| leffe |
Hi,
Anybody who has seen the ads in the mid 80's TAA about krell type schematics and buy the secrets, can it be published here or maybe it is possible to buy a copy. |
|
|
| hifi |
hello,
i got it on another computer and could possibly get it in the weekend or you could as svalander for it
(www.svalander.se)
/micke |
|
|
| mlloyd1 |
There was a guy named William C. Snyder who published a spiral book called "Class A Audio Design". Mr Snyder was an engineer at Krell for a while.
It wasn't a bad book. In my mind, nothing earth-shaking and I don't recall seeing any stated Krell product schematics. However, it's probably reasonable to assume there be a lot of similarities though.
It's written much in the style of a college course notes book. Circuits were complementary symmetry type, some talk about JFETs and MOSFETs as gain elements. Used discrete JFET input gain block as DC servo.
The copy I had was from 1990. The address at that time was:
New England Analog
Rt. 113A
P.O. Box 38
North Sandwich, NH 03259
(USA)
I wrote once to ask him a question and ask if PCBs were available for any of the circuits described. He said they would be, but I never heard anything else about it.
Hey, I'd be interested in seeing a schematic for the KSA100 myself. Not that I'd want to build it, but I'm a curious guy!:)
mlloyd1 |
|
|
| fcel |
| Speaking of Krell, is it true that their amps uses very complicated circuit design? I say complicated because there are tons of components if you look inside the chassis. Also, does Krell allow diy like us to copy and use their circuit to built our own amps? Their old chassis design looks so beautiful and now their current product looks so ..... |
|
|
| leffe |
Hi,
Yes please I am very interrested in this information please send me the info.
Regards
Leffe
i got it on another computer and could possibly get it in the weekend or you could as svalander for it
(www.svalander.se)
/micke [/B][/QUOTE] |
|
|
| Nelson Pass |
| quote: | | Their old chassis design looks so beautiful and now their current product looks so ..... [/B] |
Possibly because Desmond Harrington came to work at
Pass Labs in '97. |
|
|
| webercarbmann |
Hi There
I have actually made a Krell KSA100 MKII clone a few years ago.
It was build as monoblocks with 1200VA 40-0-40 transformers for each block. The schematics is not that complicated, but some af the original parts (Supertex fets) are out of stock and are not made annymore. The driver/output stage uses 2SC968/2SA2238, MJE15030/MJE15031, MJ15024/MJ15025. 8 otuput devices pr channel. I am working on a KMA 100 clone. I is should to be a lot better. It has a regulated pover supply for the input stage. Annyway the KSA 100 MKII curciut i originaly made was a VERRY good amp.
Peter
:cool: |
|
|
| leffe |
Hi,
It would be nice to get some schematic info about the krell KSA100 and KMA100
Leffe |
|
|
| Elso Kwak |
Hi Peter,
I would appreciate it very much receiving the schematics of your clones of the Krell amplifiers KSA100 & KMA100.
I could not email you directly. but you can email me by clicking on the email button at the bottom of my post.
Thanks in advance,
:) |
|
|
| sonnya |
Count me in, I would like to. By the way i have got my hands on Luxman M03 schematic. They use Japanese JFET's and BJT's. Funny it looks a bit like a d-self "blameless" amplifier.
Sonny |
|
|
| Freddie |
I would like to see the schematics too.. Perhaps you can post them here at www.diyaudio.com
/Freddie |
|
|
| hifi |
now i got it but the schematic is 448K what to do?
/micke |
|
|
| AuroraB |
I would very much like to add these diagrams to my collection.
Such diagrams are a very good source for ideas... |
|
|
| mlloyd1 |
You could try saving it as a two color GIF to shrink the file size IF that doesn't impact the readability. Or, zip it or post it on a web site. I can look at the file to see if GIF'ing it will shrink it, or volunteer my web site if you don't have one.
mlloyd1 |
|
|
| leffe |
Hi,
Please send a copy to me I have lots of space in my inbox.
Leffe |
|
|
| webercarbmann |
Hi again
The scematics i have are not werry good. I will have to make a better version using protel. By the way, i also have a scematics for a PAM 3 preamp. I will try to post them in a near future. Please be patient. Would some of you be interested in some KMA 100 PCB`s ??
Peter;) |
|
|
| Freddie |
webercarbmann,
Yes.. I would be very interested in the PCB layout too.
regards
/Freddie |
|
|
| jam |
| Why not just post the schematics so as we all can have a look? |
|
|
| Peter Daniel |
| Anyone interested in schematic for Mark Levinson 27.5 amp as well as older Mark Levinson gear? |
|
|
| Elso Kwak |
Hi Hifi,
Thanks for the schematic. It is <B>very</B> similar to the GAS Son of Ampzilla.
