Amplify line level to post preamp level

[geldo79]

Hi,

I still have the idea of inserting an effects loop into my M3+122 setup. Without having to modify the AO29, I think I would have to modify the signal path between the AO29 and the 8010 Kit. Before I bought and hooked up the Leslie 122, I used a self-made lineout and a leslie clone which worked really fine. I think I could reach my goal by reinstalling that line out, insert effects here, and put the signal into a Leslie Combo Preamp like the Trek uc-1a instead if my 8010 Kit. But that Combo preamp is way to expensive.....600$ !!!.....and with the 8010 I already have a good way to hook up the Leslie. Thus, I think I would just need a unit which amplifies the signal from my line out in such a way that it is hot enough again to be sent to the 8010 kit. Did anyone build a unit like that? Does anyone have ideas how to build such an amplifier? Or can I buy a unit somewhere which would do that amplification?

[enor]

Any small guitar amp would do the job. Or a small powered mixer. Or a mic preamp such as the ART Tube MP. Any amp, really ;)

[geldo79]

Ok.

The it should be possible to use the line out, put in in a powered mixer (where I can add reverb), and put the output of the mixer back to the input of the 8010 Kit?

[enor]

Short answer: Yes, it should work just fine!

[geldo79]

Sounds good. But won't I be able to make the signal too hot? Lets say I use the "line out
from a spinet" from the Hammond Wiki, put this is a mixer and turn up the volume
to maximum? I am just wondering if this works in any way, or do I have to be careful?

[enor]

Sounds good. But won't I be able to make the signal too hot? Lets say I use the "line out
from a spinet" from the Hammond Wiki, put this is a mixer and turn up the volume
to maximum? I am just wondering if this works in any way, or do I have to be careful?

You will have the potential to overdrive the Leslie, yes, but isn't that what you want?

If you use a powered mixer, use the Leslie kit "as is", including the dummy load
If you use something else that's more of a preamp (mic preamp, mixer without power stage) you might want to disconnect the dummy load from your Leslie kit.

[geldo79]

You will have the potential to overdrive the Leslie, yes, but isn't that what you want?

Yep!

Think I'll give it a try. This seems to be the easiest way to integrate effects into my setup. And it has the advantage that I can EQ the signal using a mixer.

[geldo79]

One more question: There is also a dummy load in the line out. This has to be removed anyway, or not? The Leslie kit has its own dummy load.....so i think i have to get rid of the resistor in the line out box.....??

[enor]

One more question: There is also a dummy load in the line out. This has to be removed anyway, or not? The Leslie kit has its own dummy load.....so i think i have to get rid of the resistor in the line out box.....??

No, absolutely not!

When you disconnect the organ speakers, you need a dummy load in place of the speaker as you take the signal down to line level - the one in the line out circuit.

Then you feed this line signal to a powered mixer / guitar amp, meaning you’re once again up to ”speaker level”. Depending on how the amp is designed it _might_ be fine without a dummy load, but definitely not so if you should happen to want to use a tube amp as the extra booster after your effects. So, I would make sure to have a dummy load after the intermediate amp as well; better safe than sorry, so the dummy load in the Leslie kit stays.

But - if you should happen to use a _preamplifier_ instead of a power amplifier as your intermediate amp, it likely won’t be able to drive the Leslie at the right level if the dummy is in place. So, with a preamp inserted, snip the 2nd dummy out.

[Tim_at_Jonas]

I doubt that any common solid state preamp circuit would be able to handle it. My bench generator will do 9V and it will not drive a 122 anywhere close to clipping.

[enor]

I doubt that any common solid state preamp circuit would be able to handle it. My bench generator will do 9V and it will not drive a 122 anywhere close to clipping.

Right. I would prefer a powered mixer to a line mixer, for the above reason.

However - I have successfully used the ART Tube MP (a mic preamp with plenty of drive) to drive a Leslie 760, with enough "oomph".

[geldo79]

BTW is it correct that the resistor in the 8010 Kit is a 16 ohm resistor.....not 8 ohm?
Thats what i can see in the datasheet.

[enor]

BTW is it correct that the resistor in the 8010 Kit is a 16 ohm resistor.....not 8 ohm?
Thats what i can see in the datasheet.

I don't know, but it makes no practical difference in this application.

[geldo79]

Ok.

Would a Yamaha MG10 be able to drive my Leslie? It's only a line mixer, but with mic. preamp.

[Wes]

It'll be enough to drive it loudish. MAYBE full output. MAYBE.

If you want to drive the Leslie into deep clipping, you gotta get a real amp stage in there.

The preamp isn't what's key; what it's key is how much of a voltage swing the outputs are capable of. +4dBu is only 1.2VRMS.

If your AO-29 is loud enough and you just want reverb, you might be better off modifying the amp to have an effects insert if you are good that stuff. You could even add some gain that way. Look at the installation instructions for the Organmate Reverb for ideas.

Wes