Hi,
I think there is an advantage in using a DC servo with the original DC setting components left in place AND used to manually zero the DC offset when warm.
Then the DC servo has to correct just the cold start up offset and lies nearly idle when warm.
There may be other advantages.
Any comment?
I think there is an advantage in using a DC servo with the original DC setting components left in place AND used to manually zero the DC offset when warm.
Then the DC servo has to correct just the cold start up offset and lies nearly idle when warm.
There may be other advantages.
Any comment?
when the amplifier is converted to full DC coupled and a small and possibly variable DC comes from the source.PWatts said:
When the NFB DC blocking cap is removed the amp gain multiplies the output offset and more importantly the variations in output offset also get multiplied by amp gain.
Then the the servo comes into it's own. But I still contend that the amp should be set up with the servo temporarily disconnected and output offset minimised to reduce the excursions that the servo has to apply.
Similarly the DC detect should cut off the input if the output offset from the source becomes uncorrectable.
I still invite comments!!
Mark A. Gulbrandsen said:
Hi Mark,
I sent payment for 6 boards as requested in the original WIKI, but I see on the new WIKI, which I had not looked at carefully enough, my user name has dissappeared. If there aren't enough boards for me, you can refund me, but I would still like them if they will be available.
Robert
AndrewT said:
I"ve been experimenting with connecting a shelf comparator to the output of the servo, and using the output of this comparator to control relays which protect the speakers and disconnect the
output power supply. The speaker relay can either be put in series with the speaker, or with a resistor that shunts across the speaker
SO, a DC servo could be part of a protection scheme and provide double functionality.
Al Gore would probably like all KSA100 DIY'er to also consider a hi/lo Class-A bias switch to reduce global waming.
Krell Mk2 Update- Sound update
Gentlemen
Some time back I reported that my Mk2 amp was somewhat dissapointing following an parts and wiring update.
It now seems as if the interconnect wire was interacting with the output transistors wiring. Moving it away from the wiring of the output transistors made a immediate difference.
I have also soldered back 2 uF cap on the transformers.
I dont know if the Black Gate cap is beginning to burn in but the amp is now really beginning to sound excellent. The realism is incredible. The difference is so startling that sometimes I dont even recognise my own CD's.
My gut feeling is that it is worth it to spend a bit extra on top quality parts. It really shows.
Regards
Jozua
Gentlemen
Some time back I reported that my Mk2 amp was somewhat dissapointing following an parts and wiring update.
It now seems as if the interconnect wire was interacting with the output transistors wiring. Moving it away from the wiring of the output transistors made a immediate difference.
I have also soldered back 2 uF cap on the transformers.
I dont know if the Black Gate cap is beginning to burn in but the amp is now really beginning to sound excellent. The realism is incredible. The difference is so startling that sometimes I dont even recognise my own CD's.
My gut feeling is that it is worth it to spend a bit extra on top quality parts. It really shows.
Regards
Jozua
