Audiokarma.org
Audiokarma Featured Sponsor

Go Back   AudioKarma.org Home Audio Stereo Discussion Forums > Tube Audio


We appreciate your help

in keeping this site going.
Reply
 
Thread Tools Display Modes
  #1  
Old 05-01-2010, 10:47 AM
BmWr75's Avatar
BmWr75 BmWr75 is offline
Not as old as I look
 
Join Date: Feb 2008
Location: Northeast MS
Posts: 5,238
Quality problems with Russian 6P3-E power tubes

Posted this in another thread, but think a new one is merited.

I bought 8 of these Russian 6P3-Es tubes in recent months from eBay seller basa_79. Never installed them in an amp. Got a tube tester recently and tested all 8. Five were closely matched in GM. Three of them were bad......I could see the wire windings glowly very brightly on two of them and the meter went wild on my tester. One was just dead. I think all three of the bad ones came in the 2nd purchase and were in the original paper tubes. The first quad purchased had no paper tubes.

Buyer beware with this eBay seller. I've contacted him about the problem, will share the results.
__________________

About 1/2 of what you read on the internet is true......problem is knowing which 1/2!!
Reply With Quote
  #2  
Old 05-01-2010, 12:15 PM
nerdorama's Avatar
nerdorama nerdorama is offline
AK member
 
Join Date: Nov 2004
Location: Seattle area
Posts: 1,354
This is the reason I bought from Jim McShane. I've heard a few stories like this. He takes the hit and culls that bad ones. His price isn't that much higher after shipping from Russia and they're guaranteed.

Please don't think I'm trying to rub it in. I almost bought from the auction until I heard some of these stories. If I wanted to buy a large quantity and cull them myself, then it may make sense to me. The Russian vendors from whom I've purchased items have all been very good, I just don't want to mess around with tubes that are a crap shoot in a small quantity.

I hope your seller will work it out with you.

Jim said in a post that some of his initially bad tubes worked ok after a number of hours of burn-in by just running the heaters to dissipate some internal gas problems. I think that was the story. It might be an answer to some of your bad tubes.
http://db.audioasylum.com/cgi/m.mpl?...hlight=6p3s&r=

Jim also suggests that possibly baking them in an oven would clear up some of the gas issues.
http://db.audioasylum.com/cgi/m.mpl?...highlight=6p3s


They sound very nice. I've heard them replacing both 5881's and EL34's.

Best,
John
__________________
De gustibus non est disputandum
VPI Scout, Denon DL-304,Wright WPA-200, DIY tube pre and amp, ADS 910, Lynn Olson ME2, Apogee Centaur Minor, Stax SR-X
Reply With Quote
  #3  
Old 05-01-2010, 02:37 PM
BmWr75's Avatar
BmWr75 BmWr75 is offline
Not as old as I look
 
Join Date: Feb 2008
Location: Northeast MS
Posts: 5,238
Two of the three bad tubes didn't have any silver flashing inside the top of the tube near the getters. Other than that they looked identical to the good tubes. What does the missing silver flashing mean?

I've bought from Jim McShane too, he's a good seller. I'll check out the 6CA7s he has.
__________________

About 1/2 of what you read on the internet is true......problem is knowing which 1/2!!
Reply With Quote
  #4  
Old 05-01-2010, 05:41 PM
Pio1980's Avatar
Pio1980 Pio1980 is offline
AK Member
 
Join Date: Aug 2008
Location: Angel Station, Alabama
Posts: 13,081
"What does the missing silver flashing mean?"
Either they haven't been "gettered", or if a whitish powdery appearance very gassy or no vacuum due to air leak. All very bad and useless tubes.
__________________
"Different" is easy, "Better" not so much.

