GSSL HELP THREAD!!!

[vertiges]

Ah yes, I forgot...

On my first GSSL I linked the center pin (Of the the three pins connector) to my star ground. Matta explains it in this post : http://www.groupdiy.com/index.php?topic=18855&postdays=0&postorder=asc&highlight=difference&start=0

eD)))

 

[Bluzzi]

vertiges - so I connect AC Ground and center tap of transformer to GSSL center pin?

Or do you mean one or the other? As I said before potential between AC Ground and secondaries measures over 80v!

jim

 

[3nity]

jim are you sure you got the 62083??? you should get 17.3 under no load...

For 115 volts wire primaries in parallel...yellow and red together..black and violet together....Secondaries: series....red and brown together.......Remember to keep the multimeter on AC volts...

:grin: :green: :thumb:

 

[vertiges]

From the Amveco web site :

"For 230V operation, connect primaries in series by connecting black and red lead wires together and apply 230V across yellow and violet leads wires. For 115V operation, connect primaries in parallel by connecting yellow and red lead wires together and black and violet leads wires. To parallel the secondaries, connect green and brown wires and red and blue together. To put the secondaries in series, the red and brown wires are connected together."

3nity, you're right !!!

I'm getting lost here... ????
I put the brown and green together... and use separatly the red and the blue as V+ and V- ??? Soooo I made my wiring wrong... ??? Even though I've got the good voltages everywhere... :?: :?: :?:

I need a :sam: !!! :green:

 

[Bluzzi]

[quote author="3nity"]jim are you sure you got the 62083??? you should get 17.3 under no load...

For 115 volts wire primaries in parallel...yellow and red together..black and violet together....Secondaries: series....red and brown together.......Remember to keep the multimeter on AC volts...

:grin: :green: :thumb:[/quote]

Hi amigo,

Yes its the 62083 and yes that is exactly my wiring. I get the 17 or so volts between the Blue and centre wires as well as the Green and center wires.

My fear is why do I get more than 80v when I measure from AC Ground to Blue or Green!

jim

 

[3nity]

Maybe you shouldn't measure it that way!!

Remember that you can take apart the wire jumpers and the 10R resistors before the 12V regulators and then you power the PSU!

 

[Bluzzi]

But doesn't AC Ground have to reach the GSSL board at some point?

I don't think its right to have 80vac potential between Ground and secondaries. If so someone please explain it to me.

I built my p2p LA2A with a regular XFR and have no problems understanding that.

jim

 

[vertiges]

Have you checked your multimeter ?
Last week I got weird mesurements with a cheap Mastercraft multimeter. It gave me 56 volts on the +15 rail !!! I check the multimeter with an 120 Volts outlet, it gave me 160 Volts !!! And the battery was good... :wink:

Mhhh

 

[vertiges]

Well... I made some measurements with my spare 62053.

I connected the primary : Yellow-Red together and Black-Violet together.
I connected the secondary : Red & Brown together.

The measurements I got:

Between Blue and Red-Brown : 19.7 volts
Between Green and Red-Brown : 19.7 volts

Between Blue and the ground : 54.8 volts !!!
Between Green and the ground : 38.64 volts !!!

:shock: :shock: :shock:

PS : I bought a new multimeter !! :wink:

 

[vertiges]

Well... I made some OTHER measurements with my spare 62053.

That's the way I wired the 62053 of my first (working with a very small hum) GSSL.

ATTENTION that's not the good way !!!

I connected the primary : Yellow-Red together and Black-Violet together.
I connected the secondary : Brown-Green together.

The measurements I got:

Between Red and Brown-Green : 19.7 volts
Between Blue and Brown-Green : 19.7 volts

Between Red and the ground : 57.8 volts !!!
Between Blue and the ground : 58.6 volts !!!

Between the ground and the Brown-Green more than 50 volts in this case AND in the case described in my previous post.

