Dear forum members
Is there anybody out there who has a schematic of the PROTEUS 1.6SW amplifier module from Thommessen? The one I have died on me since the last electrical storm we had.
Music doesn't sound al that good without my active sub.
Thanks in advance.
Walter
Is there anybody out there who has a schematic of the PROTEUS 1.6SW amplifier module from Thommessen? The one I have died on me since the last electrical storm we had.
Music doesn't sound al that good without my active sub.
Thanks in advance.
Walter
Hi Walter,
Okay, so does it power up? Do you have a voltmeter?
There are only so many ways to make an amplifier. They are then just variations on a theme. What have you done so far to troubleshoot it?
-Chris
Okay, so does it power up? Do you have a voltmeter?
There are only so many ways to make an amplifier. They are then just variations on a theme. What have you done so far to troubleshoot it?
-Chris
Hi Chris
To be honest, the darn thing has been sitting in a cupboard for quite a while now. At the time I did the following:
I replaced a zener diode and the two voltage regulators. The amp works but at a certain level it start to sound distorted. Also before it played much, way much louder. If I replace the op-amps there's no difference. I also replaced the powertrannies, again no difference.
It would be so much easier if I had a schematic of the *******r 😕
Regards
To be honest, the darn thing has been sitting in a cupboard for quite a while now. At the time I did the following:
I replaced a zener diode and the two voltage regulators. The amp works but at a certain level it start to sound distorted. Also before it played much, way much louder. If I replace the op-amps there's no difference. I also replaced the powertrannies, again no difference.
It would be so much easier if I had a schematic of the *******r 😕
Regards
Attachments
Hi Walter,
I see a pair of large outputs, drivers and a bias transistor in your picture. Possibly that is driven by an op amp, or there may be a voltage amp stage if your supplies are greater than +-18V.
Were the power transistors replaced by the exact number? If not, what where the original numbers?
-Chris
I see a pair of large outputs, drivers and a bias transistor in your picture. Possibly that is driven by an op amp, or there may be a voltage amp stage if your supplies are greater than +-18V.
Were the power transistors replaced by the exact number? If not, what where the original numbers?
-Chris
1.)
This would get more attention in the solid state forum probably.
2.)
Have you checked if the output short-circuit protection is working properly. If this sets in too early you cant get max output power anymore.
Regards
Charles
This would get more attention in the solid state forum probably.
2.)
Have you checked if the output short-circuit protection is working properly. If this sets in too early you cant get max output power anymore.
Regards
Charles
Hi guys
O.K, If there's a moderator who's willing to move this thread to the Solid Stage section.
The exact same devices: Toshiba 2SA1302 and 2SC3281
At the time I have tried to distill a schematic from the amp but I got fed up with it. It's the part of the amp that controls the two relais.
(PM related) Chris, I have two multi meters. I also have a digital scope but I hardly know how to use it. Not much as test equipment hé 😉
Regards
O.K, If there's a moderator who's willing to move this thread to the Solid Stage section.
The exact same devices: Toshiba 2SA1302 and 2SC3281
At the time I have tried to distill a schematic from the amp but I got fed up with it. It's the part of the amp that controls the two relais.
(PM related) Chris, I have two multi meters. I also have a digital scope but I hardly know how to use it. Not much as test equipment hé 😉
Regards
Thanks for moving this thread.
Mine too Jacco 😉
Edit: For some odd reason I can't upload pictures anymore!
Mine too Jacco 😉
Edit: For some odd reason I can't upload pictures anymore!
Hi Walter,
I did not receive your mail. Try bhome at sympatico dot ca. Digital scope? lovely, nice! With your multimeter, please measure the voltage of the diff pair emitters. also measure the voltage across the output terminals. You can use your 'scope to see if there is an audio signal coming on to the amp board.
Hi Jacco,
I have some real, late production 2SA1302 that are the same colour as the 2SC3281. The earlier ones were green for sure. It is possible they are fakes depending on the source. That wouldn't cause this I don't think.
-Chris
I did not receive your mail. Try bhome at sympatico dot ca. Digital scope? lovely, nice! With your multimeter, please measure the voltage of the diff pair emitters. also measure the voltage across the output terminals. You can use your 'scope to see if there is an audio signal coming on to the amp board.
Hi Jacco,
I have some real, late production 2SA1302 that are the same colour as the 2SC3281. The earlier ones were green for sure. It is possible they are fakes depending on the source. That wouldn't cause this I don't think.
-Chris
The note in post #8 was a reply on the mail you send me!? 😉
Apparently posting pictures is still not working.
Regards
Hi Walter,
Would you please attempt to send it again? Use the link in my profile, it works. If the date was messed up, who knows where the mail went? I've seen that a couple times.
Thanks, Chris
Would you please attempt to send it again? Use the link in my profile, it works. If the date was messed up, who knows where the mail went? I've seen that a couple times.
Thanks, Chris
Howdy!
Why not take advantage of that digital oscilloscope: clip one of the vertical input channels of the DSO to the output of the amp, crank it up until it just starts to sound distorted, freeze the waveform and take a picture of it, and post. I'm sure the amplifier gurus here will be able to figure out much more with a picture of what the output's doing.
Your DSO may even be able to save the waveform as a bmp, no need for a digital camera!
Cheers!
ps: guys, I had the impression that all 2SA1302/2SC3281s available are fakes, inasmuch as Toshiba stopped production many years ago?!
Why not take advantage of that digital oscilloscope: clip one of the vertical input channels of the DSO to the output of the amp, crank it up until it just starts to sound distorted, freeze the waveform and take a picture of it, and post. I'm sure the amplifier gurus here will be able to figure out much more with a picture of what the output's doing.
Your DSO may even be able to save the waveform as a bmp, no need for a digital camera!
Cheers!
ps: guys, I had the impression that all 2SA1302/2SC3281s available are fakes, inasmuch as Toshiba stopped production many years ago?!
clem_o
I would if I only knew how. I bought that thing almost three years ago and up to now I haven't used it. (I know, shame on me
)
Regards
I would if I only knew how. I bought that thing almost three years ago and up to now I haven't used it. (I know, shame on me
)Regards
Hi Clem,
There are still some real ones floating around. Service stock in some of the bigger warranty shops for one. I still have a couple, then it's off to the new numbers. I'm sure many stereo distributors have some in spares. They would be priced higher of course.
I am looking at a late model 2SA1302 in black as we speak.
-Chris
There are still some real ones floating around. Service stock in some of the bigger warranty shops for one. I still have a couple, then it's off to the new numbers. I'm sure many stereo distributors have some in spares. They would be priced higher of course.
I am looking at a late model 2SA1302 in black as we speak.
-Chris
Hi Walter,
Could you please give me a shot of the bottom of your board, output section, as well?
This will help me identify the output configuration more exactly.
Thanks, Chris
Could you please give me a shot of the bottom of your board, output section, as well?
This will help me identify the output configuration more exactly.
Thanks, Chris
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