Record speaker-output?

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good morning everybody!

I was just wondering:
It 'must' be somehow possible to connect a power-amplifier's speaker-output into some gear that would make it possible to record it (digitally)... I read about some DI Boxes which seem to do that, but these seem to be not neutral.

So, could this be done through some sort of "attenuator", and would it make sense at all (trying to record an amplifiers tonal character)?


Thank you, and enjoy the day!

day
 
Since you've posted under 'Everything Else', it is unclear whether we are talking guitar amp/stereo amp or solid state/valve, but here is a possible solution.

A simple voltage divider could be used in parallel with a connected speaker in order to reduce the output voltage to line level for recording purposes.

N.B. The speaker must remain connected to the amp output in order to provide the correct, safe working load for the amplifier.

The use of high resistance resistors will not significantly alter the load on the amplifier output.

Full description here: Speaker signal to line level

At least this simple circuit will let you know if you can successfully capture the amplifier's character without spending a lot of money.
 

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Yep, as stated above.

The reason you want this divider is that speaker level voltages are usually higher than the voltages acceptable for the input to a record device or soundcard. Line level inputs on those normally accept a max level of around 2 volts. The level at the speaker terminals can often be higher than that.

Since many people need to do this very thing, you can find speaker to line level adapters ready made. Note: If you want to record just the amp with no speaker, it's best to use a dummy load resistor of about 8 ohms.
 
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cool, thanks!

Hi Galu & Pano
That's very helpful, thanks!

It seems so easy I'm wondering why this isn't done for some evaluations/listening/comparison sessions?

Of course if a recorded amp was to be played back through another pre-/amp, it won't be totally authentic, but one might get a picture (or an ear full) of the characteristics... Or is there something more to it?


david

Since you've posted under 'Everything Else', it is unclear whether we are talking guitar amp/stereo amp or solid state/valve, but here is a possible solution.

A simple voltage divider could be used in parallel with a connected speaker in order to reduce the output voltage to line level for recording purposes.

N.B. The speaker must remain connected to the amp output in order to provide the correct, safe working load for the amplifier.

The use of high resistance resistors will not significantly alter the load on the amplifier output.

Full description here: Speaker signal to line level

At least this simple circuit will let you know if you can successfully capture the amplifier's character without spending a lot of money.

Yep, available commercially.

The attached photo shows how you might construct your own (stereo) adaptor.
 
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This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.