Bought a pair of L-07M monoblocks...

Connor G

Ear conditioned
Subscriber
Hey guys!
I came across a pair of Kenwood L-07M monoblocks and I decided to get them after reading a ton of
good things about them on here and other forums.
Cosmetically I'd say they're about a 9.5/10 and the guy said they work great.
Shipping is only a state over and he's going to be packing them well with Styrofoam and multiple boxes.
I don't want to beat a dead horse, but anyone else have any thoughts on these monoblocks?

150W w/ super low distortion, and I read that they competed with other extremely good amplifiers at the time.
Let me know what you think!!!

Pics:
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They are fantastic amps! They will need a recap if not yet done.
I am going to be taking steps in restoring these, including replacing all of the caps that happen to be drifting out of spec. Thanks for the comment!
 
They have some unobtanium parts in them, so a recap is in order.
What parts are the hardest to get? The Sanken output transistors? I am planning on doing a recap, among other things with them.
Thanks for the comment!
 
What parts are the hardest to get? The Sanken output transistors? I am planning on doing a recap, among other things with them.
Thanks for the comment!
I believe the MK ll is the one with hard-to-find parts. It's those hi-speed outputs.
 
What parts are the hardest to get? The Sanken output transistors? I am planning on doing a recap, among other things with them.
Thanks for the comment!
It has fets, it has the dual fets and it has op amps in the round case style. I think these can be found or subbed (especially the op amps).
 
They're killer amplifiers, and will absolutely SMOKE a DA-10DC assuming both are functioning properly. I really like the look of the Mitsubishi (and the matching meters are a super cool add-on!) but having owned both, there's no comparison sonically.

For best performance, get these out as close to your speakers as possible and run long, well-shielded RCA cables. They'll certainly work if you have to put them in our audio rack, but they were designed to be right next to the speaker...especially considering the small gauge wire terminals the only safely accept bare wire...14 gauge TOPS. No esoteric cables with big spade or banana plugs need apply :)

One thing to be very careful of- triple check all your signal connections before powering them up, and NEVER unplug the RCA cable while the amplifier is on. I"m not sure why, but this is a common failure mode for these amplifiers...and one of the reasons Kenwood included a special set of locking-collar RCAs with them when purchased new
 
I have them all, the Mitsubishi DA-M10-DC, DA-M15-DC, Kenwood L-09M, Kenwood L-07M, Kenwood L-07MII
No Question, the Kenwoods sound much better than the Mitsubishi´s. And the Mitsubishi VU- Level Meter looks great and sounds horrible.

Planning a restoring of this great Amps:
When I make a Revision, I change.

· ALL Capacitors

· ALL Resistors

· ALL Relays

I check the Transistors and only change them if they are not working as they should. I look after al Zener- Diodes and change them if necessary. I never had seen a damaged OPA in the Voltage Regulation of the L-07 M. For that reason, just leave it in place. Same with the double FET in the incoming section: Never had found a broken one.

Until Today I made about six or seven pairs of the L-07 Power amps and three pairs of the L-09 power amp
When you give these Amps a great revision they will surely play another 40 Years and they sound really great.


Richard
 
Great post Richard.

Which ones did look more, the l-09m or the l-07m?

I have them all, the Mitsubishi DA-M10-DC, DA-M15-DC, Kenwood L-09M, Kenwood L-07M, Kenwood L-07MII
No Question, the Kenwoods sound much better than the Mitsubishi´s. And the Mitsubishi VU- Level Meter looks great and sounds horrible.

Planning a restoring of this great Amps:
When I make a Revision, I change.

· ALL Capacitors

· ALL Resistors

· ALL Relays

I check the Transistors and only change them if they are not working as they should. I look after al Zener- Diodes and change them if necessary. I never had seen a damaged OPA in the Voltage Regulation of the L-07 M. For that reason, just leave it in place. Same with the double FET in the incoming section: Never had found a broken one.

Until Today I made about six or seven pairs of the L-07 Power amps and three pairs of the L-09 power amp
When you give these Amps a great revision they will surely play another 40 Years and they sound really great.


Richard
 
I have one Pair of L-09M and 2 Pair of L-07 M & M II
The l-09M is better at some difficult to drive loudspeaker. In Germany, we have for example the Isophon Cassiano with a Network with 50 dB or more. In this case, the L-09 sounds better.
However, with normal loudspeakers the L-07 is better in my opinion. More Detail, more Dynamic, more of everything

Richard
 
They're killer amplifiers, and will absolutely SMOKE a DA-10DC assuming both are functioning properly. I really like the look of the Mitsubishi (and the matching meters are a super cool add-on!) but having owned both, there's no comparison sonically.

For best performance, get these out as close to your speakers as possible and run long, well-shielded RCA cables. They'll certainly work if you have to put them in our audio rack, but they were designed to be right next to the speaker...especially considering the small gauge wire terminals the only safely accept bare wire...14 gauge TOPS. No esoteric cables with big spade or banana plugs need apply :)

One thing to be very careful of- triple check all your signal connections before powering them up, and NEVER unplug the RCA cable while the amplifier is on. I"m not sure why, but this is a common failure mode for these amplifiers...and one of the reasons Kenwood included a special set of locking-collar RCAs with them when purchased new
I was planning on running these on my salamander rack, but after further reading, I will probably be running them next to my speakers.
Sorry for the late reply, but thanks for the great information!!!
 
I'm going to buying a working pair of L-07Ms, not going to get exited about recapping, or re anything, if they sound good I don't really care. Everybody is always talking about recapping every vintage amp all the time. I can see that if its an amp that has been sitting in the garage for 10 years but if its being used & sounds great then why bother unless you really want to do it? My KA-4004 has never been recapped since I bought it in Jr. high in 1974., nor my Mcintosh 2100. I just bought a KA-9100 & a KA-7300, if they work & sound good then that's all i will care about as well, if not then I look into what needs to be replaced. Everbody is always recapping when something doesn't work, most of the time that is not the issue & it turns out to be some other problem, especially in the preamp section, power supplies are a different story, you can hear when a power supply is bad if it doesn't blow a transistor or a speaker or a fuse. So there is my rant about recapping recapping recapping. Ive repaired a lot of equipment & have rarely had to recap an entire amp unless its a old Fender tube amp. I'll try cap reforming on large filter caps before spending money on new ones. the bottom line is, hey, if it sounds great then just use it. Call me lazy but Id rather listen to something that's working rather than worry about which caps might be going bad, Just sayin.
I actually agree with you about rampant recapping, but if these amplifiers have the polystyrene "black flag" type of capacitors they need to be replaced or the amp can self destruct.

This model may not have them; it may be only the L-07M II that does.
 
With these recapping is important due to the design.

The high speed switching outputs need caps that are in spec or they can blow and since they don't make the outputs any more, replacing them with others (since you can't get the high speed switching ones) actually destroys the sound of these amps and you also lose your value of them.

Manual also states these amps need to be within 1 meter of the speaker (they came with special speaker wire).

The original Kenwood Trio L-07M ist not the hi- speed amp like L-07M MK2 or L-05M, they use Sanken power transistor 2SA747A/2SC1116A(about 10 Mhz) and it does not use the black flag caps so do not worry about it.
Maybe you need to replace some slow bomb transitors 2SA810/2SC1452 on the power amp boards.

The repair/re-cap work for the protection board is a bit tricky as the relay driver 2SC1735 is aged i replaced it with ZTX696B with success.
 
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