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dingobass
03-05-2013, 10:19 AM
Hi Guys,
the following is a copy of an email I received today from David McAuliff.




Some of you have heard that Andy suffered a bad shock recently after playing around with his Chinese 5E3 clone. He's now OK, just a bit crispier.

My amp go-to Eric Chan did a post mortum on the amp. Andy had put in some metal 6V6s. Eric reported this disturbing piece-

> I found that pin 1 of the 6V6 sockets are soldered in circuit relating to the screen grid which carries a high voltage. Normally pin 1 is a spare pin for 6v6GT (note GT means glass tube), but on metal 6v6s, pin 1 is connect to the outer metal case!! One may get an electric shock when you touch the metal tube! If you use spring-retention sockets, the high voltage will bleed to the CHASSIS making it live! This is very, very dangerous, and may kill.

> Please do not use any metal 6V6, also do not insert EL34 / 6CA7 whose pin 1 is connecting to the 3rd grid. I think you perhaps should inform the manufacturer of this bad news, and ask them not to use pin 1 at all.

Andy got the amp from ampmart.com, who are basically a reseller. The amp is sold by a few others as well. ampmart were kind enough to provide me with some of their documentation- it is also available as a kit. It definitely instructs a builder to connect the pin 1s on the 6V6 sockets to the high voltage screen grid. See attached image.

While you unlikely to reproduce these circumstances, it's worth noting how easily things went arse-up. The recommendation is that if you see a no-name Chinese amp that uses 6V6, 6P6P, EL84, 6CA7, or any valve that carries no current on pin 1, or if the customer presents a dead amp, you have quick look at the power valve sockets. If the pin 1 are wired into the grid, advise the customer not to use metal valves.


http://pitbullguitars.com/wp-content/uploads/2013/05/d5346-6v6.jpg

keloooe
03-05-2013, 09:08 PM
I haven't been on Facebook for a while, so I only just found out through this post, OUCH, good thing he is ok, otherwise Wudtone would be gone :o
I don't build amp kits, but ALWAYS make sure you have a good idea on how everything goes together and how they work, do a bit of research into the parts, like I did with pots, caps, and pups!!!

dingobass
03-05-2013, 09:56 PM
Hey Pestybitz,

This was a different Andy, a Guitar tech from NSW...

Our Andy is fine!

keloooe
03-05-2013, 10:20 PM
OOOOOOHHHHHHH!!!!! ok, lucky for him the fault wasn't lethal :o

Gavin1393
03-05-2013, 10:33 PM
I'm with you Pest! Also thought it was Wudtone's Andy.......