========

Normaly, the 0V reference from the secondary is grounded by the PCB as the center pin is connected to the ground of the PCB.

eD)))



PS : I bought a new multimeter !!

 

[vertiges]

OK... I confess... I'm definitely LOST !!! :green:

eD)))

 

[vertiges]

Just a idea... are these high voltages we got are something to do with the phase of the current ? I mean 120 volts we got from the outlet is one phase of the "main" tri-phase (I'm not sure if this is the word in English)...

Maybe I'm completly wrong... I need some sleep...

eD)))

 

[vertiges]

Jim,

Have you tried to short the two wires of the secondary which are together with the ground and to make the measurement again.

I did it and I get the correct voltages.

The center pin of the 3 pins connectors is connected to the ground of the main PCB. And the ground of the main PCB is connected to the ground of your building via the "ground wire" which links the input stage to the pin 1 of the xrl to the star ground. Am I clear ? :?

eD)))

 

[vertiges]

So... finally I wired the PSU of my first GSSL the correct way : red and brown of the secondary together.
My hum has been reduced +/- by 10 dB !!! :thumb:

Thank you Jim ! You made me be aware of my bad wiring... :green:

Talking about grounding... I've just discovered a strange thing : I put a "ground lift" swich which breaks the link between the pins 1 of the input XLR and the star ground. (The pins 1 of the XLR are connected to the center pins of the inputs on the main PCB). When I switch to the ground lift position when the unit is not connected by the XLR inputs/outputs all my led swich off !!! :shock:

Why ? :green:

Does it mean the 0V which comes from the PSU becomes "floating" when the ground of the PCB is disconnected from the earth ? And that the voltage difference between the ground and the earth is modified ?

OK, now, I'm going to sleep !! :grin:

 

[Bluzzi]

Yes I have a feeling that the high voltage between Ground and the secondary is normal but I would like to understand why.

Tomorrow I'll try and post a diagram of what I am doing to get these measurements and a diagram of what you are saying the wiring should be so that we can be sure we mean the same thing.

I'll verify my VOM again but I'm very sure its not at fault.

Thanks for your help here and glad my problem solved one of yours!


jim

 

[3nity]

What matta did with his wiring is that he took the 0V from an outboard PSU and send it to Star Ground and i think that his star ground now becomes his 0V but if you use the On board regulation, you only go to star ground by the XLR pins 1, This seems clear to me.

See carefully at this pic. Greg only has his center tap to the board and no star ground.....but look at the XLR!

 

[Bluzzi]

OK, I got it now.

Picture tells it all. Thanks - Gracias

Center tap wires go to center pin of AC input on GSSL. AC Ground to pin 1 of XLRs.

I'll try that tonight.


jim

 

[vertiges]

3nity,

The pic you posted describes the exact way I did my wiring.

The difference with the Matta wiring, unless I'm wrong, is that he linked the center pin of the three connectors pins (which coming from his outboard PSU) to the star ground and that he DIDN'T connect the ground on the inputs.
So I guess in the both methods the result is the same, the ground of the PCB is connected to the earth.

I do also think that those big voltages are normal and as Jim, I would like anderstand why !

And about the problem with my leds. I connected the "-" of my leds to the star ground... maybe I should have connected them to the ground of the PCB. Please someone confirm...

Thanks !

eD)))

 

[3nity]

I think you sould break the 0V to Ground only at the Input or the Output.... but not both at the same time?

not really sure.

Thanks.

 

[Bluzzi]

Well what the picture shows is the AC Ground going to chassis then to pin 1 of XLRs. Pin 1 of XLR is connected to the GSSL.

What you call 0v is what I am calling the center tap I think. That goes to center pin of the 3 pin GSSL AC input. The other 2 pins get any of the other 2 secondaries.

I have another Hammond toroidal here and I will test tonight with their wiring instructions just to see if that also gives me voltages between Ground and secondaries that are similar.


jim