Why would you want to run your preamp near its MAXimum output??
I would have a lot more gain on hand.
I would have a lot more gain on hand.
That is an excellent question.
Right now, I have too much gain in my system. I am barely out of the area where volume pot completely mistracks before I get to concert volume levels. (roughly 7:30 on the dial) This is a bit of a trouble for low volume listening.
This is due to two things: high output from my phono-stage, and preferring the sound of my EL34 PP amps with the NFB unhooked (+20db).
I think I am most likely overcompensating for my current difficulties.
Thanks for the reality check!
But I also wanted to try to design a lower amplification driver stage that could run the 300b well-- Low Z, good current capability.
Of course that may take a while. I need to learn a lot before this happens.
In the meantime I am going to build the amps in such a way that it will be relatively easy to change the driver circuit. I figure they will go through a few permutations before I settle on something.
But, yeah. A gain of 45 is probably too low.
Thanks again for your replies!
Regards,
John
Right now, I have too much gain in my system. I am barely out of the area where volume pot completely mistracks before I get to concert volume levels. (roughly 7:30 on the dial) This is a bit of a trouble for low volume listening.
This is due to two things: high output from my phono-stage, and preferring the sound of my EL34 PP amps with the NFB unhooked (+20db).
I think I am most likely overcompensating for my current difficulties.
Thanks for the reality check!
But I also wanted to try to design a lower amplification driver stage that could run the 300b well-- Low Z, good current capability.
Of course that may take a while. I need to learn a lot before this happens.
In the meantime I am going to build the amps in such a way that it will be relatively easy to change the driver circuit. I figure they will go through a few permutations before I settle on something.
But, yeah. A gain of 45 is probably too low.
Thanks again for your replies!
Regards,
John
IMD with AC filaments
Hi 6A3sUMMER,
Well, you were absolutely correct!
I had the 300b heaters wired for AC heating while I waited for a pair of Rod Coleman's Filament Regulator boards to arrive.
With AC powered heaters, the amp was a very quiet, but there was something irritating abou the sound of it-- and angular, grating je ne sais quoi, that made me not really really want to listen to music aside from checking that the amps functioned.
When I converted to DC heating with the reg boards, the amp sounded much more pleasant and have really been enjoying it.
This is just my subjective opinion, of course.
Same filament transformer, same layout, just the additional components to rectify and regulate.
Big difference! I am (pleasantly) surprised, to be honest. I really thought I might prefer AC heating.
Regards,
John
Hi 6A3sUMMER,
Well, you were absolutely correct!
I had the 300b heaters wired for AC heating while I waited for a pair of Rod Coleman's Filament Regulator boards to arrive.
With AC powered heaters, the amp was a very quiet, but there was something irritating abou the sound of it-- and angular, grating je ne sais quoi, that made me not really really want to listen to music aside from checking that the amps functioned.
When I converted to DC heating with the reg boards, the amp sounded much more pleasant and have really been enjoying it.
This is just my subjective opinion, of course.
Same filament transformer, same layout, just the additional components to rectify and regulate.
Big difference! I am (pleasantly) surprised, to be honest. I really thought I might prefer AC heating.
Regards,
John