Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: p2pAmps on August 04, 2015, 07:43:33 am

Title: My Hoffman Princeton Reverb Build
Post by: p2pAmps on August 04, 2015, 07:43:33 am
I thought i would share my Princeton Reverb build that I am working on.  I still have a ways to go as I am waiting on a few more parts to arrive.  I am pretty excited to hear this bad-boy and A/B it next to my friends 65 PR.

(http://static1.squarespace.com/static/56fbe87462cd94ff6ec9d02c/56fd593740261d3687228f54/56fd59cfb09f9560c73c2455/1459444176974/1.JPG?format=1000w)
(http://static1.squarespace.com/static/56fbe87462cd94ff6ec9d02c/56fd593740261d3687228f54/56fd59cf2b8dde5d7d1480cb/1459444176956/2.JPG?format=1000w)
(http://static1.squarespace.com/static/56fbe87462cd94ff6ec9d02c/56fd593740261d3687228f54/56fd59d0b09f9560c73c2458/1459444179717/3.JPG?format=1000w)
(http://static1.squarespace.com/static/56fbe87462cd94ff6ec9d02c/56fd593740261d3687228f54/56fd59d02b8dde5d7d1480cd/1459444177397/4.jpg?format=1000w)
(http://static1.squarespace.com/static/56fbe87462cd94ff6ec9d02c/56fd593740261d3687228f54/56fd59d02b8dde5d7d1480d0/1459444179466/5.JPG?format=1000w)
(http://static1.squarespace.com/static/56fbe87462cd94ff6ec9d02c/56fd593740261d3687228f54/56fd59d0b09f9560c73c245b/1459444177594/6.JPG?format=1000w)
(http://static1.squarespace.com/static/56fbe87462cd94ff6ec9d02c/56fd593740261d3687228f54/56fd59d02b8dde5d7d1480d3/1459444179525/7.JPG?format=1000w)
(http://static1.squarespace.com/static/56fbe87462cd94ff6ec9d02c/56fd593740261d3687228f54/56fd59d0b09f9560c73c245d/1459444178037/8.JPG?format=1000w)
(http://static1.squarespace.com/static/56fbe87462cd94ff6ec9d02c/56fd593740261d3687228f54/56fd59d12b8dde5d7d1480d5/1459444178885/9.JPG?format=1000w)
(http://static1.squarespace.com/static/56fbe87462cd94ff6ec9d02c/56fd593740261d3687228f54/56fd59d1b09f9560c73c245f/1459444178643/10.JPG?format=1000w)
(http://static1.squarespace.com/static/56fbe87462cd94ff6ec9d02c/56fd593740261d3687228f54/56fd59d1b09f9560c73c2461/1459444178601/11.JPG?format=1000w)
(http://static1.squarespace.com/static/56fbe87462cd94ff6ec9d02c/56fd593740261d3687228f54/56fd59d12b8dde5d7d1480d8/1459444179793/12.JPG?format=1000w)
(http://static1.squarespace.com/static/56fbe87462cd94ff6ec9d02c/56fd593740261d3687228f54/56fd59d1b09f9560c73c2467/1459444181122/13.JPG?format=1000w)
(http://static1.squarespace.com/static/56fbe87462cd94ff6ec9d02c/56fd593740261d3687228f54/56fd59d12b8dde5d7d1480da/1459444179079/14.JPG?format=1000w)
(http://static1.squarespace.com/static/56fbe87462cd94ff6ec9d02c/56fd593740261d3687228f54/56fd59d2b09f9560c73c246a/1459444179111/15.JPG?format=1000w)
(http://static1.squarespace.com/static/56fbe87462cd94ff6ec9d02c/56fd593740261d3687228f54/56fd59d22b8dde5d7d1480dc/1459444179195/16.JPG?format=1000w)
(http://static1.squarespace.com/static/56fbe87462cd94ff6ec9d02c/56fd593740261d3687228f54/56fd59d540261d3687229525/1459444183142/17.JPG?format=1000w)
(http://static1.squarespace.com/static/56fbe87462cd94ff6ec9d02c/56fd593740261d3687228f54/56fd59d8d51cd4972206aff6/1459444185941/18.JPG?format=1000w)
(http://static1.squarespace.com/static/56fbe87462cd94ff6ec9d02c/56fd593740261d3687228f54/56fd59e340261d36872295c3/1459444196642/19.JPG?format=1000w)
(http://static1.squarespace.com/static/56fbe87462cd94ff6ec9d02c/56fd593740261d3687228f54/56fd59e32b8dde5d7d14817f/1459444196692/20.JPG?format=1000w)
(http://static1.squarespace.com/static/56fbe87462cd94ff6ec9d02c/56fd593740261d3687228f54/56fd59e440261d36872295c5/1459444198729/21.JPG?format=1000w)
(http://static1.squarespace.com/static/56fbe87462cd94ff6ec9d02c/56fd593740261d3687228f54/56fd59e407eaa05045311eb0/1459444198177/22.JPG?format=1000w)
(http://static1.squarespace.com/static/56fbe87462cd94ff6ec9d02c/56fd593740261d3687228f54/56fd59f807eaa05045311f59/1459444218803/23.JPG?format=1000w)
(http://static1.squarespace.com/static/56fbe87462cd94ff6ec9d02c/56fd593740261d3687228f54/56fd5a1107eaa05045312032/1459444244108/24.JPG?format=1000w)
(http://static1.squarespace.com/static/56fbe87462cd94ff6ec9d02c/56fd593740261d3687228f54/56fd5a122b8dde5d7d148310/1459444243743/25.JPG?format=1000w)
(http://static1.squarespace.com/static/56fbe87462cd94ff6ec9d02c/56fd593740261d3687228f54/56fd5a132b8dde5d7d148316/1459444244501/26.JPG?format=1000w)
(http://static1.squarespace.com/static/56fbe87462cd94ff6ec9d02c/56fd593740261d3687228f54/56fd5a27d51cd4972206b245/1459444271087/32.JPG?format=1000w)
(http://static1.squarespace.com/static/56fbe87462cd94ff6ec9d02c/56fd593740261d3687228f54/56fd5a3ce707eb0e962f03cb/1459444285911/33.JPG?format=1000w)
(http://static1.squarespace.com/static/56fbe87462cd94ff6ec9d02c/56fd593740261d3687228f54/56fd5a3cd51cd4972206b312/1459444286370/34.JPG?format=1000w)
(http://static1.squarespace.com/static/56fbe87462cd94ff6ec9d02c/56fd593740261d3687228f54/56fd5a66d51cd4972206b4ba/1459444327570/42.JPG?format=1000w)
Title: Re: My Hoffman Princeton Reverb Build
Post by: sluckey on August 04, 2015, 08:04:45 am
Nice start. Hope to see some updates.
Title: Re: My Hoffman Princeton Reverb Build
Post by: p2pAmps on August 04, 2015, 08:08:47 am
Nice start. Hope to see some updates.

