Passive DI gives lower signal than HX Stomp

[javi_bassist]

Hello!

 

I have recently bought a Passive DI, a Radial STage Bug SB-2 to combine with my HX Stomp. The thing is that I find that the volume (and signal) coming from the DI is much lower than the signal sent from the HX. Is that possible? Everything else is the same (preset, volume knob, bass...) Coming out from the HX, even when I set the Out to Instrument Level, it gives much more signal then when I plug it into the DI. 

I already checked the PAD in/out of the DI and that is not the problem. Is this normal?

 

Thank you in advance

[nilebodgers]

Yes. A passive DI reduces the signal level down to something that works well with a microphone input. The loss is usually -20dB (one 10th) with 1:10 transformers.

[krispn]

Compensate at the desk. Job done no? 

[Jack]

If it helps at all the HX Stomp's outputs are balanced, no DI box needed.

[rmorris]

23 hours ago, nilebodgers said:

Yes. A passive DI reduces the signal level down to something that works well with a microphone input. The loss is usually -20dB (one 10th) with 1:10 transformers.

Just to confirm what Nile days here. Passive DIs use transformers in a step down configuration. Basically trading level for a lower impedance output that is also balanced.

[rmorris]

11 hours ago, Jack said:

If it helps at all the HX Stomp's outputs are balanced, no DI box needed.

Does the Helix DI have a 'Ground Lift' option ? It shouldn't be necessary but sometimes it is due to the way some equipment is configured in a sub optimal manner.

[javi_bassist]

Thank you everyone for your answers. I see now that it is normal. Thanks!

 

I know the HX can be configured to send a balanced signal. I even have a setero jack>XLR adapter. However, the sound guys I work with don't like that option and they always give a regular DI. That's why I bought the Radial, just in case something goes wrong. But I didn't know about the signal drop. Anyway, it works and now I understand why it happens

[Jack]

1 hour ago, rmorris said:

Does the Helix DI have a 'Ground Lift' option ? It shouldn't be necessary but sometimes it is due to the way some equipment is configured in a sub optimal manner.

No unfortunately, nor any way of blocking phantom power. I should have elaborated some more in my first post really, no DI needed as long as you trust and have a competent soundman! I do take a DI box to those situations and sometimes use it. You forget these things when you run your own pa, sorry. 

 

 

[rmorris]

6 hours ago, Jack said:

No unfortunately, nor any way of blocking phantom power. I should have elaborated some more in my first post really, no DI needed as long as you trust and have a competent soundman! I do take a DI box to those situations and sometimes use it. You forget these things when you run your own pa, sorry. 

 

 

 

A properly engineered balanced output shouldn't have a problem with 48V Phantom Power as it is likely to be capacitively coupled and also the 48V appears in Common Mode.

But I'd suggest to contact the manufacturer to confirm 😳

But yeah - it's a good while since I played live - but the SEs often have their way of doing things and don't like to deviate from that even when there's a technical alternative. Eg reduce everything to mic level and all inputs go to desk inputs configured to mic inputs.

 

[Jack]

3 hours ago, rmorris said:

 

A properly engineered balanced output shouldn't have a problem with 48V Phantom Power as it is likely to be capacitively coupled and also the 48V appears in Common Mode.

But I'd suggest to contact the manufacturer to confirm 😳

But yeah - it's a good while since I played live - but the SEs often have their way of doing things and don't like to deviate from that even when there's a technical alternative. Eg reduce everything to mic level and all inputs go to desk inputs configured to mic inputs.

 

We're perhaps a little off topic now but the common wisdom for helices is that whilst phantom won't harm, it does make weird noises. 

[rmorris]

1 hour ago, Jack said:

We're perhaps a little off topic now but the common wisdom for helices is that whilst phantom won't harm, it does make weird noises. 

Okay. Is that just when it's being switched or constantly ? 

[Jack]

I believe it's intermittent during use. I've never actually had the problem, the soundmen we work with don't match the descriptions given on BC. 😉

[rmorris]

12 hours ago, Jack said:

I believe it's intermittent during use. I've never actually had the problem, the soundmen we work with don't match the descriptions given on BC. 😉

Yeah - it's difficult when you don't control the whole signal chain. A live setup isn't the ideal environment to optimise stuff. Cheers.

Edited October 31, 2021 by rmorris