Princton Reverb here we come,Parts in, Amp Cradle done

[lego4040]

All my parts are in, Thank you Doug. So between my go to venders I got an amp to build. Ill be Building the Hoffman BFPR and pretty much be following Dougs design. Mid pot will probably go in the back. Im using Allen Amps TP 25, He said its a good upgrade for that build, plus I already have it from a previous build. OT is Classictone 40-18087. Dougs NSC Reverb driver and his cap/res list. Tubes I havent gotten yet but Every amp I own Ive tubed From Brent Jesse. I never had a bad tube, all guaranteed, matched and were NOS. They only cost me a couple dollars more. Bench is now neat and ready

[bnwitt]

Did you buy a matching front plate for the chassis?  If not you can have one made with a layout that includes a mid pot.  There is plenty of room.  I'm putting in a pull volume switch for a bright switch on mine as well. 

Will the chassis stand allow the chassis to rotate around it's horizontal axis?  It's good to have that capability when you are wiring up or even just working on an amp as it allows you to get to everything and to use gravity to your advantage at different stages.

[lego4040]

The cradle has three positions as of now(90*,20* and 40* angle) , I built it on the fly. I followed Sluckey’s cradle build as a guide line. I do have the 3/4” emt cut for sliding width but havent done that yet. I havent ordered a plate and I see Amplates is on Hiatus. I do want to have the mid pot as well as dwell. I thought about just using only one input and use the other for some switch mod. RobRobinette has some nice tweaks on his site. My Daughter made sure I hot glued Tiara back on before I got going. Santa brought the Scope, now I got learn its uses carefully.

[lego4040]

bnwitt thanks for that link, thats sweet. I'm guessing one would use that link to send to a plate maker like mojotone for instance

[bnwitt]

Lego4040.  I drew those plates in Visio.  When you draw them you have to measure all of your existing chassis holes both horizontally and vertically as every chassis (even from the same supplier) is different and it doesn't take but a 16th or two to screw up alignment between the plate and chassis.  Once you get everything accurately measured it's easy to draw the plate in Visio.  I've used Jeanne at BNPLasers.com for my plates for years and she was awesome but she just retired.  Yes Mojotone will custom engrave plates for you from your drawing.

[lego4040]

OCD kicked in and I could stand looking at my bench so I took everything off. I put ALL pedal building away and now rebuilding my bech for amps only. Got away to go but at least I can start the amp. I threw a quick board cradle together with scrap wood, pcb holder and some stain

[mresistor]

The picture is too small and when you zoom in to see notes it is all blurry . 


"red wire with yellow stripe"   this wire is the center tap for the High Voltage winding


the red wire with a green or bluish stripe is the bias tap from the High Voltage winding 


I replied to your PM about the rest of the wires. 

[bnwitt]

If that wire is labeled -52 volts it is the bias tap and should not be grounded.  It goes to your bias circuit.  The orange wire may be a shield and would be grounded if so but as mresistor states follow the wiring diagram for the PT.  Try to post a larger picture of the diagram.

By the way I updated the PR plates to match a typical chassis

[mresistor]

Here's a pic of my HPR  which might help

[bnwitt]

Aiken's website says this about the TP25:

Upgrade Power Transformer for BF/SF Champ™, VibroChamp™, Bronco™, and Princeton™.
310V-0-310V @ 150ma,
6.3V at 4.5A,
5V at 2A.
50V bias tap, This is most likely the bias wire you mentioned
center-tapped heater winding and
internal hum shield brought out to a lead for grounding. This is most likely the orange wire you mentioned

But, make sure you read the diagram and or post it here where we can read it.  By the way, are you building a standard Fender layout or a Hoffman layout?

[bnwitt]

mresistor,  Nice work.  I like the bias jacks.

[mresistor]

Thanks Barry  - I told LEGO what all the wires are on the TP-25   as I have one in that HPR


I sure wish David Allen would have spec'd that TP-25 with a 3 amp recitfier filament.  With todays wall voltages  using a 5AR4 yields high voltages that can approach the rating on the JJ cap can.
But I was running this HPR on a vintage 5U4 for years, if that winding craps out I guess I will replace the PT with one that is rated for a 5U4GB. I stuck a 5R4 in the HPR for now.