Thanks Sluckey.  I am waiting on a few key things to move on.  I kinda was thinking if I should pull the wires off the turrets and solder them underneath for a super clean look?  Any thoughts to that?
Title: Re: My Hoffman Princeton Reverb Build
Post by: sluckey on August 04, 2015, 08:35:18 am
I would not do that. One bad connection on an underboard jumper will ruin your day! And your super clean look! You likely won't find it until you power up.

I don't like underboard jumpers but sometimes you cannot avoid them. When I do underboard jumpers I like to do them like this pic. Then I don't have to wonder if the jumper will fall out of the turret when I add components later. I highly recommend this technique.

(http://home.comcast.net/~seluckey/amps/VAC15/underboard_jumper.jpg)
Title: Re: My Hoffman Princeton Reverb Build
Post by: p2pAmps on August 04, 2015, 09:00:41 am
I would not do that. One bad connection on an underboard jumper will ruin your day! And your super clean look! You likely won't find it until you power up.

I don't like underboard jumpers but sometimes you cannot avoid them. When I do underboard jumpers I like to do them like this pic. Then I don't have to wonder if the jumper will fall out of the turret when I add components later. I highly recommend this technique.

(http://home.comcast.net/~seluckey/amps/VAC15/underboard_jumper.jpg)

Great tip and makes complete sense.  I am not so far along that I can't make mine like yours, thank you
Title: Re: My Hoffman Princeton Reverb Build
Post by: p2pAmps on August 04, 2015, 05:42:16 pm
Here are a few updated pics

http://www.p2pamps.com/pr1/ (http://www.p2pamps.com/pr1/)
Title: Re: My Hoffman Princeton Reverb Build
Post by: EL34 on August 04, 2015, 05:43:35 pm
Looking good Mike
Title: Re: My Hoffman Princeton Reverb Build
Post by: p2pAmps on August 04, 2015, 05:48:13 pm
Looking good Mike

That means a lot to me Doug, thank you
Title: Re: My Hoffman Princeton Reverb Build
Post by: Fresh_Start on August 05, 2015, 07:29:08 am
Really nice looking build.

I had some noise problems on my Princeton Reverb builds. Shielded cable to and from reverb pot helped, along with keeping tremolo wires away from everything else. Don't do anything different until you start playing.  I'm just relaying my experience.

Cheers,

Chip
Title: Re: My Hoffman Princeton Reverb Build
Post by: p2pAmps on August 05, 2015, 07:32:59 am
Really nice looking build.

I had some noise problems on my Princeton Reverb builds. Shielded cable to and from reverb pot helped, along with keeping tremolo wires away from everything else. Don't do anything different until you start playing.  I'm just relaying my experience.

Cheers,

Chip

Thanks Chip.  This is my first PR so I will be learning a few things along the way.  Thank you for the tips. 
Title: Re: My Hoffman Princeton Reverb Build
Post by: lego4040 on August 05, 2015, 11:57:37 am
Holy Smokes is that super clean. Lock-tite as well, what made you pick the WGS speaker? I have a older out of production one I like as well. Thanks for the tip with shielded cable to reverb pot and tremolo wire path. Can't wait for more pics
Title: Re: My Hoffman Princeton Reverb Build
Post by: p2pAmps on August 05, 2015, 12:13:07 pm
Holy Smokes is that super clean. Lock-tite as well, what made you pick the WGS speaker? I have a older out of production one I like as well. Thanks for the tip with shielded cable to reverb pot and tremolo wire path. Can't wait for more pics

You know I thought i would start with the WGS speaker since I already had one.  I have a few others too to try, thats part of the journey for me.  I'm also going to start out with some Juniper caps and see how they do...  Thanks for the note
Title: Re: My Hoffman Princeton Reverb Build
Post by: lego4040 on August 05, 2015, 01:26:29 pm
 :huh: Jupiter Caps, straight to the top shelf I see. I don't know how many are on your circuit but that's a easy buck fifty with shipping I bet
Title: Re: My Hoffman Princeton Reverb Build
Post by: p2pAmps on August 05, 2015, 01:29:20 pm
:huh: Jupiter Caps, straight to the top shelf I see. I don't know how many are on your circuit but that's a easy buck fifty with shipping I bet

Nah, not that much.  I use Mylars on the trem circuit.  The Junipers are around 5/6 bucks each...  Come on Doug, get us some so we can buy from you :)

The signal caps needed for a PR:
3 x .1
1 x .05 (=.047)
2 x .02
Title: Re: My Hoffman Princeton Reverb Build
Post by: lego4040 on August 05, 2015, 01:59:14 pm
That's not bad for their yellow mylars, the red "astrons" are $$. I see they have speakers as well now? I'm gonna have t look into their reviews, I'd buy jupiters if you stocked them Doug
Title: Re: My Hoffman Princeton Reverb Build
Post by: EL34 on August 05, 2015, 02:07:33 pm
Quote
The Junipers are around 5/6 bucks each...  Come on Doug, get us some so we can buy from you :)


Where are you buying these?


Title: Re: My Hoffman Princeton Reverb Build
Post by: p2pAmps on August 05, 2015, 02:15:22 pm
Quote
The Junipers are around 5/6 bucks each...  Come on Doug, get us some so we can buy from you :)


Where are you buying these?

http://vintagefenderamprepair.com/maintenance/signal-cap-upgrades/jupiter-vintage-tone-premium-caps/jupiter-signal-caps-singles/ (http://vintagefenderamprepair.com/maintenance/signal-cap-upgrades/jupiter-vintage-tone-premium-caps/jupiter-signal-caps-singles/)
Title: Re: My Hoffman Princeton Reverb Build
Post by: EL34 on August 05, 2015, 02:24:21 pm
I see they have a red astron and a yellow vintage tone cap
http://jupitercondenser.com/product-category/capacitors/ (http://jupitercondenser.com/product-category/capacitors/)


I don't mind stocking them


looks like the red astrons are really expensive


You guys interested in just the yellow ones?

