NOH HT pass through

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JJF

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NOH HT pass through
« on: 27 Mar 2005, 11:16 am »
Hello John,
I am still happy with my NOH,  last year  it survived two power amps changes, lately it runs an Electrocompaniet AW250.
I am thinking of sharing the AW250 and the stereo speakers with the HT setup (they will be the front). How do I make a direct  pass through connection to allow the HT front to run through my NOH ?
I want to use the unbalanced  (RCA) NOH input to connect the HT pre/decoder. My NOH is connected via the balanced  (XLR) output to the amplifier.
Greetings,

JJ

zybar

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Re: NOH HT pass through
« Reply #1 on: 27 Mar 2005, 02:03 pm »
Quote from: JJF
Hello John,
I am still happy with my NOH,  last year  it survived two power amps changes, lately it runs an Electrocompaniet AW250.
I am thinking of sharing the AW250 and the stereo speakers with the HT setup (they will be the front). How do I make a direct  pass through connection to allow the HT front to run through my NOH ?
I want to use the unbalanced  (RCA) NOH input to connect the HT pre/decoder. My NOH is connected via the balanced  (XLR) output to the amplifier.
Greetings,

JJ


JJ,

When I had my Bent, I simply turned the volume all the way up on the Bent and set the volume on the HT receiver for the other channels.

The only issue with this is that you MUST remember to turn the volume back down before using any other source.

George

Marbles

NOH HT pass through
« Reply #2 on: 27 Mar 2005, 03:54 pm »
My TX102 has an HT bypass that is engaged with a toggle switch.

There are 4 toggles on the front of my Bent.

2 for right channel, two for left.

On each side, one toggle is for input 1/2
The other toggle is for HT bypass in/out

This may give you an idea on how it can be done, I don't know as I did not build mine.

John Chapman

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NOH HT pass through
« Reply #3 on: 27 Mar 2005, 04:12 pm »
Hello!

The toggle option can be fine but I tend to avoid adding stuff to the signal path when I can. That is why I generally used the turn the level up mode to do a bypass. Turning it down when changing sources is a factor and the toggles can be used if this is a concern - but not in your case.......  

Because you use an rca input and an XLR output to the amps you'll need to turn the volume right up for bypass. In the RCA In / XLR OUT mode you are using the tx102's to convert the signal from rca to xlr and so you can not really do a total bypass with toggles - the tx102 should stay in the signal path to do that conversion for you.

Thansk!

John

JJF

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NOH HT pass through
« Reply #4 on: 27 Mar 2005, 06:26 pm »
Hello,
thank you all for taking your time to reply. I was afraid that  to use one of the standard RCA inputs and turning the volume knob up right would be the main option. There is one problem with this option - if somebody forgets to turn the volume down later and switches the source to the CD player (connected via the balanced input) ,  you can imagine the effect on the speakers and one´s ears.

I was thinking of something else -  to disconnect one pair of the RCA inputs  from the transformer signal path and connect it directly to  the output selector switch. This would require some sort RCA-XLR adapter - I thought it could be done using the internal RCA wiring.
Any suggestions ?

Greetings,

JJ

John Chapman

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NOH HT pass through
« Reply #5 on: 27 Mar 2005, 08:09 pm »
Hello!

Often the level with the knob all the way up, although loud, is not extreme with a passive pre-amp. This can vary quite a bit with speaker and amp sensitivities though and if it is really loud in your case I understand the concern.

You could have switching inside the NOH  in the wiring to the xlr output jacks to do the job - but it is a bit tricky. Here are the connections:

In Normal Mode.

Pin 1 of the xlr out is to the Central Chassis ground (this happens naturally via the rca/xlr switch on the back now).

Pin 2 of the xlr out is from the volume switch.

Pin 3 of the xlr is the bottom of the TX102 secondary.

This wiring above is the same as you have now when the xlr output is selected.

-----------------

When you switch to bypass mode the wires to the xlr output become:

Pin 1 of the xlr out is to the HT Input Ground (body of HT rca jack).

Pin 2 of the xlr out is from the HT Input Hot (or HT center pin).

Pin 3 of the xlr out is connected to the HT Input Ground (body of HT rca jack) - same as Pin 1.

The HT Input Jack is unwired from the selector switch (or input board if you have remote selcted Inputs).

This does not 'convert'  RCA to XLR but it will function fine - basically the same connections as a simple RCA to XLR adapter would have inside it.

This takes 3 poles of toggle switch per channel. I have some 4 pole toggles here (normally used for the switchable gain on MU step-ups) that could do the trick.


Many Thanks!

John

JJF

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NOH HT pass through
« Reply #6 on: 28 Mar 2005, 02:38 pm »
Hi John,
thanks for the reply. After some  considerations I think the best solution is to leave  the NOH as it is, with the simple signal patch, no additional switches. I really like  its performance and sound qualities.
Greetings,

JJ