68 custom Princeton Reverb

Fender Amp Discussion

Moderators: pompeiisneaks, Colossal

User avatar
M Fowler
Posts: 14017
Joined: Wed Jan 16, 2008 2:19 am
Location: Walcott ND

68 custom Princeton Reverb

Post by M Fowler »

The new silverface version Fender has out now is called the 68 Custom PR and it has different tone stack and NFB compared to a 65 PR.

I started my own build a while ago but had to finish up some other projects first.
You do not have the required permissions to view the files attached to this post.
Last edited by M Fowler on Wed Dec 21, 2016 6:13 am, edited 1 time in total.
User avatar
M Fowler
Posts: 14017
Joined: Wed Jan 16, 2008 2:19 am
Location: Walcott ND

Re: 68 custom Princeton Reverb

Post by M Fowler »

The schematic.
You do not have the required permissions to view the files attached to this post.
joeboo88
Posts: 400
Joined: Thu Mar 28, 2013 8:51 pm
Location: Way up North

Re: 68 custom Princeton Reverb

Post by joeboo88 »

Nice stuff Mark. I was still ogling over your other build you just posted and now this

your turning into a Fender making machine!

your builds are so nice
User avatar
rp
Posts: 2528
Joined: Sun Apr 25, 2010 4:21 am
Location: Italy

Re: 68 custom Princeton Reverb

Post by rp »

Nice! Needs drip edge :)

What the heck is it about modern schematics that makes my head hurt? You'd think all the gee-wiz computer magic would make for an even clearer schematic than a 1950 hand drawn! Thanks nonetheless, and never knew about the tone stack.
User avatar
M Fowler
Posts: 14017
Joined: Wed Jan 16, 2008 2:19 am
Location: Walcott ND

Re: 68 custom Princeton Reverb

Post by M Fowler »

Thanks guys, yes that drip edge would be cool.

The new schematic sucks but the NFB and tone stack are the only changes I saw.
User avatar
M Fowler
Posts: 14017
Joined: Wed Jan 16, 2008 2:19 am
Location: Walcott ND

Re: 68 custom Princeton Reverb

Post by M Fowler »

Did some more wiring today.

I need to remember to recheck that NFB resistor I may have put stock value in by mistake?
You do not have the required permissions to view the files attached to this post.
User avatar
M Fowler
Posts: 14017
Joined: Wed Jan 16, 2008 2:19 am
Location: Walcott ND

Re: 68 custom Princeton Reverb

Post by M Fowler »

joeboo88 wrote:your turning into a Fender making machine!
This is the 4th Princeton Reverb build this year.
User avatar
JazzGuitarGimp
Posts: 2355
Joined: Mon Jul 23, 2012 4:54 pm
Location: Northern CA

Re: 68 custom Princeton Reverb

Post by JazzGuitarGimp »

M Fowler wrote:
joeboo88 wrote:your turning into a Fender making machine!
This is the 4th Princeton Reverb build this year.
You've got 10 more days..... I'l bet you could pop out a few more... :lol:
Lou Rossi Designs
Printed Circuit Design & Layout,
and Schematic Capture
joeboo88
Posts: 400
Joined: Thu Mar 28, 2013 8:51 pm
Location: Way up North

Re: 68 custom Princeton Reverb

Post by joeboo88 »

JazzGuitarGimp wrote:
M Fowler wrote:
joeboo88 wrote:your turning into a Fender making machine!
This is the 4th Princeton Reverb build this year.
You've got 10 more days..... I'l bet you could pop out a few more... :lol:
LOL!
User avatar
stelligan
Posts: 1444
Joined: Sat Sep 30, 2006 3:58 pm
Location: Nashvull

Re: 68 custom Princeton Reverb

Post by stelligan »

Princeton! Looks great - perfect size amp for the current gigging dude..
User avatar
M Fowler
Posts: 14017
Joined: Wed Jan 16, 2008 2:19 am
Location: Walcott ND

Re: 68 custom Princeton Reverb

Post by M Fowler »

I had used a PR OT of my shelf which I suspected was bad and yes it is now confirmed bad.

Waited for replacement to come in and I replaced it today.

The bias was -27vdc so decreased value of dropping resistor from 100k to 47k then 56k then 68k and now it's at -37vdc and should be -40vdc per schematic with 23mvdc per tube.

I will take voltages tomorrow. The amp sounds mushy at higher volume needing to reduce bass down to 3 and increase treble to 5-6 range.

Will try the Celestion Ten 30 speaker the 68 custom normally uses next time I test.
tubeswell
Posts: 2337
Joined: Thu Mar 27, 2008 6:42 am
Location: Wellington. NZ

Re: 68 custom Princeton Reverb

Post by tubeswell »

I prefer the guts of your version to the stock factory version of the RI.
He who dies with the most tubes... wins
User avatar
M Fowler
Posts: 14017
Joined: Wed Jan 16, 2008 2:19 am
Location: Walcott ND

Re: 68 custom Princeton Reverb

Post by M Fowler »

tubeswell wrote: Wed Mar 29, 2017 9:09 am I prefer the guts of your version to the stock factory version of the RI.
Thanks Pete, just think about all the RI amps we will be able to scoop up for little cash in the near future to rebuild into high quality amps.
tubeswell
Posts: 2337
Joined: Thu Mar 27, 2008 6:42 am
Location: Wellington. NZ

Re: 68 custom Princeton Reverb

Post by tubeswell »

Looks like someone is already onto that

http://www.ebay.com/itm/Fender-68-Princ ... SwnDZULr4x
He who dies with the most tubes... wins
User avatar
M Fowler
Posts: 14017
Joined: Wed Jan 16, 2008 2:19 am
Location: Walcott ND

Re: 68 custom Princeton Reverb

Post by M Fowler »

Way too much Bass, have to turn bass knob down to 3 and treble knob to 8 to get a country picking tone.

I have it wired correctly as to 68 custom specs but I'm going to lower the 18k value after the bass pot and see what that does, before I wire it to a stock PR.
Post Reply