Krell KSA 100mkII Clone

[jacco vermeulen]

see Buster Keaton.

(or Ninja Turtles. )


WOW-YEAH-RIGHT ON.

[Mark A. Gulbrandsen]

The heatsinks would be a welcome bonus, but I'm concerned about cost - not only the materials, but also the shipping for overseas builders since a padded envelope is unlikely to be feasible.

Shipping overseas is a flat 9.95 to all but a few locations. Italy is one exception as they require a special padded envelope that costs a few dollars more. I can't see any extreme shipping expense doing this....

The KMA-100 regulators are located on a seperate board. The KSA-80 regulators are on each channels audio board... and those are quite large boards at that! The driver boards are seperate and very small and pluggable between the main boards and output stage to make re-configuration to a KMA-160 very easy.

You better think GB for those Zetex MOSFETs.

None of the Zetex devices we'd be using are hard or expensive to obtain... less than $2.00 each in single quantity. Digi-Key has a huge Zetex inventory.

[Flodstroem]

ZVN/ZVP 2110G is <$ 1.00 if buying minimum 100pcs from Mouser Electronics, also I have found the Philips/NXP´s (Vertical D-MOSFETs): BSP122 (N-ch) and BSP220 (P-ch) could match those Zetex which means we have more than one alternativ (they also came in SOT-223 pack)
The Philips BSP series is also a rather cheap part (<$ 1.00)

Regards

[jacco vermeulen]

ZVN/ZVP 2110G is <$ 1.00 if buying minimum 100pcs

$60 for 100 overhere.

[AndrewT]

Hi,
Zetex is showing bulk orders @ <$0.38

Maybe Jacco could do the European distribution in letter envelopes with a little card for protection?

Zetex also show Ciss as 60pF.
What does this do to the loading on the LTP?

[Mark A. Gulbrandsen]

Here are three extrusions that M&M has. Let me know which one might work best of these....

Number 1

[Mark A. Gulbrandsen]

Number 2

[Mark A. Gulbrandsen]

Number 3

[Zen Mod]

No.2 is best ;
fattest core - better heat transfer

[Flodstroem]

Zetex is 59-75pF maximum Ciss (N-ch), Supertex is 85pf Ciss typical (N-ch)
and Zetex P-ch is 100pF Ciss maximum, Supertex is 90pF typical (P-ch), a rater close match I think. All the other (TO-220 typ) IRF, IRFD and similar has a Ciss of several hundreds of pF.

Also the linearity could be a question for the types that has a higher G-treshold other than those three brands mention in here (Zetex, Philips and Supertex is same, 0,8-3,5V max), other has a 4V G-tresh.

Zetex, Supertex and the Philips/NXP (BSP-series) are all Vertical D-MOSFETs if this counts.

It is hard to find a closer match other than those types, especially if body-size/packaging is an issue (you dont want to solder a SOT-23 when you could use the SOT-223 or the TO-92 packaging)

I think the Zetex could be a little bit faster than the Supertex (originals) due to the lower input gate capacitance ("Ciss") than the Supertex, but this is only a qualified guessing?

Regards