Radial J48 more noise than Hi-Z Input?

[YusefG]

Hi people,
I need some help figuring out why my Radial J48 has such a loud noise floor compared to the Hi-Z input of my Apollo. I don't know much about electricity stuff, so explain stuff to me like I'm the moron that I am lol.

I made a small test, where I recorded the noise I get, first half of the audio file is with the Volume Knob on my Ibanez RGR-5221 at 0%, and then I turn it up to 100%. Pickup used is a passive Bareknuckle Brute Force Humbucker in Bridge position with Tone all the way to 100%. Link to the files down below.

Signal Chain as follows:

Radial_J48: Guitar -> J48 (only 15dB PAD engaged) -> UAD Apollo Twin X (20dB Gain (10db is minimum) +48V) -> Neural DSP Fortin Cali Plugin (High Gain)
Apollo Hi-Z: Guitar -> Hi-Z input (15dB Gain (10db is minimum)) -> same Fortin Cali plugin

Gain Staging was done so that I would only clip when playing really, really hard

I tested both inputs of my Apollo with the J48, results are the same for both. And now I gotta ask a stupid question: Isn't the J48 supposed to be quieter than a built-in Hi-Z input? What produces that kind of noise and is it normal? And if not, what can I do to fix it?

Link to .wav files: https://drive.google.com/drive/folders/ ... sp=sharing

Cables used:
https://www.thomann.de/de/cordial_cci_3 ... ns_67303_2
https://www.thomann.de/de/cordial_ctm_15_fm_bk.htm

[Hugh Robjohns]

I'm not in a position to listen critically to your clips today, but I'll check them tomorrow.

The j48 and built-in DI should be similarly low-noise and I wouldn't expect one to be significantly noisier or quieter.

As for the J48, make sure you don't have 'merge' or the ground-lift option selected. Also ensure the J48 isn't placed on or near other electronic equipment which might cause interference.

It's worth trying the high-pass filter as that might help, and im wondering why you need the 15dB pad as that will inherently degrade the noise performance

[resistorman]

Why do you have the 15 db pad engaged on the DI with a passive pickup? That may be the whole problem.

[Hugh Robjohns]

As I understand it, the max input levels are +10dBu for the J48 and +12.2dBu for the Apollo Twin X, so very similar and if the OP was clipping the J48 Id have expected the Apollo to clip too.

So I don't understand why the pad is being employed on the J48 and ss said above, that choice could well explain the difference in noise performance.

[YusefG]

Thank you guys for your responses! The Bareknuckle Brute Force Pickup is a High Output pickup. It will clip easily if the 15 PAD is not engaged.

I also measured the noise floor: -34.6 for the J48 and -54.9 for the Hi-Z input (put through the Amp Sim plugin at high gain, of course!).
Gain difference should be 0.5dB at max, since it was gain staged with 0.5dB intervals, so that I would just clip with my hardest playing.

If I disable the PAD, the noise floor goes from -34.6dB to -36.7 dB, which is still significantly higher.

[Hugh Robjohns]

I'm struggling to believe the J48 clips but the Apollo DI doesn't.

Are you sure its not the apollo mic input that's clipping?

[YusefG]

I'm struggling to believe the J48 clips but the Apollo DI doesn't.

Are you sure its not the apollo mic input that's clipping?

Well yeah, when the 15dB PAD on the J48 is NOT engaged, then the Apollo Mic input clips very easy. How can I see if the J48 clips or not? Sorry if this is a stupid question.

[resistorman]

A guitar pickup is not going to clip the Radial. You likely need to pad the mic input.

[resistorman]

The Twin manual states that the preamp has a 20db pad. Try not padding the Radial and use the Twin pad instead.

[YusefG]

The Twin manual states that the preamp has a 20db pad. Try not padding the Radial and use the Twin pad instead.

This reduces the noise floor and changed the tone a tiny bit, but I'm not sure yet if I find it better or worse.