Goodness comes from getting the basics right, glory is to be found in tending to the details.
Reply With Quote
  #5  
Old 05-01-2010, 08:10 PM
BmWr75's Avatar
BmWr75 BmWr75 is offline
Not as old as I look
 
Join Date: Feb 2008
Location: Northeast MS
Posts: 5,238
Here's a picture that shows a tube with the missing silver flashing.
Attached Images
File Type: jpg IMG_2109.jpg (38.2 KB, 54 views)
__________________

About 1/2 of what you read on the internet is true......problem is knowing which 1/2!!
Reply With Quote
Audiokarma
  #6  
Old 05-01-2010, 08:20 PM
Ty_Bower Ty_Bower is offline
AK Member
 
Join Date: Mar 2008
Location: Newark, DE
Posts: 821
The flashing is still there, it has simply turned white from exposure to air. That tube has lost its vacuum and is no longer good. Nothing can be done for it.
__________________
Surface morphology is not a contributing factor other than the specularity of the finish.
Reply With Quote
  #7  
Old 05-01-2010, 08:57 PM
Bluelobster's Avatar
Bluelobster Bluelobster is offline
AK Member
 
Join Date: Jan 2004
Posts: 802
Quote:
Originally Posted by BmWr75 View Post
Two of the three bad tubes didn't have any silver flashing inside the top of the tube near the getters. Other than that they looked identical to the good tubes. What does the missing silver flashing mean?

I've bought from Jim McShane too, he's a good seller. I'll check out the 6CA7s he has.
These Russian tubes are really good once you get a quad that works and is suitably matched. Don't give up on them I think you will like them, certainly better than any 6ca7 out these days. Set them up so that they are about 23 watts output per pair, that seems to be their sweet spot.
A fellow over at the Asylum, goes by "Twystd" turned me on to them over a year ago. I first put them in an ST70, then Dynaco MKIV and was really impressed and happy.
BTW the tube with the clear top lost it's vacuum, hence no getter. These tubes have been around unused for years so it may not be the sellers fault unless he said they were checked and tested.
Reply With Quote
  #8  
Old 05-01-2010, 09:05 PM
BmWr75's Avatar
BmWr75 BmWr75 is offline
Not as old as I look
 
Join Date: Feb 2008
Location: Northeast MS
Posts: 5,238
The two tubes that have clear tops had not been tested. They were still sealed in the original paper boxes, rusty staples and all. The other bad one was probably also untested.

The 5 good ones are pretty well matched. Will give them a go in my ST70.
__________________

About 1/2 of what you read on the internet is true......problem is knowing which 1/2!!
Reply With Quote
  #9  
Old 05-02-2010, 10:17 AM
neon the cat neon the cat is offline
AK Member
 
Join Date: Jan 2010
Posts: 8
6p3e

I like this tube, and was turned on to them by Ty Bower (thanks, Ty!).
A quad I ordered from ebay seller, nixiestore, had one tube DOA (filament).
Jacob sent a new tube immediately from his Russian warehouse. Trustworthy guy, I will buy all my Russian tubes from him in future.
Since then, the tubes have been working and sounding very good.
Reply With Quote
Reply


Thread Tools
Display Modes

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


All times are GMT -5. The time now is 01:58 AM.



Friends of Audiokarma
We appreciate your help in keeping this site going.
Pro DJ Headphones - click here
Amps and Sound
Wargos Electronics
Organ Donor Parts
Sonneteer
Parts Connexion
Sound Stage Direct
Atlantic Systems
AudioClassics
Take Five Audio
AV Solutions
Audio Salon
Tone Arm Audio
Audience AV
Musical Paradise
Simply Speakers
Classic Sound Repair
BD Enterprise
McIntosh Cabinets
Howard Products
Cabledyne
FM DX Antenna
BOI Audio Works
Siliconray
Amplifiedparts
Vinyl Magic Record Cleaner
RSL Speakers
Grant Fidelity
Urban Antigue Radio
Yesterday's Audio
Many Moons Audio
DeWick Repairs
The Tube Store
Vintage Electronics Repair
Audio Doctor
Politicalchat.org
MCM Electronics
Antique Radio Classifieds
Herbies Audio Lab
Videokarma.org
   
Powered by vBulletin® Version 3.8.6
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
ęCopyright 2002-2014 AudioKarma.org, All rights reserved.