Dear All,
I am Rick from Spore. New bie in HiFi World. Need some help and guide line.
1) how can I do and check baising?
2) what is the value? and how do I find out?
3) where is the control for adjustment?
Really appreciate for all attention and feed back 🙂
Cheers!
I am Rick from Spore. New bie in HiFi World. Need some help and guide line.
1) how can I do and check baising?
2) what is the value? and how do I find out?
3) where is the control for adjustment?
Really appreciate for all attention and feed back 🙂
Cheers!
rick_bravotino said:
You work for the magazine?
If you mean "biasing" and it's not a journalistic secret, could you share what do you intend to bias?
Hi Rick,
You really work for the magazine? 😀
The answers of all your questions depend entirely on the amp you're working on, there do not exist any general answers.
By the way, if you didn't already know this, then you shouldn't fiddle with the bias.
Have fun, Hannes
You really work for the magazine? 😀
The answers of all your questions depend entirely on the amp you're working on, there do not exist any general answers.
By the way, if you didn't already know this, then you shouldn't fiddle with the bias.
Have fun, Hannes
Hi,
there is a general answer for an EF output stage.
Bias at 15mV to 25mV across each output emitter resistor.
Set the output bias with the DC offset near zero mV and with the input shorted and no load connected.
Do apply apply this rule to FET output stages nor to CFP output stages.
there is a general answer for an EF output stage.
Bias at 15mV to 25mV across each output emitter resistor.
Set the output bias with the DC offset near zero mV and with the input shorted and no load connected.
Do apply apply this rule to FET output stages nor to CFP output stages.
Hi Andrew, you really think the original poster knows what an EF is 😀
Good observation indeed...Emitter resistors in designs are generally ranging from 0.1 up to 0.47 R? The bias currents would equally range from 40mA all the way up to 200mA...
All the best, Hannes
<Post edited>
Good observation indeed...Emitter resistors in designs are generally ranging from 0.1 up to 0.47 R? The bias currents would equally range from 40mA all the way up to 200mA...
All the best, Hannes
<Post edited>
I have just finished changing all Cap on both L%R driver board. Now the Right side is hotter than the Left side. My friend said need to do baising to balance.
The driver board have 2 tiny control...but not sure how to do it...?
The driver board have 2 tiny control...but not sure how to do it...?
I have no ideal how to do baising...my friend told me send it to Krell in S'pore, which I think is expensive. Not sure where sure I put the multi-meter + & - points to monitor the reading, and what value should I look for?
I read some DIY project talking about current n voltage. But how to do it? and what value to adjust?
Thanks for the attention 🙂
I read some DIY project talking about current n voltage. But how to do it? and what value to adjust?
Thanks for the attention 🙂
You need to give us more information ie which Krell amp etc?
There are many placing that might be able to help you so which city are you in?
Personally... I do not think you should touch it.
There are many placing that might be able to help you so which city are you in?
Personally... I do not think you should touch it.
Here is the pict for Krell KSA200 driver board. Im not electronic trained, but bldg construction 🙁 Hope someone can help. Thanks.
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Now these are some exquisitely messed up boards!
Get somebody with more experience to help you out. You're risking your health and your house if the whole thing blows up.
Stay healthy, Hannes
Get somebody with more experience to help you out. You're risking your health and your house if the whole thing blows up.
Stay healthy, Hannes
I hope you are wrong.analog_sa said:
Rick had better prove otherwise!
Or is he someone returned from the dead?
I have stripped this Monster naked... Now has started changing its Organ to higher Quality parts. I prefer the parts made in Europe, like Germany, France and UK 🙂
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An externally hosted image should be here but it was not working when we last tested it.
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An externally hosted image should be here but it was not working when we last tested it.
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An externally hosted image should be here but it was not working when we last tested it.
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do i have to shorted the input to do proper bias?
is it mean that i should connect positive and negative input by jumpering it?
is it normal if i measure negative Absolute DC offset let say it show random reading from -20mv to 50mv
the best offset are near to zero so should i adjust to say 5mv to 85mv
or to -35mv to 35mv?
and also are there any bad effect to have high dan unstable absolute DC offset?
thanks and sorry for my newbness
is it mean that i should connect positive and negative input by jumpering it?
is it normal if i measure negative Absolute DC offset let say it show random reading from -20mv to 50mv
the best offset are near to zero so should i adjust to say 5mv to 85mv
or to -35mv to 35mv?
and also are there any bad effect to have high dan unstable absolute DC offset?
thanks and sorry for my newbness
Re-attached pictures... Monster Stripped naked...🙂 Will all update on the Monster Pictures!
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70mV of output offset drift with temp and operational conditions is far too high.audioholik said:
What's causing this?
10mV is probably a drift target to aim for from cold start to fully warm and after heavy use.
I set the offset either side of zero. But I generally set the warm offset slightly closer to zero than the start up offset since the first few seconds/minutes is less important in the big picture.
The symasym has about 2mV of drift and after warm up it stays within +-0.5mV offset, always.
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