Go Back   Home > Forums > >

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

Data Sheets
Data Sheets
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
Old 4th March 2021, 12:43 AM   #31
sser2 is offline sser2  United States
diyAudio Member
 
Join Date: Jan 2003
Location: Pittsburgh, PA
Keep going, guys, very entertaining.
  Reply With Quote
Old 4th March 2021, 12:54 AM   #32
PRR is offline PRR  United States
diyAudio Member
 
PRR's Avatar
 
Join Date: Jun 2003
Location: Maine USA
Data Sheets
Quote:
Originally Posted by mooreamps View Post
.......I was first to publish lamp biasing on ValveJunior.com, abouts 12 years ago.......
Page Title 2003

SRPP on Steroids 2005

Which Tube Shall I Use ? Typos 2005
  Reply With Quote
Old 4th March 2021, 01:04 AM   #33
dgta is offline dgta  United States
diyAudio Member
 
Join Date: May 2011
Quote:
Originally Posted by mooreamps View Post
I was ET in the US Navy, going back 45 years. .
So the movie was named after you?
  Reply With Quote
Old 4th March 2021, 01:05 AM   #34
leadbelly is offline leadbelly  Canada
Account disabled at member's request
 
Join Date: Dec 2002
Location: Calgary, Alberta
Quote:
Originally Posted by mooreamps View Post
1. I've been building guitar and HiFi amplifiers going back 12 years. I was ET in the US Navy, going back 45 years. I have one HiFi stereo amplifier, Surface 2, does not even use a pre-amp to drive the power tubes.

2. I was first to publish lamp biasing on ValveJunior.com, abouts 12 years ago. Then I noticed the Valve Lizard out of the UK publish on his website a bias diode shunted by an electrolytic cap. Was so funny I took a screen shot of it.

3. ...... and that would be Dr. Moore to you......
Wow, what qualifications! THE ValveJunior.com! Not THE ValveJunior.com? The forum devoted to a disposable tube practice amp? Was it hosted on a 486?

If you do manage to stick around here now that the 486 failed you'll see why qualifications don't always mean much to us.
  Reply With Quote
Old 4th March 2021, 01:17 AM   #35
PRR is offline PRR  United States
diyAudio Member
 
PRR's Avatar
 
Join Date: Jun 2003
Location: Maine USA
Data Sheets
Quote:
Originally Posted by leadbelly View Post
...Was it hosted on a 486?...
I've hosted departmental business sites on a 386SX. Inspired by an academic site hosted on a 286. A lot more than 12 years ago.
  Reply With Quote
Old 4th March 2021, 01:19 AM   #36
Tubelab_com is offline Tubelab_com  United States
diyAudio Member
 
Tubelab_com's Avatar
 
Join Date: Jul 2005
Location: West Virginia panhandle
Quote:
Originally Posted by mooreamps View Post
I am wondering, who would it be, for me to talk to, to update some of these spec's in tube data sheets...?
I don't know who you would talk to.....or if anyone would listen. The specs in question were written long ago by people who are no longer alive, and if they are, could care less about vacuum tubes. Say you could make up a data sheet for a tube that had different numbers that those published by the company that actually designed the part, and made it, what would lead anyone to trust someone who says that based on a single example that those 50 year old specs are wrong?

Based on a single example, I can say that my TSE amp has a 5AR4 tube happily feeding a 100 uF cap. That amp has had the same 50 year old Sylvania made RCA tube in it since it was built 16 years ago, it works reliably, and has never faulted. Experience tells me that stuffing a batch of new production tubes in that same socket will result in at least 10% of them failing the first time the power switch gets flipped.

Based on a single sample, I could be in the parking lot at work on a rainy Florida day, stick the gas pedal to the floor in my car, and repeatedly slam the shifter between drive and reverse while spinning donuts all over the lot. It never broke, and I had that car for several years. Would all 1970 Plymouth Valiants respond the same way? NO, I'm pretty sure that most would suffer some busted parts......there are several variables here. In this case it was the crappy tires, underpowered engine and light vehicle weight. In your case you might have a power transformer with high DCR, a tube with slightly low emission, or a high ESR cap.

Tubes are indeed mechanical devices that were assembled by humans. No two are exactly alike.

Get a rectifier tube with a perfectly round cathode, properly centered in a perfectly round plate, with a perfectly even uniform coating on the cathode, and it may indeed survive maybe 1000 uF, forever.

