Hi guys,
I was wondering if any might have a schematic for an old Fosgate PR250 amplifier (70s vintage)? I recently picked up a couple of them, as I recall they sounded great and had a novel amplifier circuit. They did break a lot though. I'll probably replace the amp portion with a chip-amp.
thanks,
Leo Smith
I was wondering if any might have a schematic for an old Fosgate PR250 amplifier (70s vintage)? I recently picked up a couple of them, as I recall they sounded great and had a novel amplifier circuit. They did break a lot though. I'll probably replace the amp portion with a chip-amp.
thanks,
Leo Smith
Leo_Smith wrote:
If you follow car audio folklore, Jim Fosgate's amp led to Fosgate, Orion and PPI. Together, they were a serious piece of the car audio pie in th e80's and 90's...
Here's the schematic in two parts. It was too big for my scanner to scan in one piece, therefore two posts.
If you follow car audio folklore, Jim Fosgate's amp led to Fosgate, Orion and PPI. Together, they were a serious piece of the car audio pie in th e80's and 90's...
Here's the schematic in two parts. It was too big for my scanner to scan in one piece, therefore two posts.
Attachments
and part two...
I can email files of better resolution if needed. After all, these were hand drawn before the computer age.
Tim
I can email files of better resolution if needed. After all, these were hand drawn before the computer age.
Tim
Thank you Tim,
I would love it if you could email them to me also.
I was working in the car stereo business as a shop manager/installer/technician when these amps came out. The two amps that I'm getting from a friend have been bouncing around for 25 years or more (probably longer). I used to have the hand drawn schematic that you scanned, but, it's vanished over time. I remember sitting in a fancy stereo display called a sound shuttle for hours, listening to lots of stereo gear. The PR250 sounded great, but the ones we sold all came back, time after time. I grew tired of removing and repairing them from my own cars, so they were sold to a friend in a time of need. I think I replaced them with a Linear Power setup... powerful, but none of that sweet sound. My plans now are to yank out the amp portion and replace it with a gainclone (LM3875), hopefully as sweet sounding, with none of the problems
Panasonic actually made a copy of this amp, I owned one of those also, but it just didn't sound anywhere near as good, go figure. It didn't blow up though.
In case you haven't guessed, I've been into car stereos for some time (I'm in my 50s) and I still love a good system in my car.
thanks again,
Leo Smith
I would love it if you could email them to me also.
I was working in the car stereo business as a shop manager/installer/technician when these amps came out. The two amps that I'm getting from a friend have been bouncing around for 25 years or more (probably longer). I used to have the hand drawn schematic that you scanned, but, it's vanished over time. I remember sitting in a fancy stereo display called a sound shuttle for hours, listening to lots of stereo gear. The PR250 sounded great, but the ones we sold all came back, time after time. I grew tired of removing and repairing them from my own cars, so they were sold to a friend in a time of need. I think I replaced them with a Linear Power setup... powerful, but none of that sweet sound. My plans now are to yank out the amp portion and replace it with a gainclone (LM3875), hopefully as sweet sounding, with none of the problems
Panasonic actually made a copy of this amp, I owned one of those also, but it just didn't sound anywhere near as good, go figure. It didn't blow up though.
In case you haven't guessed, I've been into car stereos for some time (I'm in my 50s) and I still love a good system in my car.
thanks again,
Leo Smith
Leo, you've got a few years on me! I started into car audio around '79-80 at about 13 years old. My first install was an underdash Clarion EQ/Booster in a Toyota.
Fosgate PR-250, PR 235, PR 2100
Greetings all:
While browsing for information on these old amps I stumbled upon this site. I am in the process of restoring 3 old PR-250s (model 1) and would appreciate any information about them.
Were there ever any service manuals or bulletins? The schematics posted here (years ago) provided some help, but the resolution is too fuzzy for me to read. Would it be possible to have them emailed to me?
Great site, glad I found it. BTW, does anyone know anything about the amps Fosgate made BEFORE the PR-series? I believe they were called 'Powerpunchers' or something like that.. Haven't seen any in years.
Also, if anyone has old Fosgates lying about that they don't want... contact me and maybe we can strike a deal. I'm especially interested in the PR-235 and of course the PR 2100. Dead or alive, I'm interested. Also any old packaging or advertising material (I've been looking for the classic 'panty' ad for years!)
About the only thing I don't need are PR 250 preamps.. I have lots of those. Everything else though, bring it on.
