Krell KSA 50 PCB

The KRELL is simply an over biased class B design, so we do our version that would appeal to either the guys in the Northern hemisphere to aid in house warming and those in the Southern Hemisphere who does not want anymore heat than they can stand.

Furthermore we design it for the MOSFET followers as well as the BJT followers and cater for both tastes, maybe we can at the same time establish which sound better and put the old myth to bed.

We make it to be stable over a large range of voltages so that it can be the 30 watt amp for some or the 100 watt amp for others.

I suggest we kick off with the basic old pre 83 KSA50 design, it is simple and not much different to the later 100 watt design.

There are many simulators used by the members and we could compare simulation results, part models, etc. We could during the design establish which is the best simulator for our members.

We lay several PCBs until we find the best layout (there are many of us with PCB software)

All of us with access to PCB manufacturing could provide the forum with quotes and we can find the most cost effective solution for everyone to share in.

Guys think of it, this can be an opportunity to benefit all members of the diyAUDIO community, moreover the project need not be done by the week-end.

It will be a great learning for all of us, maybe some won't benefit that much but others could.

I have always maintained the cumulative effort from many lateral thinkers far outweighs the capabilities of the single designer. If we took the abilities into account from all members in this forum we probably put to shame some of the largest audio companies known.

Kindest regards

Nico
 
Nico Ras said:
The KRELL is simply an over biased class B design, so we do our version that would appeal to either the guys in the Northern hemisphere to aid in house warming and those in the Southern Hemisphere who does not want anymore heat than they can stand.

Furthermore we design it for the MOSFET followers as well as the BJT followers and cater for both tastes, maybe we can at the same time establish which sound better and put the old myth to bed.

We make it to be stable over a large range of voltages so that it can be the 30 watt amp for some or the 100 watt amp for others.

I suggest we kick off with the basic old pre 83 KSA50 design, it is simple and not much different to the later 100 watt design.

There are many simulators used by the members and we could compare simulation results, part models, etc. We could during the design establish which is the best simulator for our members.

We lay several PCBs until we find the best layout (there are many of us with PCB software)

All of us with access to PCB manufacturing could provide the forum with quotes and we can find the most cost effective solution for everyone to share in.

Guys think of it, this can be an opportunity to benefit all members of the diyAUDIO community, moreover the project need not be done by the week-end.

It will be a great learning for all of us, maybe some won't benefit that much but others could.

I have always maintained the cumulative effort from many lateral thinkers far outweighs the capabilities of the single designer. If we took the abilities into account from all members in this forum we probably put to shame some of the largest audio companies known.

Kindest regards

Nico


No offense intended, but I don't think you read the first 300 pages of this thread. :confused:
 
K-amps said:


Why should you what.... Feel offended or Read 300 pages ?

;)

No I am not offended at all, but if you look at one of the last few replies KRELL insisted that one of the members remove it from the public domain.

As far as I can establish Krell is a registered trade mark and the designs registered as well so there is copyright infringement.

I merely suggested making a non-KRELL so this problem goes away and diyAudio have there own KRELL like amp for their own purpose.

I have also visited Jan Didden's site and his clone is significantly different from the KRELL in that a technical expert can be swayed by this fact, but then KRELL clone is not the right name either as it implies that it is a KRELL.

Lamborgini a few years back successfully stopped the sale of Lambo lookalike kits available in the USA as well as claiming damages from those who made and sold the kits.

On the other hand the forum my ask Dan for his permission to publish, use and sell his circuit and he might agree to it if he feels that he will not loose money or his product loose face by some DIY attempt at making KRELL like amplifiers.

Personally I have no need for a KRELL clone of any kind, but it seemed to have some following amongst the members here.

And my comment should be read as a suggestion, motivation and involvement, for the members from the members. I am surely not interested in KRELL or its clones, children, brothers and cousins, but the community might be.

So I take it you speak as the leader on behalf of the community. This may be a step in the right direction as a community should not be a blind headless institution. It needs a leader.

Nico
 
Pls. bear with me moderators...

Nico... the idea here at DIYaudio is to stuff for fun with NO commercial aspirations when it comes to trying out well established designs like Krell / Aleph etc.

Legalities aside, one can argue that a few DIY'ers making some clones is not going to hurt Krell sales because Krell buyers are typically not your DIY crowd. (and perhaps vice versa)

My guess is they asked Mlloyd to remove the schematic because part of the Krell Brand "Aura" is the curiousity of the unknown... the brand is built around a halo of exoticism... this is diluted if people get to know that a given design is pretty generic... give or take...

then again this is conjecture...

Danny has never been the sharing kind.... hence people here will respect the likes of a Pass more than a D'agostino. I digress again.
 
K-amps said:
Pls. bear with me moderators...

Nico... the idea here at DIYaudio is to stuff for fun with NO commercial aspirations when it comes to trying out well established designs like Krell / Aleph etc.

Legalities aside, one can argue that a few DIY'ers making some clones is not going to hurt Krell sales because Krell buyers are typically not your DIY crowd. (and perhaps vice versa)

My guess is they asked Mlloyd to remove the schematic because part of the Krell Brand "Aura" is the curiousity of the unknown... the brand is built around a halo of exoticism... this is diluted if people get to know that a given design is pretty generic... give or take...

then again this is conjecture...

