Hi all,
I almost fixed a (...completely...) broken EC AW 180M.
Adjusting dc offset & bias was quite trivial.
R44 for bias current (9-8.5mV across 0.2 ohm restistor = 45-42.5mA as the working one)
and R7A to null dc offset before ouput relay.
Now there is a third trimpot (R6P) on the so called "Sister Board" near IC protector.
EC firmly but kindly but refused to give me any help or hint 😡 .
Amplifiers measures and sounds good but ...
Is there someone who can give me any help?
Thanks in advance
I almost fixed a (...completely...) broken EC AW 180M.
Adjusting dc offset & bias was quite trivial.
R44 for bias current (9-8.5mV across 0.2 ohm restistor = 45-42.5mA as the working one)
and R7A to null dc offset before ouput relay.
Now there is a third trimpot (R6P) on the so called "Sister Board" near IC protector.
EC firmly but kindly but refused to give me any help or hint 😡 .
Amplifiers measures and sounds good but ...
Is there someone who can give me any help?
Thanks in advance
Welcome
Very nice project!!
I would like to ask for help
Electrocompaniet AW-180 schematics I need
Thanks for your help
my email address
gargafater@freemail.hu
Very nice project!!
I would like to ask for help
Electrocompaniet AW-180 schematics I need
Thanks for your help
my email address
gargafater@freemail.hu
Dear Elan,
i would like to kindly ask you for some support......
Here is the situation :
- Both of my AW180 produce little noise through tweeter (hiss) and midrange (hum) speakers - it is almost equal in left & right channel and audible from about 10 cm distance from the speakers (so, i have to be very close to the speakers to notice that).
- Also transformers in both monoblocks are slightly humming - as above i have to be close to the amps to notice that - (about 50 cm)
- DC offset floats in both amps between -2mV and +2mV (measured at the speakers terminals).
I purchased my EC as second hand - they are approx. 6 years old.
Besides above mentioned little problems amps works just fine.
Could you pls share your experience with me and tell step by step how to adjust dc offset and bias ?
What are recommended by EC values for bias ?
Is this possible to get EC AW180 schematics or service manual...?
Thank You for any reply and help !
Kind regards :
Piotrek
i would like to kindly ask you for some support......
Here is the situation :
- Both of my AW180 produce little noise through tweeter (hiss) and midrange (hum) speakers - it is almost equal in left & right channel and audible from about 10 cm distance from the speakers (so, i have to be very close to the speakers to notice that).
- Also transformers in both monoblocks are slightly humming - as above i have to be close to the amps to notice that - (about 50 cm)
- DC offset floats in both amps between -2mV and +2mV (measured at the speakers terminals).
I purchased my EC as second hand - they are approx. 6 years old.
Besides above mentioned little problems amps works just fine.
Could you pls share your experience with me and tell step by step how to adjust dc offset and bias ?
What are recommended by EC values for bias ?
Is this possible to get EC AW180 schematics or service manual...?
Thank You for any reply and help !
Kind regards :
Piotrek
I have a aw600 ( two aw180)'with the same problems and a "bump" on speaker at cool start. Have anyone a manual service or schematics to adjust and repair please? Can anyone help me? daniel.espinosa@uca.es
Thanks in advance.
Thanks in advance.
Hi all,
I fixed my EC some ago so please forgive my memory.
BUMP
EC is protected by 48dcv relays, do you hear the bump just when amplifier is switched on or after relays switch?
My relay (one of them) went broken so it did not switch so being always on, the bump was present and quite BIG. Replacing the relay is difficult since supply wires need to be desoldered, I still remeber it was not any easy task. You need a good desoldering gun to preserve pcb traces.
BIAS and DC.
I desumed the bias current from a working, never serviced 180. Not 100% sure but I think close to the real value.
Measure DC at one of 0.2Ohm big emitter resistor near the power transistor, and slowly rotate r44 to read 9mv on your dvm.
I do not remeber well where emitter resitors are placed so please send an image to better help.
For dc offset place your dvm at speaker output and rotate r7a to read as much as close to 0V, your floating measurements seem OK.
I do not think that bias or dc adjust will solve your hiss and hum.
Since you amps are humming from main trafos, it is likely your main has some dc component, see Mains DC and Transformers to better understand, maybe your extra hiss and hum are related to this.
Hope it will help.
I fixed my EC some ago so please forgive my memory.
BUMP
EC is protected by 48dcv relays, do you hear the bump just when amplifier is switched on or after relays switch?
My relay (one of them) went broken so it did not switch so being always on, the bump was present and quite BIG. Replacing the relay is difficult since supply wires need to be desoldered, I still remeber it was not any easy task. You need a good desoldering gun to preserve pcb traces.
BIAS and DC.
I desumed the bias current from a working, never serviced 180. Not 100% sure but I think close to the real value.
Measure DC at one of 0.2Ohm big emitter resistor near the power transistor, and slowly rotate r44 to read 9mv on your dvm.
I do not remeber well where emitter resitors are placed so please send an image to better help.
For dc offset place your dvm at speaker output and rotate r7a to read as much as close to 0V, your floating measurements seem OK.
I do not think that bias or dc adjust will solve your hiss and hum.
Since you amps are humming from main trafos, it is likely your main has some dc component, see Mains DC and Transformers to better understand, maybe your extra hiss and hum are related to this.
Hope it will help.
Hi Jorre,
Would it be possible to get copies of what you have, AW100DMB notes and diagrams would be very helpful to me! 🙂