cayocosta
Well-known member
Check this out.
It's a sweep of my la2a. The top is without gain reduction, and below are various levels of GR.
Interestingly, I had to open C4 all the way up 380pf to get the response flat without GR. Otherwise, the highs trailed off by about 15k! With and without compression - not good I would think.
With GR there's obviously some dips. 1 to 2 dB.
I traced the GR voltages of everything all the way back to but excluding the 12ax7 in the sidechain circuit and could not find the origin of the dips. So, I suspect it might be worked out somewhere around the 12ax7 setup.
Winston has said that UA sets C4 all the way up by the way.
Kent, you mentioned having scoped your la2a, can you elaborate on what you learned?
The sweep software is pretty cool, and there's a free version that just times out after several runs - but it's still worth getting. I found it through someone's post here - thanks.
It's here:
http://www.sumuller.de/audiotester/
It's a sweep of my la2a. The top is without gain reduction, and below are various levels of GR.
Interestingly, I had to open C4 all the way up 380pf to get the response flat without GR. Otherwise, the highs trailed off by about 15k! With and without compression - not good I would think.
With GR there's obviously some dips. 1 to 2 dB.
I traced the GR voltages of everything all the way back to but excluding the 12ax7 in the sidechain circuit and could not find the origin of the dips. So, I suspect it might be worked out somewhere around the 12ax7 setup.
Winston has said that UA sets C4 all the way up by the way.
Kent, you mentioned having scoped your la2a, can you elaborate on what you learned?
The sweep software is pretty cool, and there's a free version that just times out after several runs - but it's still worth getting. I found it through someone's post here - thanks.
It's here:
http://www.sumuller.de/audiotester/