Sick pioneer SA6200

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colin.hepburn
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#106

Post by colin.hepburn »

Mike H wrote:Yep that's why I always try to use sealed enclosed presets, including multi-turn where most appropriate.

I guess the DC bias could be as much as it will stand heat wise.

About 25 years ago I'd got meself a new Pioneer 100W per channel amp, had a big heatsink in it that was always hot even at low power / idle. From which I deduced the bias was on the high side on purpose for more class A.



Yep as you describe my Nad 352 gets burn hot to and that's still as factory settings unless it can drift perhaps I should check it agenst the manuals and see
It is a bit tempting too wind up the current for that class A sound thou :shock:
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Mike H
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#107

Post by Mike H »

Indeed! Maybe with a can of freezer spray handy :lol:




 
 
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colin.hepburn
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#108

Post by colin.hepburn »

I have just been checking the idle current of pioneer amp 1 SA- 6200 from cold @ 39.03mV after about two hours it drifts up/down like 33.mV to 38.05 is this the norm I have also found the Schematic of its little 10 Watt brother which states the idle current for it as 30mV but says to use a 8 ohm non- inductive resister on on speaker I have just connected the MM to the pins should i use the resistor
So the Little SA-5600 is @ 30mV/0.5R=60mA the SA6200 is double the power so can we run it say @about 41mV0.5R=82mA what do you think
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pre65
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#109

Post by pre65 »

On mine it says to use a dummy load when checking the idle current which is when meter reads 20mv after power switched on for 10 mins.

Do you set the DC neutral condition as well ?
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colin.hepburn
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#110

Post by colin.hepburn »

pre65 wrote:On mine it says to use a dummy load when checking the idle current which is when meter reads 20mv after power switched on for 10 mins.

Do you set the DC neutral condition as well ?
My MM is just set at the 200mA Range
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#111

Post by pre65 »

colin.hepburn wrote:
pre65 wrote:On mine it says to use a dummy load when checking the idle current which is when meter reads 20mv after power switched on for 10 mins.

Do you set the DC neutral condition as well ?
My MM is just set at the 200mA Range
Eh ?

On mine I have 4 pots, 2 for adjusting the DC neutral (to 0V) and two for setting the idle current.(for each channel)
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#112

Post by colin.hepburn »

AH no my Amp has only one pot Idle current on each channel
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#113

Post by Mike H »

colin.hepburn wrote:after about two hours it drifts up/down like 33.mV to 38.05 is this the norm
Not having monitored one like that I have no idea! I suppose some 'drift' must be expected. Whether it's warmer or cooler. And what about the difference between Summer and Winter? :D



 
 
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colin.hepburn
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#114

Post by colin.hepburn »

Mike H wrote:
colin.hepburn wrote:after about two hours it drifts up/down like 33.mV to 38.05 is this the norm
Not having monitored one like that I have no idea! I suppose some 'drift' must be expected. Whether it's warmer or cooler. And what about the difference between Summer and Winter? :D



Yep could be the temp I suppose it seems to count up to about 38/39 then down again just did not expect to watch it drop up/down I though it maybe because I haven't got a 8 ohm resistor on the speaker post
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#115

Post by pre65 »

colin.hepburn wrote: I though it maybe because I haven't got a 8 ohm resistor on the speaker post
And is the volume control at minimum ?
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#116

Post by colin.hepburn »

pre65 wrote:
colin.hepburn wrote: I though it maybe because I haven't got a 8 ohm resistor on the speaker post
And is the volume control at minimum ?
Eh the volume control has nothing to do with it
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#117

Post by Mike H »

Might if you got a 8 ohm load on and it's picking up hum or something and amplifying it. Maybe

colin.hepburn wrote:Yep could be the temp I suppose it seems to count up to about 38/39 then down again just did not expect to watch it drop up/down
Now you mention it I'll have to look for that in future!



 
 
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colin.hepburn
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#118

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Mike H wrote:Might if you got a 8 ohm load on and it's picking up hum or something and amplifying it. Maybe



I am just testing the power amp pre links have deen removed
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#119

Post by Mike H »

So the inputs are not AC grounded in any way then? Or are you actually playing music through it from something else?



 
 
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#120

Post by colin.hepburn »

Mike H wrote:So the inputs are not AC grounded in any way then? Or are you actually playing music through it from something else?



No The amp is on the table no connections in or out the MM is connected to it monitoring the current
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