Thanks!
fosman
Greetings all:
While browsing for information on these old amps I stumbled upon this site. I am in the process of restoring 3 old PR-250s (model 1) and would appreciate any information about them.
Were there ever any service manuals or bulletins? The schematics posted here (years ago) provided some help, but the resolution is too fuzzy for me to read. Would it be possible to have them emailed to me?
Great site, glad I found it. BTW, does anyone know anything about the amps Fosgate made BEFORE the PR-series? I believe they were called 'Powerpunchers' or something like that.. Haven't seen any in years.
Also, if anyone has old Fosgates lying about that they don't want... contact me and maybe we can strike a deal. I'm especially interested in the PR-235 and of course the PR 2100. Dead or alive, I'm interested. Also any old packaging or advertising material (I've been looking for the classic 'panty' ad for years!)
About the only thing I don't need are PR 250 preamps.. I have lots of those. Everything else though, bring it on.
Thanks!
fosman
need schimatic help-
hello, i'm new to this cite. i found it on the net looking for schimatics for a fosgate pr250 revision B, and i can see from the somewhat blurred 2 part schimatics that there are parts of different types on my amp. can anyone help me with finding either a clearer schimatic, or better yet a schimatic for the revision "B" version??? 😕
hello, i'm new to this cite. i found it on the net looking for schimatics for a fosgate pr250 revision B, and i can see from the somewhat blurred 2 part schimatics that there are parts of different types on my amp. can anyone help me with finding either a clearer schimatic, or better yet a schimatic for the revision "B" version??? 😕
Thanks for the photo, it is a big help. Even though my board is a revision "B", it is still the same set-up, only some of the parts are different. Do you happen to know the values of the output & power supply semi-conductors ( MJE2023, MJE2024 )? You know, voltage, amperage, hfe? I've looked on several parts listing cites, and no luck.. Since i can't find original replacements, i'll need to find substitutes that will work atleast as good as the original components.
I remembered this post from a few months ago, and finally found the schematic. This one is for the PR-250 TYPE 2 . I know it is a few months late, but hope it helps. I have the 3 models --- Type 1, Type 2, Rockford version, and one prototype (single channel model) of the PR-250's . If you need me to take a pic of a certain board, let me know.
http://i250.photobucket.com/albums/gg278/tomtomjr/P1012444.jpg
http://i250.photobucket.com/albums/gg278/tomtomjr/P1012445.jpg
http://i250.photobucket.com/albums/gg278/tomtomjr/CAR AUDIO/1017071540b.jpg
http://i250.photobucket.com/albums/gg278/tomtomjr/CAR AUDIO/0823070213.jpg
http://i250.photobucket.com/albums/gg278/tomtomjr/CAR AUDIO/1017071540.jpg
http://i250.photobucket.com/albums/gg278/tomtomjr/P1012444.jpg
http://i250.photobucket.com/albums/gg278/tomtomjr/P1012445.jpg
http://i250.photobucket.com/albums/gg278/tomtomjr/CAR AUDIO/1017071540b.jpg
http://i250.photobucket.com/albums/gg278/tomtomjr/CAR AUDIO/0823070213.jpg
http://i250.photobucket.com/albums/gg278/tomtomjr/CAR AUDIO/1017071540.jpg
For what its worth I just acquired all of Jim's old parts and I have over100 of those transistors and I was trying to figure out the numbers, which led me to this page.
I know these are old post's but the transistors were a Motorola one is marked E2023 which is a PNP and the other is marked JE2023 which is a NPN
I can post a pic if anyone is interested.
I know these are old post's but the transistors were a Motorola one is marked E2023 which is a PNP and the other is marked JE2023 which is a NPN
I can post a pic if anyone is interested.
I'm probably a few years too late....I bought my pr-2100 new only a few months before the type 2's hit the store which was a bummer cause my type 1 lasted for about 15 seconds before releasing a smoke cloud then protection ..after months of failed attempts to get it repaired I decided to learn to fix it myself..well I did..forty years later its still awesome.... nothing in it's class even comes close to it...it gets unstable about every five years and I have to replace a few transistors and burnt resistors...some mods are done to stabilize it . those three schematic versions of the pr-250 would answer years of unanswered questions and allow to make some update mods.. it's time to overhaul it again...any help would be totally appreciated ... thanks to Jim fosgate I became a repair tech..started my shop in 92..still going... thanks everyone this is my first post ever...