Got myself a blackface Princeton

Make it loud here.
User avatar
i love sharin foo
Mods
Mods
Posts: 5124
Joined: Tue Sep 12, 2006 8:26 am
Location: Pittsburgh, PA
Contact:

Re: Got myself a blackface Princeton

Post by i love sharin foo » Tue May 21, 2019 4:32 pm

Shadoweclipse13 wrote:
Tue May 21, 2019 2:39 pm
Man, all of these Princetons are gorgeous. I've been avoiding buying a vintage amp because of all the maintenance they might need, but this thread might just destroy that notion...
Other than a recap (which is really easy with an old school Fender), there isn't much else to worry about. Plus, if something goes wrong, it is MUCH easier to trouble shoot than the abyss that is a PCB amp!

nanamour wrote:
Tue May 21, 2019 3:13 pm
Agh, I thought I'd put my apartment-sized amp GAS to bed with the '64 Vox AC4 I just scooped up, but this is reminding me of the 6G2-shaped hole in my life. Congrats on a beautiful pair of amps!
A '64 AC4?! That is a great piece right there! I have a AC4HW and it's great. It adds a distinct tone to the low watt arsenal. It is at least as loud as the Princetons though.
"There are twists of time and space, of vision and reality, which only a dreamer can divine..."

User avatar
Shadoweclipse13
PAT. # 2.972.923
PAT. # 2.972.923
Posts: 7915
Joined: Fri Feb 07, 2014 9:22 pm
Location: Stuck in the dimension of imagination

Re: Got myself a blackface Princeton

Post by Shadoweclipse13 » Tue May 21, 2019 5:42 pm

i love sharin foo wrote:
Tue May 21, 2019 4:32 pm
Shadoweclipse13 wrote:
Tue May 21, 2019 2:39 pm
Man, all of these Princetons are gorgeous. I've been avoiding buying a vintage amp because of all the maintenance they might need, but this thread might just destroy that notion...
Other than a recap (which is really easy with an old school Fender), there isn't much else to worry about. Plus, if something goes wrong, it is MUCH easier to trouble shoot than the abyss that is a PCB amp!
I just dropped money for a new synth, I don't need the temptation! :wacko:

But that doesn't sound that bad. I've been toying with the idea of building my own for a little bit. I can already solder like a mofo :ph34r:
Pickup Switching Mad Scientist
http://www.offsetguitars.com/forums/viewtopic.php?f=8&t=104282&p=1438384#p1438384

User avatar
wproffitt
PAT. # 2.972.923
PAT. # 2.972.923
Posts: 966
Joined: Wed Feb 24, 2010 8:48 pm
Location: Ellicott City, MD, USA

Re: Got myself a blackface Princeton

Post by wproffitt » Wed May 22, 2019 9:10 am

Shadoweclipse13 wrote:
Tue May 21, 2019 5:42 pm
i love sharin foo wrote:
Tue May 21, 2019 4:32 pm
Shadoweclipse13 wrote:
Tue May 21, 2019 2:39 pm
Man, all of these Princetons are gorgeous. I've been avoiding buying a vintage amp because of all the maintenance they might need, but this thread might just destroy that notion...
Other than a recap (which is really easy with an old school Fender), there isn't much else to worry about. Plus, if something goes wrong, it is MUCH easier to trouble shoot than the abyss that is a PCB amp!
I just dropped money for a new synth, I don't need the temptation! :wacko:

But that doesn't sound that bad. I've been toying with the idea of building my own for a little bit. I can already solder like a mofo :ph34r:
DO IT!

User avatar
i love sharin foo
Mods
Mods
Posts: 5124
Joined: Tue Sep 12, 2006 8:26 am
Location: Pittsburgh, PA
Contact:

Re: Got myself a blackface Princeton

Post by i love sharin foo » Wed May 22, 2019 5:05 pm

wproffitt wrote:
Wed May 22, 2019 9:10 am

DO IT!
Lucky we aren't running a self help group here, hehe :D
"There are twists of time and space, of vision and reality, which only a dreamer can divine..."

User avatar
i love sharin foo
Mods
Mods
Posts: 5124
Joined: Tue Sep 12, 2006 8:26 am
Location: Pittsburgh, PA
Contact:

Re: Got myself a blackface Princeton

Post by i love sharin foo » Wed May 22, 2019 5:17 pm

My Jensen P10R was delivered today. It's 8 ohm, 25 watt, and was reconed. I already have it swapped into the AA964 Princeton. It is much more like what I wanted compared to the Weber 10F150T that was in there. If the Weber wasn't a 50w speaker, I think it would've been a lot better fit for the amp, however. The P10R will overdrive a bit and is cumulative with the power tube break up in a good way. Honestly, with the combination of that speaker and the and the amp itself, it doesn't seem like a super clean "mini Twin" anymore. It isn't as HiFi as the Weber was. The bass response is actually prettyy good. BUT, I have a rattle that I believe I have traced to the baffle itself which precludes the bass knob from rolling much above 4. I am not sure what to do about that. I at first thought it was something inside the chassis but I've since been through it and everything looked good. It did the same thing with the Weber also, so I don't believe it is the speaker itself. I am almost considering making a new baffle out of plywood and reusing the original grille cloth. It isn't a HUGE issue, but it is somewhat annoying. It really only comes about if I am droning notes against the low E or hitting chords really hard. I'll probably just say fuck it and leave it as it is. Also, since this particular P10R was freshly reconed, I expect it to open up more after some use. It is a little stiff right now. But initial impressions are good :)
"There are twists of time and space, of vision and reality, which only a dreamer can divine..."

