2 Tube questions, - diyAudio
Go Back   Home > Forums > Amplifiers > Tubes / Valves

Tubes / Valves All about our sweet vacuum tubes :) Threads about Musical Instrument Amps of all kinds should be in the Instruments & Amps forum

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 14th April 2006, 01:08 PM   #1
Trout is offline Trout  United States
diyAudio Member
 
Trout's Avatar
 
Join Date: Nov 2004
Location: Midwest Madman
Default 2 Tube questions,

#1,

I had ordered some Rectifier tubes a while back, I was looking for garden variety 5U4's for some guitar amps. They sent me J&J GZ34's instead.

I amp not sure if they can be swapped? This is for some older fender designs using PP 6L6's.

#2,

Rumaging around and organizing the hoard of tubes I have.
I came across some 6DT5's. Power Amplifier Pentodes.

Looked up the specs and wondered if these might make a couple nice SE amps. Say using those 5K Edcor transformers.
I searched the forum here and found nothing on this particular tube.

Trout
  Reply With Quote
Old 14th April 2006, 01:31 PM   #2
diyAudio Member
 
Join Date: Jul 2005
Location: North Derbyshire
Default Re: 2 Tube questions,

Quote:
Originally posted by Trout
[B]#1,

I had ordered some Rectifier tubes a while back, I was looking for garden variety 5U4's for some guitar amps. They sent me J&J GZ34's instead.
No idea on a 5U4, but a GZ34 is the standard European valve rectifier used in PA and HiFi valve amps it's rated at:

Vin 2x450V
Iout 250mA
C max 60uF
Vh 5V
Ih 1.9A

Pin connections:

1. IC
2. h
3. NP
4. a'
5. NP
6. a''
7. NP
8. h, k
__________________
Nigel Goodwin
  Reply With Quote
Old 14th April 2006, 02:09 PM   #3
SY is offline SY  United States
diyAudio Moderator
 
SY's Avatar
 
Join Date: Oct 2002
Location: Chicagoland
Blog Entries: 1
5U4 vs 5AR4/GZ34: 5U4 is filamentary, 5AR4 is unipotential (indirectly heated) cathode. Different heater/filament currents. Different pinout. Different forward drop.

Other than that, they're the same.
__________________
You might be screaming "No, no, no" and all they hear is "Who wants cake?" Let me tell you something: They all do. They all want cake.- Wilford Brimley
  Reply With Quote
Old 14th April 2006, 02:14 PM   #4
diyAudio Member
 
tubelab.com's Avatar
 
Join Date: Jul 2005
Location: West Virginia panhandle
The 5AR4 draws less filament current than the 5U4 and has a longer warm up time than the 5U4. Both of these things are generally good for your amp.

On the other hand you will get a few more volts by using a 5AR4. If you are already on the edge of melting output tubes, or blowing filter caps, as many older guitar amps are, these may not be so good.

The two tubes will give a slightly different sound in a guitar amp. The 5U4 has a higher internal resistance. This adds to the "B+ sag" effect that gives an amp good sustain when it is cranked up. The 5AR4 will give slightly more power with slightly less sustain than a 5U4.
__________________
Too much power is almost enough! Turn it up till it explodes - then back up just a little.
  Reply With Quote
Old 14th April 2006, 09:05 PM   #5
Trout is offline Trout  United States
diyAudio Member
 
Trout's Avatar
 
Join Date: Nov 2004
Location: Midwest Madman
Quote:
Originally posted by SY
5U4 vs 5AR4/GZ34: 5U4 is filamentary, 5AR4 is unipotential (indirectly heated) cathode. Different heater/filament currents. Different pinout. Different forward drop.

Other than that, they're the same.
So, In essence it should drop in ok because my B+ comes off the 5U4 Pin 8 All the other pins match, 2+8 Filaments, 4 & 6 Plates.

Extra voltage shouldnt be a problem. I have these set less than the normal self destruct critical zone.


How about those 6DT5's?

Think those could pump out a few watts in an SE amp?
Gene
  Reply With Quote
Old 14th April 2006, 09:57 PM   #6
SY is offline SY  United States
diyAudio Moderator
 
SY's Avatar
 
Join Date: Oct 2002
Location: Chicagoland
Blog Entries: 1
I'd think you could get two or three watts out of them.
__________________
You might be screaming "No, no, no" and all they hear is "Who wants cake?" Let me tell you something: They all do. They all want cake.- Wilford Brimley
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
2 tube questions electronjohn Tubes / Valves 4 7th April 2010 07:32 AM
DIY Tube Amp Questions john65b Tubes / Valves 95 24th April 2008 05:22 PM
Questions about first tube PSU! luvdunhill Tubes / Valves 2 18th September 2007 06:06 PM
24 bit / 192 kHz Tube DAC questions Overlord Digital Source 4 29th April 2003 05:14 PM


New To Site? Need Help?

All times are GMT. The time now is 05:50 PM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2