Title: Re: My Hoffman Princeton Reverb Build
Post by: p2pAmps on August 05, 2015, 02:25:46 pm
I see they have a red astron and a yellow vintage tone cap
http://jupitercondenser.com/product-category/capacitors/ (http://jupitercondenser.com/product-category/capacitors/)


I don't mind stocking them


looks like the red astrons are really expensive


You guys interested in just the yellow ones?

I would probably use more yellows than reds.  I would buy from you 100% when needed Doug...  I have all but left Mojo to be honest.  Your parts are just better quality
Title: Re: My Hoffman Princeton Reverb Build
Post by: EL34 on August 05, 2015, 02:27:14 pm
I'll inquire with them and see about dealer pricing
Title: Re: My Hoffman Princeton Reverb Build
Post by: Ed_Chambley on August 05, 2015, 02:30:31 pm
Nice work.  Did you get the faceplate from Dr Tube?  If you don't mind me asking where and also how much coin?

She might be a little woofey with that ceramic speaker, but I'll bet you know just what to do.  I can tell this ain't your first rodeo. :icon_biggrin:

I have a huge stockpile of Caps.  Doubt I would be buying any Jupiters Doug, but I would think some would like to try them.  A load of guys are using them and I have seen the Red ones in a lot of Tweed Clones.
 
Title: Re: My Hoffman Princeton Reverb Build
Post by: p2pAmps on August 05, 2015, 02:36:15 pm
Nice work.  Did you get the faceplate from Dr Tube?  If you don't mind me asking where and also how much coin?

She might be a little woofey with that ceramic speaker, but I'll bet you know just what to do.  I can tell this ain't your first rodeo. :icon_biggrin:

I have a huge stockpile of Caps.  Doubt I would be buying any Jupiters Doug, but I would think some would like to try them.  A load of guys are using them and I have seen the Red ones in a lot of Tweed Clones.

The faceplate was an ebay buy and the backplate including the brass ground plate in front of the pots came from a guy in Thailand named Songwut.  His email is noojwut@yahoo.com  I think I have about 150.00 in all...  Little high but I really wanted it since its going to be my personal amp.  Cabinet came from Mather (1st class)...  I kinda discovered Hoffman along the way and now I'm sold 100%.
Title: Re: My Hoffman Princeton Reverb Build
Post by: p2pAmps on August 05, 2015, 02:42:46 pm
Nice work.  Did you get the faceplate from Dr Tube?  If you don't mind me asking where and also how much coin?

She might be a little woofey with that ceramic speaker, but I'll bet you know just what to do.  I can tell this ain't your first rodeo. :icon_biggrin:

I have a huge stockpile of Caps.  Doubt I would be buying any Jupiters Doug, but I would think some would like to try them.  A load of guys are using them and I have seen the Red ones in a lot of Tweed Clones.

Also Ed, you're right, this ain't my first rodeo but I still have tons to learn and am humbled daily by the large number of good tube amp guys. 
Title: Re: My Hoffman Princeton Reverb Build
Post by: Ed_Chambley on August 05, 2015, 02:53:16 pm
Yes, and what is nice about the Forum here is I have yet to work on anything that Sluckey and or PRR cannot help with.  I mean anything, even a tractor blower motor switch. :laugh:

But with amps, my God, if you think it someone can tell you how to do it.  BWT, I love the Princeton Reverb.  I use a Dual amp setup and for small places I use a 2, 10 Princeton Reverb and the Head version of the AC15 that Sluckey revised the layout.  2 Great sounding low watt amps.  Plenty loud for me and I actually get to turn them up to their sweet spots.

Rock on!
Title: Re: My Hoffman Princeton Reverb Build
Post by: lego4040 on August 05, 2015, 02:55:31 pm
Id buy the yellow ones for my next build, those red ones are 2xs the price as the red ones
Title: Re: My Hoffman Princeton Reverb Build
Post by: EL34 on August 05, 2015, 03:03:19 pm
Thanks for the feedback
I emailed Jupiter and inquired about becoming a dealer
Title: Re: My Hoffman Princeton Reverb Build
Post by: sluckey on August 05, 2015, 09:45:57 pm
Quote
--- going to ground
Y on cap going to A on the board, pin 8 on the rectifier, Y to the OT

First, is this right?
Yes, that's right.

Quote
Next does it really matter where O,U, and X on the cap go on the board B,C,D?
No.
Title: Re: My Hoffman Princeton Reverb Build
Post by: p2pAmps on August 05, 2015, 11:32:50 pm
Quote
--- going to ground
Y on cap going to A on the board, pin 8 on the rectifier, Y to the OT

First, is this right?
Yes, that's right.

Quote
Next does it really matter where O,U, and X on the cap go on the board B,C,D?
No.

Thank you Sluckey...  I hate it when I second guess myself...  Getting really close now

(http://p2pamps.com/pr/27.jpg)
Title: Re: My Hoffman Princeton Reverb Build
Post by: Willabe on August 06, 2015, 12:28:30 am
I see they have a red astron and a yellow vintage tone cap

looks like the red astrons are really expensive

Yes, VERY!     

But I think they are going after the vintage 'look' with them? For the 'vintage' guys who have to replace an old Fender tweed coupling cap or 2, or 3, or.... they are the closets look. The yellows they have made for them, I think.... are the same cap internally, but are just 'tape wrapped' no molded shell.

I just bought a few of the astron 'clones' yellows and reds @ .02 to test in a Champ against SoZo yellows/blues, Mallorie's 150's and Orange drops 715 and 415(?) the OD caps Tubenit uses. 

I think...... that the only difference between the yellow/red astron 'clones' is that the reds have a molded exterior shell, like the old Fender BF blue caps????? I think... the yellow/red astron 'clones' are both film/foil, as are the SoZo's, as apposed to metalized polyprop's, no foil.     
Title: Re: My Hoffman Princeton Reverb Build
Post by: purpletele on August 06, 2015, 01:26:06 am
I would not do that. One bad connection on an underboard jumper will ruin your day! And your super clean look! You likely won't find it until you power up.