User avatar
StevenO
PAT. # 2.972.923
PAT. # 2.972.923
Posts: 17404
Joined: Wed Oct 18, 2006 7:06 pm

Re: Got myself a blackface Princeton

Post by StevenO » Wed May 22, 2019 5:43 pm

Thats's awesome! :)

Definitely a better fit for that amp. Now, with that said, I absolutely LOVE the 50 watt 10F150T in my Princeton Reverb. It made the amp a gigging amp, which is exactly what I need as someone who plays primarily in their living room. Sits nicely next to my Weber-loaded Silverface Vibrolux Reverb. ;)

But for real, I'd love to get a Blackface or Silverface Princeton and put a nice low powered speaker in there. It would just be so, so good.

I'm really glad you're enjoying the Princetons, both of them. I was kind of worried they'd be too much of a departure from your big amps!

User avatar
Shadoweclipse13
PAT. # 2.972.923
PAT. # 2.972.923
Posts: 7915
Joined: Fri Feb 07, 2014 9:22 pm
Location: Stuck in the dimension of imagination

Re: Got myself a blackface Princeton

Post by Shadoweclipse13 » Wed May 22, 2019 8:14 pm

wproffitt wrote:
Wed May 22, 2019 9:10 am
Shadoweclipse13 wrote:
Tue May 21, 2019 5:42 pm
But that doesn't sound that bad. I've been toying with the idea of building my own for a little bit. I can already solder like a mofo :ph34r:
DO IT!
Funny enough, I just ordered a reprinted copy of the old RCA RC-30 Tube Receiving Manual this morning :ph34r: :ph34r:

i love sharin foo wrote:
Wed May 22, 2019 5:05 pm
wproffitt wrote:
Wed May 22, 2019 9:10 am
DO IT!
Lucky we aren't running a self help group here, hehe :D
:D :D :D

Glad your new speaker is working Justin! That low frequency rattle is interesting. I wonder if it's because it was just reconed...
Pickup Switching Mad Scientist
http://www.offsetguitars.com/forums/viewtopic.php?f=8&t=104282&p=1438384#p1438384

User avatar
wproffitt
PAT. # 2.972.923
PAT. # 2.972.923
Posts: 966
Joined: Wed Feb 24, 2010 8:48 pm
Location: Ellicott City, MD, USA

Re: Got myself a blackface Princeton

Post by wproffitt » Thu May 23, 2019 3:17 am

Sorry for the derail. How is the baffle secured to the cabinet in these? It’s built in in my SFPR, but I would imagine it’s secured with screws in a BF. If so, I suppose there’s nothing superb obvious happening, like a loose screw, right?

User avatar
i love sharin foo
Mods
Mods
Posts: 5124
Joined: Tue Sep 12, 2006 8:26 am
Location: Pittsburgh, PA
Contact:

Re: Got myself a blackface Princeton

Post by i love sharin foo » Thu May 23, 2019 4:20 am

wproffitt wrote:
Thu May 23, 2019 3:17 am
Sorry for the derail. How is the baffle secured to the cabinet in these? It’s built in in my SFPR, but I would imagine it’s secured with screws in a BF. If so, I suppose there’s nothing superb obvious happening, like a loose screw, right?
Yeah, these ones have four screws. I’ve had the baffle out a couple times now. It’s in there nice and tight. I’ve been through the chassis now also, nothing there that I can find. Every other screw has been checked.. tube sockets, transformer bolts, handle screws, etc. It resonated at the same frequency with both speakers, too, leading me to believe that it is not speaker related. With my ear right next to the grill cloth (not super fun with the volume dimed :derp: ), it sounds like it is coming from the baffle somewhere between the outside edge of it and the speaker. The other possibility is the speaker fasteners themselves. Someone cut the factory bolts off. It now has regular screws. There’s a possibility that it just isn’t possible to get the speaker tight enough with those. The only repair would be to pull the grill cloth and install new ones from the front.
"There are twists of time and space, of vision and reality, which only a dreamer can divine..."

User avatar
kosmonautmayhem
PAT. # 2.972.923
PAT. # 2.972.923
Posts: 5763
Joined: Sun Mar 14, 2010 8:26 am
Location: Chicago

Re: Got myself a blackface Princeton

Post by kosmonautmayhem » Thu May 23, 2019 7:11 am

Check your solder joints.

I had this happen to me on my PR. I thought for sure it was a speaker or tube or tube socket or something mechanical since it was always due to vibration. Took me a month or more to sort out and ended up being a loose solder joint that would jump whenever the amp made certain frequencies.