Danny has never been the sharing kind.... hence people here will respect the likes of a Pass more than a D'agostino. I digress again.

I must admit there are a few slightly more interesting post on the rest of the forum, not much but less boring.
 
K-amps said:

Legalities aside, one can argue that a few DIY'ers making some clones is not going to hurt Krell sales because Krell buyers are typically not your DIY crowd. (and perhaps vice versa)

My guess is they asked Mlloyd to remove the schematic because part of the Krell Brand "Aura" is the curiousity of the unknown... the brand is built around a halo of exoticism... this is diluted if people get to know that a given design is pretty generic... give or take...
.... hence people here will respect the likes of a Pass more than a D'agostino. I digress again.

You hit the nail on the head there...
 
I'm with Nico, just like every other amp designer out there that ever built an amp...I'm not one of those folks, btw. I think and wish I could easily tap the resources and knowledge here and make all my wishes come true. I am certain if "you" take another's design and put your "own" spin on it, then it is yours to do as you wish. How the heck do you think all these designs ended up here any way? Good goly are you kidding me? Well you can't kid me.

Take it

Tweak it

Play with it

Make it your own

If you are lucky, few are, you will stumble upon new horizons and break limitations that the status quoe have already deemed as "never".
 
troystg said:



Have YOU read the 300+ pages in this thread?


All of them and sooo may more threads too. What is your point? What do I write that you take ill point of? Be specific as i think the "entire trade" is open game and has always been, to think otherwise makes you a fool.

I love the DIY for DIY purposes but I know many folks profit from these postings. My point is that there are always sharing and borrowing of others ideas, how the heck does a chap like Nelson(for example) BUILD A FOUNDATION FOR HIS OWN IDEAS AND LEARNING? I'm a little older now and recall coveting every schematic I could get my hands on for study reasons when I was a young lad in the seventies and early eighties.

Take it
tweak it
make it your own
do what you want with it

What is so wrong with this? Has it not been going on since...man? Tell me I'm wrong? Show me? I want to see your point of view.
 
Jozua said:
Nico

This thread is aimed at recreating an EXACT copy of a Krell amp.

Your intention is to create a NEW design which should possibly run it's own thread.

Regards

Jozua


I modified the above quote. It is the internet(all things are possible) I did this to state clearly what the author of this post( Jozua) intended. I really changed nothing but yes I made a change.

I think I like what Jozua says and that a new thread should commence. I'm not your man cause if I was I already would have spun it. This is not my focus but merely a very strong interest, these old Krells we have here.
 
just to clarify, the person who generously shared all the krell info before "the management" requested its removal was lloyd, not mlloyd1.
:whazzat:
at least they let him keep the nice photos on the site ...

my real question, has anybody ever seen the schematic for the pam-3 preamp?

mlloyd1

(who never actually owned a krell, but loved to open and listen to the early models in his nearby audio saloon :D )

K-amps said:
....
My guess is they asked Mlloyd to remove the schematic because part
...
 
Recreating past audio experiences

Nico & others

I suspect that for many of us who partook building Krell clones it was a matter of recreating a special era in our listening experiences and not so much a case of building the ultimate class A amp.

I am in a position to compare the older Krell amps with their more modern brothers and I can safely say that in many respects the modern amps are better and smoother. But when it comes to meatyness, soundstage and the recreation of three dimensional depth the older pure class A Krells are still in a class of their own.

If I was Dan I would try to cash in on that era by issuing an affordable special collectors edition of the original amps. In that sense it will be a sad day if Krell was to embark on a witch hunt to kill of this interest.

Regards

Jozua
 
Duh, you mean like THIS ?
(sure, why not flush every itty bit of heritage and have Hyundai build a re-issue of the classic Pontiac GTO)

Speaking of a great classic adios amp for TO-3 lovers : the Threshold S/SA series is scalable from 50W in full Class A to a 750W Stasis slider and everything inbetween.
There is nothing in this world you can do with TO-3 output devices that will even come close to the original Stasis amps.
The truly Classic Siliconix dual N-channel JFET at the input of the Stasis amps can still be bought for less than $3 each HERE and there's still 1300 left.

Anyway, a big thank you to Lloyd MacLean for the schematics and pretty pictures he made available to all of us, maybe the KSA50 is not current SOTA but to assemble it was a great trip into memory lane.
 
"All of them and sooo may more threads too. What is your point? "

If you read the entire thread you would see that the "group" voted on what they would like. The first set of manufactured PCB's included modifying the original design for the low bias setting. The second set of manufactured PCB's was closer to the original configuration.

So my POINT is, this thread has been there and done that.

You and Nico come in after the fact and say "hey I have a great idea!"

I politely said read the thread, your idea is not original, it has been covered and you are more than welcome to get a set of the PCB's and modify / tweak until your hearts content. In fact I encourage you to do so.. If you did you would see how good an amplifier this actually was.

Again, not being negative or condescending, just stating that this thread has been there and back already. We are just waiting for more completions and pictures. (I promise mine will be finished one day, I am still homeless with no facilities to work on it).
 
Member
Joined 2005
Paid Member
I built the PM Krell Clone KSA-50. I liked it so much I sold off half my amp stash and bought two more boards.

I never had the opportunity or funds to listen to a real KSA, but I am quite happy with what I have. Nothing short of impressive.

Mr A'gostino's attempt to keep the schematic out of the public domain tells me it's something quite special as is.