1977 Fender Princeton Reverb Rebuild

Micky · 05-16-2012, 08:30 AM

Greetings. I hope you enjoy this thread, please feel free to leave comments or ask any questions.
Let me first preface this by saying I am not an amp builder. I can hack away at it with the best of them, but this older technology leaves a lot to be desired and I do what I can with the parts that I can obtain. I also tend to keep things on a low budget...

So a student comes into my office (I work at a public school) knowing I like guitar amps and such. He has a Hurricane Irene water-damaged 1977 Fender Princeton Reverb amplifier. Apparently his dad wants it disposed of and out of the garage. I offer to purchase it from him and he says yes.

Here are a few photos of the amp as I got it, sorry for some of the blur...

And here are a couple shots of the innards:

I knew all along that I would need to strip this baby down to refinish it properly, but there was not a lot I needed to do to the chassis other than repair what was broken and replace a few caps. Mojotone.com had a few of the parts I needed, and I already had quite a few of the resistors on hand. Here is a shot of some of the typical damage I came across. Note the two 100K resistors tied to the power lamp - Obviously broken in half and in need of replacement.

The resistors are in the center of the photo just left of the power xfmr...

Anyway, it was kinda difficult to find the exact schematic for this one, as things changed from Blackface to Silverface and then to the Princeton Reverb II model. This one is stuck in the middle of the Silverface era, kinda rare as it has the volume knob pull-boost switch. This schematic is extremely hard to find... but if you Google for the 014875 Fender/Rogers/Rhodes version you can find it. Here is a link to that particular schematic:

http://www.webphix.com/schematic%20h...boostpedal.pdf
(you will need Adobe Reader or some other .pdf file reader to view this)

When I get a bit more time I will post more photos, I have a ton of gut shots and some nice ones of the cab refinish as well as tolex...

But for now I am interested in hearing your comments and suggestions.

12barjunkie · 05-16-2012, 09:05 AM

Wow man, good luck; I'm sure you'll work some real magic on it

AlvisX · 05-16-2012, 09:50 AM

Good score
Now if it was me , I'd wire up a brown princeton preamp in there

Micky · 05-16-2012, 10:30 AM

Quote:

Originally Posted by AlvisX

Good score
Now if it was me , I'd wire up a brown princeton preamp in there

Because it is a '77 with the pull-boost, I believe the components are already there. This thing has more gain than any Fender I have ever heard. I am currently running a 12AT7 in V1 in order to get the clean headroom back.

You should hear it with the original 7025 (12AX7A) in V1! With my LP and a hot MHD pickup there is no need for a fuzz pedal. It is that hot! Talk about natural crunch!

I considered modifying it a bit, but after hearing how sweet the thing sounded I decided to leave it alone for now. But that is not to say someone ELSE can't mod it...

Micky · 05-17-2012, 10:44 AM

After I got the thing taken apart, it was readily apparent that it needed some major structural work in order to get this back into playing condition. It was never my intent to get this back to original looks and vintage appeal, I need this to be a functional, heavy-duty, gig every night if I have to type of amp. This is gonna be a heavy-duty rebuild, so there is never any need to baby this thing in order to enjoy it for a good long time.

I stripped it down, removing the tolex and whatever else I could without ruining what was left of the particle-board cabinet. The speaker was heavily rusted, I would imagine someone might want it, but I sure don't. The reverb tank had some surface rust on the outer part, but the springs and other electronics inside were flawless for a 35 year-old amp. Here are some shots of the cab:

This is the cab upside down - note the mildew and water-damaged bottom...

This is some of the screws I put in to reinforce the joints - tolex will cover these.

I needed to sand the cab quite a bit to remove the mold and mildew on the surface, water had also expanded the bottom of the cab and I needed to sand it down so the new corners would fit over the tolex. I thought about cutting a 12" hole for the new speaker, but then realized the integrity of the baffle would be compromised. And besides, on an open-back combo, no one is gonna hear the difference between a 10" hole and a 12" hole... It was actually quite easy to mount the new speaker on an existing stud and fit it in there. More about that later...

Here is the sanded cab ready for tolex:

You will have to wait for the final set of photos to see the newly tolexed cab with the black corner guards. Looks sweet. Not the best tolex job, but it is not meant to be perfect, just to be playable. And to that end it is time to get to the guts of this amp.

This one was definitely a kitchen-table project, as my test bench was filled with other crap left over from the last project. I built a 2-piece jig from 2X4's and set this up and assembled all the tools despite the evil looks from my wife. Parts were on order from MojoTone.com and Parts-Express.com, and soon I would be into the thick of things...

