Kit Ryan mod for Adcom GFA-555 - diyAudio
Go Back   Home > Forums > Amplifiers > Solid State
Home Forums Rules Articles diyAudio Store Gallery Wiki Blogs Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

Solid State Talk all about solid state amplification.

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
Thread Tools Search this Thread
Old 12th October 2006, 07:00 PM   #1
Mayank is offline Mayank  United States
diyAudio Member
Mayank's Avatar
Join Date: Oct 2004
Location: Falls Church, VA
Question Kit Ryan mod for Adcom GFA-555

Hi All:

I was going through some old Audio Amateur magazines and came across a detailed article by Kit Ryan on building a Power Supply regulator for the Adcom GFA-555. According to the article, with this modification, "the transient response of the amplifier is dramatically improved, bringing increased resolution, imaging and sound stage definition with it. The best part is that these qualities are maintained from low volume levels right up to when the green 'overload' LEDs on the front panel light up".

This looks very attractive and I would like to start this project and modify my GFA-555.

2 questions - has anyone on the forum built this? Are the results of the modification really as described?

Thanks in advance
  Reply With Quote
Old 12th October 2006, 07:27 PM   #2
anatech is offline anatech  Canada
diyAudio Moderator
anatech's Avatar
Join Date: Jun 2004
Location: Georgetown, On
Hi Mayank,
I'm not sure about that one. Regulating some of the parts in the voltage amp section should do it.

Adcom had an option for this, but I've never seen one installed. Try it, but make sure you can back out as well.

  Reply With Quote
Old 29th October 2015, 03:03 AM   #3
diyAudio Member
Join Date: Sep 2015
Hello Mayank - I have a 555 on my bench now with the ryan regulator kit installed in is not working very well and I was wondering if you still have that article and might could send it to me???
Thanking you in advance!
  Reply With Quote
Old 29th October 2015, 06:47 AM   #4
djk is online now djk
diyAudio Member
djk's Avatar
Join Date: Feb 2001
Location: USA
" I was wondering if you still have that article and might could send it to me???"

You need the errata that was detailed in a letter later on.

"Regulating some of the parts in the voltage amp section should do it."

A much better solution.

I sold a friend a higher power, higher voltage Hafler DH500 transformer to replace the Adcom transformer, which he then ran into the Ryan regulator.

It would have been simpler to regulate the front-end voltage, that's what does the most good.
Candidates for the Darwin Award should not read this author.
  Reply With Quote


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
Ryan regulators not regulating? bobschneider Solid State 0 15th August 2007 10:14 PM
Hey there This is Ryan from Michigan ragsports Introductions 1 1st August 2007 10:49 PM
Adcom GFA-585 went bad - calling Adcom experts hangguy Solid State 14 24th December 2004 08:09 PM
Need source of silicone for Ryan's Regulators... Greg Stewart Parts 0 13th July 2003 04:11 AM

New To Site? Need Help?

All times are GMT. The time now is 09:04 PM.

vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Copyright 1999-2017 diyAudio

Content Relevant URLs by vBSEO 3.3.2