Hi,
Audiolab.
How is the pot connected? via wired leadouts or via the PCB.
If mounted separatly then consider a 20k or 50k instead.
If PCB mounted you will need one with identical size and pin pitch.
It might be worth just experimenting with a temporary hookup on long (150mm) wire leads to dis/prove what is faulty.
Audiolab.
How is the pot connected? via wired leadouts or via the PCB.
If mounted separatly then consider a 20k or 50k instead.
If PCB mounted you will need one with identical size and pin pitch.
It might be worth just experimenting with a temporary hookup on long (150mm) wire leads to dis/prove what is faulty.
Enric or Woody78 did you ever solve the problem and fix your Amps?
I am looking at an AUDIOLAB 8000A with a similar problem.
Diagnosis so far No output from the speakers but ok from the headphones, the preamp still works. power LED comes on red (is this normal or is it suppose to go green??)
A quick investigation has shown that the protection circuit on one channel has 2 burnt resistors 470R and 1 white capacitor is also blown in mine. I have not investigated further but the transistors seem ok on both outputs (not protection circuit).
I will try and have a good look but I think the trick is to identify what else blew with the protection circuit.
I have looked at a few threads with similar problems but no straightforward solutions are forthcoming nowadays on here. I think we have too many diy experts who seem to always deviate from what the initial problem/ fault is. Most threads seem to trail off into never ending design philosophy discussions.
I am looking at an AUDIOLAB 8000A with a similar problem.
Diagnosis so far No output from the speakers but ok from the headphones, the preamp still works. power LED comes on red (is this normal or is it suppose to go green??)
A quick investigation has shown that the protection circuit on one channel has 2 burnt resistors 470R and 1 white capacitor is also blown in mine. I have not investigated further but the transistors seem ok on both outputs (not protection circuit).
I will try and have a good look but I think the trick is to identify what else blew with the protection circuit.
I have looked at a few threads with similar problems but no straightforward solutions are forthcoming nowadays on here. I think we have too many diy experts who seem to always deviate from what the initial problem/ fault is. Most threads seem to trail off into never ending design philosophy discussions.
Attachments
Audiolab 8000a low output
Hi,
I am new to this forum and having same problem of low out put from left channel in my Audiolab 8000a amp which I bought (used)recently. What I feel is the problem would be volume control.
Can anyone tell me, where I will get the the vilume control in India or can any one suggest perfect alteration without loosing
its performance.
I have gone thr. all threads but searching for perfect solution
Thanks n regards
Samar p
Hi,
I am new to this forum and having same problem of low out put from left channel in my Audiolab 8000a amp which I bought (used)recently. What I feel is the problem would be volume control.
Can anyone tell me, where I will get the the vilume control in India or can any one suggest perfect alteration without loosing
its performance.
I have gone thr. all threads but searching for perfect solution
Thanks n regards
Samar p
hello all..
i am new here also and new to hifi / electronics in general..
my father has passed me down his audiolab 8000a amp, which altho is abit of a relic still sounds really nice.. the problem i have is that the amp seems to fail to deliver signal to both speakers.. one sounds nice the other sound distorted, if i swap the leads over the problem swaps speaker (exactly the same happened when we tried the amp with my dads new system) suggesting a problem with the amp..
upon opening her up, there was noticeable damage to some of the resistors.. the problem i have is that i cannot tell the value of the resistors as they are completely black and charred!! i have looked at a schematic and altho im a draughtsman my knowledge of electronics is basic to say the least.. if i were to photograph the problem resistors and their location on the pcb would someone be able to assist me in identifying them?!?
im young and dont really have the budget for a repair let alone a new amp, i was really hoping i may just be able to replace the resistors at a fraction of the cost!! PLEASE HELP!!!
i am new here also and new to hifi / electronics in general..
my father has passed me down his audiolab 8000a amp, which altho is abit of a relic still sounds really nice.. the problem i have is that the amp seems to fail to deliver signal to both speakers.. one sounds nice the other sound distorted, if i swap the leads over the problem swaps speaker (exactly the same happened when we tried the amp with my dads new system) suggesting a problem with the amp..
upon opening her up, there was noticeable damage to some of the resistors.. the problem i have is that i cannot tell the value of the resistors as they are completely black and charred!! i have looked at a schematic and altho im a draughtsman my knowledge of electronics is basic to say the least.. if i were to photograph the problem resistors and their location on the pcb would someone be able to assist me in identifying them?!?
im young and dont really have the budget for a repair let alone a new amp, i was really hoping i may just be able to replace the resistors at a fraction of the cost!! PLEASE HELP!!!
You could probably identify them yourself by looking at the good channel. But post a pic, can't help without that.
I would also add NOT to connect speakers to this until it is repaired. You've been lucky up to now... a DC offset fault would destroy the speakers. Replacing just the resistors and hoping its fixed could produce a DC offset with disastrous results.
An externally hosted image should be here but it was not working when we last tested it.
attempted posting images...
1st image is from a distance, 2nd a close up of the burnt out resistors..
thanks for the response, like i said im no electrical engineer, im a noob with an interest!!!
im all ears to sound advise guys!!
Last edited:
Looks like the 470R resistors in the protection circuit. There is going to be more wrong than just these burnt resistors, you will need to find what caused this. A good place to start will be to check the output devices are OK.
EDIT: where have the pics gone ?
EDIT: where have the pics gone ?