[sluckey]

Lego, if you intend to follow Hoffman's layout then just tape off that bias wire. The Princeton Reverb circuit does not use a bias tap.

[mresistor]

Where is the green/yellow going to on the board?  Is it getting elevated above ground?


It says right on the layout that the red/green bias tap is "not used" in this amp.

If you are building an Allen 5F1 with the TP-25 maybe consider starting a new thread for it.   
Reason is people think you are using the TP-25 for a Hoffman Princeton which is this threads title.
Confusion.

[BruceF]

And if you do use the bias tap from the transformer be sure to adjust the size of the bias range resistor.  on the 6l6 powered princetons i built I used a 470 ohm 3 watt.

[mresistor]

Seems this is what Lego is building with the TP-25  or is contemplating building. It's Allen 5F1+

[lego4040]

   I should have been more clearer. I had built that 5F1+ from Allen Years ago and that is how I wound up with the TP25 Transformer which I am using in the Homman Princeton Reverb. I am posting the pic and schematic to show how it is installed in that circuit.

[bnwitt]

Ok, as Sluckey said just tape off and don't use the bias tap wire.  You'll be running a wire from terminal 6 of the rectifier tube socket over to the 100kohm bias range resistor on the board to get your bias voltage for the power tubes.

[lego4040]

I removed those pics, It was brought to my attention if I had David permission to post the schematic. I dont so I removed them

[lego4040]

Ok just so we are clear here. I am not building the Allen Amp 5F1+, I built that amp way back in 2007 and it was my very first tube amp build. I did however "Borrow" the PT from it and It is now installed in Hoffmans BFPR that I am currently building. I searched my emails with David and this is what the wire color codes are:

The two black wires or black and white wires are the 120V primary leads.

The two red wires are the HV secondary.

The two yellow leads are the 5V fillament.

The two green leads are the 6.3V heaters.

The red/green lead is the 50V bias tap.

The red/yellow lead is the HV center tap.

The green/yellow lead is the heater center tap.

The orange leads is the hum shield.

The last 3 leads are normally grounded to the chassis.

I think I confused not only myself but others here. This amp is a incredible amp  and Allen has great kits

[sluckey]

Mresistor is the only one that doesn't know you are building a Hoffman Princeton Reverb.

[mresistor]

Hardly,  I know he is  - but what are you supposed to think when someone sends you a PM asking about TP-25 wiring in and sends along 5F1+ schematics.


But hey , if you get a kick out of it at my expense  -  enjoy.   
 

[mresistor]

Here's my response to his PM question to me ..   note the times and then look at the times on the thread      you be the judge ..




Re: the erroneous AA764 PR« Sent to: lego4040 on: January 29, 2018, 12:14:23 pm »

Reply[/r]

• Quote
• =delete;f=sent;start=0;a23c5d932874=15de22ce2a6f6ea61bc24483aafe4876]Delete

Quote from: lego4040 on January 29, 2018, 11:46:30 amMrisistor, how are you today. I have a question on how you hooked up the TP25. I attached a picture of the Allen Amp 5F1+ amp schematic. How did you hook up the extranious wire taps. On the 5F1 the red/green isnt used,red/yellow wire and orange wire is grounded to the neg side of the (330ohm25w/50uf)cathode/bias. Am just grounding all those wires again? That red/yellow is a -53 center tap   




You need to specify wire codes properly  = red wire / green stripe  = correct


The red wire / yellow stripe   and the green wire / yellow stripe go to ground   - these are the center taps for the HV and 6.3vac filament windings  If you are not using the 6.3vac center tap then you can use two 100 ohm resistors off the lamp as an artificial center tap. Remember the original 5F1 did not have a center tapped 6.3vac filament winding. I highly suggest you wire it up modern with either form of center tap and twisted pairs of wires to each tube.


The red wire with either blue or green stripe is the bias tap. You will insulate the end of it with heat shrink tubing and tuk it away as a 5F1 is class A cathode biased.


