It's a single ended diff input pair with the tail fed from an active current source.
The VAS, which is cascoded and has an active current source, is driven by a resistive load in the diff pair.
LEDs are used in the current sources.
Very simple.
Musical Concepts even shows the board layout at their site.
The VAS, which is cascoded and has an active current source, is driven by a resistive load in the diff pair.
LEDs are used in the current sources.
Very simple.
Musical Concepts even shows the board layout at their site.
I know that-and that's reason why I asked for schmtcs;
I just wanna see values and to do some analysis,not to copy it.
anyway-tnx for reply 😉
I just wanna see values and to do some analysis,not to copy it.
anyway-tnx for reply 😉
Are you people discussing the Musical Concepts replacement boards or something from Audio Concepts?
I have MC PA3-B boards installed in a Hafler chassis and love their sound. It is my reference amp. More smooth and detailed than the Hafler with clear solid bass (not boomy or muddy).
But, the LC-100 kit of PS caps should also be installed. They do make a difference.
I have MC PA3-B boards installed in a Hafler chassis and love their sound. It is my reference amp. More smooth and detailed than the Hafler with clear solid bass (not boomy or muddy).
But, the LC-100 kit of PS caps should also be installed. They do make a difference.
Yes Musical Concepts Mod PA-3C
I'm new to these forums...have followed your journey w/ Hafler mods through many threads. I have the MC manual for what they call their PA-3C mods. Any comments as to its value and sound improvements. My Hafler 200 was purchased and assembled by me in 1981.. (Paid $279.00 for the kit..I still have the receipt!)
PS:I sent you an email with same questions while you were answering my first post
I'm new to these forums...have followed your journey w/ Hafler mods through many threads. I have the MC manual for what they call their PA-3C mods. Any comments as to its value and sound improvements. My Hafler 200 was purchased and assembled by me in 1981.. (Paid $279.00 for the kit..I still have the receipt!)
PS:I sent you an email with same questions while you were answering my first post
"I just wanna see values and to do some analysis,not to copy it."
The tail current for the diff pair is 3.6mA, 1.8mA per device.
The cascoded CCS is 22mA for the cascoded Vas.
Green LEDs are used at 3.7mA for voltage references for the CCS.
The tail current for the diff pair is 3.6mA, 1.8mA per device.
The cascoded CCS is 22mA for the cascoded Vas.
Green LEDs are used at 3.7mA for voltage references for the CCS.
- Status
- Not open for further replies.