05-16-2012, 08:30 AM	#1 (permalink)
Micky Senior Member Join Date: Apr 2010 Location: Vermont Posts: 6,818	1977 Fender Princeton Reverb Rebuild Greetings. I hope you enjoy this thread, please feel free to leave comments or ask any questions. Let me first preface this by saying I am not an amp builder. I can hack away at it with the best of them, but this older technology leaves a lot to be desired and I do what I can with the parts that I can obtain. I also tend to keep things on a low budget... So a student comes into my office (I work at a public school) knowing I like guitar amps and such. He has a Hurricane Irene water-damaged 1977 Fender Princeton Reverb amplifier. Apparently his dad wants it disposed of and out of the garage. I offer to purchase it from him and he says yes. Here are a few photos of the amp as I got it, sorry for some of the blur... And here are a couple shots of the innards: I knew all along that I would need to strip this baby down to refinish it properly, but there was not a lot I needed to do to the chassis other than repair what was broken and replace a few caps. Mojotone.com had a few of the parts I needed, and I already had quite a few of the resistors on hand. Here is a shot of some of the typical damage I came across. Note the two 100K resistors tied to the power lamp - Obviously broken in half and in need of replacement. The resistors are in the center of the photo just left of the power xfmr... Anyway, it was kinda difficult to find the exact schematic for this one, as things changed from Blackface to Silverface and then to the Princeton Reverb II model. This one is stuck in the middle of the Silverface era, kinda rare as it has the volume knob pull-boost switch. This schematic is extremely hard to find... but if you Google for the 014875 Fender/Rogers/Rhodes version you can find it. Here is a link to that particular schematic: http://www.webphix.com/schematic%20h...boostpedal.pdf (you will need Adobe Reader or some other .pdf file reader to view this) When I get a bit more time I will post more photos, I have a ton of gut shots and some nice ones of the cab refinish as well as tolex... But for now I am interested in hearing your comments and suggestions. poeman33 likes this. __________________ I can understand stupidity, but there is no excuse for ignorance... Marshall MHZ15, DSL40c, M4, 4X12 full stack, Gibson LP, VOX, Eminence, Celestion, Ovation, Fender & more... Last edited by Micky; 05-17-2012 at 10:06 AM.

05-16-2012, 09:05 AM	#2 (permalink)
12barjunkie Senior Member Join Date: Dec 2011 Posts: 1,111	Re: 1977 Fender Princeton Reverb Rebuild Wow man, good luck; I'm sure you'll work some real magic on it Micky likes this. __________________ ____________________________________ "I play guitar because I love to play guitar"

05-16-2012, 09:50 AM	#3 (permalink)
AlvisX Senior Member Join Date: May 2011 Location: I-55 Corridor Posts: 668	Re: 1977 Fender Princeton Reverb Rebuild Good score Now if it was me , I'd wire up a brown princeton preamp in there Micky likes this. __________________ www.alvinyoungbloodhart.net https://www.facebook.com/alvin.y.hart Follow me on Twitter @MotivSpkr6L6

05-17-2012, 10:44 AM	#5 (permalink)
Micky Senior Member Join Date: Apr 2010 Location: Vermont Posts: 6,818	Re: 1977 Fender Princeton Reverb Rebuild After I got the thing taken apart, it was readily apparent that it needed some major structural work in order to get this back into playing condition. It was never my intent to get this back to original looks and vintage appeal, I need this to be a functional, heavy-duty, gig every night if I have to type of amp. This is gonna be a heavy-duty rebuild, so there is never any need to baby this thing in order to enjoy it for a good long time. I stripped it down, removing the tolex and whatever else I could without ruining what was left of the particle-board cabinet. The speaker was heavily rusted, I would imagine someone might want it, but I sure don't. The reverb tank had some surface rust on the outer part, but the springs and other electronics inside were flawless for a 35 year-old amp. Here are some shots of the cab: This is the cab upside down - note the mildew and water-damaged bottom... This is some of the screws I put in to reinforce the joints - tolex will cover these. I needed to sand the cab quite a bit to remove the mold and mildew on the surface, water had also expanded the bottom of the cab and I needed to sand it down so the new corners would fit over the tolex. I thought about cutting a 12" hole for the new speaker, but then realized the integrity of the baffle would be compromised. And besides, on an open-back combo, no one is gonna hear the difference between a 10" hole and a 12" hole... It was actually quite easy to mount the new speaker on an existing stud and fit it in there. More about that later... Here is the sanded cab ready for tolex: You will have to wait for the final set of photos to see the newly tolexed cab with the black corner guards. Looks sweet. Not the best tolex job, but it is not meant to be perfect, just to be playable. And to that end it is time to get to the guts of this amp. This one was definitely a kitchen-table project, as my test bench was filled with other crap left over from the last project. I built a 2-piece jig from 2X4's and set this up and assembled all the tools despite the evil looks from my wife. Parts were on order from MojoTone.com and Parts-Express.com, and soon I would be into the thick of things... __________________ I can understand stupidity, but there is no excuse for ignorance... Marshall MHZ15, DSL40c, M4, 4X12 full stack, Gibson LP, VOX, Eminence, Celestion, Ovation, Fender & more...

Thread Tools
Show Printable Version Email this Page
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode

Today
Marshall Amps	Sponsored Links __________________ This advertising will not be shown in this way to registered members. Register your free account today and become a member on Marshall Amp Forum