pakko
Member
Hello everybody!
After updating several Kenwoods I started to make some experiments the last years. Mostly to get better sound out of the old units.
This time I overworked my KA-9150 in a special way. After recapping the whole unit I decided to optimize the Signal Path dramatically. I did this already with some KA-7300 and other smaller Kenwood amps with great results. Now I wanted to figure out how much you can get out a big KA-9150 - a good sounding amp anyway... so after the standard treatments (cleaning the Vol. Pot, full recap with Panasonic FC´s ...) I shortened the signal path in the unit. The signal goes a long way from the inputs through all the switches to the pre outs - the power ams - back to the relay board and then again through the LS-selector switch and finally to the outputs. Long way.
I made two tests and pick up the signal once directly at the Volume pot and then in a second try at the control board after the flat amp. The difference of course was the amplification, because at the Vol. Pot you have only 150 mV and after the flat amp you find 1 V output.
In the first try I was impressed how clean and silent the amp plays - of course with less power, because the output was dramatically reduced (around 5 times less power). In this case you reduce around 1 Meter cable way and most of the switches. You can hear this!
In the second and final setup I included the flat amp and picked up the signal at 1 V (minus of Ci9/Ci10) and optimized the output caps and feedback caps (Ci7 to Ci10) to Elna silmic II. I went from there directly into the Power amps.
And I shortened the signal path one more time from the relay board and went from there directly into the LS-outputs (to avoid the speaker select switch, because I installed much better speaker bindings just for only one speaker set). I used a good solid silver cable to do this (blue in the pics).
Now - after a few days burn-in time the result is more than good.
The Kenwood plays now with much more transparent and a lot more detailed.
For everybody who thinks I disturbing my nice Kenwood....yes I own some more KA-9100´s - most of the in a 100% original condition. And because of this it´s easy to listen to the sound differences from the original to the updated amp. I can tell you - it´s a big step!
Of course you loose some functions - but honestly I never use the Tone controls and Filter options - all time I listen as strait as possible to the music!
Just for testing I added a Furutech Gold plug and power cable to see if it makes a difference - and yes - it gives you some more details and sound potential in the bass cellar. This is a lot of work, because you need to cut a bigger hole into the rear panel but to be consequent I had to test it
OK, here he is the beauty in a nearly mint wooden case - enjoy!
Greetz from Hamburg / Germany
pakko/eckart
After updating several Kenwoods I started to make some experiments the last years. Mostly to get better sound out of the old units.
This time I overworked my KA-9150 in a special way. After recapping the whole unit I decided to optimize the Signal Path dramatically. I did this already with some KA-7300 and other smaller Kenwood amps with great results. Now I wanted to figure out how much you can get out a big KA-9150 - a good sounding amp anyway... so after the standard treatments (cleaning the Vol. Pot, full recap with Panasonic FC´s ...) I shortened the signal path in the unit. The signal goes a long way from the inputs through all the switches to the pre outs - the power ams - back to the relay board and then again through the LS-selector switch and finally to the outputs. Long way.
I made two tests and pick up the signal once directly at the Volume pot and then in a second try at the control board after the flat amp. The difference of course was the amplification, because at the Vol. Pot you have only 150 mV and after the flat amp you find 1 V output.
In the first try I was impressed how clean and silent the amp plays - of course with less power, because the output was dramatically reduced (around 5 times less power). In this case you reduce around 1 Meter cable way and most of the switches. You can hear this!
In the second and final setup I included the flat amp and picked up the signal at 1 V (minus of Ci9/Ci10) and optimized the output caps and feedback caps (Ci7 to Ci10) to Elna silmic II. I went from there directly into the Power amps.
And I shortened the signal path one more time from the relay board and went from there directly into the LS-outputs (to avoid the speaker select switch, because I installed much better speaker bindings just for only one speaker set). I used a good solid silver cable to do this (blue in the pics).
Now - after a few days burn-in time the result is more than good.
The Kenwood plays now with much more transparent and a lot more detailed.
For everybody who thinks I disturbing my nice Kenwood....yes I own some more KA-9100´s - most of the in a 100% original condition. And because of this it´s easy to listen to the sound differences from the original to the updated amp. I can tell you - it´s a big step!
Of course you loose some functions - but honestly I never use the Tone controls and Filter options - all time I listen as strait as possible to the music!
Just for testing I added a Furutech Gold plug and power cable to see if it makes a difference - and yes - it gives you some more details and sound potential in the bass cellar. This is a lot of work, because you need to cut a bigger hole into the rear panel but to be consequent I had to test it
OK, here he is the beauty in a nearly mint wooden case - enjoy!
Greetz from Hamburg / Germany
pakko/eckart