Hi guys
Just got back from my business trip to Saudi. I've seen that Mark is busy with the prototype boards.
A big thumbs up to Al, those boards came out very nice. I can conclude that you are a qualified Eagle designer now.
Also noticed that Jacco still can come up with some smart-*** comments😀
Just got back from my business trip to Saudi. I've seen that Mark is busy with the prototype boards.
A big thumbs up to Al, those boards came out very nice. I can conclude that you are a qualified Eagle designer now.
Also noticed that Jacco still can come up with some smart-*** comments😀
I'm just hoping Mark remembers that the boards are designed for MPSA pinouts, and doesn't solder in 2SA/SCs...😉
Not to worry guys! UPS came by today and I have alot of all the needed semi's.
Personally, I would rather install the 2S..... jap versions but went ahead and used the MPSA versions instead since they "go right in". The 2S.... versions will require some teflon tubing on at last one lead, or a fancy lead bending job to fit in cleanly. I am aware that the MPSA versions are easier for many people to aquire.
One of my comparisons on this prototype will be do do distortion measurements with both types of devices.... ole Dan musta used the 2S.... devices for a very good reason but I will find that out later! Forst lets see of the board works...(of course it will!).
The fun continues......
Mark
Personally, I would rather install the 2S..... jap versions but went ahead and used the MPSA versions instead since they "go right in". The 2S.... versions will require some teflon tubing on at last one lead, or a fancy lead bending job to fit in cleanly. I am aware that the MPSA versions are easier for many people to aquire.
One of my comparisons on this prototype will be do do distortion measurements with both types of devices.... ole Dan musta used the 2S.... devices for a very good reason but I will find that out later! Forst lets see of the board works...(of course it will!).
The fun continues......
Mark
Member
Joined 2002
Mark A. Gulbrandsen said:
it should work.. looks like some hard work went into this.. Does this layout need huge heat sinks ?
YEP! Real biggons for staticn heat dissipation.... Or air tunneled smaller ones...... or water cooled if ya can.....
Mark
Member
Joined 2002
Mark A. Gulbrandsen said:
This sux.. i wish we had a surplus store up here or some thing.. i need heat sinks.. : O ( :bawl:
Jason,
Scan back through the whole thread and look at the sinks I bought, that should take till you find some good sinks. I got mine off E-Bay for less than 35 bucks. Keep an eye open there..... look for the seller barredboss
Mark
Scan back through the whole thread and look at the sinks I bought, that should take till you find some good sinks. I got mine off E-Bay for less than 35 bucks. Keep an eye open there..... look for the seller barredboss
Mark
Member
Joined 2002
Donno how much I will get done tonight as I am very tired...... and I am neck deep in those darned MCM anti static bags so gotta get a grip and clean those up.... They pack one device per anti stat bag..... those guys are packing maniacs over there!
I've been dreaming about getting this first one up and running and during my dreams I always get this message........
When I get the first channel running and everything powers up perfectly, l hear angels with heavy bass descend from my ceiling, and one of the cherubs looks like Dan, another like Nelson, and the final one will be Bruce Rozenblit, yelling, "Pay me for using my Grid schematics you theif! Or I'll choke you with those damn speaker braids!"
What does all this mean? Am I on Krell overload or something?
I've been dreaming about getting this first one up and running and during my dreams I always get this message........
When I get the first channel running and everything powers up perfectly, l hear angels with heavy bass descend from my ceiling, and one of the cherubs looks like Dan, another like Nelson, and the final one will be Bruce Rozenblit, yelling, "Pay me for using my Grid schematics you theif! Or I'll choke you with those damn speaker braids!"
What does all this mean? Am I on Krell overload or something?
Member
Joined 2002
Mark A. Gulbrandsen said:
ILL have them static baggies i need some for the mini A group buy's..
also i never got them resistors you sent out....
Guys
If we are going to try and make a Krell badge- where can one find a on-off- switch similar to the model that was used with the original models ?
Jozua
If we are going to try and make a Krell badge- where can one find a on-off- switch similar to the model that was used with the original models ?
Jozua
Krell Klone badge
Hi,
on this badge thing.
Can you acquire yellow or gold anodised aluminium sheet?
Then you have a robust surface with a two tone signature.
I would like some badges, can they be produced in time to be included in the board distribution?
Hi,
on this badge thing.
Can you acquire yellow or gold anodised aluminium sheet?
Then you have a robust surface with a two tone signature.
I would like some badges, can they be produced in time to be included in the board distribution?
What we really need is someone with a CAD/CAM engraving machine lying around doing nothing...
Personally, I think its engugh that we are using Dan's circuit, yes its an old design that has been out of production now for decades now but when you start using a companys logo or trademark, or even a slight alteration of such, you'd better check on its copyright or get permission first. Remember that Nelson had a logo designed specifically for Pass DIY builders and its not like his regular Pass logo...... I don't think we should tee off Dan, on your own if you want to but at least please don't anyone offer them on this site......
Now a custom designed "KSA-50 CLONE" logo would sit all right by me.
Mark
Now a custom designed "KSA-50 CLONE" logo would sit all right by me.
Mark
My toughts exactly Mark. We gone far enough as it is with copying.
If one wants an engraved logo on his or her amp fine, but make it something personal and leave the Krell logo alone.
Regards
If one wants an engraved logo on his or her amp fine, but make it something personal and leave the Krell logo alone.
Regards
Al, Stewart and others,
I did not use the output device base resistors when I built my first KSA-50 and its been fine for two months now. Why were these put in Jans original board and are they really needed? I am at that point in assembly and was wondering..... I would rather leave them out myself as they were not in the original Krells...... just more parts for the sudio signal to have to Pass through.....
Mark
I did not use the output device base resistors when I built my first KSA-50 and its been fine for two months now. Why were these put in Jans original board and are they really needed? I am at that point in assembly and was wondering..... I would rather leave them out myself as they were not in the original Krells...... just more parts for the sudio signal to have to Pass through.....
Mark
sharing...
Don't need 'em...
I think people were under the impression that the base resistors would somehow encourage current sharing. AFAIK, in this design the emitter resistors are what do this, and it is only as the emitter resistors go down in value that sharing *might* become an issue. If people are using 0r5 and above there won't be a problem. The big krell now has 10 pairs of outputs and the sharing is within 3% across the 20 outputs, using 0r68 Re...and nothing was matched, same lot code for transistors, but thats it...
The big krell is getting it's power supply rebuilt today, but yesterday I was seeing rail to rail swings dumping >10a into a 4 ohm load...rails collapsed from 85 to 72 volts...
Stuart
Don't need 'em...
I think people were under the impression that the base resistors would somehow encourage current sharing. AFAIK, in this design the emitter resistors are what do this, and it is only as the emitter resistors go down in value that sharing *might* become an issue. If people are using 0r5 and above there won't be a problem. The big krell now has 10 pairs of outputs and the sharing is within 3% across the 20 outputs, using 0r68 Re...and nothing was matched, same lot code for transistors, but thats it...
The big krell is getting it's power supply rebuilt today, but yesterday I was seeing rail to rail swings dumping >10a into a 4 ohm load...rails collapsed from 85 to 72 volts...
Stuart
Re: sharing...
So basically a little over 600 watts "RMS" into 4 ohms right?
Stuart Easson said:
So basically a little over 600 watts "RMS" into 4 ohms right?