I don't like underboard jumpers but sometimes you cannot avoid them. When I do underboard jumpers I like to do them like this pic. Then I don't have to wonder if the jumper will fall out of the turret when I add components later. I highly recommend this technique.

(http://home.comcast.net/~seluckey/amps/VAC15/underboard_jumper.jpg)

That is a great tip.  I have struggled with jumpers.
Title: Re: My Hoffman Princeton Reverb Build
Post by: eleventeen on August 06, 2015, 07:36:16 pm
Looks terrific, very nice work!


Excellent pix, too. Eagerly awaiting the A/B vs the '65 PR!


The only thing I would do differently is on your e-cap, generally I like to have ground connnections *under* the B+ wires. Or, I might slip a piece of ins tubing over the B+ wire (to prevent abrasion) if you want to use the bare ground wire to keep the B+ wire close to the chassis. That's about 1/57th of one nit I could pick on your excellent work.
Title: Re: My Hoffman Princeton Reverb Build
Post by: p2pAmps on August 06, 2015, 07:51:40 pm
Looks terrific, very nice work!


Excellent pix, too. Eagerly awaiting the A/B vs the '65 PR!


The only thing I would do differently is on your e-cap, generally I like to have ground connections *under* the B+ wires. Or, I might slip a piece of ins tubing over the B+ wire (to prevent abrasion) if you want to use the bare ground wire to keep the B+ wire close to the chassis. That's about 1/57th of one nit I could pick on your excellent work.

Thanks so much, and yes I am waiting patiently myself to A/B with the 65.  It's killin me LOL

It's funny what you said about that ground wire as I saw that and changed it right before your post!  Good times

(http://p2pamps.com/pr/38.jpg)
Title: Re: My Hoffman Princeton Reverb Build
Post by: EL34 on August 07, 2015, 06:07:52 am
I uploaded a new PR PDF file this morning.
The power supply page still showed 22uf x 4 for the caps

The new PDf shows 40x20x20x20
http://el34world.com/Hoffman/files/Hoffman_PrincetonReverb.pdf (http://el34world.com/Hoffman/files/Hoffman_PrincetonReverb.pdf)
Title: Re: My Hoffman Princeton Reverb Build
Post by: p2pAmps on August 07, 2015, 06:11:19 am
I uploaded a new PR PDF file this morning.
The power supply page still showed 22uf x 4 for the caps

The new PDf shows 40x20x20x20
http://el34world.com/Hoffman/files/Hoffman_PrincetonReverb.pdf (http://el34world.com/Hoffman/files/Hoffman_PrincetonReverb.pdf)

Thanks Doug.  I also noticed on that layout that the PT blue and brown were reversed...  I used brown on pin 3 on V6 and blue on pin 3 V5. 
Title: Re: My Hoffman Princeton Reverb Build
Post by: EL34 on August 07, 2015, 06:14:42 am
That would depend on the OT transformer you used
Title: Re: My Hoffman Princeton Reverb Build
Post by: sluckey on August 07, 2015, 06:25:25 am
Quote
I used brown on pin 3 on V6 and blue on pin 3 V5. 
There is usually a 50/50 chance you'll need to reverse the brown and blue wires since this amp uses NFB.
Title: Re: My Hoffman Princeton Reverb Build
Post by: p2pAmps on August 07, 2015, 07:28:28 am
That would depend on the OT transformer you used

I am using a Classic Tone Deluxe Reverb output tranny:
"Fender Style 20W Output Transformer 4/8 ohm 40-18038"
Title: Re: My Hoffman Princeton Reverb Build
Post by: EL34 on August 07, 2015, 07:39:01 am
I  was using a different brand and so my hookup was different than yours


Like Steve said, it's a 50/50 dice roll
It's just one of the things that you adjust when firing up an amp for the first time


I never cut the the OT wires going to the power tubes until I know which way is correct
Title: Re: My Hoffman Princeton Reverb Build
Post by: p2pAmps on August 07, 2015, 07:42:49 am
I  was using a different brand and so my hookup was different than yours


Like Steve said, it's a 50/50 dice roll
It's just one of the things that you adjust when firing up an amp for the first time


I never cut the the OT wires going to the power tubes until I know which way is correct

I'll hold my ears LOL....

So is there a way to test before hand so I get it right?  Or is this just like you said, fire it and see what happens?
Title: Re: My Hoffman Princeton Reverb Build
Post by: EL34 on August 07, 2015, 07:51:02 am
You fire it up after doing all the voltage checks, etc
Set the volume on low and you know right away


If you are using the same OT for multiple builds, then you already know which way is the correct way
Title: Re: My Hoffman Princeton Reverb Build
Post by: p2pAmps on August 07, 2015, 07:55:40 am
You fire it up after doing all the voltage checks, etc
Set the volume on low and you know right away
(http://proguitarshop.com/media/cms/blog/holdingears.jpg)
Title: Re: My Hoffman Princeton Reverb Build
Post by: Fresh_Start on August 07, 2015, 09:15:05 pm
You fire it up after doing all the voltage checks, etc
Set the volume on low and you know right away


If you are using the same OT for multiple builds, then you already know which way is the correct way

IIRC another approach is to leave the negative feedback disconnected for initial power-up. That way you can check voltages, etc. before worrying about the output transformer leads.

Cheers,
Chip
Title: Re: My Hoffman Princeton Reverb Build
Post by: PRR on August 07, 2015, 10:57:06 pm
> leave the negative feedback disconnected for initial power-up.

+1

Also, when the amp works no-NFB, you can then *tap* the NFB wire to where it should go. If the small hum gets smaller, that's correct. If it HOWLS, it is probably not correct. And with the "tap" you can un-NFB it instantly, instead of suffering while you wait for the power to bleed down.
Title: Re: My Hoffman Princeton Reverb Build
Post by: HotBluePlates on August 08, 2015, 12:13:01 am
I thought i would share my Princeton Reverb build that I am working on.  ...  I am pretty excited to hear this bad-boy and A/B it next to my friends 65 PR.


Looking great!!


I'm somewhat partial to the blackface Princeton Reverb, as that was my first good tube amp. I've had a number of black- and silver-face Princetons over the years.