I know from the Periphery 3 and 4 documentaries that they recorded guitar as well as bass DI with the J48 (guitars into Focusrite Pre8X and bass into the Apogee Symphony, I think) and both have the 15dB Pad engaged.
Now, their productions seem really top notch, but why would they record their DI's with so much noise if it wasn't somehow avoidable? This is what confuses me.

[resistorman]

Hard to say. The signal coming from a passive pickup is already tiny and attenuating it makes no technical sense. Possibly they have very hot active circuitry in their instruments. Or maybe settings had changed by the time they filmed it. Or maybe they saw someone else doing it and thought that is the way it's done, the noise didn't bother them, and they just got on with making music.

[resistorman]

BTW, what are you trying to accomplish by using the Radial?

[Wonks]

What is the Apollo connected to? A lot of noise issues are caused by using laptops with no or high resistance ground/earth paths due to double insulated PSUs. This stops the normal screening properties of cables from working correctly, with a resulting increase in noise pickup.

[Wonks]

Also, have you tried using a different guitar, guitar lead and XLR-XLR cable, just to rule out any of those as causing the issue?

I presume the recordings were done prior to adding the Fortin Cali plugin?

Add a hi- gain plugin that may be adding 60dB of gain to any input signal and the background noise will be brought right up. E.g. add 60dB of gain to a signal with a background noise level of -95dbFS and the noise level will now be -35dbFS.

This is why noise gates and downward expanders are used so much to process modern metal guitar sounds.

Almost every distortion and overdrive pedal has a high pass filter that rolls off the low end to remove as much 50Hz/60Hz noise as possible. Any pedal with diode clipping can boost the signal to the point where even a small amount of 50/60Hz hum is boosted to the signal clip level, making it the same amplitude as the guitar signal and the clipping adding in harmonics of 50/60Hz that aren’t related to the guitar signal. A plug-in that models diode clipping should do the same thing (but it should also model that hi-pass filtering). But a high-gain valve amp can do a similar thing (but without such extreme clipping), but is unlikely to have the hi-pass filtering, and a model of it will be the same.

So it may be worth trying a hi-pass filter before the amp plug-in set to roll-off the low end. You may notice it playing solo, but you won’t in a mix and the guitar(s) will sound clearer.

You may already be doing all this, but we need to ask as only you know all the finer detail of your recording set-up.

[YusefG]

BTW, what are you trying to accomplish by using the Radial?

I got the Radial to use it like any other DI box, and I use it when I only record DIs because I dont like the thought of having 2 different signal chains for DI sounds. This is the first time I ever noticed that the Hi-Z input has much lower noise, because I never tried it out. I figured, if Periphery use the J48 and it's good enough for them, then it's good enough for me.

[Hugh Robjohns]

The J48 is a very good active DI box. I have a couple gear and use them often... and I've never had a noise problem.

I think the only time I've used the pad option was with an active bass.

[YusefG]

What is the Apollo connected to? A lot of noise issues are caused by using laptops with no or high resistance ground/earth paths due to double insulated PSUs. This stops the normal screening properties of cables from working correctly, with a resulting increase in noise pickup.

The Apollo is connected to my 16" Macbook Pro 2019. Unfortunately, I have no other possibility to test this exact signal chain with, because my Windows PC has no TB3 support.

[YusefG]

Also, have you tried using a different guitar, guitar lead and XLR-XLR cable, just to rule out any of those as causing the issue?

I presume the recordings were done prior to adding the Fortin Cali plugin?

Add a hi- gain plugin that may be adding 60dB of gain to any input signal and the background noise will be brought right up. E.g. add 60dB of gain to a signal with a background noise level of -95dbFS and the noise level will now be -35dbFS.

This is why noise gates and downward expanders are used so much to process modern metal guitar sounds.

