Go Back   Home > Forums > >
Home Forums Rules Articles diyAudio Store Blogs Gallery Wiki Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

The Lounge A place to talk about almost anything but politics and religion.

John Curl's Blowtorch preamplifier part III
John Curl's Blowtorch preamplifier part III
Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 12th July 2018, 05:38 PM   #6651
RNMarsh is offline RNMarsh  United States
diyAudio Member
 
RNMarsh's Avatar
 
Join Date: May 2012
Location: 2457 Cascade Trail; Cool, CA. 95614
Quote:
Originally Posted by Mark Johnson View Post
Good old Seymour Cray did liquid cooling in the 1960's by brazing copper pipes to the PCB card racks and running chilled Freon through the pipes. {CDC-6600 supercomputer, delivered to Livermore in 1965}

Then he did liquid cooling in the 1970's by including stainless steel pipes in the card racks and running Freon from those pipes into a refrigeration unit located directly below the computer (in the basement). Each circuit board was bonded to a copper plate, which was clamped to the racks where the coolant flowed. {Cray-1 supercomputer, delivered to Livermore in 1975}

Then he did liquid cooling in the 1980's by submerging the entire computer in liquid coolant, a very expensive liquid called Fluorinert. {Cray-2 supercomputer, delivered to Livermore in 1985}
Yes, I was there for some 23 years from 6600 onward ( to the early '90's) and actually saw the whole pcb with processor in liquid running just fine. we watched the demo thru clear window (plastic? Glass?)
The more semiconductors and denser the circuitry is, the more heat produced and harder to get rid of it fast enough. That one big pcb was running 300A thru it! Big buss bars to it and into the solution. This solution to the heat issue was developed at LLNL.

But it was the robotic photo storage library (called Elephant) that really took my breath away.

Today this is used --> News | Lawrence Livermore National Laboratory

For stock pile stewardship.... hahahaha... sure. Still doing design as usual, I'm sure.


THx-RNMarsh

Last edited by RNMarsh; 12th July 2018 at 05:59 PM.
  Reply With Quote
Old 12th July 2018, 06:01 PM   #6652
Mike Gergen is offline Mike Gergen  United States
diyAudio Member
 
Join Date: Sep 2004
Location: Elk River MN
How well does it work as a music server? Where do I plug in my sound card and I want to do mods to it. Of course mods will make it sound better.
  Reply With Quote
Old 12th July 2018, 08:16 PM   #6653
DPH is online now DPH  United States
diyAudio Member
 
Join Date: Dec 2008
Location: Portland, OR
That'd be one *heck* of a cap reroll. Wonder if any of those "ancient" system are up and running still. The lifetime on their components makes me wonder.
__________________
Happy DIYing, Daniel
  Reply With Quote
Old 12th July 2018, 09:22 PM   #6654
billshurv is offline billshurv  United Kingdom
diyAudio Member
 
billshurv's Avatar
 
Join Date: Mar 2014
John Curl's Blowtorch preamplifier part III
NMOC at Bletchley Park has two Crays. Sure they will try and get them running.
  Reply With Quote
Old 12th July 2018, 09:47 PM   #6655
Destroyer OS is offline Destroyer OS  United States
diyAudio Member
 
Destroyer OS's Avatar
 
Join Date: Nov 2005
Location: PNW
John Curl's Blowtorch preamplifier part III
Quote:
Originally Posted by RNMarsh View Post
Which dominates? CM or DMode?


-RNM
Are yo asking what is the dominate enoise on the AC line, or if the filter is dominate for CM or DM?

The filter with the Comoco is neat because you get CM and DM filtration. The DM filtration is significant. The smallest one has up to 1000uH DM.

Where as using the Bourn's 8120/8121 units are primarily CM. Their differential leakage is approximately the amount of DM filtration they offer, which isn't a lot.


From the AC line it's a mix. CM is fairly strong from what's in the air. But you'll get DM particularly from other things in the house. So there's a lot of factors. But I must point out that a lot of the DM is very hard to filter at significant current levels for amplifiers and such. The cost become prohibitive for many - largely because a lot of it is lower in frequency, too. Where as CM is actually rather useful for helping reduce shared enoise among your equipment. The high capacitance in small transformers for sources and maybe SMPS (not enough personal testings to comment on too much with SMPS) form CM noise, which the CM filtration assists with. So they work to help isolate the equipment from each other, or at least in a more controlled manner if the grounding schemes are decent.
  Reply With Quote
Old 13th July 2018, 05:40 PM   #6656
nezbleu is offline nezbleu  Canada
diyAudio Member
 
nezbleu's Avatar
 
Join Date: Dec 2009
Location: Halifax, Nova Scotia, Canada
John Curl's Blowtorch preamplifier part III
Quote:
Originally Posted by gpapag View Post
IMO, one of the great motivations in the DIY audio world is that provided by the documentation of Siegfried Linkwitz work.
It is a pity not to try his elegantly simple constructions and listen to the music through them.

I couldn't agree more.
__________________
"In the world of commerce and finance it is thought quite remarkable if a man is both clever and honest." -- Demosthenes
  Reply With Quote
Old 13th July 2018, 08:21 PM   #6657
DPH is online now DPH  United States
diyAudio Member
 
Join Date: Dec 2008
Location: Portland, OR
Any updates on his health? I'm hoping for peaceful at this point for SL.
__________________
Happy DIYing, Daniel
  Reply With Quote
Old 13th July 2018, 09:44 PM   #6658
Nelson Pass is offline Nelson Pass  United States
The one and only
 
Nelson Pass's Avatar
 
Join Date: Mar 2001
John Curl's Blowtorch preamplifier part III
I talked with him a few minutes ago, mostly about the LXmini crossover,
full range Seas drivers in sealed boxes, the group delay figures of the
bass EQ network in the first Thiel loudspeakers in '77, and the good old
days when we had the time to drink beer and watch the channel 2
monster movies on a Saturday afternoon....

He is in good spirits, but tires easily.
  Reply With Quote
Old 13th July 2018, 09:59 PM   #6659
scott wurcer is offline scott wurcer  United States
diyAudio Member
 
scott wurcer's Avatar
 
Join Date: Jan 2004
Location: limbo
Quote:
Originally Posted by Nelson Pass View Post
and the good old
days when we had the time to drink beer and watch the channel 2
monster movies on a Saturday afternoon....
I miss those days Creature Double Feature and at night The Ghoul (with lots of fine wine). Years later it was The New Avengers with Purdy, any of you Brits remember?
__________________
"The question of who is right and who is wrong has seemed to me always too small to be worth a moment's thought, while the question of what is right and what is wrong has seemed all-important."
  Reply With Quote
Old 13th July 2018, 10:06 PM   #6660
billshurv is offline billshurv  United Kingdom
diyAudio Member
 
billshurv's Avatar
 
Join Date: Mar 2014
John Curl's Blowtorch preamplifier part III
Who could forget, but I was more into Emma Peel era Avengers*. Mind you the tricked up Jag he drove in new Avengers I couldn't forget.


*in the re-runs. Honor Blackman close second.
  Reply With Quote

Reply


John Curl's Blowtorch preamplifier part IIIHide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


New To Site? Need Help?

All times are GMT. The time now is 07:10 AM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 14.29%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Copyright ©1999-2018 diyAudio
Wiki