how adj a2 ac gain ?

[ne5532]

how adj a2 ac gain ? thank you.

 

[Nelson Pass]

Assuming that you are referrring to a production Aleph 2,
you can increase the values of R5 and R7 for more gain,
or decrease them for less.

 

[ne5532]

dear Nelson Pass

dear Nelson Pass:
thank you is reply.i English very too bad.please understanding.
A2 Active Current Source whether need adj?
i think aware of A2 Active Current Source of Current should is total ac Current of percent how much:50%?or75%or66%? whether adj r21.
thank you.

 

[jeapel]

hi

if you want just the value 50% is the normal value

if you want all the details check my aleph 3 post the
principle is same for aleph 2 just check for resistor
number equivalent

http://www.diyaudio.com/forums/showthread.php?s=&threadid=76697&highlight=

 

[ne5532]

thank you

thank you. but a2 must adj to how much current?

 

[JEKYLL]

http://www.diyaudio.com/forums/showthread.php?s=&threadid=38033&highlight=

 

[jeapel]

hi

1-for dc bias adjust the 56.2 kohm
normal bias = (.5volt / 1 ohm) x 6 give ~= 3 A / channel

2-for ac gain adjust the 681 ohm

AC gain%= I upper 1 ohm ( x 6 for aleph 2) / Iout

step by step:
1-put a power 8ohm resistor on output maybe
around 50 watt
2-put a signal to get around 20 volt peak to peak
on output

check AC volt with a scope (just ac not dc)
I upper=(Vac upper 1 ohm / 1ohm) x 6
Iout = Vacrout / rout (rout=.47ohm/6= .0783ohm)

if you don t get a scope do the test with 50 or 60hz and
check ac volt with a normal multimeter

bye

 

[ne5532]

thank you jeapel

hi
AC gain%= I upper 1 ohm ( x 6 for aleph 2) / Iout must adj to 50%or60%or75%?
thank you.

 

[jeapel]

50%

 

[ne5532]

thank you

thank you.VERY MUCH

 

[carpenter]

perhaps this has already been answered before

Is R5 the 100k or the 10k resistor? Both values share the same R5 label.

John🙂