KLH-1 Score

[plenumpete]

Thanks for info Remek. That's a very convenient feature on the Kenwood. My integrated amp only has pre out.
I've still have some original documentation for the KLH-n speakers, I uploaded copies to the Classic Speakers Pages site years ago.
I've also noticed that I have a simpler crossover circuit in my units, serial numbers 004949 and 005066, compared to your schematic. There is only a single 25 uF capacitor in the bass filter across the woofers, and a single 50 uF in the mid range.

 

[Remek70]

That’s true.
It’s an interesting point, and I wonder how it affects the sound of these speakers.
It’s rather unlikely that anyone has already tinkered with this crossover.

 

[plenumpete]

The terminal configurations on my units are the same as yours.

I think so—it’s about phase alignment.

You can tell from your photo of the crossover that “it hasn’t had an easy life.”

View attachment 3833477

Terminal configuration on mine:

 

[Remek70]

My original crossover looks like this:

 

[Remek70]

Terminal configuration on mine:

Your terminal configuration is identical to that of the user ‘Goldjazz KLH1s’ at the start of this thread.

 

[plenumpete]

That’s true.
It’s an interesting point, and I wonder how it affects the sound of these speakers.
It’s rather unlikely that anyone has already tinkered with this crossover.

I'm at the point of upgrading the crossovers but torn between keeping the original configuration or changing to conform with your setup. I really wanted to get the speakers correctly measured but finding someone to do it and then do a refurb is difficult. I'll probably do a couple of try outs with both configurations and listening tests.

 

[Remek70]

And that’s probably the best way to go about it.
You’ll be able to compare which crossover configuration makes the speakers sound better.

 

[Remek70]

BrownDog has arrived, is already installed, and is warming up. It’s nice, but it’s hard to say if it’s better, because at this stage of the upgrade, the changes are pretty subtle. There seems to be a bit more high-end and detail.
So, to sum up, the ABC has undergone a full service. All capacitors, resistors, etc., have been replaced. All solder joints have been re-soldered. Three UA741TC op-amps were replaced with 1 x Sygnetics NE5534AN and 2 x AD797AN, and the RC4136J quad op-amp was replaced by a BrownDog adapter with two OPA1612A op-amps.

It sounds great to my ears, and for now I don’t plan on changing anything, though I’m sure some ideas will pop up over time.