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-   -   Tapping out from speaker level signal to get extra line out (https://www.gearslutz.com/board/so-much-gear-so-little-time/606280-tapping-out-speaker-level-signal-get-extra-line-out.html)

Hotsteppah 27th April 2011 09:16 PM

Tapping out from speaker level signal to get extra line out
 
Hello, I have an organ with great speakers, but I'd like to also have an additional line out from the speaker signal so I can put it into a PA when I need the extra boost (and still keep my speakers running at full volume for monitoring purposes). What's the easiest way to go about this? The speaker signal I'm tapping from is 30 watts at 8 ohms. I'm pretty handy with a soldering Iron, just my electronic theory needs a little work. I don't need a dummy load of course, I just would like to have the cleanest possible line level signal and an amplified signal from the same amplified signal level source.
Thanks!

kennybro 27th April 2011 10:11 PM

Somewhere in that circuit, probably the signal that feeds the power amp inputs that drive the speakers, is a line level signal that you can tap. A competent electronics person, armed with a schematic can find it.

theblue1 27th April 2011 10:18 PM

A rough rule of thumb is to tap the signal flow just before the volume potentiometer. When I was a kid, that was where I usually tapped to get a de facto line out. But I'm no EE.

junkshop 27th April 2011 10:57 PM

You could use something like this -
Radial JDX Reactor reactive amplifier direct box - introduction

I use it on bass amps all the time. It'll give you a very good mic'd amp sound (but without the mic).
You could connect it in-line with the speaker cable or make a speaker cable with a 1/4" jack on one end and alligator clips on the other. Clip one end to the speaker terminals and plug the other into the amp DI.

Hotsteppah 27th April 2011 11:30 PM

Quote:

Originally Posted by theblue1 (Post 6588063)
A rough rule of thumb is to tap the signal flow just before the volume potentiometer. When I was a kid, that was where I usually tapped to get a de facto line out. But I'm no EE.

Thanks for the quick responses! I think my problem is half solved. Yes, I will go back and look at the schematic for an earlier tap....only I might do it after the volume (expression pedal) because I do need it to translate musical volume changes to the line out. Only Problem with this (and I should have maybe included this in the original post....sorry) is that there are two amps/signals, one for bass and the other for main. I'd like to be able to tap after the expression pedal, and combine both of these signals into one jack. I have the schematic so I can probably find where to do this, I just need to know if I can combine two signals together and what parts I need other than a quarter inch jack. They kind of already do this later in the organ at the headphone jack, but this is accomplished by combining both amplified signals into the jack via 100 ohm resistors from both sources. Once headphones or a cable is plugged into the headphone jack, all signal to the speakers is cut. Fine for a tap-able output, but now there is nothing coming out of the speakers. I figure they did this for a reason (other than wanting to practice quietly), or is it safe to manipulate this headphone jack so when a cable is plugged into it, signal will still be passed to the speakers as well as the headphone jack (by fiddling with the jack internal switching assembly). If not, or if the other way is better....what is the best way to tap and combine 2 line level signals into 1, while making sure enough is still being put through to the amplifier for clean speaker output?

Hotsteppah 27th April 2011 11:59 PM

Well, I did a search and I found this page:
Simple mixer

Basically says to combine two line signals into one (like a mixer I guess) you should put a 10k resistor in between the signals and the jack. Cool! If I tap like this, will this affect the signal flowing to the amplifier? Worried about volume drop and since the signals are now combined at this tap, are they now combined through the rest of the circuit? Would still like the signals to reach the amps in as much of their seperated form as possible.

Boschen 28th April 2011 12:13 AM

If you don't want to DIY it, you might try a line level converter;

Audioplex SPKCNV - Speaker Level to Line Level Converter

Converts powered speaker signal to RCA line level out.
My wholesale cost on 'em is about 40 bucks. Not sure about retail.

Hotsteppah 28th April 2011 12:22 AM

Nah, I'm down to DIY it, that's a little expensive and I have a great electronics parts shop not too far away. I don't think that has an amp through on it either, though you could probably just put it in between I guess. Thanks though!