Can I create a volume controlled 'line out' in my integrated amp

[bumpy]

My integrated has four switchable phono inputs (only one of which is used) but no line level out (volume controlled).

Is it practical to isolate one of the pairs of phonos and rewire them so they become a volume controlled line level. To a novice this seems an easy thing to achieve.

This would be to feed a DSP subwoofer amp which almost exclusively need a line level input.

[Light Dependant Resistor]

My integrated has four switchable phono inputs (only one of which is used) but no line level out (volume controlled).

Is it practical to isolate one of the pairs of phonos and rewire them so they become a volume controlled line level. To a novice this seems an easy thing to achieve.

This would be to feed a DSP subwoofer amp which almost exclusively need a line level input.

Hi Chris
Line Level out, sort of by definition does not involve routing audio through a volume control. If you need a volume control from one source
the way I would do this is to arrange a small jiffy box ( or more formal if you wish ) to have two or more pairs of RCA, one as LR input from your source(s) and the other
adjustable in level to connect to your subwoofer amp.

The most common form of volume circuit is called a L pad and has what is called series resistance ( from your source ) and at the same time shunt resistance to signal ground
A purist method would see signal paths not being wiped by mechanical contacts, rather NSL32SR3 LDR's can be arranged both as an attenuator and as a contact less switch.

This way you are not changing your rather unique amplifier from its original specification.

[Firebottle]

Yes you can, the only thing you need to be careful of is that the input impedance of the subwoofer amp isn't particularly low.

I'm guessing that the input impedance of the Transcription Audio is quite high, most probably the impedance of the volume control.

[bumpy]

Yes you can, the only thing you need to be careful of is that the input impedance of the subwoofer amp isn't particularly low.

I'm guessing that the input impedance of the Transcription Audio is quite high, most probably the impedance of the volume control.

Good advice thanks.

[bumpy]

Hi Chris
Line Level out, sort of by definition does not involve routing audio through a volume control. If you need a volume control from one source
the way I would do this is to arrange a small jiffy box ( or more formal if you wish ) to have two or more pairs of RCA, one as LR input from your source(s) and the other
adjustable in level to connect to your subwoofer amp.

The most common form of volume circuit is called a L pad and has what is called series resistance ( from your source ) and at the same time shunt resistance to signal ground
A purist method would see signal paths not being wiped by mechanical contacts, rather NSL32SR3 LDR's can be arranged both as an attenuator and as a contact less switch.

This way you are not changing your rather unique amplifier from its original specification.

Just for clarity, is this 'volume control' fed from additional wires from the speaker terminals of my main amp. What the subwoofer people refer to as high level. Thanks

[Lawrence001]

This is starting to get into worrying territory is everyone else happy with the advice here?

Sent from my BLN-L21 using Tapatalk

[bumpy]

This is starting to get into worrying territory is everyone else happy with the advice here?

Sent from my BLN-L21 using Tapatalk

What concerns you Lawrence? I want to run a separate amp and active DSP low pass filter to my bass drivers whilst leaving my mid range driver and tweeters to run unhindered from the main amp.

BUT I cant use commercially available stuff with DSP as they are mostly line level inputs and a) I don't have one b) I need to have just one overall volume control for the whole system.

So I may need to find a way of
a) Using the high level speaker output and knocking it back to approx 2v max, much as seems to be done in most subwoofers.
b) Tapping into the 'line level' after the volume control of my main amp

I am ambitious in what I wish to achieve, but not being skilled at electronics I am at the mercy of others, so would be more that pleased to hear your concerns.

[Lawrence001]

That's exactly my concern, you're not experienced (and neither am I) but you're being told it's simple to isolate the variable pre out signal inside your (unknown) integrated amp and connect it to one puff the RCA pairs on the back. To me this sounds like a high risk change that could seriously damage the amp or other equipment even if you were experienced.

Sent from my BLN-L21 using Tapatalk

[bumpy]

That's exactly my concern, you're not experienced (and neither am I) but you're being told it's simple to isolate the variable pre out signal inside your (unknown) integrated amp and connect it to one puff the RCA pairs on the back. To me this sounds like a high risk change that could seriously damage the amp or other equipment even if you were experienced.

Sent from my BLN-L21 using Tapatalk

Fear not Lawrence, I am one of the most risk averse people you might meet. All I am doing at present is background research so I approach all jobs from a position of knowledge.

If it steps over the line of 'DIY' I will default to getting an expert to do it, but as a scientist I am always hungry for knowledge so I can select the best option both from a safety and sound quality perspective.

[StanleyB]

My integrated has four switchable phono inputs (only one of which is used) but no line level out (volume controlled).

Is it practical to isolate one of the pairs of phonos and rewire them so they become a volume controlled line level. To a novice this seems an easy thing to achieve.

It depends on whether your integrated amp is old enough to have a RECORD monitoring option on it. If it hasn't then you don't stand much chance. If it does, you can then take the signal from the REC monitor output to a passive volume control.