Go Back   Home > Forums > > >
Home Forums Rules Articles diyAudio Store Blogs Gallery Wiki Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

Tubelab Discussion and support of Tubelab products, prototypes and experiments

Reply
 
Thread Tools Search this Thread
Old 10th February 2020, 12:21 AM   #21
Steady7 is offline Steady7  United States
diyAudio Member
 
Join Date: Feb 2015
Quote:
Originally Posted by MikeR View Post
It looks like you wired the resistors in parallel, not in series. The effective resistance in parallel would be around 118 ohms. 20 volts at 118 ohms would be 169 mA per tube. You may have blown the output tubes.
Good deal my tubes are still fine. I was wondering why they seemed to really be getting hot quick. I'll wait for my correct resistors to arrive and wire them in. I'm sure those tubes lost a few hours of listening time! I can't believe I didn't realize how i was wiring those up....after all I am an industrial electrician! I'm just glad I wasn't at work and made a mistake like this, I'd never live it down. I haven't dealt with series and parallel circuits since school. I'm usually just given a schematic and wire it up, Or babysit my machines and replace a prox!

Last edited by Steady7; 10th February 2020 at 12:38 AM.
  Reply With Quote
Old 10th February 2020, 04:28 PM   #22
w5jag is offline w5jag  United States
diyAudio Member
 
Join Date: Feb 2007
Location: Arkansas
Quote:
Originally Posted by Steady7 View Post
Good deal my tubes are still fine. I was wondering why they seemed to really be getting hot quick ...
That was about 64 watts / 6L6GC, before they went into runaway and blew the fuse, so, once you get your amp squared away, I would put fresh tubes in it, and save these 6L6GC for testing or emergency spares.

When the tubes get really hot, like these must have, they can outgas impurities and reduce the vacuum in the tube, which makes it more likely they can overheat and runaway again, unpredictably, so, as cheap as new production tubes are, I just would not trust them. If they runaway and the fuse does not blow, a transformer could get damaged. Generally when a transformer is damaged, you throw it away and buy another. It looks like you have expensive transformers in your amp ...

You also put about 360 ma through your rectifier tube before the power tubes went into runaway and blew the fuse. It was also grossly overloaded, so I would put in a fresh rectifier tube as well; you can keep the present tube as an emergency spare.

You should never see red in any metal part of a tube, except for the heater and cathode, which will usually be a dull orange in receiving tubes. If you do see red, turn the amp off immediately - something is wrong. There are some transmitting tubes where red is okay, but you won't be using those in an SSE.

None of us are born knowing this stuff, we all have to learn it somehow or sometime. That's what makes the sub forum such a valuable resource.
__________________
Win W5JAG
  Reply With Quote
Old 10th February 2020, 04:45 PM   #23
Steady7 is offline Steady7  United States
diyAudio Member
 
Join Date: Feb 2015
Quote:
Originally Posted by w5jag View Post
That was about 64 watts / 6L6GC, before they went into runaway and blew the fuse, so, once you get your amp squared away, I would put fresh tubes in it, and save these 6L6GC for testing or emergency spares.

When the tubes get really hot, like these must have, they can outgas impurities and reduce the vacuum in the tube, which makes it more likely they can overheat and runaway again, unpredictably, so, as cheap as new production tubes are, I just would not trust them. If they runaway and the fuse does not blow, a transformer could get damaged. Generally when a transformer is damaged, you throw it away and buy another. It looks like you have expensive transformers in your amp ...

You also put about 360 ma through your rectifier tube before the power tubes went into runaway and blew the fuse. It was also grossly overloaded, so I would put in a fresh rectifier tube as well; you can keep the present tube as an emergency spare.

You should never see red in any metal part of a tube, except for the heater and cathode, which will usually be a dull orange in receiving tubes. If you do see red, turn the amp off immediately - something is wrong. There are some transmitting tubes where red is okay, but you won't be using those in an SSE.

None of us are born knowing this stuff, we all have to learn it somehow or sometime. That's what makes the sub forum such a valuable resource.
Thanks for the detailed reply. I was figuring the tubes were pretty much shot even if they worked. I have a spare rectifier tube but I'll get some more 6L6 tubes on the way and let the amp sit until all my right stuff gets here. This forum has been a great resource for me. This is my first amp build, first tube amp, so I was expecting a bit of a learning curve. I'm just glad I didn't fry anything, glad the fuse blew first!
  Reply With Quote
Old 10th February 2020, 04:58 PM   #24
cogitech is offline cogitech  Canada
diyAudio Member
 
cogitech's Avatar
 
Join Date: Jan 2011
Location: Kamloops, BC
SSE Checkout
A bit painful to be "watching" you go through this, brother. Really sorry to hear about what happened.

