Category 5
Well-known member
Please forgive me for jumping right in. I am new here and a bit of a novice in this realm. I am glad to have found all of you to learn from! Hopefully this time next year I'll be helping other noobs get started.
In the mean time, I have decided to build a pair of Seventh Circle A12 mic pres. The kits look very simple based on my intermediate soldering and electronics skills, and I think they'll make a great first project.
I have experimented with my P r e s o n u s MP20 by replacing the input trannys with the Jensen parts (originals were generic) and also replacing the 5534 chips (Phillips type which I understand are the best) with Burr Browns and Ad797s. I found the Jensen/AD797 combo to be the best sounding and have left it at that.
Now I am doing the A12 and want to substitite a real 2520/990 type op-amp for the included chip based dughterboard.
My first choice would be a real 2520. I could buy some A-P-I line cards from a local electronics guy and sacrifice them for the op-amps (and save the trannys for a future project).
How would you describe the difference in sound between the various generations of 2520?
My other choices would be Millennia's M99, The Forssell 992, the John Hardy 990, the Avedis (Brent Averill), or even the OSA (are these available?).
What kind of differences in sound can I expect? I know your opinions are subjective and will be very general, but as of right now I have NOTHING to go on.
My only 2 preamps currently are the modified P r e s o n u s MP20 (which is actually quite nice) and a new G-r-e-a-t River MP-2NV. I am just looking for new flavors, and thought it was a great opportunity to get my feet wet with a real full kit.
I believe the kit uses a Cinemag CMMI-8-PCA input tranny and a Profile output tranny that are said to sound very close to the original API parts. Since the power to the op-amp is variable from +/- 15v to +/- 35v I can use any of the above op-amps without problems. What should i try?
Thanks! I hope to eventually become a contributor to your community. Until then, please offer any help you can and thanks in advance!
Shane
In the mean time, I have decided to build a pair of Seventh Circle A12 mic pres. The kits look very simple based on my intermediate soldering and electronics skills, and I think they'll make a great first project.
I have experimented with my P r e s o n u s MP20 by replacing the input trannys with the Jensen parts (originals were generic) and also replacing the 5534 chips (Phillips type which I understand are the best) with Burr Browns and Ad797s. I found the Jensen/AD797 combo to be the best sounding and have left it at that.
Now I am doing the A12 and want to substitite a real 2520/990 type op-amp for the included chip based dughterboard.
My first choice would be a real 2520. I could buy some A-P-I line cards from a local electronics guy and sacrifice them for the op-amps (and save the trannys for a future project).
How would you describe the difference in sound between the various generations of 2520?
My other choices would be Millennia's M99, The Forssell 992, the John Hardy 990, the Avedis (Brent Averill), or even the OSA (are these available?).
What kind of differences in sound can I expect? I know your opinions are subjective and will be very general, but as of right now I have NOTHING to go on.
My only 2 preamps currently are the modified P r e s o n u s MP20 (which is actually quite nice) and a new G-r-e-a-t River MP-2NV. I am just looking for new flavors, and thought it was a great opportunity to get my feet wet with a real full kit.
I believe the kit uses a Cinemag CMMI-8-PCA input tranny and a Profile output tranny that are said to sound very close to the original API parts. Since the power to the op-amp is variable from +/- 15v to +/- 35v I can use any of the above op-amps without problems. What should i try?
Thanks! I hope to eventually become a contributor to your community. Until then, please offer any help you can and thanks in advance!
Shane