I was hoping for the FET input schematic..........:( |
|
|
| scottnixon |
Looks like Bill Snider had a hand in that one!
Thanks for posting. |
|
|
| Nelson Pass |
I can state with authority that the circuit existed at
Krell before Mr. Snider. |
|
|
| sonnya |
Okay is this what we pay a lot of money for!!!!!!!!!!!!!!
Sonny |
|
|
| scottnixon |
| I will re-phrase. Looks like Krell had a hand in Bill Snider's Class A Handbook. :D |
|
|
| scottnixon |
| Afterall this guy was around way before Snider:D |
|
|
| Tube_Dude |
my mouth is still open with the scmatic of KSA 100.
First of all a run of the mill project that not even use corrent sourses in the LTPs but even worse use a electrolitic capacitor with no dc voltage across the emiters of the LTPs.
Amazing world!!!
Regards from Portugal
ps:sorry for my english! |
|
|
| Elso Kwak |
Hi
The picture is of Mr. Krell himself Dan d'Agostino in his younger years. |
|
|
| audio_cf |
What about the ML 27.5 schematic I couldnt find it on the site that was linked in the earlier post ???
Best regards
/// Carl-Fredrik |
|
|
| leffe |
Hi,
It would be very nice with PCB,s |
|
|
| Peter Daniel |
| ML 27.5 is not on a site dedicated to Mark Levinson gear, probably because it's not old enough. I have the schematics but they are way more complicated than Krell and would use 5 times more space. With the current bias toward posting images on a forum I would be rather hesitant to do that. If someone can offer a web space I would do it there. |
|
|
| jam |
Peter,
Go for it . It's not a gratuitous image ...well some people might think so, but we could all learn from it. Don't let a few peoples opinion spoil it for the rest of us.
Jam |
|
|
| GRollins |
As far as I recall, schematics weren't included in the gratuitous category--just girls, motorcycles, album covers, postcards, restaurants...
Grey |
|
|
| Freddie |
HPotter,
Go ahead and post the schematics..
Or if you prefer, I have some webspace to offer.
If you want me to upload the schematics to the webserver, mail the schematics to fty@spray.se
regards
/Freddie |
|
|
| Franklin |
Hello,
My name is Franklin a Dutch newbie to this forum.
Really inspiring developments going on here.
Has anyone been able to figure out the right transistor types
on the posted Krell KSA 100 schematic? Looks interesting.
BTW I have the complete schematics of the ML 20.5.
Also very interesting. Only a bit too much to post as an attachment.
If someone is willing to host it on a site (free) I will scan and
mail them. You can e-mail me in the usual way.
I think sharing information, experience and knowledge
is what makes this forum very special.
Thanks,
Frank |
|
|
| Peter Daniel |
| OK. Here is ML 23.5 front end part 1: |
|
|
| Peter Daniel |
| And this is part 2. I guess quality is not too good so before posting output stage and regulators I have to figure out better way to do it. |
|
|
| Peter Daniel |
| For some reason second picture is better. Both looked the same on my screen. This is output stage: |
|
|
| HarryHaller |
Can you take another shot of the first image? The last one looked very good. I go go through this all the time with my digital camera.
Thanks,
H.H. |
|
|
| Peter Daniel |
| Here is the first one again: |
|
|
| Peter Daniel |
| And finally the last part of our journey into ML teritory. Front end regulator and missing part of output stage. |
|
|
| HarryHaller |
We appreciate your gratuitous image posting. I'll add them to my collection of hundreds of audio schematics.
H.H. |
|
|
| tortello |
Me too.
Thanks!:) |
|
|
| Peter Daniel |
| I guess that's what they good for. I was after high end gear schematics in 1993 but when I saw this one I wasn't even thinking about copying that design. Too complicated. The only thing I used was the front end PS regulator which I used in my A75 project. |
|
|
| sonnya |
Thanks HPotter!! For a 1993 design this is advanced with lots of "floating" cascode stages...
The Luxman M03 schematic is in a PDF file and has the size of 5MByte... So those who want a "copy" could just send there email address to me.
Sonny |
|
|
| Peter Daniel |
| You could send it to me. Thank you. |
|
|
| Freddie |
I'm going to post the Mark Levinsson 20.5 schematics on the web (the files are pretty big so posting them here is not possible) probably this weekend or in the beginning of next week.
I'm also going to post schematics for the Luxman M03 if that is OK with Sonny.
I will let you all know the web adress, when I have uploaded the schematics.