The orange wire goes to a chassis bolt   same as the  red/yellow stripe   green/ yellow stripe


the dark green wires go to filaments


the yellow wires go to the rectifier filament connections


the red wires go the rctifier HV connections  pins 4 and 6 I believe


the white wire goes to neutral of the power cord


the black wire goes to one side of the power switch after the fuse.




this is how my princeton is wired with a TP-25


I cannot see your TP 25 nor your Allen 5F1 which I have never seen before


by all means do post in a thread if you need help   it's what the forum is for..


cheers
 

[mresistor]

Nowhere in this thread does it say he pulled this TP-25 pt from an Allen 5F1+ to use in the PR prior to my posting.

[sluckey]

...Ill be Building the Hoffman BFPR and pretty much be following Dougs design. Mid pot will probably go in the back. Im using Allen Amps TP 25...

That quote from lego's original post on Jan 12 pretty much says it all. Don't be so thin skinned.

[mresistor]

Still doesn't say he is using a TP-25 from an Allen 5F1+ .  Not thin skinned at all sluckey. I was helping this guy , gave him the information he needed, told people I
did and he still got the same information from others.   I was confused, not afraid to say, but am I the one not reading the thread? 


And please tell me how  you feel this "Mresistor is the only one that doesn't know you are building a Hoffman Princeton Reverb."   is not offensive in the least?

[shooter]

is not offensive

try starting from the premise that the comment was meant as "workplace humor". the guys that taught me well, typically said really bad things about my heritage, and mental capacity,...

[mresistor]

is not offensive

try starting from the premise that the comment was meant as "workplace humor". the guys that taught me well, typically said really bad things about my heritage, and mental capacity,...

good point shooter      thanks         

[sluckey]

And please tell me how  you feel this "Mresistor is the only one that doesn't know you are building a Hoffman Princeton Reverb."   is not offensive in the least?

There was no offense intended. I simply stated a fact. You said you were confused. I just repeated what you said. I think you're being too sensitive.

It seemed to me you were wanting to head in the direction of "he's building an Allen 5F1". I had no idea where that came from. I was simply trying to steer the discussion back on track to the HPR. I'm not concerned with where the Allen TP25 came from. I happen to have that same transformer in my '57 Harvard amp, but there's no reason to mix that up in this thread. All I know is he is going to put it in his Hoffman Princeton Reverb, just as you did. And he should tape off that bias wire just as you did. And get his AC for the bias supply from the HT winding at the rectifier socket, just like you did.

Hopefully the confusion has dissipated and the thread can get back to building a HPR.

[mresistor]

Sluckey   when I said "offensive" it was too strong a word   I should have said  "unsettling"  ..  I'm with you only trying to help the OP figure it out..   


And now back to the regularly scheduled program..   

[lego4040]

Just got back to office from my plant rounds and  .I am really sorry for the confusion, missed information, asking to many questions, etc.. This forum is great and it lets you connect with people you'd never ever meet due to distances, It totally sucks not to be able sit around a table and build amps with fellow builders, and that would be a pretty big frigging table too
If it wasn't for you guys I never would have made it to 5th build without electrocuting myself or burning down my house.  You see I didn't mention blowing anything up, yep, Blew up that 5F1+ first time powering.
  I didn't mention, I should have mentioned and thanked Mresistor  here for all his help and insight on this PT and build outside of this thread. I got great help and info regarding it and tips on rectifiers. In Mresistor's defense, I was asking him questions about this PT in the PR and then out of left field I sent him a pic/schematic of the 5F1+ that I already built and which has that PT. I should've explained myself better as to why I was showing this schematic in reference to my question on a BFPR.
Thank you guys for all the help here and my other threads

[bnwitt]

Ok so I'm in the process of building two HPR amps and I'm finishing up my plan set for the builds.  Attached are some pages from that plan set which I hope may help.  Now bear in mind I am adding a pull bright switch and a middle control to my amps but other than that it is the same.  I've checked the board drilling mask and the loaded board for errors and they seem ok.  I'm still error checking the wiring plan though.  If anyone sees anything wrong on it let me know.