:ph34r:

User avatar
i love sharin foo
Mods
Mods
Posts: 5124
Joined: Tue Sep 12, 2006 8:26 am
Location: Pittsburgh, PA
Contact:

Re: Got myself a blackface Princeton

Post by i love sharin foo » Thu May 23, 2019 9:26 am

kosmonautmayhem wrote:
Thu May 23, 2019 7:11 am
Check your solder joints.

I had this happen to me on my PR. I thought for sure it was a speaker or tube or tube socket or something mechanical since it was always due to vibration. Took me a month or more to sort out and ended up being a loose solder joint that would jump whenever the amp made certain frequencies.

:ph34r:
I think I’ll have a second look at it!

I’m in the middle of recapping the 6G2 right now. I didn’t check to see what the tubes are biased at right now, but it had a 15k resistor in the bias circuit...
"There are twists of time and space, of vision and reality, which only a dreamer can divine..."

User avatar
kosmonautmayhem
PAT. # 2.972.923
PAT. # 2.972.923
Posts: 5763
Joined: Sun Mar 14, 2010 8:26 am
Location: Chicago

Re: Got myself a blackface Princeton

Post by kosmonautmayhem » Thu May 23, 2019 9:41 am

Oooh ! You're in it. Take some pics!

User avatar
wproffitt
PAT. # 2.972.923
PAT. # 2.972.923
Posts: 966
Joined: Wed Feb 24, 2010 8:48 pm
Location: Ellicott City, MD, USA

Re: Got myself a blackface Princeton

Post by wproffitt » Thu May 23, 2019 10:05 am

kosmonautmayhem wrote:
Thu May 23, 2019 9:41 am
Oooh ! You're in it. Take some pics!
Please do.

User avatar
i love sharin foo
Mods
Mods
Posts: 5124
Joined: Tue Sep 12, 2006 8:26 am
Location: Pittsburgh, PA
Contact:

Re: Got myself a blackface Princeton

Post by i love sharin foo » Thu May 23, 2019 12:32 pm

kosmonautmayhem wrote:
Thu May 23, 2019 9:41 am
Oooh ! You're in it. Take some pics!
The lighting in my dining room sucks, but I took a few along the way. I discovered one thing which I have no explanation for... the 56k just before the speaker jack.. I measured it at 1.5k-1.6k double checking it with a second meter. I replaced it with a fresh one, fitted it up, everything sounds right, but I was back in there to adjust the bias again, so I rechecked the NEW one... 1.5k... I rechecked the old one now that it is out of the amp... 58k... I am sure there is some explanation but I just don't get it.

At any rate, I used a 24k in the bias circuit to get it back up and running. It sounded great but I had a tremolo issue (there's the tip off, right??) where I had this weird almost overtone like thing going on a little lower in volume than the actual signal. So I checked the bias, and these tubes are WAY mismatched! One was idling at about 19ma, the other about 11. I tried an 18k (which measured 18.5k) in there and it was much better but still a little off as evidenced by the term being a little weak at the top of the dial. At this point I'm reading about 22.4 on tube and 31(!) on the other. Not wanting to waste too much more time with these shitty tubes (because I already have a nice NOS pair of Raytheons on the way), I laid a 1k in series with the 18.5k and now the trem is better still and I'm idling at 20.1 and 28.6. These numbers were actually even worse with the sockets swapped. As soon as the new Raytheons get here, I'll be in business!

The amp is really quiet now, even up full. It is WAY more dynamic and touch sensitive. It was a bit stiff and flat before. It now has a better range of overdrive from none until about 5, then you gradually get more until the mini Marshall tones kick in about 9-10. I liked the way it sounded before. I :-* it now!

It was a bunch of work cleaning all the shitty ass work up. It had one 150uF cap SILICONED to the chassis instead of the 3 way can :fp:

Image
Image
Image
Image
Image
Image
Image

And the AFTER!
Removed the death cap, kept the ground switch for aesthetics, and the grounded cord I went with is GRAY! I ground down and reused the old strain relief so that I didn't have to enlarge the hole in the chassis.
Image

The whole thing. Right back to stock. I noticed afterward that there is an extra ground on the topside of the board that his since been removed.
Image

AT this point I don't think it's too apparent that anything was ever done, except for the new cloth wire on 2 of the legs of the cap can.
Image

Couple markings inside the cabinet:
Image
Image
Image
"There are twists of time and space, of vision and reality, which only a dreamer can divine..."

User avatar
kosmonautmayhem
PAT. # 2.972.923
PAT. # 2.972.923
Posts: 5763
Joined: Sun Mar 14, 2010 8:26 am
Location: Chicago

Re: Got myself a blackface Princeton

Post by kosmonautmayhem » Thu May 23, 2019 4:20 pm

Oh that looks (and probably sounds) so much better now!

With a more matched set of tunes you'll be in business. You should totally consider a bias pot replacing the ground switch. What are you checking bias with?

Post Reply