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100V to line level - cheapest or easiest


TomHoward

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Evening all

 

I have a possible need to get line level out of 100V. It's a one-off job so ideally I don't want to spend too much on it.

I know there are some products available, but they usually run £100+. I'm happy to buy one as a second option.

Is there any easy circuit or transformer to drop from 100V to line level output? I have a box of transformers down to 8ohm off old speakers, don't know if they could be combined with a DI box or similar to provide a low level output?

 

Many thanks for any pointers

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It's a notional 100:1 (probably nearer 50:1 for practical purposes) step-down, so maybe a bit of experimentation with your box of transformers? Or something like a 68k to 1k resistive pad, with a 1:1 transformer on the end.
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Evening all

 

I have a possible need to get line level out of 100V. It's a one-off job so ideally I don't want to spend too much on it.

I know there are some products available, but they usually run £100+. I'm happy to buy one as a second option.

Is there any easy circuit or transformer to drop from 100V to line level output? I have a box of transformers down to 8ohm off old speakers, don't know if they could be combined with a DI box or similar to provide a low level output?

 

Many thanks for any pointers

 

I've made several:

speaker transformer tapped 1W.

1K resistor in series with a 1K pot .

1K resistor from slider to hot of o/p socket.

transformer, bottom of pot & cold of o/p socket common.

Next thing I try to do is place a small speaker and switch across another part of the secondary for testing/monitoring purposes.

 

Edit: Look at my profile picture

 

Edited by sunray
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Until he wants to post a new pic ?

Slide show??? Back to the OP - as with the laptop-sound question, there are lots of ways of attenuating a signal, none of them a "right" way; everyone will have a method, that works for them.

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I'd guess they should match or exceed the tap, so if the tap is 1W they should be 1W or larger?

 

If transformer is for 8 ohm speaker then max output is just shy of 3 volts so as the resistors are 1k , worst case 3x3/1000 = 9 milliWatts

 

If you use the 2.5 watt transformer the output will be 20 volts so increase the input resistor to 6k8 and all will be well with 1/4 watt resistors.

Brian

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