It is a learning curve for sure. I hope to avoid such mistakes, but I have recently learned that I can't trust myself to always be sharp.

I guess with high voltage stuff, everything is fine as long as it didn't kill you.
  Reply With Quote
Old 10th February 2020, 08:08 PM   #25
Steady7 is offline Steady7  United States
diyAudio Member
 
Join Date: Feb 2015
Quote:
Originally Posted by cogitech View Post
A bit painful to be "watching" you go through this, brother. Really sorry to hear about what happened.

It is a learning curve for sure. I hope to avoid such mistakes, but I have recently learned that I can't trust myself to always be sharp.

I guess with high voltage stuff, everything is fine as long as it didn't kill you.
Hey all is good! My amp still works, tubes can be used as test tubes from here on out. All of this was self inflicted on my part by not following the checkout process as one should and not properly reading the data sheets for my tubes. As long as someone else can gain from my mistakes and not repeat them I am happy.

I am just glad there is such a great resource for help here!

I hope you have better luck!
  Reply With Quote
Old 15th February 2020, 10:10 PM   #26
Steady7 is offline Steady7  United States
diyAudio Member
 
Join Date: Feb 2015
Just got my shipment in from Digikey with the new 680ohm 5 watt resistors and binding posts. Also installed new tubes and my current inrush limiter, no blown fuses so far!

No red plating! I am now down to right at 25watts dissipated
Thanks again for all the help!
  Reply With Quote
Old 17th February 2020, 04:37 PM   #27
cogitech is offline cogitech  Canada
diyAudio Member
 
cogitech's Avatar
 
Join Date: Jan 2011
Location: Kamloops, BC
SSE Checkout
Quote:
Originally Posted by Steady7 View Post
Just got my shipment in from Digikey with the new 680ohm 5 watt resistors and binding posts. Also installed new tubes and my current inrush limiter, no blown fuses so far!

No red plating! I am now down to right at 25watts dissipated
Thanks again for all the help!
Great news, man! Glad to hear you got it all figured out.
  Reply With Quote
Old 17th February 2020, 07:14 PM   #28
Tubelab_com is offline Tubelab_com  United States
diyAudio Member
 
Tubelab_com's Avatar
 
Join Date: Jul 2005
Location: West Virginia panhandle
I have owned these cheap Chinese 6L6GC's since I pulled them out of a Fender Bandmaster because the amps owner wanted new tubes. This was at least 20 years ago.

I use them any time I want to try something where the tube may not live. Oddly enough they are BOTH still working, but one does work a little better than the other.

They have been into the red zone too many times to remember.....

The 6BQ6GA's that I pushed past red, past orange, and into white hot, are still technically working, but have some distortion issues.....I probably rearranged the molecular structure of some of their inner guts.

While working on a little SPUD amp I found a 21LR6 tube that had a crack in the glass running up the entire side of the tube. I figured that it would be gassy, or shatter when powered up, so I almost tossed it....Then I decided that I would at least blow it up before trashing it. So I cranked it well into the red zone and waited for something bad to happen.....nothing just good sounding music. After about an hour of running in the red, I decided to save it. That was 10 years ago and it still works.

Sometimes our old tubes will take a beating and ask for more, other times they just blow up for no reason.
Attached Images
File Type: jpg 6L6_maxed.jpg (137.7 KB, 48 views)
File Type: jpg Chinese_6L6GC.jpg (302.7 KB, 44 views)
File Type: jpg 6BQ6GA.jpg (228.4 KB, 48 views)
File Type: jpg Cracked.jpg (169.0 KB, 48 views)
File Type: jpg 500volts_no_signal.jpg (293.7 KB, 45 views)
__________________
Tubelab, it's 5 year mission. To explore strange new tubes, to seek out new circuits and topologies, to boldly go where no tube has gone before......
  Reply With Quote
Old 17th February 2020, 09:32 PM   #29
cogitech is offline cogitech  Canada
diyAudio Member
 
cogitech's Avatar
 
Join Date: Jan 2011
Location: Kamloops, BC
SSE Checkout
I like your style, George! Hahhaa!
  Reply With Quote

Reply


SSE CheckoutHide 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

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Tubelab SE-II Checkout Duke58 Tubelab 29 7th January 2020 07:00 PM
tubelab sse checkout zxx222 Tubelab 6 5th January 2015 10:37 PM
TSE pre checkout check. mudchute Tubelab 10 10th July 2014 11:04 PM
Checkout problem TSE. Markman65 Tubelab 21 10th April 2014 03:25 PM
45 TSE Checkout Fail Alan Hope Tubelab 13 17th January 2012 08:42 PM


New To Site? Need Help?

All times are GMT. The time now is 09:44 AM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2020 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 15.00%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2020 DragonByte Technologies Ltd.
Copyright ©1999-2020 diyAudio
Wiki