Strange issue:
I tried to do a comparison between 2 different cd players on how they sound, so i connected them to the cd and the tuner inputs of the Audiolab 8000A (early version).
The player that is connected to the tuner input sounds louder than the other connected to the cd input.
I did the same with only one player, connected at a time in different inputs, same thing;i have to adjust a little higher the volume knob.
While the volume is louder when connected to tuner and tape 1&2 inputs,it's quiter when connected to the cd input.
Cd players are NAD521bee and Marantz CD63 SE KI.
According to the Audiolab's manual all inputs have the same sensitivity 100mV/20K and i guess they should sound of the same level.
Nad's output level at 0dB is 2.1V rms with output impedance 200Ω.
Is this normal behaviour or the CD input of the amp is faulty?
I tried to do a comparison between 2 different cd players on how they sound, so i connected them to the cd and the tuner inputs of the Audiolab 8000A (early version).
The player that is connected to the tuner input sounds louder than the other connected to the cd input.
I did the same with only one player, connected at a time in different inputs, same thing;i have to adjust a little higher the volume knob.
While the volume is louder when connected to tuner and tape 1&2 inputs,it's quiter when connected to the cd input.
Cd players are NAD521bee and Marantz CD63 SE KI.
According to the Audiolab's manual all inputs have the same sensitivity 100mV/20K and i guess they should sound of the same level.
Nad's output level at 0dB is 2.1V rms with output impedance 200Ω.
Is this normal behaviour or the CD input of the amp is faulty?
The CD is possibly a direct connection from vol pot to power amplifier.
The other inputs possibly have a gain stage added in. It might be as little as +6dB (2times voltage gain). This stage may be before the vol pot. So be careful, an early located gain stage can be overloaded. Some testing of the various inputs should identify what is happening.
The other inputs possibly have a gain stage added in. It might be as little as +6dB (2times voltage gain). This stage may be before the vol pot. So be careful, an early located gain stage can be overloaded. Some testing of the various inputs should identify what is happening.
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Hello!!
-- earlier versions had 220 volt primary windings now days most countries have 230V
( in such a bad design the few more volts might be critical )
--PSU capacitors right side of the amp placed horizontally some years ago, combine horizontally with excessive heat that tends to concentrate in the sealed box and your caps are toasted
--Manufacturer likes to run drivers hot that could actually destroy quiet a lot of pcb area and expect plenty of soldering to be done
--expect other smaller capacitors to be toasted favorite areas around the drivers and secondary power supply
--expect also toasted or grilled resistors that often have values that drifted from original value
--expect the all situation to be even worst of the amplifier has been working for long time in ambient temp above 22 degrees
--expect the bias to be already drifted to anything and vary from ch A to Ch B benefit of the all above situation
--Presuming that the above is fixed you need to find out how the hell you will be able to set the bias and that can be a rather painful story
--If you have the time to bother with this and decide how much bias and how it will be ever possible to set it , you may verify your setting at 22 degrees in your listening area and then you will be very surprised to realize that the presumed set bias will vary once if the amplifier is working with the cover on or not, and even if the temperature in your listening area goes higher than 22 degrees to something like 28 for example for any possible reason IE room thermostat failure or summer !!! ...variations though are quite high
Was that enough ?
Hello!!
-- earlier versions had 220 volt primary windings now days most countries have 230V
( in such a bad design the few more volts might be critical )
--PSU capacitors right side of the amp placed horizontally some years ago, combine horizontally with excessive heat that tends to concentrate in the sealed box and your caps are toasted
--Manufacturer likes to run drivers hot that could actually destroy quiet a lot of pcb area and expect plenty of soldering to be done
--expect other smaller capacitors to be toasted favorite areas around the drivers and secondary power supply
--expect also toasted or grilled resistors that often have values that drifted from original value
--expect the all situation to be even worst of the amplifier has been working for long time in ambient temp above 22 degrees
--expect the bias to be already drifted to anything and vary from ch A to Ch B benefit of the all above situation
--Presuming that the above is fixed you need to find out how the hell you will be able to set the bias and that can be a rather painful story
--If you have the time to bother with this and decide how much bias and how it will be ever possible to set it , you may verify your setting at 22 degrees in your listening area and then you will be very surprised to realize that the presumed set bias will vary once if the amplifier is working with the cover on or not, and even if the temperature in your listening area goes higher than 22 degrees to something like 28 for example for any possible reason IE room thermostat failure or summer !!! ...variations though are quite high
Was that enough ?
