Kenwood ka 3500 fully service/restored
Вставка
- Опубліковано 7 лис 2022
- Bought this Kenwood at a yard sale and brought it home to service it...
check out this nice amp and it full 40+ watts per channel will sound and look great in your music room.
#Capacitorwizard, #Vintageaudio, #Kenwood KA,
PLS subscribe to my channel and encourage me to save more of these vintage audios.
* Important Note: most of my video's that are on my channel may involve high voltages that could cause harm to yourself or even death...If you follow my video's and try repairs yourself, you are doing so at your own risk!!!
PLEASE be careful!!! - Навчання та стиль
Thanks for the tip regarding the wrap-around tool! :o)
It's amazing the number of tools you need to do a job, and often more to facilitate improvisational 'work arounds'.
Very true!...
Just beautiful. Love the old stuff.
are you around Jon? let me know how to contact you.
I just picked one of those up with the matching tuner, nice little entry level vintage system.
Gotta get me one of those wire-rap tools!
yes, it's really handy to have, specially on them vintage amp...
Nice work Joe!, watched it to the end!
Really remarkable work ❤️.
Awesome. Clean and neat.
I just picked up a kenwood Ka-1500 it looks similar to yours before it was repaired. Dusty and and inside terrible 😢. Need a lot of work to do. To give this back to life. I love vintage hifi and amplifier.
Great job you have do. Keep it up.
Thank you....hope you have fun with your Kenwood ka1500...should be a good project
@@VintageAudioFever thank you so much.
q lindo trabajo y se notan los resultados muchas felicidades x ese bello trabajo
muchas gracias/Thank You so much!!!
sir gud am, i have defective kenwood int. amp. can i perform dc biasing without connecting output transistor for my KA-990d, thnk you so much for your reply...God bless
Excelente trabajo. Tengo uno desde 1977, y necesito hacer un chequeo para solucionar un problema en un canal, pero no tengo el manual de servicio y reparación.
Me podría decir que es lo que tengo que hacer para poder obtener una copia...?
Gracias de antemano por su respuesta...
Hi Miguella, you can download these service manual online,
what's your email address, I will send you the link to
I really love this video. Great work. I have had the KA-6100 version of this amp for years, mostly listening to it with headphones at work. I recently started putting it to speakers. It worked fine but one day, after a good jam session with the fam, it started being thin and having little power on both channels. I have the schematic but I barely know what it's saying. Any thoughts on where I should look first? A smarter guy than I can probably knock half the boards off the list, since it's happening on both channels. FYI, bias was set to 20 on each side and DC offset is around 12 mV. Same on each side. I didn't replace any caps. I just cleaned the pots. Unit looks mint.
Hey....hope you are well?
You do have a beautiful amplifier and powerful at that.
Just a question...since you say on both channels...and you hear this fated sound through your speakers...both speakers Right?
Try plugging throught your head phones jack with head phones and see if the issue can be heard through your headphones...
@@VintageAudioFever I assume the headphone jack avoids much of the amplification? Good idea! I don't have larger jack headphones on me but I'll grab a pair I have at work.
Correct, the sound is the same on each side. If I turn things up to improve the sound there's some crackle and pop going on. Before this happened, I planned to calibrate the VU meters (they seem way off) and I'll also be able to tell if the watts are very low.
One question about the schematic. (I'm very green). It's starting to make sense after staring at the board and the manual. If I see a point marked that says 35v or -35v, does that mean I should apply the positive lead of a multimeter there and the negative to the chassis? I assume something like that but no one ever says HOW to check. They just say to check. Thanks!
Also....which output were you using Phono,AUX, etc
Is it doing it on all output's
Hi again....always use the black probe(COM) for ground(chassis) , if you are looking for a negative voltage then your multimeter will display - signe. the other way around , you will get the same voltage reading but I won't show you the polarization correctly... in a receiver/amplifier you have 2 big capacitors from your power supply and those are your B+ B- voltage...it's important to know .
@@VintageAudioFever I think I may have had a temporary issue happen. It seemed thin but I cleaned the pots and it seemed thin for a bit but all went back to great the next day. I did a VU meter calibration (they were actually pretty close) and was able to generate 50 watts easily. I did have to crank the volume more than half way, but that seemed reasonable. Thanks for your help and the great vids! I'm awaiting an ESR meter and I might just recap this thing in the near future anyway.
What was the volume knob set at when u got the most power without clipping? I have one KA3500 and the matching tunerKT5300. I would like recap the amp and then fix the tuner but all I know about electronic repair is to wet my fingers first.
Hi Lawrence
I didn't really go by the volume pot...rather when the scope tells me I have distortion at the deformation of the original audio waveform.you can't really adjust the distortion...that is just the amplifiers saying I have distortion. Every amplifier would be different but yours would be fairly close to what I had if it's all working properly....not sure if that makes sense to you...
Thank you for the reply. I guess what I was thinking was that I could put a mark on the volume control so I wouldn’t play it in distortion. But then my speakers might be distorting before the amp. Is there a sound mic I could use to see the total system distortion that comes out?
@@sailguy2010 Don't go further than about 2/3 of the max volume, is a simple rule of thumb.
If you happed to have a testsound (preferably on a CD), for example a 80hz sinewave you could do the following test.
Disconnect all speakers. Connect an old speaker in series with a 3,3 microfarad bipolar 100v or higher capacitor to the left or right speaker output. Now play your testsound. You should't hear anything.
Start turning up the volume. As soon as you hear sound, that is the clipping point of your amp.
Note that this is an approximation because the input levels do matter also.
A CD player for example has a rather high output, compared to a tuner, tape or phono.
So playing a CD reaches the clipping point the first.
You can't go by the volume dial point. Speakers have different impedance and efficiently levels. One set of speakers may reach audible distortion at 10 o'clock and the other at 2 o'clock. If you start to hear sound breaking up, dial it back a few notches. Your ears won't lie.