Kenwood L-07CII Preamplifier Restoration 

Many salutes to your love and passion in restoring such amplifiers from the glorious past...over and above your technical knowledge and skills!! You make many people happy with your videos. Thanks a lot👌👌👍👍

Thank you for taking the time to do this restoration and capture it on video, and share it with the rest of the world. I have owned many of the Kenwood L-series pre amps and amps and as a person who does hobby restoration, I ran into the same issues in trying to restore my MKI L07C... the traces lifted and I admitted defeat and ended up scrapping the unit. Damn shame because I got so many years (decades actually) of enjoyment. I also ran into the oscillation issues with the L07MII amps in where I immediately put them up for sale and reverted back to the MKI amps. Even with these issues, they are just such quality pieces of gear and they provide such a beautiful sound. Thinking back I want to say I've gotten about 30+ years of enjoyment out of them before parting ways and going with newer equipment. I ended up replacing the L07C with a Sony TA-E88 which I feel is superior, but still the Kenwood stuff is just great. Thanks again for the video and hard work, it shows!

What a transformation! Excellent work.

Love it! A pleasure to watch these amps get restored! And longer the better, look forward tobthe next one.

Nice video, enjoyed the detail. I think that releasing a single video is better that's searching for all of the episodes

Great work and thanks for sharing your experience. I’ve been working on gear for about two years and I agree with your approach of replacing to avoid issues rather than only fixing things that have failed. I note the occasional comment from those who believe the opposite. A couple of things I do as a matter of course, one electronic, one cosmetic. On the rectification circuit, I add R-C snubbers, using price appropriate capacitors and resistors. The switching noise drop is significant in most cases and clearly audible. Having said that, I did have one CD player where it wasn’t the case, so it’s not a universal solution if the circuit already contains suitable noise suppression. On the cosmetics, it involves addressing the scratches on the paint. I use automotive touch up paint in either a brush form or, if the case has many scratches, I respray it, having first flatted the scratches out with abrasive paper of increasingly fine grades, finishing at 600. It many not be original but it looks factory fresh.

Wow! Incredible restoration. Love the attention to detail.

Thank you for sharing and explaining what you're doing. You do a great job filming this. And the tools you share. You're an asset to this field and vintage audio all together. Very professional. 💯

Masterpiece

Dude you are meticulous. I love it. Subscribed.

Kensonic ) Jiro was one of the best Audio engeeners of his time and founder of Accuphase ,Jiro believed in high quality componetes just like the founder of Sansui Mr Kikuchi . Great Job !!

Great video! Always impressed to see what goes behind your restorations, really gives insight to how tedious the process is and makes you appreciate well done work. Getting better every time, nice job man!

What a good looking piece of gear. Glad to see this vintage piece get some work done!

Very nice. Yes, very nice. 😁

Excellent restoration!!! Tee-Jay was right..your skills are top notch.

Sounds very good...

What A fabulous beautiful restoration, what a credit to you. Exceptional.

Wow ! Impressive restoration ! ❤

Très bel appareil, Kenwood démontrait là son savoir faire concernant la Hi-Fi de très haute qualité, merci pour ce reportage ! 😉

Excellent work!!

Amazing job and absorbing video.

Another fabulous restoration. Well done king👑

Amazing restoration......Congrats man !!!

Very impressed with your attention to detail! Hope you own your own shop and passing along some skills to others! And I hope your making the money your skill deserves.

That was quite the project, great video!

Hi Connor Excellent restoration. It's definitely not a 'run of the mill' kind of work. A lot of thought has gone into it. Never knew people with such passion, skills and patience existed. Congrats sir What were the diodes, zeners or transistors replaced in this restoration. Please share location and what has been used. Regards

Excellent restoration. I enjoyed this video. I would have loved to see the process of defluxing the board and the chemicals used. I was amazed at how good the board looked after you cleaned it up. I would love to learn that process. The board looks better than factory. I have a L07C mark 1 that I will be restoring soon. Im not looking forward to the double sided solder and weak traces lifting.

wow , looks like a fun job.

Thanks

Stunning work!

Wow amazing restoration 🙏

Just saw you your great video! Upgrade the fuse!! Synergistic purple, you will be astonished!!

Miracle Worker.... Amazing.... !

dam i wish u lived near me or in my country lol u would have been my go t o guy this workmanship is top class

Great work.. gotta love some Nichicons

Very nice work again

Great video Connor

Hello, I have a Kenwood L-07CII too and would like to know what this level of restauration cost.

