During a repair of my KR 6050 I saw in the service manual that there is no bias current adjustment on the final power amp boards XO7-1700-10. If you look at the board or on the schematic, you will notice they have two resistors positioned in parallel on each board which sets the bias. Example is R1 a 33ohm 1/2 watt resistor and R3 a 22ohm 1/2 watt resistor. In place of R1 I put in a Bourn 0 to 100 ohm 1/2 watt 25 turn trim pot. Did this for R2 on the other channel power amp board as well. Once installed I followed the values as found on page 17 of the service manual and set the current between 20 to 200ma with recommended value of 40 ma. The DC voltage found between the test points 15 and 16 on one board and 17 and 18 on the other should range between 4.4 to 44mv. I can now set the bias and the Bourn enclosed 25 turn pot worked very well. Also, when I bought my used Kenwood and powered it up, sparks came out of my alps switch, which I burnished to get it up and running. Now a few years have passed it looks like I will have to do it again or replace with a toggle or other latching on off switch. Great radio and hope you are enjoying yours. Thanks for the video. Nice job and I always like someone providing helpful info ☝☝

Thank you for your video's. I really like how you take the time to explain what you are doing. It is kind of relaxing to see how you do things step by step, whithout rushing to conclusions.

As a little comment, the tuning capacitor bearings grease dries out, giving intermittent contact and the scratching noise while tuning. A little shot of Deoxit will clear it up. Thanks for you’re videos. They motivate me to find projects in retirement.

I seem to recall those ads in Stereo magazines for DC receivers. It was a selling point, made us audiophiles think these were the best.

These sounded so good , Kenwood was absolutely underrated It would destroy my new Marantz Easily as this was my first reciever I found it in the garbage. Best amp I ever had , better than my P7000 halfler . Kenwood vintage is the shit

I have one of these. Found it at a Goodwill for $30.00 maybe 10-12 years ago. You were right on the money $$$ with the issues associated with the power switch. I saw this in another video, I took mine apart and it was a beeotch to get back together, but I got it back together. As for my tuner section it is incredibly selective. With a basic dipole I'm picking up stations I normally don't even pick up, clearly with my Marantz 2352B or my Pioneer SX950. It's a better than average receiver. Play-test with some JBLs and it is sounds as good as my other higher ones....

The lamps flickering with the power switch is a VERY common problem with any Kenwood using that gray Alps box-switch. It will also cause interference on nearby AM receivers. ( The earliest AM transmitters were spark-gaps)

Solis stage power stages do not require a 'phase inverter'...the genus of the transistors take care of that (;- ). Coupling capacitors along with the accompanying resistors create a phase shift. Also, coupling capacitors are selected to pass the lowest frequency expected so that shouldn't affect ' frequency response'. Personally i agree that back in the 80's the companies were working very hard to convince idiots with money to burn about where they needed to spend their money (;- ). There were a lot of gimmicky things going on.

I own this receiver and it works great.

I have a MINTY looking model Eleven GX ,,, but dang the thing puts off heat... Even the metal vent screen on the case has come unglued which i think was from the heat.... Looking for any possible adjustments , Bias ??

That relay seemed to take twice as long to click on than it should have taken.

I wish there was greater detail. Details matter.

Really great videos I love them a lot! I have a Kenwood KR 7600 that I have owned since 1987. It's 10 years older than that so it's birthday is around 40 maybe 41 years. It has always had a weak Left Channel. I had a technician measure its output and he said it was about one-third the output of the right Channel. Any ideas at all? I'm going to check the bias voltage tonight, but I am really frustrated and certainly no expert in this area but fairly handy with electronics. The output in the left channel is weaker whether I use the radio or any other input source it is weak in headphones as well as on either speaker a b or c and if I put it to Mono the left side still is weaker than the right. Go figure that.? The volume discrepancy is much more Apparent at very low volumes because of the way sound pressure and loudness works, but I'm really tired of running the balance way over toward the Left Channel. I really really want this correct. Anybody have any thoughts? the pots are all clean and have no crackling in them. I will measure the resistance on the pots tonight as well.

So the kr-6050 usually heat up? Because mine does and iam concerned so i guess i need clearnce and why.

what is the biggest amp you have ever worked on

Hi! I recently came into this receiver matched with a Technics SL-3350 and two Altec Lansing 893A Corona speakers with what seems like all the original hookups and wiring. I have absolutely no idea how to hook everything up. Would you possibly be able to guide me through it if I sent you images of equipment? Thanks!

MY KR 6050 is doing pretty much the same thing..lights flicker power going in and out..

Ei Tony, Since I consider you are an expert, can I ask you for advice? I'm currently repairing a sanyo jcx2300KR and found out one of the STK082 ICs is fried. Do you have any advice where to get a suitable replacement? I know there's quite a few fake STKs out there... Regards, VP

Tuner in mine hardly works at all FM is weak and meters hardly move and no MPX stereo. AM is intermittent with a loud cracking noise. So I'm looking for a working replacement tuner board. I know the FM detector coil is shot.

Power output: 60 watts per channel into 8Ω (stereo) Kenwood KR 6050

This schemattics is not the real. Note a Q27 transistor in the IC2 HA12002 protection. Don't have in the document... please, check it!

we're are you working on these units in Illinois I figure any way I got a Kenwood kr 9600 2 of them and I got , 2 Kenwood basic m2a rated 220 per channel

Hello, enjoyed the video. I also would like to ask your advise. I picked one of these up on eBay. when i hooked it up, nothing. so I started researching and came across your video. I noticed the protection relay did not click in. so i figured it was junk since i know nothing about electronics. Just for the heck of it I unplugged the outputs. turned it on, and the relay kicked in. so my question is, Is it safe to say that the outputs are the problem? I found some on eBay, tested and working. But I do not want to change them if there is a possibility of ruining the new ones. Hope you can help me

Still looking for a tuner board or detector transformers for mine. I get some FM but no stereo.

I noticed your schematic was for a KR6650.

I would recap it

WOW,It's amazing how all the other companies(Marantz,Sansui,Kenwood,and Technics copied Pioneer.There are those that will argue on who was first with that look.BUT IT WAS PIONEER!