Tubing Testing...how are these numbers? - 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 7th May 2008, 08:00 AM   #1
diyAudio Member
 
whubbard's Avatar
 
Join Date: Oct 2007
Location: New York, NY
Default Tubing Testing...how are these numbers?

Hi,

I'm looking to buy a pair of siemen's 7308s, and I've found a good seller who has tested the tubes. Here are the results:


Quote
Tube1 - A1 = 18,0/13,0 A2 = 18,0/13,0

Tube2 - A1 = 18,0/13,0 A2 = 18,0/13,0

Both tubes have A6 9C stamped on small plates inside. If you know how to dechifer the siemens codes please share that information with me.


For a 7308 is this good/bad? It will be used in an preamp.

I can guess by the numbers that these tubes are obviously matched, but is this 18/13 good. (frankly, what does it mean)

Also, I read abou it somewhere else, but I believe A6 means it was the 6th production, I've heard the 4th was the best, but for the price, I think these will be fine.

Thanks,
West
  Reply With Quote
Old 7th May 2008, 09:11 AM   #2
cerrem is offline cerrem  United States
diyAudio Member
 
Join Date: Jun 2005
Location: San Diego, CA
The only thing that comes to mind is the 18 is 18mA where the test took place..and the 13 is 13mA/V for transconductance...

Chris
  Reply With Quote
Old 7th May 2008, 09:15 AM   #3
diyAudio Member
 
whubbard's Avatar
 
Join Date: Oct 2007
Location: New York, NY
Would you say the tubes are good by that guess? Or is it still hard to tell?
  Reply With Quote
Old 8th May 2008, 02:53 AM   #4
cerrem is offline cerrem  United States
diyAudio Member
 
Join Date: Jun 2005
Location: San Diego, CA
Quote:
Originally posted by whubbard
Would you say the tubes are good by that guess? Or is it still hard to tell?
Yes....that would make the tubes test in the high range...

Chris
  Reply With Quote
Old 8th May 2008, 05:28 AM   #5
diyAudio Member
 
whubbard's Avatar
 
Join Date: Oct 2007
Location: New York, NY
Thank you Chris.

-West
  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
Teflon tubing for jacket material otto88 Parts 15 15th October 2013 02:06 AM
Magnesium tubing jlsem Analogue Source 1 3rd March 2008 03:02 AM
shrink tubing for DIY Speaker Cables billiam Everything Else 3 23rd March 2003 10:04 PM
Re-tubing Quickie M60 (EL34 quads) wheezer Tubes / Valves 10 4th March 2003 02:52 AM


New To Site? Need Help?

All times are GMT. The time now is 01:45 AM.


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