• The move to the new server is done. There are some software and database maintenance updates in process. This has us passing the hat around to help out. We appreciate any donations. Seriously, even a dollar helps. The payment page may be found here - https://www.audiokarma.org/support.html

Sansui AU-999 DC problems?

Sp33ls said:
Sorry to revive an old thread, but it's related to the original topic.

Here's a video on the cones moving during power-on. It seems excessive, no?
Click to expand...
No, thats about right.
Its best to just turn the speaker selector off during power on and power off.
Its completely normal for this to happen as voltages stabilise during the power on process.
 
kevzep said:
No, thats about right.
Its best to just turn the speaker selector off during power on and power off.
Its completely normal for this to happen as voltages stabilise during the power on process.
Click to expand...
Ah, interesting, thanks Kev!

Is this just a characteristic of the direct-coupled topology of the AU-999? I've not noticed it before with any of my other amps.

If my relatives do not turn the speaker selector off each time they use it, would that place a risk to the crowbar circuit overtime? Tried to measure it with the (crummy) multimeter they had and saw a brief spike of around a couple volts DC.
 
Sp33ls said:
Ah, interesting, thanks Kev!

Is this just a characteristic of the direct-coupled topology of the AU-999? I've not noticed it before with any of my other amps.

If my relatives do not turn the speaker selector off each time they use it, would that place a risk to the crowbar circuit overtime? Tried to measure it with the (crummy) multimeter they had and saw a brief spike of around a couple volts DC.
Click to expand...
Its not exclusive to the 999, many other amplifiers without any kind of speaker/protection relay will do this or similar.


If you do not turn the speaker selector off, no damage will occur to the speakers or amp. I prefer to turn the speaker selector off, but its not necessary......
 
kevzep said:
Its not exclusive to the 999, many other amplifiers without any kind of speaker/protection relay will do this or similar.


If you do not turn the speaker selector off, no damage will occur to the speakers or amp. I prefer to turn the speaker selector off, but its not necessary......
Click to expand...
I keep forgetting there's no relay in the 999 to eliminate that at startup. :)

On another note, I hadn't heard it in a few years, and coming back to hearing this again at my relatives place... Man, this was a nice gift. :D It sounds great with the recommended mods.

It also runs really cool. After a listening session, the top of the chassis is pretty much room temperature. I recall following the current biasing instructions, but it makes me wonder if I had set the amp at a lower than normal bias, or if it just doesn't run warm.
 
You must log in or register to reply here.
Back
Top Bottom