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since you are able to read Greek you may wana take a look at this
Audiolab 8000 ?????? ??? ??????????
Audiolab 8000 ?????? ??? ??????????
The only issue i noticed after some hours of listening at low volume,is that the front left side of the amp gets quite hot, measured it at 37C on the chassis,you cannot even touch the amp.
I took some measurements inside the amp and this area goes up to 50-52C.
Is this normal or maybe should i return the amp?It's the early version.
Thanx for your link, i'm still a member but the last years i have moved in the UK.
Please advise what to do
I took some measurements inside the amp and this area goes up to 50-52C.
Is this normal or maybe should i return the amp?It's the early version.
Thanx for your link, i'm still a member but the last years i have moved in the UK.
Please advise what to do
There may be a high dissipation discrete headphone amplifier bolted to the side of the chassis. Open it up and have a look.
Hello and thank you very much indeed for the very valuable input
and yes ... this enough for me to be
I have bought lately this very amp ... not the one in the picture but it is exactly the same.
on the basis of a nice price and good reviews and because i have a soft spot for sanken bjts ... wonderful !
Unfortunately the sound fails to convince me
It is grainy and flat and without dynamic
I am not sure about what can be done to improve it, if possible.
I think you have written already something on this amp but i cannot find again the 3D.
I remember an advice to drill the lid.
But i do not know if it is worth the effort.
Maybe listening to it with the lid removed could help ?
Any kind advice would be very welcome.
Thanks a lot
Kind regards, gino
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Even though there is 120W worth of transistors per ch the rest of the circuit fails to produce dynamics .
The actual sound of this amplifier is exactly as you described it :
Unfortunately the sound fails to convince me
It is grainy and flat and without dynamic
Even if you spent money on it very little things are going to change ...It could be suitable for rock music or music with 2D and one voice with one piano Other than that any average Japanese amplifier of the same era like a Sansui AU217 will outperform the Audiolab for breakfast in any possible aspect , power , speed , bandwidth, image , sound stage , 3D , and so on ..
Kind regards
Sakis
The actual sound of this amplifier is exactly as you described it :
Unfortunately the sound fails to convince me
It is grainy and flat and without dynamic
Even if you spent money on it very little things are going to change ...It could be suitable for rock music or music with 2D and one voice with one piano Other than that any average Japanese amplifier of the same era like a Sansui AU217 will outperform the Audiolab for breakfast in any possible aspect , power , speed , bandwidth, image , sound stage , 3D , and so on ..
Kind regards
Sakis
Hello !
thanks very much for the very kind and valuable reply
This amp has been a surprise to me. I read so many positive reviews
But i am sincerely perplexed
I see. Nevertheless i would try to replace the two big caps.
I understand that the heat inside the unit is not little and this could have dried them out maybe, or at least reduced their performance.
I do not like as you pointed out the horizontal arrangement ... but i do not see alternatives.
In my little experience dried out caps are very detrimental to the sound
Or said differently .. a good pair of new caps adds dynamics and decreases noise (not that the amp is really noisy by the way)
Then there is the internal heat issue.
I could replaced the top lid with a metallic mesh maybe ?
In the weekend i will take a picture of this unit ... just for show
Thanks a lot again
Regards, gino
Hello and thanks a lot again
But i am not sure to understand well the modification you suggest
As an aside and watching only the pictures in the web .. are not the PS caps too small ?
I would say that a 20mF pair should be a minimum for an amp like this
I understand they wanted to keep the slim size
For a SS preamp ok ... but for an integrated
I will remove the lid and have a look .. at least out of curiosity
Regards, gino
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