/Freddie |
|
|
| trigon |
Thanks Sonny
Trigon. |
|
|
| sonnya |
I have tried to mail to Hpotter (What is your mail address?) and Mikek which have to less space in his mail box.
Everybody else should have got i by now!?
Sonny |
|
|
| popes |
please send me
my e-mail (bluemonday@orgio.net)
thanks, |
|
|
| Freddie |
sonnya,
I didn't recieve the email..
I had too little space on my email account.. But now I have deleted all old messages, and I have currently about 6MB free.
If it ain't too much trouble, can you mail it again..
fty@hotbrev.com
Thanks in advance
/Freddie |
|
|
| Freddie |
can be found here:
http://w1.889.telia.com/~u88905801/
As I told earlier, the ML 20.5 schematics will be posted when I have recieved them. Which probably will be on sunday.
Thanks Sonnya, HPotter, Hifi for posting the amp schematics.
/Freddie |
|
|
| popes |
thanks all
sonny,freddie,Hpotter |
|
|
| Franklin |
Hello,
Has anyone been able to figure out the right transistor types on the KSA 100 schematic posted earlier?
It concerns Q1/Q2, Q3/Q4, Q5 and Q6.
Is there a schematic available of the KSA 100-S with the sustained plateau bias or any info on such method?
I have scanned the ML 20 files have been able to mail them partly to Freddie. Due to the size of the files (6 files of 2.5MB each) his mailbox being full rejects my e-mails.
I hope to get them all to him tomorrow and he will put them on a site where they can be downloaded.
That's it for now.
Thanks, |
|
|
| Freddie |
Frank,
It's kind of hard to read out the transistor types on the Krell schematic.
But it looks to me that:
Q1, Q2 = 2N6421
Q3, Q4 = 2N6433
Q5 = 2N6538
Though I'm not 100% sure.
/Freddie |
|
|
| Freddie |
http://medlem.spray.se/frty/
Thanks Frank for the ML20.5 schematics.
And Sonnya, Hifi.... for the other schematics.
In case you have something you want me to upload to the site, send me an email.
/Freddie |
|
|
| djk |
| "Has anyone been able to figure out the right transistor types on the KSA 100 schematic posted earlier? It concerns Q1/Q2, Q3/Q4, Q5 and Q6." Who cares? Q1, Q2 = 2N6431 Q3, Q4 = 2N6433 but these are not the best for diff pairs anyway. Q5,6 were TO202 case style parts, good luck finding them. The current version of the Leach amp is much better, just run the bias to what you want and as many outputs as you need. If you want to get fancy build the Super Leach with the Nelson Pass patent 5,343,166 Copy and paste this number into the search here http://164.195.100.11/netahtml/srchnum.htm Then go to the patent and click on 'images'.You will need a TIFF viewer AlternaTIFF: http://www.alternatiff.com/ |
|
|
| Franklin |
Hi djk,
Thanks for additional info. Primarily I wanted to know
the correct transistor types to simulate the behaviour
of this Krell KSA 100. I do this with Micro Cap V
which is very pleasing to work with. Unfortunately
it is a registered version with a dongle, so I cannot provide anyone with a copy. I mention this just in case the question would pop up sooner or later. However
for those interested there is a free student version
which can be downloaded at: http://www.spectrum-soft.com.
Of course if there are better topologies with even better
results than the current Krell, it is interesting to study them. I'll take a look at the links you mention.
Thanks for the info. |
|
|
| leffe |
Hi,
If you have to build a power amp I think that the Krell still is the best, sound versus cost, its sound is just great much power in the low and a relaxed sound from mid and up.
Just clone it ! I think that will be a easy thing to do with all references we have from all kind of **** power amps kit or ready built from all kind of people who earned a lot of money showing the next best constructions the past 25 years. |
|
|
| Franklin |
Hi Leffe,
The reason I'm specifically interested in the Krell KSA-100
and even more in the KSA-100S (Sustained Plateau Bias, schematics anyone??) is that my set of speakers the legendary Infinity RS-1B which consists of two mid/high screens and two bass columns (6 x 8" each) which can best be driven by a Krell amp with lots of power.
I have downloaded the Krell patent (5,331,291) and try to figure out how this bias thing works. Some have already metioned here that the KSA-100S sounds better. Some will definitely disagree on this method of biasing an output stage.
