Chapter 1: History of the thread

[grimberg]

Once upon a time…
Original Thread, Post #1

[toc]FORCE[/toc]

Well it all started when user “bra” posted the following schematic and said that he would like to make a Krell KSA-50.

[h=Threads from 2004: KSA 50 Board Research And Development.]%2[/h]
[Post #5] - Our main man Jan then stepped up to the plate and said “I can make the PCB-layout”.

[Post #7] - Luke sorta requested the board be single sided and Jan in [Post #9] agreed that it would be easier for DIY’ers to make their own if it were.

[Post #31] - Jan publishes his schematic for thread review, quick work in my opinion.

[Post #38] - Pavel suggested and Jan agreed that the project remain a Krell Klone and not be an “improved version”.

[Post # 55] - Jan requests last minute updates before making the PCB layout.

[Post #264] - Rabstg has taken on a group buy for the boards designed by Jan, and posts preliminary information on the boards.

[h=Threads from 2005: Boards (More Boards) and Building.]%2[/h]

[Post #399-400] A Krell [Group Buy #1 (Jan's Boards) Wiki] is created, edited, and eventually by 14 January 2005, 112 boards are ordered.

[Post #403] Jan, designer of the 1st PCB board set, posts the following remarks:

Amazing that this thread should reach more then 400 replies
There must be some interest for this project

Turns out to be quite the understatement.

[Post #690] The PCB Boards from the first group buy are shipped.

[Mike W's KSA 50] is posted in a separate thread March 3, 2005.

[Post #1114] NUTTR has his Krell Clone working on March 5, 2005. Pics in [Post #1131],[Post #1232], [Post #1256].

[Post #1116-17] Mark A. Gulbrandsen posts a pic of his KSA 50 (not in chassis) with data indicating that his build is working as of March 5, 2005. See also [Post #1234], [Post #1142], [Post #1298], [Post #1377]

[Post #1142] Links to the original KSA 50/100 soft start circuit schematics.

[Post #1164] Pics of Algar_emi's hardware for use in the Krell Clone.

[Post #1325] Mark makes the following statement:

If you have studied many amplifiers like I have over the last 25 years you will find that the circuit really is nothing very special and its very simple. And thats what I like. The result is one of the best sounding Krell amplifiers ever designed and it is considered one of the top ten amps ever designed and still used by many reviewers today as their refrence amp........ Thats also what I like.

[Post #1326] Stuart responds:

No-one in this group is building the KSA50 because we think they are the best at any cost (I hope), most of us aren't even fooling ourselves that they are the best for the costs we are incurring...
Basically we are building them for a lot reasons including but not wholly limited to...
They are cool,
Can be built easily,
have soul,
Sound 'good enough',
set a standard in their time,
won't involve litigation,
and are in their original form a minor work of art...

[Post #1387] A pic of the Pinkmouse output stage.

[Post #1400-1405] Pictures of Wim's KSA 50 are posted March 24, 2005.

[Post #1423] This "BUILD" Wiki page is created with a blank page.

[Post #1426] K-Amps posts his "Class A Spreadsheet" in a Zip file.

[Post #1502] Pinkmouse is designing a new board, schematic shown in this post. Board in [Post #1517]. People immediately show an interest in ordering these boards.

[Post #1601] Pinkmouse prototype board is shown. Hardware shown in followup postings.

[Post #1602] Assesears shows a pic of his krell hardware being tested.

[Post #1640-47] Pinkmouse shows oscilloscope square wave measurements of his prototype with different capacitances on Q107/108 (C105 & C106). See also [Post #1669] and 1674.

[Post #1693] Pinkmouse schematic for Pinkmouse board as tested and working, parts list in #1694.

[Post #1762] "Final" Pinkmouse boards, see up to #1780.

[Post #1827] Coloumb posts a pic of his chassis.

[Post #1848] Stuart gets a new girlfriend (congrats!) but more importantly (for us) begins work on a very high power version of the Krell clone.

[Post #1859] NUTTR realizes that the Krell clone is heating up his room by quite a bit.

[Post #1860] Stuart posts a pic of his basic output stage.

[Post #1875] Stuart has a bunch of non-inductive output resistors and people start buying them from him.

[Post #1995] Link to temp calculator on Analog Devices website.

[Post #2420] KMJ posts the following observation:

Damn you guys can keep a conversation goin, I'm without internet for 2 days and already theres so much to read.
My mothers sewingcircle doesn't have a thing on you.

[Post #3485] Mark posts a prototype of boards for the 2nd Group Buy.

[Post #3502] Terry's amp is up and running. Looks nice.

[Post #3609] LGreen's amp is up and running. Looks good.

[Post #4371] Mark has shipped all the boards for the 2nd Group Buy.

[Post #4612-15] neychi posts pictures of his Krell style chassis.

[Post #4814] Mark G orders another 100 boards, for a third group buy of Krell KSA 50 clone PCBs.

[Post #4886] Mark and Lyndon have successfully operated a new Krell clone, not yet in a chassis, using Mark's boards.

[Post #4902] Luke finishes his clone and puts up some pics. Hopefully a chassis is in the works.

[h=Posts From 2006. Boards are Available and Amp Building Resumes.]%2[/h]

[Post #5260] Happy New Year!

[Post#6011] Bra, who started this whole thing (3/27/04), has finally built a Krell clone (3/18/06). Two years and 6000+ posts, go figure.

[h=Posts From 2007. Building continues...]%2[/h]

[Post#7180] and [Post#7186] Happy New Year!

[Post#7185] Once again, a discussion of fans and how to keep things quiet.