Almost every distortion and overdrive pedal has a high pass filter that rolls off the low end to remove as much 50Hz/60Hz noise as possible. Any pedal with diode clipping can boost the signal to the point where even a small amount of 50/60Hz hum is boosted to the signal clip level, making it the same amplitude as the guitar signal and the clipping adding in harmonics of 50/60Hz that aren’t related to the guitar signal. A plug-in that models diode clipping should do the same thing (but it should also model that hi-pass filtering). But a high-gain valve amp can do a similar thing (but without such extreme clipping), but is unlikely to have the hi-pass filtering, and a model of it will be the same.

So it may be worth trying a hi-pass filter before the amp plug-in set to roll-off the low end. You may notice it playing solo, but you won’t in a mix and the guitar(s) will sound clearer.

You may already be doing all this, but we need to ask as only you know all the finer detail of your recording set-up.

Yes, I tried the following:
- different guitars
- different XLR cable
- different guitar cable

The recordings we're exported with the Fortin Cali Plugin active, so what you are hearing is through the amp sim!

Man this is making me crazy, I would love to know whether I am doing something wrong or maybe Periphery have the noise as well, but just don't care? Not knowing makes me crazy. If I won't be able to find out or solve this, I might just resort to just using the Hi-Z input...

[resistorman]

There is nothing wrong with using the Hi z input if you're close to the input... being an Apollo I bet it loads the pickup properly and sounds great.

[Drew Stephenson]

This ^^^. If the Hi-Z input works well, just use that.

[Wonks]

I’d try adding a good ground connection to the system to see in that improves the noise at all.

I’d also look at the noise levels before any amp sim. That’s the actual noise level from the DI box. Any gain from the amp sim will definitely bring up the noise floor.

You’d get very similar noise levels from miking up a similar style hi-gain amp.

Noise gates, or preferably downward expansion or level automation is what will be used in the studio. Jack Ruston who used to post here fairly regularly, has worked on a lot of this style of music (e.g. he did the last Judas Priest live album) and he was always saying how much level automation was needed to remove all the hiss between notes/phrases.

[Hugh Robjohns]

The Apollo is connected to my 16" Macbook Pro 2019.

Hmmm. As Wonks suggested, the problem is likely to be an absent ground since, AFAIK, most macbook mains power supplies are double insulated types.

Is anything else plugged into the Apollo, like powered monitor speakers?

[Sam Spoons]

My MBPs (2011, 2012 and 2020) all have a metal earth pin on the PSU, the short plug (which makes the PSU into a wall wart) connection to the MBP chassis is open circuit but if you use the extension lead it is connected to the MBP chassis but the resistance to ground is high at 1kΩ.

[YusefG]

The Apollo is connected to my 16" Macbook Pro 2019.

Hmmm. As Wonks suggested, the problem is likely to be an absent ground since, AFAIK, most macbook mains power supplies are double insulated types.

Is anything else plugged into the Apollo, like powered monitor speakers?

No, nothing, except my Sennheiser HD650s. I also tried running the Macbook Pro on the battery, but that didn't change anything.
The noise is also only very loud when phantom power is engaged. Could this mean that the DI box is faulty or something?

[Hugh Robjohns]

No, nothing, except my Sennheiser HD650s.

So nothing external to provide a solid grounding.

I also tried running the Macbook Pro on the battery, but that didn't change anything.

If the problem is due to an absent ground, I wouldn't expect it to.

The noise is also only very loud when phantom power is engaged. Could this mean that the DI box is faulty or something?

It's an active DI box, so it won't work at all when phantom is switched off!

Of course it's possible your J48 is faulty, but its very unlikely. Everything you've said suggests to me that your interface -- and therefore the J48 and your guitar -- lack a solid ground reference, and that's allowing much unwanted noise to enter the system.