However if anyone has more detailed info on the Krell
KSA-100S or the Sustained Plateau Bias system or suggestions on how to achieve the same or better result in modyfiying the KSA-100 let him, so to say, speak. |
|
|
| Freddie |
There were some problems with the webpage I put up earlier (with ML schematics). So I have know changed webserver. The new page can be here:
http://snow.prohosting.com/frty
Hope this one works better |
|
|
| djk |
Consider figure 26 page 14.
http://www.onsemi.com/pub/Collateral/AN1308-D.PDF
If we delete Q5,6 we have basically the Krell, with better semiconductors. Consider figure 35 page 17. Same front end with a cascode, and series connected outputs. Replace R36,43 with 6.3V zener diodes and bring in +/- 40V with an ORing diode at the collectors of Q19,20,21,22 and Q23,24,25,26 .This is of course a variation of the Pass patent. It runs just like the Krell up to 40V, then it becomes a cascode for the rest of the way. |
|
|
| Martin |
Hi Freddie,
sorry, but your last posted link is also not working. Hope that your next try will work;)
Martin |
|
|
| Martin |
| I had a problem with my Netscape, but with the Internet Explorer it´s working. :D |
|
|
| Jules |
Hi, I couldn't email you so here goes.
You state that you built the Ksa100 with 1200va transformers,
Was that the rating that Krell used?
I ask because I have some large Avel Lindberg transformers that
I bought years ago,but I don't know the VA rating, the seller claimed that they were the same spec as the Ksa100 transformers.
The secondary o/p is 40-0-40 the only numbers on them are
40/5629 and the date of manufacture is 1986. They weigh about 20lb each.
If you can shed any light it would be of help
Jules |
|
|
| Nelson Pass |
A 20 lb Avel would typically be about 1 KVA, which
means you can get about 12 amps on each winding.
This will probably support about 150w/ch stereo
at Class A or near Class A if you ventilate it well. |
|
|
| Jules |
Thanks Nelson, I've a couple of them, so they're forming the supply for my Aleph 4 monoblocks along with 8x 47000uf 100 volt caps (4 per block).
Jules |
|
|
| ben goh |
Hi
Does anybody has the infor on Krell KSA250 or
the service manual for it? |
|
|
| purer |
| quote: | Originally posted by Martin
Hi Freddie,
sorry, but your last posted link is also not working. Hope that your next try will work;)
Martin |
|
|
|
| The Saint |
How about a schematic for a Carver 800 watt design, I would really like to see that!:D
Anthony Holton |
|
|
| Freddie |
The ML20.5 schematics and Luxman schematics seem to have been removed from, snow.prohosting.com/frty, for some reason..
And due to a computer virus, some things got lost including the schematics:(
I may have a backup somewhere though.
/Freddie |
|
|
| sonnya |
I can send the luxman schematic again... no problem!
Leo : I have tried but your mailbox rejected it ~ 3Mbyte
sonny |
|
|
| purer |
Freddie
Mark Levinson 23.5 schematic
Please send to my E-MAIL ycljx_yjb@21cn.net
21M
Thank |
|
|
| purer |
| I had got your luxman schematic |
|
|
| YongHo |
HPotter
I'm very interested in Mark Levinson 27.5 schematic.
Please send to my E-MAIL softicon@dreamwiz.com
(14Mega byte free space)
Thank you.
;) |
|
|
| leo529 |
HPotter
do u mind give me a copy of the ML27.5sch too?
my e-mail. leo529@sinatown.com thx |
|
|
| Peter Daniel |
| If you look at the beginning of the thread you'll see that he posted that schematic.;) |
|
|
| audio_cf |
| quote: | Originally posted by webercarbmann
Hi again
The scematics i have are not werry good. I will have to make a better version using protel. By the way, i also have a scematics for a PAM 3 preamp. I will try to post them in a near future. Please be patient. Would some of you be interested in some KMA 100 PCB`s ??
Peter;) |
How is your work progressing ? Any chanse that you could post the schematics of KMA-100 and PAM-3.
///CF |
|
|
| traderbam |
| I'm keen to see the KMA-100 schematics. I have some concerns about the KSA-100 schematic posted on page 2 by hifi in that my prior information about the KSA-50 seems to be at odds with this schematic. Specifically, Dan d'Ag said in an interview that the KSA-50 was designed to work with very little negative feedback (14dB or so?). The input Z of Krell amps is usually >50k. The KSA-100 schematic shows a high feedback (like op-amp) circuit with about 23k input Z. There are some other things in the circuit that seem a little unlikely to me too :xeye:. I would like to see the KMA version to confirm the design. |
|
|
| Nelson Pass |
I have it on good authority that the front end circuits were
virtually identical. Open loop at mid-band would give more
than 14 dB feedback, but at some arbitrarily high frequency
this figure would be achieved.
