John Linsley Hood Ripple Eater - diyAudio
Go Back   Home > Forums > Commercial Sector > Group Buys

Group Buys Members group buys

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 22nd May 2010, 06:40 AM   #1
diyAudio Member
 
Join Date: Oct 2002
Location: UK
Default John Linsley Hood Ripple Eater

Hi All,

This is a GB for the JLH Ripple Eater. It's a small run of 200 boards and is non-commercial. All profits will be going to Cancer Research UK, and I will also make a small donation to this forum.

As this GB spans a couple of forums, I have put all details here:

JLH Ripple Eater

If you'd like to register interest, please use the linked email address on the site, and you will get a holding reply. I will update the interest totals (currently 88 boards) on a regular basis.

Cost will be 3GBP per board, plus packing + postage to wherever on the planet you are - at cost.

Thanks for looking, and hopefully for your support!

Jon

JLH Ripple Eater

This will be a high-quality, professionally produced, double-sided PCB measuring 103mm x 31mm (4.06 x 1.22 ins approx). It may be used to smooth positive or negative power supplies in high-quality audio equipment. My notes below are largely based on JLH’s 1994 article.

History behind JLH Ripple Eater – original article.

The original circuit was designed by John Linsley Hood MIEE (February 9, 1925 to March 11, 2004) and published in Electronics Today International in April 1994. Further development of the circuit and layout has taken place over recent years by members of Rock Grotto forums - Rock Grotto - where the circuit is used to clean up power supplies on DIY headphone amplifiers and DACs.

What is it?

The JLH Power Supply Ripple Eater is an add-on circuit that sits between a power supply and end user. The Ripple Eater measurably reduces power supply output noise and ripple. JLH demonstrated a reduction in noise and ripple on his own bench supply from a figure, measured over the range of 20Hz to 20KHz, of 300uV to 4uV. When he connected a good quality 470uF electrolytic capacitor across the same bench power supply, there was no measurable improvement in ripple. In a similar experiment, the output noise from a selected 7815 IC voltage regulator was reduced from 60uV, itself better than the maker’s specification, to 3.5uV, when measured over the same bandwidth.

Why would you need one?

Need a quieter power supply? Of course you do!! Although JLH was reluctant to claim that this add-on circuit would lead to an improvement in the sound of audio equipment operated from simple IC stabilised power supplies, because he could not know what other people would hear, he was satisfied that, according to his test instruments, it did a useful job. We think JLH was being modest. Many JLH Ripple Eater users report audible improvements when using this circuit in their power supply chain.

How does it work?

The circuit consists of two parts: a ‘ripple detector’ arrangement based on a long-tailed pair, and a constant current source. Any ripple voltage present across the supply line can modulate this current. The aim being that if the output voltage were to momentarily increase or decrease, the current drawn would automatically increase or decrease to oppose these output voltage fluctuations. The impedance of the circuit depends on the size of the capacitors used – particularly that of C4, which can be large since it only needs to be 1V working. With the values chosen in this iteration, the circuit generates the electronic equivalent of about half a Farad or more.

It’s also been observed that “In essence it is an AC feedback loop”.

Why the new edition?

We were considering a new iteration of this design. A double-sided version that was slightly more compact than the original. This would also be a single board that could be stacked for a smaller in-chassis footprint.

Board design is 99% finalised, but expect: Double-sided, through-hole plated, coloured solder mask, gold flashed pads, 1.6-2mm FR4 board material, electrically tested etc.
  Reply With Quote
Old 22nd May 2010, 07:11 AM   #2
Liliya is offline Liliya  Norway
diyAudio Member
 
Join Date: Aug 2003
Location: 3370 Vikersund
Hi

I am in. Two boards

Eivind Stillingen, Norway
  Reply With Quote
Old 22nd May 2010, 07:46 AM   #3
diyAudio Member
 
Join Date: Oct 2002
Location: UK
Welcome aboard, Eivind!!
  Reply With Quote
Old 22nd May 2010, 09:02 AM   #4
audi0 is offline audi0  Australia
Account disabled at member's request
 
Join Date: May 2009
Location: 37.34 degrees South
Blog Entries: 5
Hi Jon,

I remember reading about these ages ago in ETI, and again recently in another forum.

Put me down for TWO

Cheers.. Steve
  Reply With Quote
Old 22nd May 2010, 10:17 AM   #5
diyAudio Member
 
Join Date: Oct 2002
Location: UK
Thanks Steve!

Thats a total of 92 so far...
  Reply With Quote
Old 22nd May 2010, 12:34 PM   #6
diyAudio Member
 
sandbasser's Avatar
 
Join Date: Sep 2008
Location: Riverside, CA - USA
Please put me down for FOUR.
__________________
- Ray
  Reply With Quote
Old 22nd May 2010, 01:49 PM   #7
Jaimo is offline Jaimo  Canada
diyAudio Member
 
Join Date: Oct 2005
Pls put me down for 4 boards.

Thanks
  Reply With Quote
Old 22nd May 2010, 04:10 PM   #8
EUVL is offline EUVL  Europe
diyAudio Member
 
Join Date: Oct 2003
4 please.

Thanks,
Patrick
  Reply With Quote
Old 22nd May 2010, 04:37 PM   #9
housing is offline housing  Hong Kong
diyAudio Member
 
Join Date: Nov 2006
Put me down for 4 boards. please.
  Reply With Quote
Old 22nd May 2010, 06:31 PM   #10
diyAudio Member
 
sandyhooker's Avatar
 
Join Date: Dec 2005
Location: Arizona
Please include me for 2 boards!!
  Reply With Quote

Reply


Hide 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
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
John Linsley Hood FM tuner article/s djsb Analogue Source 44 6th August 2013 01:59 PM
Help wanted please - Linsley Hood article index Geoff Everything Else 2 5th March 2013 04:57 AM
John Linsley Hood RIAA Preamp? roger-k Solid State 5 16th March 2007 07:10 PM
John Linsley Hood "Valve and Xstor" amps jackinnj Swap Meet 0 4th July 2002 02:14 AM
Linsley Hood SE 10W amp Asen Solid State 35 8th October 2001 09:07 PM


New To Site? Need Help?

All times are GMT. The time now is 06:13 PM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2