You are a forum newbie, thus under moderation. Each of your posts must be approved by a moderator before it shows in the thread. This should have been explained when you signed up and also each time you post.Pano- diyAudio Moderator.
kool... i understand the moderation thing, but it seems like one minute the pics are there and then they re not... im gonna post this and leave it for a while!! think that maybe its me keep posting and then editing em.. anyhoo i ll check after a while an see if they re up.. then any comments wil be appreciate.. thanks eggontoast 🙂
If you are to stand any chance of fixing this then you are going to have to do some basic checks to begin within, followed by checks with it powered up (but no speakers connected 🙂)
Its really up to you and how determined you are. It won't be a two minute fix... it will involve testing and determining exactly what the failure mode has been and then replacing the failed components as required.
For attaching pictures in future try attaching directly to the forum,
"To add a photo, files or non standard files.
First click "go advanced" in the box below the "quick reply" message box. Doesn't matter if you decide half way through a message to do that, it carries it foward.
Then click "Manage attachements". Maximise the new Window so that you can see all the text.
Click browse in the first box at the top and find your picture. Repeat for any more pictures.
Click upload... a message appears "uploading"
When complete the files will show as being attached. Now click the small text that says "close this window"
The pictures should now be attached and when you submit your post they will appear.
Make sure your pics aren't too big, a couple of 100k is plenty, and many members object when they are massive and it alters the margins
It tells you in the attachments window what max sizes are allowed.
If you want to attach a file that has a non standard format for example excel, circuit simulation etc then try putting the files in a zipped folder and attaching that. "
Its really up to you and how determined you are. It won't be a two minute fix... it will involve testing and determining exactly what the failure mode has been and then replacing the failed components as required.
For attaching pictures in future try attaching directly to the forum,
"To add a photo, files or non standard files.
First click "go advanced" in the box below the "quick reply" message box. Doesn't matter if you decide half way through a message to do that, it carries it foward.
Then click "Manage attachements". Maximise the new Window so that you can see all the text.
Click browse in the first box at the top and find your picture. Repeat for any more pictures.
Click upload... a message appears "uploading"
When complete the files will show as being attached. Now click the small text that says "close this window"
The pictures should now be attached and when you submit your post they will appear.
Make sure your pics aren't too big, a couple of 100k is plenty, and many members object when they are massive and it alters the margins
It tells you in the attachments window what max sizes are allowed.
If you want to attach a file that has a non standard format for example excel, circuit simulation etc then try putting the files in a zipped folder and attaching that. "
Hi guys, just thought id update you!!
tbh i was kind of hoping that by just switching out the knackered resistors might give me a quick fix, but as you guys have said that is not the case i think i may have to give up and put it in for a repair.. like i said i have a basic understanding of electics, and although i am keen to learn more, i think that testing to find the problem is probably beyond me at the moment.. i wouldnt rele know where to start!!
i do not know what you mean by the failure mode nor do i know what you mean by output devices (although i would guess these to be the ouputs of the amp ie tape, cd, tuner etc.)
any estimates on how much this cost to repair?! or any advice on how to test the circuits if this is a simple task.
tbh i was kind of hoping that by just switching out the knackered resistors might give me a quick fix, but as you guys have said that is not the case i think i may have to give up and put it in for a repair.. like i said i have a basic understanding of electics, and although i am keen to learn more, i think that testing to find the problem is probably beyond me at the moment.. i wouldnt rele know where to start!!
i do not know what you mean by the failure mode nor do i know what you mean by output devices (although i would guess these to be the ouputs of the amp ie tape, cd, tuner etc.)
any estimates on how much this cost to repair?! or any advice on how to test the circuits if this is a simple task.
A lot depends on how determined you are 🙂
Testing first involves basic tests using your meter to see if there are any "obvious" problems such as short circuit outputs (the big transistors on the heatsink 🙂) and open circuit resistors, particularly those 0.22 ohm that connect to the outputs.
That's something you can quickly and easily measure with the amp off. Using your meter on the "diode" range measure between the middle leg of each "output transistor" to the other two legs on that transistor. If any reads really low such as 0.00 or 0.1 etc then we have a problem. Check those 0.22 ohm resistors using the "low" ohms range on the meter. Are any open circuit or very high in value ?
The service manual is widely available on the web for the 8000A
Following the outcome of that, testing with it on (to measure voltages) involves powering the amp via a 100watt household filament bulb. This connects in series with the mains and limits current in the event of a problem, hopefully saving any transistors from blowing.
Testing first involves basic tests using your meter to see if there are any "obvious" problems such as short circuit outputs (the big transistors on the heatsink 🙂) and open circuit resistors, particularly those 0.22 ohm that connect to the outputs.
That's something you can quickly and easily measure with the amp off. Using your meter on the "diode" range measure between the middle leg of each "output transistor" to the other two legs on that transistor. If any reads really low such as 0.00 or 0.1 etc then we have a problem. Check those 0.22 ohm resistors using the "low" ohms range on the meter. Are any open circuit or very high in value ?
The service manual is widely available on the web for the 8000A
Following the outcome of that, testing with it on (to measure voltages) involves powering the amp via a 100watt household filament bulb. This connects in series with the mains and limits current in the event of a problem, hopefully saving any transistors from blowing.
Hello, My 8000a needs some of the PCB phono blocks replacing. Can anyone recommend which ones I should get and where ? I have found this site but not sure which ones I should order.
CLIFF Electronic Components - RCA Phono Connectors
Many thanks in advance 😉
CLIFF Electronic Components - RCA Phono Connectors
Many thanks in advance 😉
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