I'd suggest you not completely judge your work until you also hear your amp through the old Jensen in your friend's amp. Hopefuly the speaker cord/plug will reach when your two amps are back-to-back.
Title: Re: My Hoffman Princeton Reverb Build
Post by: p2pAmps on August 08, 2015, 08:15:43 am
Well I finally got my caps in and fired her up this morning.  Sure enough the blue and brown in the OT were backwards.  Quick change up and 2nd fire.  Set the bias around 27mA. 

(http://p2pamps.com/pr/39.jpg)
(http://p2pamps.com/pr/40.jpg)
(http://p2pamps.com/pr/41.jpg)
Title: Re: My Hoffman Princeton Reverb Build
Post by: p2pAmps on August 08, 2015, 10:00:52 am
Sound check

WOOT WOOT

https://www.youtube.com/watch?v=3mb3ig0S11U&feature=youtu.be (https://www.youtube.com/watch?v=3mb3ig0S11U&feature=youtu.be)
Title: Re: My Hoffman Princeton Reverb Build
Post by: EL34 on August 08, 2015, 10:07:11 am
Sounds great Mike
I guess you nailed down the reverb issue



Title: Re: My Hoffman Princeton Reverb Build
Post by: p2pAmps on August 08, 2015, 10:13:02 am
Sounds great Mike
I guess you nailed down the reverb issue

Yeah, really dumb mistake, plugged in backwards LOL...  some kids I swear
Title: Re: My Hoffman Princeton Reverb Build
Post by: HotBluePlates on August 08, 2015, 11:15:00 am
Sounds perfect! And the cab, grill cloth, faceplates, etc look so spot-on it's a near-forgery!  :icon_biggrin:


Really great job!
Title: Re: My Hoffman Princeton Reverb Build
Post by: Willabe on August 08, 2015, 11:15:13 am
Yeah, really dumb mistake, plugged in backwards LOL...  some kids I swear

 :laugh:    Can happen to the best of them.

Really, really, nice looking build!  :bravo1:
Title: Re: My Hoffman Princeton Reverb Build
Post by: Willabe on August 08, 2015, 11:24:03 am
All right, now wait a second here, I just listened to your clip.

WHO ARE YOU? AND WHERE DO YOU LIVE? LA? Nashville? NO? NY?

You are definitely a high level pro player. Your covering a LOT of musical style bases there. 

Are you a studio cat? Out on the road? Your not just playin out at the local pub every other month.

Man you can play, I'd love to hear you stretch out on a few different styles with a nice sized band.     :blob8:
Title: Re: My Hoffman Princeton Reverb Build
Post by: HotBluePlates on August 08, 2015, 11:38:09 am
All right, now wait a second here, I just listened to your clip.

WHO ARE YOU? AND WHERE DO YOU LIVE? LA? Nashville? NO? NY?


 :l2:  He lives near Nashville, in a smallish town I used to live in up to 2000.


I can get around on the guitar, but every now & then someone would ask me in a bar in Nashville, "Hey man, do you play?" And I said, "Yep. I play the stereo..."
Title: Re: My Hoffman Princeton Reverb Build
Post by: EL34 on August 08, 2015, 11:53:50 am
Overall, great job on assembling my PR board

I'll put a link to this thread on my PR turret board thread
Just to show guys that it can be assembled and work right off the bat
(well, you had just a couple minor issues)


But you went back over it and found them right away

Not trying to get down on anyone, but I see some guys doing builds here that just keep posting over and over again about the amp not working
It seems they are not able to go back over their work and find the problem


Let this be an example of how it is done properly
Title: Re: My Hoffman Princeton Reverb Build
Post by: Willabe on August 08, 2015, 12:25:51 pm

I can get around on the guitar, but every now & then someone would ask me in a bar in Nashville, "Hey man, do you play?" And I said, "Yep. I play the stereo..."

All I can play in is mono.   :laugh:
Title: Re: My Hoffman Princeton Reverb Build
Post by: p2pAmps on August 08, 2015, 12:58:22 pm
Overall, great job on assembling my PR board

I'll put a link to this thread on my PR turret board thread
Just to show guys that it can be assembled and work right off the bat
(well, you had just a couple minor issues)


But you went back over it and found them right away

Not trying to get down on anyone, but I see some guys doing builds here that just keep posting over and over again about the amp not working
It seems they are not able to go back over their work and find the problem


Let this be an example of how it is done properly

Honored you would say that Doug
Title: Re: My Hoffman Princeton Reverb Build
Post by: p2pAmps on August 08, 2015, 01:02:35 pm
All right, now wait a second here, I just listened to your clip.

WHO ARE YOU? AND WHERE DO YOU LIVE? LA? Nashville? NO? NY?

You are definitely a high level pro player. Your covering a LOT of musical style bases there. 

Are you a studio cat? Out on the road? Your not just playin out at the local pub every other month.

Man you can play, I'd love to hear you stretch out on a few different styles with a nice sized band.     :blob8:

Ha!  I'm a nobody man.  Name is Mike Scaggs and I am from Murfreesboro Tn, about 40 minutes south of downtown Nashville.  Born and raised in Sacramento, CA and moved here 10 years ago for good this time.  I toured with some artists in the mid 90s but found I liked being home with the family better.   I have been a cyber security guy now for 19 years and play music at church now.  Been doing sessions since I was 21, 54 now.  Too many to list both good, bad, and really bad LOL...  I love guitars, amps, pedals, Harleys, woodshopin, and the lord.

That about sums up me... Glad to be here

Title: Re: My Hoffman Princeton Reverb Build
Post by: John on August 08, 2015, 02:07:22 pm
Well, I don't know what I'm more jealous of, your playing ability or building ability. So I'll just take both for $400, Alex. Cheers!
Title: Re: My Hoffman Princeton Reverb Build
Post by: lego4040 on August 08, 2015, 04:54:48 pm
:worthy1:
Title: Re: My Hoffman Princeton Reverb Build
Post by: Willabe on August 08, 2015, 06:15:13 pm
I toured with some artists in the mid 90s but found I liked being home with the family better. I have been a cyber security guy now for 19 years and play music at church now. 