[Sam Spoons]

The Radial D48 is an active device and needs phantom power to function which might explain why there is no noise when phantom power is off. The problem is likely due to a lack of a low resistance earth path which running the MBP on batteries does nothing to remedy, try connecting the chassis of the MBP/Apollo/Radial to a known good earth (the metal screws of a wall socket for example*), you can use a guitar lead by touching the tip connection to a metal part of the Apollo and the the tip of the other plug to the screw.

[YusefG]

The Radial D48 is an active device and needs phantom power to function which might explain why there is no noise when phantom power is off. The problem is likely due to a lack of a low resistance earth path which running the MBP on batteries does nothing to remedy, try connecting the chassis of the MBP/Apollo/Radial to a known good earth (the metal screws of a wall socket for example*), you can use a guitar lead by touching the tip connection to a metal part of the Apollo and the the tip of the other plug to the screw.

Well, there is still noise with phantom power turned off, even more noise that with the Hi-Z input.
If there is no low resistance earth path, shouldn't the Hi-Z input have high noise as well, then? Sorry if this question is stupid, but I have no idea about that stuff haha.
I will try and connect my monitors to it.

[Sam Spoons]

The Radial D48 is an active device and needs phantom power to function which might explain why there is no noise when phantom power is off. The problem is likely due to a lack of a low resistance earth path which running the MBP on batteries does nothing to remedy, try connecting the chassis of the MBP/Apollo/Radial to a known good earth (the metal screws of a wall socket for example*), you can use a guitar lead by touching the tip connection to a metal part of the Apollo and the the tip of the other plug to the screw.

Well, there is still noise with phantom power turned off, even more noise that with the Hi-Z input.
If there is no low resistance earth path, shouldn't the Hi-Z input have high noise as well, then? Sorry if this question is stupid, but I have no idea about that stuff haha.
I will try and connect my monitors to it.

Is there any guitar signal being passed when phantom switched off?

Different devices have different susceptibility to EMI.

Have you tried providing a good earth as I suggested, it may help?

[YusefG]

The Radial D48 is an active device and needs phantom power to function which might explain why there is no noise when phantom power is off. The problem is likely due to a lack of a low resistance earth path which running the MBP on batteries does nothing to remedy, try connecting the chassis of the MBP/Apollo/Radial to a known good earth (the metal screws of a wall socket for example*), you can use a guitar lead by touching the tip connection to a metal part of the Apollo and the the tip of the other plug to the screw.

Well, there is still noise with phantom power turned off, even more noise that with the Hi-Z input.
If there is no low resistance earth path, shouldn't the Hi-Z input have high noise as well, then? Sorry if this question is stupid, but I have no idea about that stuff haha.
I will try and connect my monitors to it.

Is there any guitar signal being passed when phantom switched off?

Different devices have different susceptibility to EMI.

Have you tried providing a good earth as I suggested, it may help?

I did connect one monitor to it (Yamaha HS8), which didn't help. Then I took a guitar cable and connected the metal casing of the Apollo to the earth of an outlet (was helped by my girlfriend, who does electrician stuff for a living) and that didn't help, either. She also said that wouldn't make any sense, because if the Apollo was constructed in a way so that it needed a ground, then the power cable would be one with a ground. But it isn't.
So the cluelessness continues haha. Should I contact Radial about this and ask?

[Hugh Robjohns]

I took a guitar cable and connected the metal casing of the Apollo to the earth of an outlet (was helped by my girlfriend, who does electrician stuff for a living) and that didn't help, either.

That's disappointing...

She also said that wouldn't make any sense, because if the Apollo was constructed in a way so that it needed a ground, then the power cable would be one with a ground. But it isn't.

Not necessarily. Many interfaces are class-II and rely on being connected to grounded devices like powered monitors...

Should I contact Radial about this and ask?

I imagine they'll be as bamboozled as the rest of us... but before you do that, you didn't answer one of my previous questions which was whether you had the ground lift switch activated on the J48? That could make a lot of difference to the noise you're getting so it's definitely worth checking.