Radial JDX - any similar DIY projects?

Was wondering if anyone knows of or has made a device similar to the Radial JDX - Guitar Direct Box. It takes a direct feed from the connection after the amp head and before the cabinet. And it drops the level down to mic output level for feeding into a mic preamp and then recording device.

https://www.radialeng.com/product/jdx-48

It needs to be used with a speaker cabinet or dummy load box.

I have one and it works well but Im now possibly needing 4 units, so it would be great to be able to DIY something. Does anyone have any ideas about how they do this? Or similar projects that already exist like this?

I don't see it on their website now but I remember back in the 80s/90s Peavey sold a cheap accessory speaker eliminator. This was not intended for recording use but live performance so artists could reduce the stage volume during gigs by running their axe through the PA board. 

My recollection was it used a small (cheap) transformer with some passive EQ to shape the response of the output to better mimic a a guitar cabinet (probably a bandpass).

JR

What features of the box do you need? A super simple recording solution would be to just attenuate the signal and use a speaker IR.

thanks for the replies.

i’m mainly looking for the level attenuation aspect. so i can get the signal attenuated to line level to go into a sound card.

i don’t really need the speaker modeling. that’s a great idea about the IR.

i supposed i might just be able to use a transformer? any idea for ratios / specs foe this application?

20 dB should be sufficient.  You could use a 1:10 transformer in reverse.  Or just simply do a resistive divider. Something like a 10k resistor with a 1k pot if you need more control as shown here:
https://www.thegearpage.net/board/index.php?threads/aikens-reactive-dummy-load.1072793/

I've found a resistor divider feeding a good transformer based mic pre to work well.

john12ax7 said:

20 dB should be sufficient.  You could use a 1:10 transformer in reverse.  Or just simply do a resistive divider. Something like a 10k resistor with a 1k pot if you need more control as shown here:
https://www.thegearpage.net/board/index.php?threads/aikens-reactive-dummy-load.1072793/

I've found a resistor divider feeding a good transformer based mic pre to work well.

Click to expand...

hey thanks for the help.
I think i'll do something like the diagram in that thread.

If i just need the resistive load and output level control, I can build that diagram with everything to the left of the blue switch? resistive load only? and the inductors / caps can be omitted?

All you would need is the 10k resistor and 1k pot. If using an actual speaker cab everything else can be omitted.

outoftune said:

Was wondering if anyone knows of or has made a device similar to the Radial JDX - Guitar Direct Box. It takes a direct feed from the connection after the amp head and before the cabinet.
And it drops the level down to line output level for feeding into a recording device.
https://www.radialeng.com/product/jdx-48

Click to expand...

You should correct your first post, the Output is not "Line Level" it is "Mic Level".
Mix level is around 40db's lower than Line Level.

As for a DI that accepts Speaker outputs, there's a lot of products on the Market for many years now, basically any DI that has a 40db pad in the input:







You can modify the input of any DI to accommodate a 40db PAD (make it switchable) being it a commercial unit or a DIY unit.
You can do that with the Bo Hansen DI