Home and family are better.   :icon_biggrin:

I started to get chances/offers to go out on the road for 2 to 3 months at a time. Turned them down. I almost moved to NOLA.
I was in my mid to late 40's, if it would have happened earlier, 30's, I probably would have jumped at it.  :laugh:

(I ended up playing in church for some years. Was a very good decision for me.)
Title: Re: My Hoffman Princeton Reverb Build
Post by: p2pAmps on August 08, 2015, 06:54:50 pm
Thanks to each person who showed interest in my PR build.  Guys, if you're on the fence on one of Doug's PR don't hesitate.  The schematic and layout is good and easy to follow.  Take your time and enjoy the ride, its a great project you will have for years to come.

And here she is all done and dialed in...  woot woot!

(http://p2pamps.com/pr/42.jpg)

https://www.youtube.com/watch?v=jByGobiixBY&feature=youtu.be (https://www.youtube.com/watch?v=jByGobiixBY&feature=youtu.be)
Title: Re: My Hoffman Princeton Reverb Build
Post by: TIMBO on August 08, 2015, 09:31:19 pm
 :bravo1:
Title: Re: My Hoffman Princeton Reverb Build
Post by: smackoj on August 08, 2015, 10:06:19 pm
sounds superb.  that's one to be very proud of Mike.

 :icon_biggrin:
Title: Re: My Hoffman Princeton Reverb Build
Post by: Fresh_Start on August 09, 2015, 09:12:32 am
:bravo1:

+1 Very nice!

Cheers,

Chip
Title: Re: My Hoffman Princeton Reverb Build
Post by: p2pAmps on August 09, 2015, 02:26:27 pm
so,.... the tremolo was a little weak in my mind on this build.  thanks to STUCKEY's great advise, I swapped out a 1M resistor for a 470K in the tremolo circuit and all the sudden I had magic!  Now I'm stuck on PR tremolo...

Thank you Mr Stuckey

(http://p2pamps.com/pr/1m.jpg)
Title: Re: My Hoffman Princeton Reverb Build
Post by: EL34 on August 09, 2015, 02:31:19 pm
Nice, the forum boys come through again

Title: Re: My Hoffman Princeton Reverb Build
Post by: Willabe on August 09, 2015, 04:03:36 pm
Sluckey's got a way with trems for sure.    :icon_biggrin:
Title: Re: My Hoffman Princeton Reverb Build
Post by: lego4040 on August 09, 2015, 05:51:05 pm
Slucky's gotten outta a jam or three. How's that WGS sounding? Apparently the one I have is a 2007 vintage 12". They now call the The Veteran, can't wait to here it. I think Dougs PR is my next build, I have a 290cax Hammond in box still and will look to see if that will work
Title: Re: My Hoffman Princeton Reverb Build
Post by: p2pAmps on August 09, 2015, 06:03:42 pm
Slucky's gotten outta a jam or three. How's that WGS sounding? Apparently the one I have is a 2007 vintage 12". They now call the The Veteran, can't wait to here it. I think Dougs PR is my next build, I have a 290cax Hammond in box still and will look to see if that will work

You know what, that WGS sounds really nice man.  I have 4 others to try but hey, I might just keep this one in there.

Don't hesitate on building Doug's PR.  It's such a clean layout and sounds freakin amazing, I mean it.  You can do it so just get started.  My cab came from Mather.  3 week turn around.  I added the relic-ed grill for 25 bucks and glad I did.  Life is short so go get ya some...

Cheers
Title: Re: My Hoffman Princeton Reverb Build
Post by: EL34 on August 09, 2015, 06:10:55 pm
I love happy endings  :icon_biggrin:
Title: Re: My Hoffman Princeton Reverb Build
Post by: lego4040 on August 09, 2015, 06:26:15 pm
My cab for the 5G9 is being lacquered as I write, Mergili is making mine. I just started getting the dust off my tools. I switched jobs and I have to rebuild my work bench at my new shop
Title: Re: My Hoffman Princeton Reverb Build
Post by: DummyLoad on August 09, 2015, 10:28:35 pm
very nice work mike.

did you ever wire in the mid control in the rear?

--pete
Title: Re: My Hoffman Princeton Reverb Build
Post by: p2pAmps on August 09, 2015, 10:55:21 pm
very nice work mike.

did you ever wire in the mid control in the rear?

--pete
Thanks a lot...
I did solder up the mid pot.  I'm starting with a 10K and going to increase it till I find the sweet spot... 

Title: Re: My Hoffman Princeton Reverb Build
Post by: Ed_Chambley on August 10, 2015, 03:59:29 pm
Great build and very nice chord vocabulary.  I picked up an idea from around 1:30 sliding in and out.  What a great sound, a Well played Les Paul and one heck of a clone.

I like a mid pot myself.  Good stuff, thanks!
Title: Re: My Hoffman Princeton Reverb Build
Post by: lego4040 on August 10, 2015, 05:02:48 pm
Was the mid pot in the layout or schematics somewhere? I remember, I think seeng it
Title: Re: My Hoffman Princeton Reverb Build
Post by: p2pAmps on August 10, 2015, 05:20:00 pm
Was the mid pot in the layout or schematics somewhere? I remember, I think seeng it

No, the mid pot is not on the schematic or layout but is very easy to add on.  I used the hole where the ground switch would have been and ran a wire over to the bass pot from there.  You remove the 6.8k resistor from the left lug on the Bass pot and connect your mid pot there.  You will need to ground you mid pot too.  The mid pot basically becomes a rheostat.  I started with a 10K pot and get 6.8K around 3 o'clock.  I plan to play around with the pot values to see what I get out of it.  Some good tech on the forum have suggested a 50K which I plan to try out.
Title: Re: My Hoffman Princeton Reverb Build
Post by: lego4040 on August 10, 2015, 06:32:05 pm
Now I remember, when I was thinking about building Dougs AB763 that's where I saw the mid pot. Looks like it can be followed the same way
Title: Re: My Hoffman Princeton Reverb Build
Post by: p2pAmps on August 11, 2015, 12:27:34 pm
Well today is the big Hoffman PR / 65 PR shootout.  We are going to set these side by side and see what we got.  My dear friend and top session guy in town will be very critical so I'm holding my breath.  I think the Hoffman is going to WIN!  More to come....
Title: Re: My Hoffman Princeton Reverb Build
Post by: lego4040 on August 11, 2015, 01:47:02 pm
Blind fold him during the test and swap amps arounds
Title: Re: My Hoffman Princeton Reverb Build
Post by: eleventeen on August 11, 2015, 04:22:46 pm
There's a local "summer jazz camp" here, conducted at a nearby school. I think they have about 200-250 kids come in, and there are very strong local musicians who teach 1-week classes. To cover all the amps they need, they borrow lots of amps and drum kits and keyboards from all the local schools.


