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my su v9 goes silent

markdi

markdi

Natural born thread killer
If it is over driven or turned up too far. :D

Using my technics su v9 to Power a pair of spealerlab days 7 speakers.

I guess the overload protection works.

Turn down the gain and cycle power and it works again.

This is the first amp I have ever owned with this feature.

The first time it went silent it Kinda freaked me out but it was obvious that
I was overpowering it and i could not turn down the remote controlled source fast enough.
Verry directional remote.

2nd time no obvious distortion - just really really loud.

Is this a standard feature on integrated amplifiers ?
I know amps have overheat shut down but the su v9 must be detecting clipping
 
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I have a realistic sa 2001 that does not shut down when overloaded

Not sure if my yamaha ca 810 does

Maybe if they get too hot
 
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bktheking said:
Where was the vol knob when it went into protection?
Click to expand...

4 or 40% and 6 beers and 1 jack and diet coke

I turned the source up too far

The su v9 was not overheating - i know most amps have overheat and dc detect shutdown.

I know the volume control is a gain adjustment and not a power control - well ya know what i mean :D

I think the su v9 can detect clipping or something and go into protection.
 
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Most amps- shutdown has nothing to do with overheating, in fact, most amps don't have an overheat temp sensor that will shut it down. 40% of 100% should have not put it into protection- sounds like the unit needs work. Protection issues are 2 fold- first fold is that it has to be up to spec to work properly, if there are issues with the protection circuit it can cause the amp to go into protection when really it shouldn't- take the pioneer sx880 that I just repaired- the current sense transistors were faulty and it would go into protection at low volume.

Second fold is current sensing- it's to protect the speakers from DC- has nothing to do with AC which is the voltage you are putting out to the speakers. The idea is to measure DC before the relay. You should be able to take any amplifier, hook it load up to it and swing the volume pot to 80% without it going into protection, even clipping won't send it into protection- I've benched many units, observed clipping and backed it down to just before clipping to take measurements- they don't go into protection nor should they.
 
I guess 40/100% is possible when speaker related (impedance too low for instance), but normally indeed it shouldn't, unless perhaps indeed the input source voltage is way too high.
 
I have a emotiva umc 200 plugged into the aux input on the su v9 and a xbox 360 plugged into the umc 200 and the
Su v9 powering 4 ohm speakerlab das 7 speakers.
I am pretty sure nothing is wrong with the protection system but i could be wrong.
The first time it shut off it was obviously clipping - a song started playing that was much louder than the previous songs
I could not find the remote or make it to the su v9's volume knob fast enough.

2nd time is fuzzy in my brain because of the beer.
I remember it was very very loud.

I have had and still own amps with over temp sensors on the power transformers and heat sinks.
They usually have to cool off before they work again.

Turn down the gain and cycle power and the su v9 sings again.
 
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I guess it's that. I have a Technics SU-3500 that I overpowered at the phono input, suddenly an enormous loud noise and then into protection.

It tricked me though, this amp has a relay driven protection, but here the relay kicks in at problems, the amp then still plays, but very distorted (this system bleeds the large filter caps!), so I thought I had blown my speakers. Switching the amp off and on solved the problem :).
 
jeromach said:
I guess it's that. I have a Technics SU-3500 that I overpowered at the phono input, suddenly an enormous loud noise and then into protection.

It tricked me though, this amp has a relay driven protection, but here the relay kicks in at problems, the amp then still plays, but very distorted (this system bleeds the large filter caps!), so I thought I had blown my speakers. Switching the amp off and on solved the problem :).
Click to expand...

Wow it bleeds the big caps

As far as i know My su v9 just disconnects the speakers.
 
Yes, that's what it does, most Technics amps have this system (if they have a relay), but apparently the older ones like the SU-3500 do it differently. The SE-9200 uses the same system as the 3500, probably the SE-9600 too. These amps have sound nearly directly when switched on. Like for instance a Marantz 1060, only this amp does not have a relay and it keeps playing for a while when you switch it off (until the big caps are bled :)).
 
The su v9 has a servo controlled power supply and a multi tap transformer.
It measures the impedance of the speakers connected to it and adjusts its self

4 ohm speakers - no problem

I might dust off one of my o scopes a tektronix 794d and see how much clipping or what ever it takes to go into protection.

Or just listen to it
 
markdi said:
The su v9 has a servo controlled power supply and a multi tap transformer.
It measures the impedance of the speakers connected to it and adjusts its self

4 ohm speakers - no problem

I might dust off one of my o scopes a tektronix 794d and see how much clipping or what ever it takes to go into protection.

Or just listen to it
Click to expand...

Yes it does, interesting- it measures the impedance using a circuit that is ADJUSTABLE. Rather than dusting off the scope I'd be looking at measuring and adjusting that detection circuit- perhaps it has drifted and isn't detecting the loads properly. Food for thought.
 
bktheking said:
Yes it does, interesting- it measures the impedance using a circuit that is ADJUSTABLE. Rather than dusting off the scope I'd be looking at measuring and adjusting that detection circuit- perhaps it has drifted and isn't detecting the loads properly. Food for thought.
Click to expand...

Yes it could need adjustment
It is old


it gets really loud and distorts before it trips
 
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