Krell KSA 100mkII Clone

[Upupa Epops]

Sweet is sugar, honey, wine... What is sweet sound ? Is here technical forum or club of cooks ?

[konst]

i think we should stick as close to the original desing as possible, including using devices that are as close to the original as are avalalble, otherwise this would not be a Krell clone.

[pinkmouse]

Some things might be easy, others more complicated. What are the pinouts of the JFets and ZTX. Do the JFets need extra support components, or will they drop straight in?

You guys need to come up with answers, not more questions!

[pinkmouse]

Originally posted by Upupa Epops
Is here technical forum or club of cooks ?

Pavel, I just keep flipping the burgers and shaking the fries. I know my place!

[Upupa Epops]

Me too, Al...I was cooking at AM...

[Mark A. Gulbrandsen]

i think we should stick as close to the original desing as possible, including using devices that are as close to the original as are avalalble, otherwise this would not be a Krell clone.

Couldn't agree more but it needs to be the Mk-2 board. It would be easily backwards compatable with those desiring to be backwards in wanting to build the older versions. These older versions can be easily built on the existing KSA-50 boards we already have. Also just jumpering out some of the un-needed parts on the KSA-100 MK-2 board would also allow the same.


Flodstroem, Andrew,

Take a look at Mr Macleans site and look at the actual KSA-80 manuals and also at JWB's thread. I believe that the KSA-80 used a similar supply. Take a look at JWB's thread and schematic starting in Post 12 of the KSA-80 regulated supply. It is probably very similar to the KMA-100's. Note that the power supply WAS part of the KSA-80 main board and its a relatively simple supply.

Andrew......

Unfortunately I let go of the KSA-80B about 6 years ago. I wish I had kept the thing. The manual states that the rails in the KSA-80 were +/= 75 volts and the bias was 325mv across the 1 ohm emitter resistors. On all versions of the KSA-100 the bias was set for 575mv across those 1 ohmers. Hopefully this will help you out......

Al, The fries are getting overdone! Here is the Zetex ZVP3310A and the ZVN3310 And the 1N5309 Current regulator Zener

JWB did not thermally couple his together in his KMA-160 rebuild, they are quite small in size so it is probably not really necessary since they will change temp from the ambient quite rapidly. Other than these parts I think you are already familiar with everything else used.

Mark

[Mark A. Gulbrandsen]

Here is a link to data on the old Supertex MOSFETS that were used but are now obsolete. Krell used the TO-220 versions of these devices.

VP0210N5

VNO210N5

Mark

[pinkmouse]

It's tempting to adapt the input stage of the KMA, just so we have a balanced option.

[konst]

Mark I agree totally.

[Flodstroem]

pinkmouse:

t's tempting to adapt the input stage of the KMA, just so we have a balanced option.

konst:

Mark I agree totally.

Al and konst: an excellent suggestion . I also agree to this option for the KSA 100 mk-2, though my plan was to implement a balanced circuit input board for my planned KSA 50/100W building project.

Regards