Welcome To the Hoffman Amplifiers Forum

September 08, 2025, 02:22:11 pm
guest image
Welcome, Guest. Please login or register.
-User Name
-Password



Hoffman Amps Forum image Author Topic: Dual 5Y3  (Read 4577 times)

0 Members and 1 Guest are viewing this topic.

Offline Mats

  • Level 1
  • *
  • Posts: 67
Hoffman Amps Forum image
Dual 5Y3
« on: September 08, 2015, 09:39:22 am »
Hi
Im trying to get my schematics in order. I got to this one, Angela Super Singel-Ended.
My question here: Dual 5Y3 in a PSE amp ??
Perhaps its just a cool thing, with two rectifiers.
The schematic says, the PT is Fender Deluxe or equivalent.
Can that PT really handel two 5Y3 ?
/Mats

Offline Willabe

  • Global Moderator
  • Level 5
  • ******
  • Posts: 10524
Hoffman Amps Forum image
Re: Dual 5Y3
« Reply #1 on: September 08, 2015, 09:50:59 am »
5Y3 draws 2A, Deluxe/Reverbs use GZ34/5AR4 they draw 1.9A. Latter Deluxe? Reverb's used 5U4, 3A current draw.

So 2x5Y3=4A heater current draw. Even if the Fender PT had a 3A/5v heater that's still 1 amp short.

Why not just use a single GZ34? Just have to watch the B+ plate dcv. A single 5V4 (2A heater) will give less B+dcv than a GZ34. (Our host Doug sells a new 5V4 that's spot on for dcv compared to a NOS 5V4 for a very good price.)

Or Classic Tone might make a small PT that has enough 5v heater current and B+ current to run 2x5Y3's and 2x6V6's? SE 6V6 Champ's only draw ~40mA B+. So 2xParallel SE 6V6= ~80mA. 
« Last Edit: September 08, 2015, 10:11:53 am by Willabe »

Offline sluckey

  • Level 5
  • *******
  • Posts: 5075
    • Sluckey Amps
Hoffman Amps Forum image
Re: Dual 5Y3
« Reply #2 on: September 08, 2015, 10:04:22 am »
If I paid $50 for a transformer that was rated for 5V@2A I definitely would not put a 4A load on it. I think the dual rectifiers are just show. I'd put a 5AR4 in it and move on.
A schematic, layout, and hi-rez pics are very useful for troubleshooting your amp. Don't wait to be asked. JUST DO IT!

Offline Mats

  • Level 1
  • *
  • Posts: 67
Hoffman Amps Forum image
Re: Dual 5Y3
« Reply #3 on: September 08, 2015, 12:21:12 pm »
Hi
Thanks for answers.
Yes, 4A for dual 5Y3.
Thats, as you say, its just for show.
I wonder why they put it in there in the schematic ?
/Mats


Offline shooter

  • Level 5
  • *******
  • Posts: 11018
  • Karma Loves haters
Hoffman Amps Forum image
Re: Dual 5Y3
« Reply #4 on: September 08, 2015, 01:53:20 pm »
Quote
I wonder why they put it in there in the schematic

Marketing?

I did a build that where I wanted "symmetry"  and the tube regulator made it "un-balanced"  so I took a bad octal, drilled out the base, stuck in and led and used it as a power indicator, walla, 2 tubes for balance
Went Class C for efficiency

Offline kagliostro

  • Level 5
  • *******
  • Posts: 7740
Hoffman Amps Forum image
Re: Dual 5Y3
« Reply #5 on: September 08, 2015, 03:15:27 pm »
Quote
I wonder why they put it in there in the schematic

Having two rectifier tubes in parallel halves the resistance and modify the drop of voltage, so there is an increase in B+ level

may be the reason is this ?

K
« Last Edit: September 08, 2015, 03:18:10 pm by kagliostro »
The world is a nice place if there is health and there are friends

Offline DummyLoad

  • SMG
  • Level 5
  • *****
  • Posts: 5791
Hoffman Amps Forum image
Re: Dual 5Y3
« Reply #6 on: September 08, 2015, 04:42:38 pm »
Quote
I wonder why they put it in there in the schematic

Having two rectifier tubes in parallel halves the resistance and modify the drop of voltage, so there is an increase in B+ level

K



again, quoting sluckey, just use a 5AR4 if that's the case.


--pete

Offline billcreller

  • Level 4
  • *****
  • Posts: 2616
  • 1934
Hoffman Amps Forum image
Re: Dual 5Y3
« Reply #7 on: September 11, 2015, 08:28:22 pm »
What if I have a lot of 5Y3s & no 5AR4s ?
I'll never figure this out......

Offline shooter

  • Level 5
  • *******
  • Posts: 11018
  • Karma Loves haters
Hoffman Amps Forum image
Re: Dual 5Y3
« Reply #8 on: September 11, 2015, 09:12:37 pm »
Quote
So 2x5Y3=4A heater current draw

I didn't do the math tween tube cost and tranny but I'm thinking the tube looses, well, unless you have lots of dual 5Y3 trannies :icon_biggrin:
Went Class C for efficiency

Offline foghornleghorn

  • Level 1
  • *
  • Posts: 85
Hoffman Amps Forum image
Re: Dual 5Y3
« Reply #9 on: September 18, 2015, 12:58:06 pm »
I used two 5Y3GTs in a 4x6V6 amp with an AES tweed Bassman PT. So 3A 5V winding. It has not given any problems. I sold it a while ago to a pro player and have had no frantic phone calls about it since.


So I'd say a 3A winding is OK, but I wouldn't put two 5Y3s on a 2A winding, I think that's asking for trouble.

Offline Mats

  • Level 1
  • *
  • Posts: 67
Hoffman Amps Forum image
Re: Dual 5Y3
« Reply #10 on: September 21, 2015, 11:20:16 am »
Hi
Thanks
If 3A is OK for a up and running amp.
Perhaps the winding 5V 3A, of that PT is underrated a little
and can deal with the dual 5Y3 at 4A.
/Mats

 


Choose a link from the
Hoffman Amplifiers parts catalog
Mobile Device
Catalog Link
Yard Sale
Discontinued
Misc. Hardware
What's New Board Building
 Parts
Amp trim
Handles
Lamps
Diodes
Hoffman Turret
 Boards
Channel
Switching
Resistors Fender Eyelet
 Boards
Screws/Nuts
Washers
Jacks/Plugs
Connectors
Misc Eyelet
Boards
Tools
Capacitors Custom Boards
Tubes
Valves
Pots
Knobs
Fuses/Cords Chassis
Tube
Sockets
Switches Wire
Cable


Handy Links
Tube Amp Library
Tube Amp
Schematics library
Design a custom Eyelet or
Turret Board
DIY Layout Creator
File analyzer program
DIY Layout Creator
File library
Transformer Wiring
Diagrams
Hoffmanamps
Facebook page
Hoffman Amplifiers
Discount Program