Get one assembled late Friday afternoon near "quittin time" or on a Monday morning after a party weekend, and all of that start up current will flow at the point on the cathode where the coating is the thinnest because it heats up the quickest, and if that happens to be a bit closer to the plate because the alignment is a bit off, sparks will fly, and tubes will die. Been there, blown that!

41 years as a product development engineer at Motorola, most of that on "mission critical equipment" (people could die if it doesn't work) has taught me to design to a very conservative spec on incoming parts.

Change all the specs you want, I'll stick with the ones I trust.....and verify what I don't.

I spent nearly two days curve tracing some 6KT6 tubes. I have found 7 different variants of that relatively obscure TV tube. No two of them are alike, and only the 50 year old RCA tube comes close to the 1966 RCA data sheet. I will make sure that all will work in my design.

I'm sure that there are a lot of things called "EZ81" or "6CA4." Some will naturally be stronger than others, but a good designer MUST design to the weakest one, because someone somewhere will stick one in his amp, and crank it to ELEVEN.

Do what you want with your own personal amp, but if you build amps for sale, someone somewhere will find a way to blow it up. Your job as an amp designer is to make their task harder.
__________________
Tubelab, I blow stuff up so that you don't have to.
  Reply With Quote
Old 4th March 2021, 01:44 AM   #37
leadbelly is offline leadbelly  Canada
Account disabled at member's request
 
Join Date: Dec 2002
Location: Calgary, Alberta
Quote:
Originally Posted by PRR View Post
I've hosted departmental business sites on a 386SX. Inspired by an academic site hosted on a 286. A lot more than 12 years ago.
I did my engineering 1st year heat transfer project on an Atari 8bit, so there! If you say PDP11 I give up.
  Reply With Quote
Old 4th March 2021, 07:26 AM   #38
v4lve lover is online now v4lve lover  Netherlands
diyAudio Member
 
Join Date: Aug 2010
Location: Surrounded by glass, no really my room is full of tubes
Data Sheets Data Sheets
Quote:
Originally Posted by FlaCharlie View Post
Seriously?? You probably need to contact a psychic who can perform a seance. The engineers who designed the tubes and came up with these specs are long dead. And they didn't just pull the data sheet specs out of a hat. They are the result of extensive testing.



Ive been looking on Amazon for a Ouija board. But most of these are made by the Chinese.. I have some questions regarding the best practices.


Edit nevermind, appearantly all the information is out there.


How to Use a Ouija Board | Psychic Abilities - YouTube

Last edited by v4lve lover; 4th March 2021 at 07:31 AM.
  Reply With Quote
Old 4th March 2021, 03:29 PM   #39
jhstewart9 is offline jhstewart9  Canada
diyAudio Member
 
jhstewart9's Avatar
 
Join Date: Apr 2013
Location: near Toronto
I put customer lists on an HP71B handheld running in BASIC. And got the HP2225A inkjet printer for it. Also the HP9114 disc drive & a compatible CRT display. And some 3rd party extra memory to load it up. And the interface board to a PC. Still have all here in the pile & another HP71B given by a former HP employee.
There was a whole line of products that interconnected on the HPIL Loop. The command set for that a lot like the HPIB that became IEEE488 / IEC625
  Reply With Quote
Old 4th March 2021, 04:42 PM   #40
mooreamps is offline mooreamps  United States
diyAudio Member
 
Join Date: Apr 2012
Location: San Jose, Ca.
Quote:
Originally Posted by leadbelly View Post
Wow, what qualifications! THE ValveJunior.com! Not THE ValveJunior.com? The forum devoted to a disposable tube practice amp? Was it hosted on a 486?

If you do manage to stick around here now that the 486 failed you'll see why qualifications don't always mean much to us.
you watch your mouth , boy....
  Reply With Quote

Reply


Data SheetsHide this!Advertise here!
Thread Tools

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

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Needed: Tweeter data sheets and pairing recommendations Jennice Multi-Way 5 10th July 2004 08:02 PM
Power Transistor data Sheets... where to find Harlan Parts 3 21st February 2004 03:03 PM
Data sheets for japanese transistors? Cradle22 Parts 2 8th September 2003 11:22 AM
M5238 data sheets??? Christer Parts 5 30th March 2003 04:07 PM
Japanese data sheets HarryHaller Solid State 1 16th May 2002 06:54 AM


New To Site? Need Help?

All times are GMT. The time now is 03:48 PM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2021 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 14.29%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2021 DragonByte Technologies Ltd.
Copyright ©1999-2021 diyAudio
Wiki