Will my TSE zap my children? - Page 2 - diyAudio
Go Back   Home > Forums > Commercial Sector > Vendor Forums > Tubelab

Tubelab Discussion and support of Tubelab products, prototypes and experiments

Reply
 
Thread Tools Search this Thread
Old 2nd January 2012, 02:59 PM   #11
diyAudio Member
 
tubelab.com's Avatar
 
Join Date: Jul 2005
Location: West Virginia panhandle
Quote:
Most of the valve/tube DIY builds seen on these pages would not comply to national safety standards.
Virtually NONE would comply with the product safety standards in the US and most other countries. In the US the maximum temperature on any user accessible surface must not exceed 60C. This rules out all exposed vacuum tubes.

Quote:
Better is to take reasonable steps and then put the amp out of reach of persons who may come to harm.
I have stated this multiple times as well. Curious kids will do unexpected things. My own electronics career started at about age 5 when the paper clip met the wall outlet. Electricity is a useful servant, but MUST be respected. It has the power to kill you.

Quote:
Earth testing with a multimeter alone is futile. You need to pass some amps between the chassis and mains earth
True, the path from the chassis and all user accessible conductive surfaces must have a LOW RESISTANCE path to the earth ground. Technically to be compliant there must be a green wire with a yellow stripe from the ground pin on the IEC connector to the chassis! Green with no stripe is acceptable in some countries. Black or any other color will not pass UL or CE standards.

A multimeter test does not verify the resistance in the sub ohm range, but a multimeter test AND a visual inspection should be sufficient provided the builder understands the reason for all of this.

The most probable mechanism for an electrical shock related failure in a tube amp, especially a vintage tube amp or a new one built with vintage components is the transformers. If you think about it the transformer is wound with enameled wire and paper or mylar insulation. The only thing seperating the chassis of the amp from hundreds of volts is paper and enamel. A 50 year old transformer may have absorbed enough moisture to start breaking down the insulation. This is why I stress that ALL metal surfaces MUST be connected to earth ground INCLUDING the transformer cases AND the speaker secondaries. I have personally seen two bad transformers in my 40+ years of tube amp work. Both functioned normally but represented serious shock hazards. Both were in vintage amplfiers. One had almost 300 volts on the speaker leads and the other had 70 volts AC on the chassis. BOTH amps blew the mains fuse once the chassis was properly grounded with a 3 wire line cord.

As I stated on my web site the TSE was not intended for novice builders. In fact it started out as a design for my own use that people kept wanting. The grounding requirements are spelled out much more clearly in the SSE manual. The SSE manual section on grounding AND the section on safety should be read and understood before operating the amplifier. If is is not perfectly clear, the amp should be checked out by someone who understands the requirements.
__________________
Too much power is almost enough! Turn it up till it explodes - then back up just a little.
  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
FS: ZAP Filter Mk2 naamanf Swap Meet 0 1st January 2012 11:25 PM
Zap Pulse or UcD carlos spud Class D 19 9th September 2005 12:09 PM
Ucd400 vs Zap Pulse trex Class D 0 5th March 2005 11:12 AM
ZAP filter nFORCE Digital Source 5 19th December 2002 07:25 PM


New To Site? Need Help?

All times are GMT. The time now is 02:33 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