One or two years ago, a school amp came in and it was a BF Princeton Reverb, maybe 1966-1967 in absolutely museum-grade condition. I was stunned that a "school" amp would be in such good shape. I have to tell you it was all I could do to not walk out with thing. I should have offered three new Fender SS amps in trade.
Title: Re: My Hoffman Princeton Reverb Build
Post by: p2pAmps on August 11, 2015, 07:16:32 pm
Well, the shootout went well.  We compare the Hoffman build to a Vintage Sound 15 as well.
The Hoffman was more punchy than both the 65 and the Vintage Sound.  The Vintage Sound 15 was very hifi sounding probably due to all the orange drops they use.  Not saying it sounded bad, just sounded hifi...  The 65 did break up faster than the Hoffman which may be due to the speaker and the fact that the I used a Deluxe OT in my build.  The guitar used on this clip was a 61 335

It was the opinion of 5 top session guys that the Hoffman PR won!  I was pretty dang excited. 

Here is a little clip.  My camera work sucks ...  The 65 is on the right, my build on the left. 

! No longer available (http://www.youtube.com/watch?v=KAvbpjxDrxE#)
Title: Re: My Hoffman Princeton Reverb Build
Post by: SleepLess on August 17, 2015, 02:40:40 pm
so,.... the tremolo was a little weak in my mind on this build.  thanks to STUCKEY's great advise, I swapped out a 1M resistor for a 470K in the tremolo circuit and all the sudden I had magic!  Now I'm stuck on PR tremolo...

Thank you Mr Stuckey

Congrats for this build! And your playing as well!
As for the Trem, I actually even reduce that 1M resistor down to 220K! It's much more useable!
Have fun, the PR is on my top-5-amps list!
Title: Re: My Hoffman Princeton Reverb Build
Post by: Ed_Chambley on August 17, 2015, 02:42:36 pm
I meant to ask, did you listen to the amp before the Jupiter caps were installed.  I would like to know you opinion of the difference.

Respectfully,
Ed
Title: Re: My Hoffman Princeton Reverb Build
Post by: p2pAmps on August 17, 2015, 03:38:35 pm
I meant to ask, did you listen to the amp before the Jupiter caps were installed.  I would like to know you opinion of the difference.

Respectfully,
Ed

Hi Ed,

The truth is no, I just soldered them in and fired the amp.  It sounds so good I cringe at the thought of changing anything now LOL...
Title: Re: My Hoffman Princeton Reverb Build
Post by: lego4040 on August 17, 2015, 04:57:25 pm
What happened to the video clip? Can you repost
Title: Re: My Hoffman Princeton Reverb Build
Post by: p2pAmps on August 17, 2015, 05:21:29 pm
What happened to the video clip? Can you repost

The videos I have are on this thread...

 :guitar1
Title: Re: My Hoffman Princeton Reverb Build
Post by: Fresh_Start on August 22, 2015, 06:26:09 am
What happened to the video clip? Can you repost

Link still works despite label.

Chip
Title: Re: My Hoffman Princeton Reverb Build
Post by: p2pAmps on September 08, 2015, 10:17:07 am
Here is a little something I played on with the PR I built to give you an idea what it sounds like with pedals and a 57 mic.  I played all the parts on this cut with a 85 LesPaul too...

https://www.youtube.com/watch?v=Lpty3_yYMDA (https://www.youtube.com/watch?v=Lpty3_yYMDA)
Title: Re: My Hoffman Princeton Reverb Build
Post by: Willabe on September 08, 2015, 10:30:22 am
Oh man!!!!!     :blob8:

That sure don't sound like no PR! Sounds like a tweed Bassman or a Marshall half stack. WOW!

What pedals?  :undecided:
Title: Re: My Hoffman Princeton Reverb Build
Post by: p2pAmps on September 08, 2015, 10:40:01 am
Oh man!!!!!     :blob8:

That sure don't sound like no PR! Sounds like a tweed Bassman or a Marshall half stack. WOW!

What pedals?  :undecided:

I was using an old Nobels ODR-1 ....
Title: Re: My Hoffman Princeton Reverb Build
Post by: Willabe on September 08, 2015, 10:56:43 am
I was using an old Nobels ODR-1 ....

Sounds great.  :icon_biggrin:
Title: Re: My Hoffman Princeton Reverb Build
Post by: EL34 on September 08, 2015, 11:15:40 am
That sounds great!
Title: Re: My Hoffman Princeton Reverb Build
Post by: p2pAmps on September 08, 2015, 12:43:00 pm
That sounds great!

Aweee man, thanks Doug...  Same ole tired licks and one chop LOL
Title: Re: My Hoffman Princeton Reverb Build
Post by: Willabe on September 09, 2015, 02:42:11 pm
Does a Strat sound good through that pedal?    :dontknow:
Title: Re: My Hoffman Princeton Reverb Build
Post by: p2pAmps on September 09, 2015, 03:18:48 pm
Does a Strat sound good through that pedal?    :dontknow:

I think everything sounds great through an ODR-1
Title: Re: My Hoffman Princeton Reverb Build
Post by: Willabe on September 09, 2015, 03:25:41 pm
Ok, thanks.  :icon_biggrin:

I'm gonna talk with Jojo about it, he builds a lot of pedals. 
 
Title: Re: My Hoffman Princeton Reverb Build
Post by: Ritchie200 on September 09, 2015, 07:09:24 pm
Wow!  Not only a great looking and great sounding amp, but holy cats your playing is phenomenal!  Really shows it off.  Great job on all fronts! You did all the parts in that recording? :worthy1:

Jim
Title: Re: My Hoffman Princeton Reverb Build
Post by: p2pAmps on September 10, 2015, 04:15:49 am
Wow!  Not only a great looking and great sounding amp, but holy cats your playing is phenomenal!  Really shows it off.  Great job on all fronts! You did all the parts in that recording? :worthy1:

Jim

Thank you Jim...  Well, I did all the guitar parts.  I think I did 3 tracks on this one...
Title: Re: My Hoffman Princeton Reverb Build
Post by: jojokeo on September 11, 2015, 01:43:17 pm
I finally caught up, re-read the thread, and watched the vids. Love Snake Bite's words too not just the playing, tone, & production which were also really nice and something to be proud of. Just curious on the odr-1 is it an early or recent model (not that it matters much) and if you've seen/played the newer one with a gain switch mod also?
Title: Re: My Hoffman Princeton Reverb Build
Post by: p2pAmps on September 11, 2015, 01:46:47 pm
I finally caught up, re-read the thread, and watched the vids. Love Snake Bite's words too not just the playing, tone, & production which were also really nice and something to be proud of. Just curious on the odr-1 is it an early or recent model (not that it matters much) and if you've seen/played the newer one with a gain switch mod also?