I had to clean up & re-cap some boards on a vintage SONY (TA-2000f) pre-amp. They were all plug-in boards so it wasn't that hard to work on each board. I've used old analog TV "Contact Cleaner" for the boards and pins.

Wonderful and clean job, some good ideas to do in my one L-07CII. I have to check the other comments of you already answered but I will like to know the reference for the new voltage regulators and the new feet. The metal polish really enlighten me. Thanks!

Wow what a restoration well done .how many houra work do you estimate in total? Im soon to have one and would like this work done but im in the UK and need to understand the hoursbto work out whatva engineer would charge iver here for the job..and the parts cost too please? Many thanks

Hello! I enjoyed watching the videos on Kenwood L-07CII & 07MII maintenance. I now have the opportunity to purchase the complete set - TRIO L-07CII & 07MII (exactly Trio). But they will definitely need a maintenance, since the condition is from the manufacturer, 50 years ago. I don’t know how to do this myself, but I want to give it to a specialist. In this regard, I have a question: could you send me a list of those parts (if you still have them) that you replaced in those amplifiers? So that I start looking for them in advance, since here we have a difficulties with this. Will there be a big difference in the components of Trio and Kenwood? I would be very grateful. If necessary, I will write my email. Thanks in advance.

Looks almost exactly the same as an Onkyo I had many years ago. I recall the Phono input was a little on the noisy side. Not watched the video yet, be interesting if you find this one noisy.

Wonder whats the difference in sound before and after restoration? I have this preamp..Thanks.

How does it sound before and after. Any improvement?

A real neat job ! Why are most of the capacitors raised up ?

Really convenient tool, the Erem 554tx. BUT its price is 130$ and upwards, for this form plier for passive components legs. Was drooling over your toolbox with weller special hand tools.. got sidecutter and fine plier, but the cost is out of this world as hobbyist..

👍👍👍👍👍👍👍👍

Very nice work! I just finished a Mark I trio (07c and pair of 07m monos) and a trio of the Mark II (same, L07 series) all for the same client. I did roughly the same work, but may I ask, what made you decide to go ceramic for the black flag replacements? Strictly cost? Any reason you chose not to eliminate the tantalums? This era of tantalum is known for growin tin whiskers and will eventually short. I’ve run into tantalums that have shorted in this series. And yes, for such a nice preamp that grounding design for the RCAs is one of the worst I’ve seen. I replaced them on the Mark II preamp I just did as the grounding was very intermittent. Any info on those bookshelf speakers you were using at the end? Just curious as to what they are.

When you are reflowing the board, what temperature do you have your iron set to? thx!

very good job! congrats! I wonder how did simichrome not removed the letters on the face plate? isn't that abrasive enough ? thank you !

I dont think the traces have started bubbling, I think they were like that from new. Lots of old 8 bit computers are like that and they were like that from new. This was common on Spectrum, Commodore machines even upto the Amiga era with memory expansions.

Are not polystyrene caps considered "use for superior sound quality" NOS is still available in canada. Same source has polyprop radial caps. Would not the polystyrene been used in the signal path PartsConnexion. I'm a firm believer in film cap use. Ie Sansui B2101 C2101.

regards face plate, after cleaning have a try WD40, I’m using it on brushed aluminium and plastics, it makes black blacker and, in many cases, eliminate the stains which remain after cleaning or old discoloration. have try on any as experiment and you’ll se the different.

Hi. Where did you purchase the solid aluminum feet for the Kenwood L-07MII Power Amplifier?

My SANSUI AU 717 special snacks on Kenwoods🌚

Great vid once again, mate. I appreciate that you take the time to show the handy tools you use in your resto's. The wire unwrapper and top flush cutter have given me tool lust ( ͡° ͜ʖ ͡°) Love your thoroughness and drive to do a quality job.

what do you use to deflux? i tried alcohol, but had a really hard time getting the flux off the board, it will always be sticky afterwards.

Would metal clad caps be better .

It's sad to see such a top device from Kenwood being built with such cheap electrolit condensers

I have the same preamp I would love to sell it

My opinion - Obsolete. The power supply just isn't clean enough on the output.

Việt nam ok nam👍👍

If it's not broken, don't fix

The camera moves too fast and too frequently