable replacement
b. Q5-8 2SA912 T0-92 replace with MJE350 T0-126
c. Q9,10 2SC1400 looking for suitable replacement
d. Q11,12 2SC1885 T0-92 replace with MJE340 T0-126
e. DE1,2 EQA01-24 zener replace with 1N5252B
4. replace trimmers with Bourns 3229Y 500 ohm 1/2W
5. Refresh thermal compound on TA-100W IC
6. Replace De3-6 1S2076 with 1N4148
This is all I can think of to do to this amp. You guys see any problems with the plan or is there something I should do that I haven't listed. Any problems with my substitutions. Any feedback will be greatly appreciated. I am no electronics tech but have done some light work. I have restored a Sansui G9000DB, Restored a Marantz 1060 amp, repaired Marantz 2230, 2220 receivers. Also repaired a Kenwood KR-5400. I can say this KA-9100 is a bitch to take apart and I'm sure desoldering and soldering parts is going to be a lot of funmay be
The Onsemi part number is a little different but the specs are pretty much identical. I say use it. Just to let you know I'm not a an et by any stretch so take what I say with a bit of caution. Although I believe that diode will be fine. The other information you glean from my thread was provided by the guys-in-the-know who help us out. You can mostly always run with their recommendations. But read anyway because there is a lot to learn and fun doing it. Enjoy the
THD
Active Member
Just parallel the the contacts on the switch, there is a set they didn't use simple. Why go to all that trouble? Or better yet leave the switch on and use a master switch for the system, thats what I use.
