ksa-50

[MikeW]

Re: ... still not as good as the Aleph ...

Have you only basic imagination about internal wiring of an amp ? With this " wire salat " you can't wait miracles - miracle is fact, that this connection is able to work.

I have never listened to one of your amps. Where can I get one?

 

[Elso Kwak]

Labyrint

I have never listened to one of your amps. Where can I get one?

Hi, The electrons won't get lost in that labyrint but your eyes do when building and servicing.

 

[Upupa Epops]

To Mike : I don't think it badly. Probably I understand to your impatienty to hear results , but you don't like pretty made things ? By my opinion is to make it little bit " combed " is only little bit work over.

 

[MikeW]

I always build more than one. The first one to work on and fix the way I like. The 2,3,4 and 5th to look good enough to pass along.

It does have a nice blood wood front panel.

 

[K-amps]

Mike,

Hope not too late, but something I had not noticed before , the Toroid I sent you has a thermal breaker that is NOT normally connected with the primaries. In order to use the Thermal cutout, you need to use the brown wire not yellow one.... it's in the schematic.

If you already did, please disregards this post.

 

[MikeW]

Cut off

I already cut that one off. I have another lower voltage transformer coming. I want to run this a little higher in class A with a little less heat.

 

[stokessd]

Your heat sink fins are turned the wrong way. You'll get a lot better convective cooling if the fins are vertical.

Thta may allow you to aviod evil evil fans...

Sheldon

 

[K-amps]

Shoulda consulted you before he put his pics on the forum,

This is not his final design and people and launched into him, lol.

 

[MikeW]

Heatsinks

Those heatsinks are the biggest ones I have. 17 x 9 with 3 inch fins. They were sucking up 140 watts per channel before I turned down the bias. My kids tend to leave things on over night. Better safe than sorry.

 

[troystg]

Just put the amp "face" down so the fins are vertical.

Then the natural convection should kick in and help considerably.

 

[Mark A. Gulbrandsen]

So can anyone tell me what that .01 and 10 ohm resistor in series across the output does.......? So far I have left it out of mine......

Thanks!

Mark

 

[tmblack]

Hi MikeW

glad yours is up and running.
Which transistors and size of transformer did you use in your amp?

Rom

 

[MikeW]

I am only using 2 sets of outputs (mjl 4381,4302). K-amps supplied the transformer. I have turned up the bias a bit and drilled some holes in the top for airflow. One amp bias running about 45 deg C.

 

[AndrewT]

Hi Mark,
just spotted your Q.
Assuming .01 is 10nF then your answer is half Thiel network on the output (commonly called output Zobel).
However the value of cap is a bit small, most would use between 47nF and 220nF, at 10nF IMO the frequency is too high.
The other half of the Thiel is the damped inductor from amp output to hot terminal.
Some designers put the parallel string before the series inductor and some after the inductor. According to Thiel both locations are correct but the component values are different.
Read Dr. Cherry on Thiel network and Cherry's expansion to cover the whole range not just the two limit values quoted by Thiel.

 

[lgreen]

Nice work!

Hey, I love your Krell amp! nice job and nice work not taking shi**t from those with negativity. Why don't you update yourself on the wiki krell-o-tracker? link is here

I've posted pics of mine, but in view of the reception you got, i'll go ahead and not link to them! So far people have been nice enough not to criticize me and i like it like that...actually sounds great too.