hello I want to adjust the bias of my threshold s / 450e and I don't know at what points I should take the readings and how much they have to give me can you help me
Perhaps he is living up to his name....
There will be a bias pot for each channel. You can read the voltage off
of the emitter resistors of the output transistors which I recall to be 1 ohm.
Check several of them. The S450e has 6 of those in parallel, so the
bias current with the 1 ohm resistor is 6 times the voltage you read.
.1V = .6 amps bias
You will want to be careful, as you can damage the amp or yourself
doing something like this. Make adjustments in small steps and allow
the amp to sit with the cover on for a while before re-checking.
Best advice - bribe a technician to do it for you.
There will be a bias pot for each channel. You can read the voltage off
of the emitter resistors of the output transistors which I recall to be 1 ohm.
Check several of them. The S450e has 6 of those in parallel, so the
bias current with the 1 ohm resistor is 6 times the voltage you read.
.1V = .6 amps bias
You will want to be careful, as you can damage the amp or yourself
doing something like this. Make adjustments in small steps and allow
the amp to sit with the cover on for a while before re-checking.
Best advice - bribe a technician to do it for you.
miguelnoda,
NP wants you to do the same thing ZenMod has asked for 100%...
Measurements on several resistors to confirm consistancy of measurement as to tolérance of source/emitter resistors I suppose.
The measurement you give are of no use to help you.
NP wants you to do the same thing ZenMod has asked for 100%...
Measurements on several resistors to confirm consistancy of measurement as to tolérance of source/emitter resistors I suppose.
The measurement you give are of no use to help you.
You may want to buy the rubber high voltage gloves technicians use on electric/hybrid cars. You can find them at most electric supply stores.
They are bulky and uncomfortable, your hands will sweat inside them, however, it sure beats accidentally touching 78 vdc, That kind of early retirement is not what it's cracked up to be.
They are bulky and uncomfortable, your hands will sweat inside them, however, it sure beats accidentally touching 78 vdc, That kind of early retirement is not what it's cracked up to be.
I would start with .1V and see how hot that gets the amp.
And you can use the following guide to get to 50 deg C.
Attachments
threshold s450e
thanks for helping me but I'm a little lost
Where do I have to take a voltage as a reference and what should it be?
I have the temperature probe.
thanks for helping me but I'm a little lost
Where do I have to take a voltage as a reference and what should it be?
I have the temperature probe.
There are a bunch of 1 ohm resistors on the output stage. Each of them has
two wires coming out at the end. The DC voltage is between one of those wires
and the other.
two wires coming out at the end. The DC voltage is between one of those wires
and the other.
Threshold s450e
I already have it set at 45 degrees Celsius and it is perfect.
Now I have to adjust a T200 that I don't have the adjustment values.
Thanks for the help
I already have it set at 45 degrees Celsius and it is perfect.
Now I have to adjust a T200 that I don't have the adjustment values.
Thanks for the help
Just got a couple of SA-2 that run a bit cold to the touch.
I am planning to inspect them and adjust the bias if needed.
Would anyone be able to confirm that 150mV is the correct value for the voltage drop across the emitter resistors?
Thank you in advance for any help.
Marco
I am planning to inspect them and adjust the bias if needed.
Would anyone be able to confirm that 150mV is the correct value for the voltage drop across the emitter resistors?
Thank you in advance for any help.
Marco
