Radial JDI speaker DI frequency response?

[Ben Clarke]

Anyone use the JDI connected to a tube amp's speaker output? I'm wondering how it sounds, as it has a bandpass filter that they describe as emulating the response of a "typical 12" speaker". I'm concerned about the LF response for use with bass.

I sent Radial an email through their website about a week ago, but nothing back yet.

[JimmyM]

did it once, didn't use the bp filter. no loss of low end. there was more than i needed and they rolled it off at the board.

[Ben Clarke]

It wasn't too hot? The way I read the Radial lit made me think it had to be engaged:

Connect your amp as usual, then connect a ¼” to ¼” cable from the second (parallel) speaker cabinet jack to the JDI.
Because of the high impedance and low draw from the JDI, the amp will only see the speaker cabinet so you do not have
to change the amplifier’s impedance setting. Depressing BOTH the -15dB PAD switch and the SPEAKER switch inserts a
special circuit that will protect the JDI from overload and allow the parallel speaker connection to be made safely. Depressing
the SPEAKER switch also introduces a band-pass filter circuit that rolls off the highs and lows in order to better emulate
the performance of a typical 12" speaker.

[JimmyM]

oh, the speaker switch was the bp filter? in that case i did use it. i thought it had to be on to use it as a speaker di. but no, it wasn't too hot as far as i knew. nobody complained.

[bassboysam]

Originally Posted by JimmyM

oh, the speaker switch was the bp filter? in that case i did use it. i thought it had to be on to use it as a speaker di. but no, it wasn't too hot as far as i knew. nobody complained.

Yup the speaker switch is the filter. The 15db pad is what needs to be pressed. I did contact radial and they said the speaker switch does not have to be used.

[Ben Clarke]

ahh - cool. thanks for the info, both of you.

[JGR]

The Countryman DI also has provisions to hook to a speaker output, and doesn't have a rolloff as far as I know, so you may want to consider that as well.

[steve_rolfeca]

The frequency response on the JDI is more than adequate (with the speaker emulator off), and the overall fidelity is probably better than any active device you've ever owned. Just engage the pad, and let 'er rip...

[bassboysam]

Originally Posted by steve_rolfeca

The frequency response on the JDI is more than adequate (with the speaker emulator off), and the overall fidelity is probably better than any active device you've ever owned. Just engage the pad, and let 'er rip...

Not enough people use the JDI in this manner, especially with a tube amp. Every time I have done it in the studio or live the sound guys loved it.

[Ben Clarke]

it all makes sense now. The way I read it, the SPEAKER switch had an additional pad as well as the BPF, and that both the -15dB pad & speaker switches had to be engaged. I'm used to seeing -40dB pads with cheap passives kicking around, which also makes sense considering the saturation of a less costly transformer.

[Son of Bovril]

cast/ Ressurection

So if I read above correctly you can use the JDI as a speaker DI without engaging the speaker switch, as long as the -15db pad is engaged?

Thus not engaging the BPF?

[bassboysam]

I have done this in the past with no problems at all. However it does sound better with the speaker switch, especially if you have any OD, distortion or fuzz in your sound.