need 13fd7 curves - diyAudio
Go Back   Home > Forums > Amplifiers > Tubes / Valves
Home Forums Rules Articles diyAudio Store Gallery Wiki Blogs Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

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
Thread Tools Search this Thread
Old 23rd August 2004, 02:30 PM   #1
alejo is offline alejo  Argentina
diyAudio Member
Join Date: Jun 2004
Unhappy need 13fd7 curves

Hello, I interesting to buil a little SE amp around a disimilar triode 13fd7.
In Duncanamps page find datashet for this double triode but not find curves, I need this for desing.
The 6V version of this triode name is 6fd7.

Plese, if you now where I can find this.....
  Reply With Quote
Old 24th August 2004, 01:57 AM   #2
diyAudio Member
Join Date: Jul 2004
Location: middle-o-nowhere Saskatchewan
Default 13fd7

I think the closest you are going to get, is the 6em7. Triode 1 is identical. Judging by other circuits (6em7), run triode 2 as per the manual for a 6fd7. In this case 150v, -17.5v at 40ma.
  Reply With Quote
Old 24th August 2004, 03:41 AM   #3
diyAudio Senior Member
fdegrove's Avatar
Join Date: Aug 2002
Location: Belgium

Maybe this will help:


I haven't checked if any of the references have a published datasheet showing curves.
Seeing what the tubes were designed for, I doubt any of them will.
I recall having had to plot the curves ourselves when trying to decide which of those disimilar triodes was best suited for a headphone amp....

  Reply With Quote
Old 24th August 2004, 08:27 AM   #4
EC8010 is offline EC8010  United Kingdom
diyAudio Moderator Emeritus
EC8010's Avatar
Join Date: Jan 2003
Location: Near London. UK
Aaargh! I looked up that reference, Frank, and it had 6ES8 as a replcement for 6DJ8! Now we know where all that trouble started.

(For those of you who didn't know, 6ES8/ECC189 is a variable-mu double triode, whereas 6DJ8/ECC88 is constant, so if you try to use 6ES8/ECC189 for audio, you can count on increased distortion.)
The loudspeaker: The only commercial Hi-Fi item where a disproportionate part of the budget isn't spent on the box. And the one where it would make a difference...
  Reply With Quote
Old 24th August 2004, 08:15 PM   #5
diyAudio Senior Member
fdegrove's Avatar
Join Date: Aug 2002
Location: Belgium

Now we know where all that trouble started.
Oh dear...
I doubt they were the cause of the confusion. Many publicized documents list it as being a substitute anyway.

What caused the troubles is some greedy vendors rebranding their stock of ECC189s turning them into fake ECC88s IMO.

Either way, it's generally good practice to know that most so called substitutes will "work" in most circuits although far from optimally in quite a lot of cases.
For a finely tuned audio circuit it would be good practice to carefully check with the datasheets first.

  Reply With Quote
Old 24th August 2004, 11:51 PM   #6
diyAudio Member
Tom Bavis's Avatar
Join Date: Jun 2002
Location: Macedon NY
For what it's worth, the 6DE7 (10DE7, 13DE7) DOES have curves at Frank's place (though the smaller triode has lower gain), and it's pin-compatible with the 6FD7. So you could start with that one, and if you need the gain, drop in the 6FD7. They all are probably close to 6EM7 / 6FG7 / 6FM7 etc.
  Reply With Quote


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
PHL Curves - anybody have? Bill Fitzpatrick Multi-Way 3 30th November 2012 10:52 AM
DIY U-L curves Bandersnatch Tubes / Valves 10 1st August 2008 11:00 AM
Derive Triode Curves from Pentode Curves? dsavitsk Tubes / Valves 3 14th May 2007 06:10 PM
Curves, curves, and more curves CarlyBoy Tubes / Valves 5 1st December 2006 10:11 AM
where's the curves? bostonswoop Multi-Way 13 13th March 2006 12:32 AM

New To Site? Need Help?

All times are GMT. The time now is 03:54 PM.

vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Copyright 1999-2017 diyAudio

Content Relevant URLs by vBSEO 3.3.2