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Re: Class A, AB1, B, C Operation/Modes [message #96481 is a reply to message #96475]

Mon, 06 March 2023 19:01

positron
Messages: 97
Registered: May 2020

Viscount

A I had an experience that moved me to post.

I went to an audiophile friend's house after he mentioned being
shocked when he plugged in an ic to his ST70 amplifier. It turned
out that the pin 1 (ground wire) was not connected to the chassis
and the power transformer internally shorted resulting in some
high AC voltage on the chassis. Of course the ics were grounded,
so when connecting to the ST70s, he was shocked.

ST 70s are known for power transformer failures, so
I would make sure you do not defeat the ground wire to your ST70,
or someone else has not done so. This includes not using a 3 to 2
plug adapter.

If it is disconnected, please reconnect it. If you cannot, please
disconnect all AC power plugs before connecting audio component ics.
Then plug in your components.

It has made me a little sensitive in this area.
The resistor wattages I use are multiple parallel 10 watters with
total resistance around 1.5 - 2 ohms or so. This keeps the chassis
ground to jacks/signal grounds at very low voltage differences, so
no shocks. The resistors also do not open while the fuse blows as
intended.

As a former designer/manufacturer, I plug and unplug ics all the
time and I need personal protection, and to keep all component
plugs connected to outlets when performing listening tests.
Unplugging and plugging in the power cords could possibly taint
the listening tests.

I use my own non shielded 6N copper wire in my ics to the amp
for improved sonic quality. (Also for other source components
to the preamplifier inputs.) As for any hum, I designed a circuit
specific 60hz hum canceling circuit in my amplifiers. Fortunately,
ear on the driver and zero hum.

(I edited for fuller and easier understanding of why I do what I do.)

cheers to all.

pos

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[Message index]

		Class A, AB1, B, C Operation/Modes By: positron on Sun, 05 February 2023 20:40
		Re: Class A, AB1, B, C Operation/Modes By: Wayne Parham on Sun, 05 February 2023 20:54
		Re: Class A, AB1, B, C Operation/Modes By: gofar99 on Mon, 06 February 2023 20:38
		Re: Class A, AB1, B, C Operation/Modes By: positron on Tue, 07 February 2023 16:13
		Re: Class A, AB1, B, C Operation/Modes By: gofar99 on Tue, 07 February 2023 19:33
		Re: Class A, AB1, B, C Operation/Modes By: positron on Tue, 07 February 2023 20:37
		Re: Class A, AB1, B, C Operation/Modes By: gofar99 on Thu, 09 February 2023 21:01
		Re: Class A, AB1, B, C Operation/Modes By: positron on Thu, 09 February 2023 21:35
		Re: Class A, AB1, B, C Operation/Modes By: positron on Tue, 28 February 2023 19:04
		Re: Class A, AB1, B, C Operation/Modes By: Wayne Parham on Wed, 01 March 2023 08:28
		Re: Class A, AB1, B, C Operation/Modes By: gofar99 on Wed, 01 March 2023 19:45
		Re: Class A, AB1, B, C Operation/Modes By: positron on Sun, 05 March 2023 00:33
		Re: Class A, AB1, B, C Operation/Modes By: Wayne Parham on Sun, 05 March 2023 08:05
		Re: Class A, AB1, B, C Operation/Modes By: gofar99 on Sun, 05 March 2023 08:10
		Re: Class A, AB1, B, C Operation/Modes By: positron on Mon, 06 March 2023 19:01
		Re: Class A, AB1, B, C Operation/Modes By: positron on Sat, 06 May 2023 22:32
		Re: Class A, AB1, B, C Operation/Modes By: gofar99 on Tue, 09 May 2023 21:30
		Re: Class A, AB1, B, C Operation/Modes By: positron on Thu, 11 May 2023 00:26
		Re: Class A, AB1, B, C Operation/Modes By: positron on Tue, 05 September 2023 23:48
		Re: Class A, AB1, B, C Operation/Modes By: gofar99 on Fri, 08 September 2023 21:12
		Re: Class A, AB1, B, C Operation/Modes By: BreakneckRedneck on Sun, 24 September 2023 00:42
		Re: Class A, AB1, B, C Operation/Modes By: positron on Thu, 12 October 2023 11:21
		Re: Class A, AB1, B, C Operation/Modes By: positron on Fri, 03 November 2023 12:22
		Re: Class A, AB1, B, C Operation/Modes By: gofar99 on Fri, 03 November 2023 20:58
		Re: Class A, AB1, B, C Operation/Modes By: positron on Sun, 05 November 2023 01:38
		Re: Class A, AB1, B, C Operation/Modes By: positron on Thu, 07 December 2023 23:12
		Re: Class A, AB1, B, C Operation/Modes By: gofar99 on Mon, 18 December 2023 20:20
		Re: Class A, AB1, B, C Operation/Modes By: positron on Tue, 16 January 2024 21:32
		Re: Class A, AB1, B, C Operation/Modes By: gofar99 on Wed, 24 January 2024 20:31

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