Hi my friend, you got PM...
R11 on my circuit is 15k, & all part just like in this schematic:
To Mr. Mile ...
may I change input transistor to 2SK170 ?
(have been mentioned in old post but no one make it)
If can, please tell us what need to be changed...
Regards
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sr200 studio refer.
Look at this.
I use this Elektor published curve tracer.
Keep in mind that with all theese circuits you can match small signal transistors only.
It's not recommented to match power transistors with that's circuits.
For power transistors matching you need high current and high voltage devises.
I see circuits like this in Elektor but i haven't made something like this yet.
Thanks my friend.
Look at this.
I use this Elektor published curve tracer.
Keep in mind that with all theese circuits you can match small signal transistors only.
It's not recommented to match power transistors with that's circuits.
For power transistors matching you need high current and high voltage devises.
I see circuits like this in Elektor but i haven't made something like this yet.
Attachments
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59.6V on R14 .... This value is with or without servo?
63mV bace to ground Q2 is with or without servo?
Thim,
R33 (220r) in post1323 sets the driver bias current. This will make the drivers run warm.
What resistor value and what voltage do you have across R33 in your builds?
R33 (220r) in post1323 sets the driver bias current. This will make the drivers run warm.
What resistor value and what voltage do you have across R33 in your builds?
Hi Mr Adrew R33=220R
This time haven't circuit diagramme on my hands (where i has write some measurments) i come back in a few minutes.
Thanks for all.
V R33=1.2V
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That seems normal.
~5mA will be warm.
Where does 5mA put the transistor in it's typical hFEvsIc & fTvsIc?
Maybe the drivers are too far away from optimum Ic to operate as fast drivers.
~5mA will be warm.
Where does 5mA put the transistor in it's typical hFEvsIc & fTvsIc?
Maybe the drivers are too far away from optimum Ic to operate as fast drivers.
sr200 studio refer.
Dit you believe that raising power supply voltage affect the offset ?
O no just now i remember that asymmetric presents with servo also even if offset is zero.
Dit you believe that raising power supply voltage affect the offset ?
O no just now i remember that asymmetric presents with servo also even if offset is zero.
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Hi brother!! sorry my mistake...wrong written, I mean 10pf not 20pf...
I have some of 10pf caps but no 20pf caps. It is stated that 18 pf cap should put in the amp as compensation cap. So, which is the best practice? install 10 or 20 pf...if 20pf is the best I will put 2 X 10pf in parallel...
Thank you.
Best Regards...
Apex,
could you make a designer's comment on my post 1330?
Could a very low driver bias current make the amplifier susceptible to component variations?
Could two apparently identical builds end up behaving differently due to the transistor parameters being sufficiently different?
could you make a designer's comment on my post 1330?
Could a very low driver bias current make the amplifier susceptible to component variations?
Could two apparently identical builds end up behaving differently due to the transistor parameters being sufficiently different?
This is the reason why the design was changed to a triple emitter follower for SR800
Hi Mr. Mile,
SR800 is not for share, but can we optimize this SR200?
Can I changed the resistor that AndrewT said not optimal...
I want more driver current for feeding the Sanken's(100mA bias or more)
What need to be changed please help
sr200 studio refer.
Everything starts from here.
This modification is the cause of the problem.
Today early in the morning about 5.30 o'clock i examined the amplifier again.
But this time I was sure for the pcb because it passed the point to point test.
As changing transistors and matchig didn't solve the problem, having in mind that the others' amplifiers didn't have the problem,i decided to return to the original circuit.
So i put at R11 the original value 15K.and that was all!
Thanks everyone for trying to help .
Especialy thanks Mr AdrewT who advised me to stabilize the LTP without servo.
Thanks a lot to John Balli for your instant reply in mine request for measurments.
Last but not least thanks overall feedback for his atempt to help.
Thanks again Mr.Mile for this excellent amplifier.
I also attach this hopping that it will be useful
Everything starts from here.
This modification is the cause of the problem.
Today early in the morning about 5.30 o'clock i examined the amplifier again.
But this time I was sure for the pcb because it passed the point to point test.
As changing transistors and matchig didn't solve the problem, having in mind that the others' amplifiers didn't have the problem,i decided to return to the original circuit.
So i put at R11 the original value 15K.and that was all!
Thanks everyone for trying to help .
Especialy thanks Mr AdrewT who advised me to stabilize the LTP without servo.
Thanks a lot to John Balli for your instant reply in mine request for measurments.
Last but not least thanks overall feedback for his atempt to help.
Thanks again Mr.Mile for this excellent amplifier.
I also attach this hopping that it will be useful
Attachments
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