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

Solid State Talk all about solid state amplification.

Idiot seeks help with Hiraga
Idiot seeks help with Hiraga
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 24th August 2017, 07:21 AM   #1
farflungstar is offline farflungstar
diyAudio Member
 
Join Date: Aug 2017
Default Idiot seeks help with Hiraga

So I have a Hiraga, it's over 30 years old and may well have been an original build by Hiraga or created by another for Expolinear speakers - it's branded Expolinear and i was told was used to demo their speakers back in the day.

It sounds very very good, beating my big Cary valve amps in almost every area except soundstage. To fix this id like to try changing some components but as there are so many different schematics out there I have no idea which applies to my amp. So, if I take some pics could someone point me in the right direction?

Adey
  Reply With Quote
Old 24th August 2017, 08:38 AM   #2
av-trouvaille is offline av-trouvaille  Netherlands
diyAudio Member
 
Join Date: Aug 2003
Location: Near Rotterdam
Interesting. Hiraga has designed several amplifiers, you may consult the (elaborate) threads about them at this diyaudio forum.
In order to reflect on your question, the specific schematic of your amplifier would be helpful. Do you have the original schematic? If not, can you please re-engineer the schematic, preferably inclusive the type of components? An existing schematic as can be found on this forum or on internet may help you getting started. The type of output transistors as found in your amplifier can point towards the appropriate design.

BTW, I do not grasp the meaning of the word 'idiot' as used in the heading of your post. If meant as is in 'we are all idiots building and modifying diy-stuff', it is superfluous. Otherwise, Hiraga is all but an idiot.

Last edited by av-trouvaille; 24th August 2017 at 08:46 AM.
  Reply With Quote
Old 24th August 2017, 08:40 AM   #3
farflungstar is offline farflungstar
diyAudio Member
 
Join Date: Aug 2017
I don't have any schematics. I know it's the 20w class A. I will open it up and check it out tomorrow on my day off.
  Reply With Quote
Old 24th August 2017, 10:58 AM   #4
lisoformio is offline lisoformio  Italy
diyAudio Member
 
lisoformio's Avatar
 
Join Date: May 2008
Location: near Florence
This one?
Attached Images
File Type: jpg hiragaclassa20w.jpg (91.3 KB, 763 views)
  Reply With Quote
Old 24th August 2017, 11:05 AM   #5
farflungstar is offline farflungstar
diyAudio Member
 
Join Date: Aug 2017
No, mover is the earlier black cap - it is very old. Wait I have a pic...Click the image to open in full size.
  Reply With Quote
Old 24th August 2017, 11:16 AM   #6
lisoformio is offline lisoformio  Italy
diyAudio Member
 
lisoformio's Avatar
 
Join Date: May 2008
Location: near Florence
Wow... never seen that! The Hiraga 20W Class A I know of is that in the image I posted.
By the way I found this: For sale - General Amp Clear Out, Jean Hiraga, Gate Audio, Yves cochet
They say it is the clone.
  Reply With Quote
Old 24th August 2017, 11:50 AM   #7
farflungstar is offline farflungstar
diyAudio Member
 
Join Date: Aug 2017
Yes I bought it from Jake (the URL you have). He only knows that it was built around 30yrs ago to demo Expolinear speakers, and is branded Expolinear. The black cap is rare - there is reputedly another but it may in fact be the same one. I added the wooden strive to the marble.
  Reply With Quote
Old 25th August 2017, 02:19 PM   #8
farflungstar is offline farflungstar
diyAudio Member
 
Join Date: Aug 2017
Okay I've taken some pics...
To be honest I can't see what could be changed - oh it was built in 1981 - the date is on the inside.Click the image to open in full size.Click the image to open in full size.Click the image to open in full size.Click the image to open in full size.
  Reply With Quote
Old 25th August 2017, 02:26 PM   #9
Pano is offline Pano  United States
diyAudio Moderator
 
Pano's Avatar
 
Join Date: Oct 2004
Location: SW Florida
Idiot seeks help with Hiraga
The PCB looks right, but I've never seen that chassis. I visited the production line of the Lectron amp a few times, and built a couple of my own, but don't know that model you have.

What I don't understand is why you want to change it? It's a wonderful amp, why mess with it? You can buy kits to build from scratch on eBay. Maybe you want to try that and use your power supply? What are your goals?
__________________
Take the Speaker Voltage Test!
  Reply With Quote
Old 25th August 2017, 02:29 PM   #10
farflungstar is offline farflungstar
diyAudio Member
 
Join Date: Aug 2017
I love it and just want to improve soundstage, particularly depth. In my naivety I assumed it would be packed wth electrolitics and thought changing them f for better quality might help - but really there's nothing to change.
  Reply With Quote

Reply


Idiot seeks help with HiragaHide 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

Similar Threads
Thread Thread Starter Forum Replies Last Post
new member seeks info. giblaut762005 Introductions 1 4th November 2013 02:20 PM
new member seeks info. giblaut762005 Parts 0 3rd November 2013 08:22 PM
new member seeks info. giblaut762005 Parts 0 3rd November 2013 08:07 PM
new member seeks info. giblaut762005 Parts 0 3rd November 2013 07:59 PM
Newbie seeks driver approval markg Multi-Way 10 19th October 2002 05:39 AM


New To Site? Need Help?

All times are GMT. The time now is 03:50 PM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 15.00%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Copyright ©1999-2018 diyAudio
Wiki