It is commonly believed that the KSA50 was the better
sounding of the two. |
|
|
| purer |
I'm very interested in Mark Levinson 27.5 schematic and Mark Levinson 23.5 schematic¡_¡_¡_¡_¡_¡_¡_¡_¡_¡_¡_¡_
Please send to my E-MAIL ycljx_yjb@21cn.net
(21Mega byte free space)
Thank you. |
|
|
| carlmart |
Webercarbmann,
Can you tell me a bit more about that Krell KSA clone you did and the KMA you're planning now?
Those might be projects I'd like to try.
Thanks!
Carlos |
|
|
| leiade |
[QUOTE]Originally posted by carlmart
[B]Webercarbmann,
Can you tell me a bit more about that Krell KSA clone you did and the KMA you're planning now?
Did Webercarbmann ever get out from his cave and posted some schematics and pcb's or was it sombody else.:( |
|
|
| leiade |
I have been to a party and listen to a Krell KSA 100 Ok! I admitt just amazing, what is the magic solution I can't wait to the wizard is here, so... I opened the sh.t and what was I found just an ordinary circuit as posted here before.
But I started to think, if this is the final solution and this is the SOTA power amp but... how about the Pass power amps what are they? the second SOTA or... I will try to search for more obscure schematics simulate them into the Pspice or equivalent software and build them just to know.:) |
|
|
| Peter Daniel |
| quote: | Originally posted by leiade
I have been to a party and listen to a Krell KSA 100 Ok! I admitt just amazing |
What was your alcohol consumption on that day?;) ;) |
|
|
| mirlo |
... is equal parts of:
1: competent, class-A, but otherwise standard circuit design, (emphasis on class-A) and
2: finely crafted metalwork and internal build quality.
Somehow I think even the most coldly analytical listeners experience an audio placebo effect, when they know the music they are listening to comes from beautifully built equipment. |
|
|
| Peter Daniel |
| quote: | Originally posted by mirlo
Somehow I think even the most coldly analytical listeners experience an audio placebo effect, when they know the music they are listening to comes from beautifully built equipment. |
Sometimes it is, but not always. It all depends on the state of (your) mind and the people you listen with. I remember the last session I was attending. In the beginning it was all confusion (what the heck he's trying to impress us with?). But after an hour of tweaking I finally got to the point I felt comfortable with, and the equipment spoke for itself.
I have nothing else to say.;) |
|
|
| leiade |
Maybe just too much, but I was not deaf, I always think of my buddy's HiFi and an amplifier he used, it was a Hafler a rather big heavy power amp used to drive a small electrostatic system it never sounded good lack of bass and no drive at all.
When he bought this KSA power amp I thought that it would not makes things to happen but... it did lot of drive lot of bass he had to get rid of his subwoofer system.
I can't explain what happens to this small electrostatic loudspeakers from Audiostatic but the Hafler amp could not drive them, so this oldie must be a very good amplifier even today maybe it is the very large classic power supply that makes it I don't know.
:o |
|
|
| traderbam |
What I want to know is why Naim users deride Krell for sounding lifeless/rhythmless and Krell users say Naim lacks soundstage, depth and resolution?
What is it about the two design approaches that causes this polarisation of views? Does anyone here agree/diagree with these views? |
|
|
| leiade |
Gosh ! don't name Krell together with Naim, KRELL is SOTA product and Naim is not and can't ever be sorry
:o |
|
|
| dhengkoel |
| quote: | Originally posted by traderbam
... information about the KSA-50 seems to be at odds with this schematic. Specifically, Dan d'Ag said in an interview that the KSA-50 was designed to work with very little negative feedback (14dB or so?) ... |
Where I can found the KSA-50 schematic????
Thanks & Regards: ragil.hastomo |
|
|
| Denis |
| quote: | Originally posted by leffe
Hi,
If you have to build a power amp I think that the Krell still is the best, sound versus cost, its sound is just great much power in the low and a relaxed sound from mid and up.
Just clone it ! I think that will be a easy thing to do with all references we have from all kind of **** power amps kit or ready built from all kind of people who earned a lot of money showing the next best constructions the past 25 years. |
I disagree. The only wise thing in KSA100 circuit is the use of right transistors in right quantity in respect to the power rating and the high bias current. The rest looks like any opamp-like SS circuit of commercial area repeating the same blames.
The global NFB loop with an electrolytic capacitor in the divider circuit first comes to mind. Next, that stupid complementary differential input stage.
Just take a standard PA amp with good heatsinks and the same power transistors, rewind the mains transformer to lower secondary voltage, disable the now unnecessary protection circuit and increase the idle current. A Krell is born!
There are much more refined and simpler ss circuits, some of them are much older than 25 years. |
|
|
|
