Mains Connection to Amplifier

fmak · 1st May 2001, 09:05 PM

Can anyone explain why Accuphase (P100 Amp) connects neutral phase to power transformer via a rectifier (SEEMS TO BE) bridge with plus and minus out shorted and ac terminals across neutral and transformer bypassed by a 10 Ohm resistor? This raises the input impedance and creates a 0.8 V rms tophat shaped voltage drop across the mains terminals. Puzzles me!

I intend to take this out when I am able to understand why this arragement is used.

GRollins · 2nd May 2001, 01:34 AM

Here in the US, neutral is a term that refers to the grounded side of a 120VAC line. I believe that you're using 220VAC over there. 220V here is two lives and a ground (no 'neutral' per se), so I'm not clear as to what you're referring to when you say neutral. In other words, we may have a bit of a terminology problem here.
Is there any chance that you can post a schematic?

Grey

grataku · 2nd May 2001, 04:16 AM

Fmak
I don't have a CLUE of what's going on with your Accuphase (that wouldn't be the first time). I need a schematic too.

Grey,
in Europe the tri-phase is three conductors at 380V so the phase-neutral is 380/sqrt(3)=220V.
So it's the same deal over there like you have here, just a little different.

Novicar · 2nd May 2001, 09:35 AM

Fmak,

It looks like an earth loop breaker. You can find more about that circuit on Elliot Sound Product's web page:\
http://sound.au.com/earthing.htm (Figure 3)
BTW, the whole site is packed with excellent stuff!!

GRollins · 2nd May 2001, 11:59 PM

fmak,
If what you've got is what's shown on the ESP site, I'd say it's safe to remove it. I'd say to bypass it first. If you develop a ground loop, then hook it back in. Otherwise, go for it.
Incidentally, I'd be curious to know if you notice a sound quality difference with/without it...

Grey

2nd May 2001, 09:35 AM	#4
Novicar diyAudio Member Join Date: May 2001	Mains Connection to Amplifier Fmak, It looks like an earth loop breaker. You can find more about that circuit on Elliot Sound Product's web page:\ http://sound.au.com/earthing.htm (Figure 3) BTW, the whole site is packed with excellent stuff!!

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Super Triode Connection Amplifier Build with 6BM8 and 6AK5	DerFly	Tubes / Valves	35	3rd November 2009 07:45 AM
MAINS... simple, old style amplifier, plugged into mains electrical outlet (110)	destroyer X	Solid State	2	15th June 2008 02:31 PM
Class D amplifier? mains powered?	ThyDntWntMusic	Solid State	2	3rd February 2008 08:40 AM
Best possible connection between computer and amplifier? Need help!	Erik Johansson	Everything Else	7	28th April 2004 01:32 PM

New To Site?	Need Help?
Register to Participate Search Privacy Statement Contact Us	Frequently Asked Questions Did you forget your password? Mark Forums Read


	Please consider donating to help us continue to serve you. Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving

1st May 2001, 09:05 PM	#1
fmak diyAudio Member Join Date: May 2001 Location: London UK	Can anyone explain why Accuphase (P100 Amp) connects neutral phase to power transformer via a rectifier (SEEMS TO BE) bridge with plus and minus out shorted and ac terminals across neutral and transformer bypassed by a 10 Ohm resistor? This raises the input impedance and creates a 0.8 V rms tophat shaped voltage drop across the mains terminals. Puzzles me! I intend to take this out when I am able to understand why this arragement is used.

2nd May 2001, 01:34 AM	#2
GRollins diyAudio Member Join Date: Feb 2001 Location: Columbia, SC	Here in the US, neutral is a term that refers to the grounded side of a 120VAC line. I believe that you're using 220VAC over there. 220V here is two lives and a ground (no 'neutral' per se), so I'm not clear as to what you're referring to when you say neutral. In other words, we may have a bit of a terminology problem here. Is there any chance that you can post a schematic? Grey

2nd May 2001, 04:16 AM	#3
grataku diyAudio Member Join Date: Dec 2000 Location: -	Fmak I don't have a CLUE of what's going on with your Accuphase (that wouldn't be the first time). I need a schematic too. Grey, in Europe the tri-phase is three conductors at 380V so the phase-neutral is 380/sqrt(3)=220V. So it's the same deal over there like you have here, just a little different.

2nd May 2001, 11:59 PM	#5
GRollins diyAudio Member Join Date: Feb 2001 Location: Columbia, SC	fmak, If what you've got is what's shown on the ESP site, I'd say it's safe to remove it. I'd say to bypass it first. If you develop a ground loop, then hook it back in. Otherwise, go for it. Incidentally, I'd be curious to know if you notice a sound quality difference with/without it... Grey

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)