[lego4040]

I am planning adding that bright switch, I want to add a dwell next to reverb and on the back where ext speaker is I want to turn that into a swamp switch     Its the deep tremolo that Sluckey added to his AC 15 and the one I built

[bnwitt]

Is the swamp switch a simple on or off switch or a selector type?

[lego4040]

I just used a single pole switch to put a cap in parallel, this is how Sluckey did on the build. I just leave mine on and slip into the Delta, Great for Credence stuff
http://sluckeyamps.com/VAC15/Vox_AC15_mods.pdf

[bnwitt]

Well then you could get a 250ka pot with a switch to activate that on the front without having to add another hole in the back

[purpletele]

Ok so I'm in the process of building two HPR amps and I'm finishing up my plan set for the builds.  Attached are some pages from that plan set which I hope may help.  Now bear in mind I am adding a pull bright switch and a middle control to my amps but other than that it is the same.  I've checked the board drilling mask and the loaded board for errors and they seem ok.  I'm still error checking the wiring plan though.  If anyone sees anything wrong on it let me know.

Nice work Barry!

I may have to build one of those.

[bnwitt]

Thanks PT.  One of them is for my studio and the other one for a local player.  They are quick to build unlike the AB763 and sound pretty good too.  I have to decide which speaker to use on them though.  I'm doing 12" baffles so that gives me a lot of lee way.  The ones I built back in 08' had Reverend Alltone speakers and they sounded pretty good.

[lego4040]

Thoughts, I had this and tried it out. Not as shinny on finished soldering, maybe because lead percentage?

[bnwitt]

I use Kester 44 63/37 solder and it's pretty shiny when done correctly but it can be dull if not soldered correctly due to the rosin not bubbling up to the top

[lego4040]

Im always afraid of melting the wires if heating to long and Im not sure if this has rosin core. Here is my Hakko setting, and where I left off today. Going to BBKings tonight to see a Bob Matley tribute band

[mresistor]

Hey Lego - Since you're building an HPR with bigger iron I thought you might be interested in reading this thread. It has a ton of info on PRs and using them with 6L6's which the TP-25 allows you to do.


http://el34world.com/Forum/index.php?topic=9301.0

[lego4040]

I will read that Mrisistor, where Im at now. Seems even with along weekend I didnt acomplish much. 6L6’s sounds intersesting.

[mresistor]

There was a lot of good info in that thread.  and I kind of like phsyco's posts..   just pop the 6L6's in there and rebias..    One of these days I will give that a try..

[lego4040]

Fired up the scope and figured out which ends are the foil side, know I know this is an old topic here and its been said that it doesnt matter much in these circuits. I did this more for my learning on the scope and understanding the schematic and layout orientaion. Now I need to do just that. Im going to do just that next and Ill check what i think against P2P amp pictures.
So far all the Brown drops I got from Doug are showing: With the writing side facing you the foil side on right leg

[mresistor]

I think that's pretty cool you're doing that, sure can't hurt..  you're the first person that I've heard state what side is foil side from a perspective of "as viewed" ......

[sluckey]

Any progress on the amp?

[lego4040]

Cant lie Steve, things have been tough and stressful at home lately and how Im keeping it together is a mystery. I got that “never a good late phone call last night” my Dad called to tell me his Mom passed. 98 years young. As for the amp, I will flip the pots over to inside in the morning and run the lines off them that head to back of chassis and the mid pot. Im putting a dwell next to it. Now that I got those caps sorted out with foil side Ill start the board as well. Mresistor made a cool suggestion of running 6L6’s so the on board bias pot may be moved to a spot? were I can rebias easily without taking chassis out. I was also looking at your tweed deluxe reverb and Id like to do the bias point jacks like you did, Mresistor has his with them as well. On Doug’s build isnt the one ohms off each 6v6’s pin 1&8 that? Doug has them on the board only.

[lego4040]

These are What I was thinking to use maybe for back panel bias pot. If not Ill get the 10KL from Doug

[lego4040]

Somemore rearranging. I wanted to be able to have room for kids to sit and do there projects  at my bench when Im workkng there.