Hi,  Thank you... yeah, Snake Bite was a fun tune to record...

The ODR-1 is an old one.  I bought it at Mike Es Music in the Nashville Area in 1995.  I have not done an A-B test against a new one but I am told the old ones are better by reliable ears I know.  I have a few other OD pedals such as a XTS, Zen Drive, and Misc others not worth mentioning.  The ODR however is my favorite and has been on a lot or sessions...
Title: Re: My Hoffman Princeton Reverb Build
Post by: jojokeo on September 11, 2015, 06:08:02 pm
Nothing "vintage" or different between circuits and most parts from '95 so I'm not sure there should be something extreme? But possibly different (4558) OpAmps would be a guess and that would make the most difference.
Title: Re: My Hoffman Princeton Reverb Build
Post by: p2pAmps on September 14, 2015, 04:48:16 pm
I decided to throw in a old D-120F and oh man, I can't find a reason to go any further. Very sweet cleans and the pedals sound amazing. I found a keeper...


(http://p2pamps.com/pr/44.jpg)
(http://p2pamps.com/pr/43.jpg)
Title: Re: My Hoffman Princeton Reverb Build
Post by: jojokeo on September 14, 2015, 04:51:36 pm
Is that a 12" cab?
Title: Re: My Hoffman Princeton Reverb Build
Post by: p2pAmps on September 14, 2015, 05:20:10 pm
Yeah 12" cab from Mather and  deluxe OT too
Title: Re: My Hoffman Princeton Reverb Build
Post by: rhodco on September 21, 2015, 11:00:28 pm
My cab is also on order from Mather. I'm going with a 12" baffle as well.

Hey Mike, do you remember which way you switched the blue and brown OT wires? I remember from the posts back that you fired it up the first time, then switched the OT wires, but the photo looks the same to me as the first photos. It looks like you have the blue OT wire going to V5 (on the left looking down with pots pointing toward you), and the brown wire going to V6 on the right.

Do you now have the blue going to V6-3, and the brown going to V5-3 ?

Thanks
Title: Re: My Hoffman Princeton Reverb Build
Post by: p2pAmps on September 22, 2015, 07:22:23 am
My cab is also on order from Mather. I'm going with a 12" baffle as well.

Hey Mike, do you remember which way you switched the blue and brown OT wires? I remember from the posts back that you fired it up the first time, then switched the OT wires, but the photo looks the same to me as the first photos. It looks like you have the blue OT wire going to V5 (on the left looking down with pots pointing toward you), and the brown wire going to V6 on the right.

Do you now have the blue going to V6-3, and the brown going to V5-3 ?

Thanks


Brown V5
Blue V6

Take a look at the pics here, this should answer all your wiring questions ok....  These are two different PR I build with Doug's layout and turrets

http://p2pamps.com/pr (http://p2pamps.com/pr)

http://p2pamps.com/kbpr (http://p2pamps.com/kbpr)


Also, Another small change I made was using a 220K in the tremolo circuit instead of the 1M resistor.  It give you way more intensity.  I also added a 50K Pot in the grouund switch hole to use as a middle control.  You can experiment around with pot values there if you decide to add a mid.  I started with a 10K then bumped it to a 50K.  So far the 50K is pretty cool...

(http://p2pamps.com/trem.jpg)
Title: Re: My Hoffman Princeton Reverb Build
Post by: jojokeo on September 22, 2015, 09:00:19 am
I've been meaning to ask, what's on all the solder contacts - nail polish? Why did you feel a need to mark them all?
Title: Re: My Hoffman Princeton Reverb Build
Post by: p2pAmps on September 22, 2015, 09:15:20 am
I've been meaning to ask, what's on all the solder contacts - nail polish? Why did you feel a need to mark them all?

(http://p2pamps.com/goop.jpg)

This is what I use.  I have two reasons, first it is my way of doing a self QA process.  It forces me to look at every single solder point and make sure I didnt miss anything.  Second, if I sell it and it comes back after someone else worked on it I should see the red lacquer disturbed.  Plus, it reminds me of my vintage Marshalls :) :icon_biggrin:
Title: Re: My Hoffman Princeton Reverb Build
Post by: Ritchie200 on September 22, 2015, 10:11:06 am
That is a great idea!  Even on the nuts. 

Wow, Dykem - I've sniffed a lot of that over the years....  It also works well painted on the frames of your "buddy's" safety glasses that might just happen to come in contact with his face!  High spot blue is good for long term interaction.... :icon_biggrin:

Jim :dontknow: :icon_biggrin:
Title: Re: My Hoffman Princeton Reverb Build
Post by: rhodco on September 22, 2015, 10:26:32 am
Thanks. I do see that you reversed it on the second build so I'll go with that.

I decided to try a 470K ohm in that tremolo circuit to see how it sounds. Will hopefully post video later.

Title: Re: My Hoffman Princeton Reverb Build
Post by: p2pAmps on September 22, 2015, 10:33:05 am
Thanks. I do see that you reversed it on the second build so I'll go with that.

I decided to try a 470K ohm in that tremolo circuit to see how it sounds. Will hopefully post video later.

470K will be fine.  220K will give you a ton of intensity but you can always turn the knob down :)
Title: Re: My Hoffman Princeton Reverb Build
Post by: rhodco on September 26, 2015, 10:45:48 am
I just bought a few of the astron 'clones' yellows and reds @ .02 to test in a Champ against SoZo yellows/blues, Mallorie's 150's and Orange drops 715 and 415(?) the OD caps Tubenit uses... 

Willabe, when you test those caps I would really like to know what you think of the results. Which kind do you like best?