Hi people!
Once I took a look on PGA2500 datasheet, it was some years ago,
I said "Hmmm....crap! Another chip pre? Nope!"
My bad taste is discrete, trafo-coupled, colored, etc. I'd cut my hand if I go to build chip-based pre!
Then, I heard evaluation board and said "Hmmmm....Too fast and clean to be truth!"
Many commercial pre's based on this chip appeared on market, like HV-3R, Prism Orpheus, etc.
Most of them are in very high priced range....
Well, there was PGA2500 thread on this forum...
I built a proto and was very surprised.
Studio people who tested this proto wery liked it as well.
This pre deserves name of an excellent clean preamp.
Use poly caps on input and good output stage, this is the cooking receipt.
And yes, it is possible to fit 8 pre's in 1RU.
Here's finnished, tested, fixed and polished final version of pcb's.
More hi-res pics, schematics, comp placement:
Audio board:
http://i251.photobucket.com/albums/gg291/diy33609/PGA2500_KITS/pga2500_audio.jpg
http://i251.photobucket.com/albums/gg291/diy33609/PGA2500_KITS/pre_pcb_top.gif
http://i251.photobucket.com/albums/gg291/diy33609/PGA2500_KITS/pre_pcb_btm.gif
http://i251.photobucket.com/albums/gg291/diy33609/PGA2500_KITS/pre_sch.gif
Controll board:
http://i251.photobucket.com/albums/gg291/diy33609/PGA2500_KITS/pga2500_contr1.jpg
http://i251.photobucket.com/albums/gg291/diy33609/PGA2500_KITS/pga2500_contr2.jpg
http://i251.photobucket.com/albums/gg291/diy33609/PGA2500_KITS/pga2500_contr3.jpg
http://i251.photobucket.com/albums/gg291/diy33609/PGA2500_KITS/contr_pcb_btm.gif
http://i251.photobucket.com/albums/gg291/diy33609/PGA2500_KITS/contr_pcb_top.gif
http://i251.photobucket.com/albums/gg291/diy33609/PGA2500_KITS/contr_schem.gif
Power supply:
(can handle up to 8 pre's):
http://i251.photobucket.com/albums/gg291/diy33609/PGA2500_KITS/pga2500_ps1.jpg
http://i251.photobucket.com/albums/gg291/diy33609/PGA2500_KITS/pga2500_ps2.jpg
http://i251.photobucket.com/albums/gg291/diy33609/PGA2500_KITS/ps_SCH.gif
http://i251.photobucket.com/albums/gg291/diy33609/PGA2500_KITS/ps_pcb.gif
Whole thing:
http://i251.photobucket.com/albums/gg291/diy33609/PGA2500_KITS/pga2500_pre_full.jpg
PCB's hi-res:
http://i251.photobucket.com/albums/gg291/diy33609/PGA2500_KITS/pga2500_pcbs.jpg
Measures:
http://i251.photobucket.com/albums/gg291/diy33609/pga2500_meas.gif
I ordered 50 pcb sets...think they will go fast.
Ordering:
http://www.groupdiy.com/index.php?topic=29771.0
BOM, support, etc, coming soon.
Once I took a look on PGA2500 datasheet, it was some years ago,
I said "Hmmm....crap! Another chip pre? Nope!"
My bad taste is discrete, trafo-coupled, colored, etc. I'd cut my hand if I go to build chip-based pre!
Then, I heard evaluation board and said "Hmmmm....Too fast and clean to be truth!"
Many commercial pre's based on this chip appeared on market, like HV-3R, Prism Orpheus, etc.
Most of them are in very high priced range....
Well, there was PGA2500 thread on this forum...
I built a proto and was very surprised.
Studio people who tested this proto wery liked it as well.
This pre deserves name of an excellent clean preamp.
Use poly caps on input and good output stage, this is the cooking receipt.
And yes, it is possible to fit 8 pre's in 1RU.
Here's finnished, tested, fixed and polished final version of pcb's.
More hi-res pics, schematics, comp placement:
Audio board:
http://i251.photobucket.com/albums/gg291/diy33609/PGA2500_KITS/pga2500_audio.jpg
http://i251.photobucket.com/albums/gg291/diy33609/PGA2500_KITS/pre_pcb_top.gif
http://i251.photobucket.com/albums/gg291/diy33609/PGA2500_KITS/pre_pcb_btm.gif
http://i251.photobucket.com/albums/gg291/diy33609/PGA2500_KITS/pre_sch.gif
Controll board:
http://i251.photobucket.com/albums/gg291/diy33609/PGA2500_KITS/pga2500_contr1.jpg
http://i251.photobucket.com/albums/gg291/diy33609/PGA2500_KITS/pga2500_contr2.jpg
http://i251.photobucket.com/albums/gg291/diy33609/PGA2500_KITS/pga2500_contr3.jpg
http://i251.photobucket.com/albums/gg291/diy33609/PGA2500_KITS/contr_pcb_btm.gif
http://i251.photobucket.com/albums/gg291/diy33609/PGA2500_KITS/contr_pcb_top.gif
http://i251.photobucket.com/albums/gg291/diy33609/PGA2500_KITS/contr_schem.gif
Power supply:
(can handle up to 8 pre's):
http://i251.photobucket.com/albums/gg291/diy33609/PGA2500_KITS/pga2500_ps1.jpg
http://i251.photobucket.com/albums/gg291/diy33609/PGA2500_KITS/pga2500_ps2.jpg
http://i251.photobucket.com/albums/gg291/diy33609/PGA2500_KITS/ps_SCH.gif
http://i251.photobucket.com/albums/gg291/diy33609/PGA2500_KITS/ps_pcb.gif
Whole thing:
http://i251.photobucket.com/albums/gg291/diy33609/PGA2500_KITS/pga2500_pre_full.jpg
PCB's hi-res:
http://i251.photobucket.com/albums/gg291/diy33609/PGA2500_KITS/pga2500_pcbs.jpg
Measures:
http://i251.photobucket.com/albums/gg291/diy33609/pga2500_meas.gif
I ordered 50 pcb sets...think they will go fast.
Ordering:
http://www.groupdiy.com/index.php?topic=29771.0
BOM, support, etc, coming soon.