Schematic for CambridgeAudio A3i - diyAudio
Go Back   Home > Forums > Amplifiers > Solid State

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
Reply
 
Thread Tools Search this Thread
Old 20th April 2008, 09:42 AM   #1
OXAUDIO is offline OXAUDIO  United Kingdom
diyAudio Member
 
Join Date: Sep 2006
Question Schematic for CambridgeAudio A3i

Does anyone have, or know where I can get, a scematic diagram/service manual for the above? The 2SA1216 in the LH Channel has failed(Base/Collector short-circuit). Having 'cold checked' and visually inspected other components, I replaced both output transistors(The NPN one is a 2SC2922) only to find that the centre rail, which should be 0v is about +25v w.r.t. ground. The relay and driver transistors check out OK 'cold'
Any suggestions as to what else needs replacing??
  Reply With Quote
Old 20th April 2008, 12:18 PM   #2
diyAudio Member
 
east electronics's Avatar
 
Join Date: Jan 2006
Location: Athens GREECE
Default check drivers

also for short circuit and if this circuit includes clamp diodes check them also ....also check rail fuses to see if they are ok
__________________
SERVICE ΕΝΙΣΧΥΤΩΝ ΚΑΙ ΙΑΠΩΝΙΚΩΝ ΜΗΧΑΝΗΜΑΤΩΝ ΗΧΟΥ www.eastelectronics.gr
  Reply With Quote
Old 20th April 2008, 01:24 PM   #3
OXAUDIO is offline OXAUDIO  United Kingdom
diyAudio Member
 
Join Date: Sep 2006
Default Cambridge Audio A3i Amplifier

The two 4amp fuses in the transformer secondary circuit had blown, due to the original fault. Replacement 4A(T) Fuses OK after amp was powered for a couple of minutes whislt checking it. The driver Transistors check OK 'cold', don't know about clamp diodes, though I will check for them, but a schematic would still be helpful, if one can be obtained. There are a number of green LEDs on the main amp PCB. Not certain what they are there for, but they all illuminate.
  Reply With Quote
Old 20th April 2008, 02:23 PM   #4
diyAudio Member
 
Sonusthree's Avatar
 
Join Date: Dec 2005
Location: Sussex, UK
I'm pretty sure there are more threads about this amp with input from the designer. At least two people in those threads offer a schematic.

The search button can be very useful sometimes.
__________________
Martin
+ + =
  Reply With Quote
Old 20th April 2008, 05:00 PM   #5
OXAUDIO is offline OXAUDIO  United Kingdom
diyAudio Member
 
Join Date: Sep 2006
Default Schematic for Cambridge Audio A3i

I had done a search before posting my request, but, unless I've missed something(quite possible!!) there are no threads on this forum relating specifically to the A3i Amplifier, which include a schematic diagram. I will have another look, however, in case something has appeared since this morning(UK Time)
  Reply With Quote
Old 21st January 2009, 07:35 AM   #6
diyAudio Member
 
homertooties's Avatar
 
Join Date: Nov 2005
Location: suffolk
Hi there dont know if you fixed amp or not but also check the big resistors for open circuit and when the output blows normally takes the little black trim pot with it also ,,and replace all leds (green) these set up the current in amp.make sure they stand above board get hot...
__________________
if you strip it for parts keep them for years as soon as you get rid you will want them .....................
  Reply With Quote
Old 21st January 2009, 09:30 AM   #7
OXAUDIO is offline OXAUDIO  United Kingdom
diyAudio Member
 
Join Date: Sep 2006
Default Reply to post by 'homertooties'

Hi,
I had actually fixed that amplifier sometime in April/May last year, having obtained a circuit diagram for it. In the end, from memory, I replaced at least one faulty LED(They, as you no doubt know, don't fail too often), and some other parts. After setting it up, I test ran it for several hours a day, then it went back to it's owner. So far as I know it's working fine to this day. Your post may help others having problems with Cambridge Amplifiers, though.
  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
looking for a pre-amp schematic steamPunk Tubes / Valves 3 3rd August 2008 01:49 PM
DBX 500 schematic d3imlay Solid State 0 2nd August 2008 05:12 PM
F3 schematic kenev Pass Labs 2 24th January 2008 03:24 PM
Help with this schematic? imix500 Parts 4 11th August 2004 10:08 AM


New To Site? Need Help?

All times are GMT. The time now is 08:43 AM.


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