Any reasons to get an AR133 over a J48?

Chris Nixon

Junior
Jul 23, 2012
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Northern Ireland
I have a small mic kit intended for improving upon mics for some of the fundamental band inputs, rather than outright replacing the mics provided by venues etc. Currently I have mics for Kick, Snare, Guitar cabs and Lead vocal.

I'm going to be buying one good DI to add to this, for either electric bass or acoustic guitar depending on the show. All research I've done points to the J48 and AR133 being the two best, with the J48 being a bit better. The only things that concern me about the J48 is that it only has a 15dB pad, as opposed to the two 20dB pads on the BSS, and the maximum output level on the BSS also seems to be 18dB higher than the J48 if my calculations are correct.

Radial J48
Signal to noise at Max Output 108.4dB
Noise Floor -140dB
=Max Output -31.6dB

BSS AR133
Signal to noise at Max Output 111.2dB
Noise Floor -125dB
=Max Output -13.8dB

http://www.radialeng.com/pdfs/Radial-BlueReport-on-DIs.pdf

Of these two I've only used the AR133, on acoustic guitar with an active pickup. There were no problems, but obviously I didn't compare it to the Radial. The J48 seems like it will be sonically better so it's what I'd like to get, but am I likely to miss the extra features of the BSS? Has anyone had any issues with running out of headroom on the J48?

Thanks,

Chris
 
Re: Any reasons to get an AR133 over a J48?

I have never needed the pad on the J48. I imagine a super hot keyboard or track output could possibly overdrive the unit but I have not seen that yet either. You can always turn the output down from the keyboard or computer etc. at sound check anyway. If you are gained in correctly and running through the monitors the musician will typically back it down if it gets a little hot anyway. I have not used the AR133 that I can remember so I can't compare them sonically. You really should have at least 6 DI in your kit even if 4 of them are very cheap ones. It is pretty easy to need them these days. Bass, a couple of acoustic guitars and a stereo keyboard is 5 right off the bat. I run into things like mandolin and violin along with the acoustic guitars and keyboards on many of the country acts I run sound for. The way the direct box loads the pickup on a guitar or bass is going to effect the sound a great deal. You can get away with the economy units on keys and tracks but you should always use your best units on anything with a pickup. I carry 4 active and 6 passive units in my mic kit.
 
Re: Any reasons to get an AR133 over a J48?

You really should have at least 6 DI in your kit even if 4 of them are very cheap ones. It is pretty easy to need them these days. Bass, a couple of acoustic guitars and a stereo keyboard is 5 right off the bat.

It's not a provider or venue kit, it's to supplement mics from venue kits with better options. Eg. the venue will have an SM57 I can use on snare, but I'd rather use an M201, so I bring one. Guitar cabs? the venues SM57's will be fine, but my e906's will be better.

Chris
 
Your two examples split my choices. I almost always go with a JDI on a bass and a J48 on an acoustic guitar.

So my easy answer is both.

Sent from my DROID RAZR HD
 
Re: Any reasons to get an AR133 over a J48?

How often do you find you need to use the pad switch? The BSS will definitely work and won't overload, but if the Radial won't overload either... I'll probably go with the J48, and if I get more DI's in the future I'll get 133s for their versatility.

Chris
 
Re: Any reasons to get an AR133 over a J48?

It's not a provider or venue kit, it's to supplement mics from venue kits with better options. Eg. the venue will have an SM57 I can use on snare, but I'd rather use an M201, so I bring one. Guitar cabs? the venues SM57's will be fine, but my e906's will be better.

Chris

Ah, I see. Are you ever having to use a DI pad on anything now? Like I said, I have never needed one. I am sure someone has needed one or there would not be one available at an extra expense to the manufacturer. I assume it would have to be some type of line level signal to overload a DI in the first place. Good choice on the e906 by the way. Even your SM57 would most likely be a better choice than a venues abused and worn out SM57.
 
Re: Any reasons to get an AR133 over a J48?

I have lots of both of these di's. They both sound excellent. I would not give the nod to one over the other sonically. The Radial is simpler in design and will prove slightly more robust in the long haul. The BSS has xlr in and xlr out available. This is a big deal if you find yourself in a station where you want to transformer isolate a line level signal.
Get some of each.
 
Re: Any reasons to get an AR133 over a J48?

Ah, I see. Are you ever having to use a DI pad on anything now? Like I said, I have never needed one. I am sure someone has needed one or there would not be one available at an extra expense to the manufacturer. I assume it would have to be some type of line level signal to overload a DI in the first place. Good choice on the e906 by the way. Even your SM57 would most likely be a better choice than a venues abused and worn out SM57.

I've had an acoustic guitar provide a signal that only needed about 6dB of gain to bring it up to line level, but nothing that actually caused a problem. That was with an ART XDirect. I'll get the J48 and if I find myself needing more than the 15dB available pad I'll sell it and get the BSS, that seems unlikely. :razz:



Thanks for the help,

Chris
 
Re: Any reasons to get an AR133 over a J48?

The BSS has xlr in and xlr out available. This is a big deal if you find yourself in a station where you want to transformer isolate a line level signal.

That input XLR on the BSS is a placebo. It's not really balanced. Pin 2 is the tip, and 1 and 3 connect to the sleeve of the input jack.

Not sure where Chris got the numbers on the J48. I just measured one here, and without the pad, that maximum output is about +8 dBu with +4 dBu going in. The noise floor is about -57 dBu, band limited from 22-22kHz. I measured a Radial Pro48 a while ago, and it was virtually the same as the J48, except slightly more output. To my mind, the Pro48 is the sleeper of the lineup, at about half the price of the J48.

The BSS does give you the option of battery instead of just phantom power however. That might be important for some people. We have a few BSS boxes as well. Here are the numbers on one random sample, running off phantom, not a battery.

Gain without pads: -1 dB
Maximum output: +11 dBu
Noise (input terminated): -62 dBu

Caution: to the casual A/B tester, the Radial, with 5 dB more gain, will sound "better". Don't get sucked into that trap! Normalize the gain, then LISTEN 8)~:cool:~:cool:

GTD
 
Re: Any reasons to get an AR133 over a J48?

The double 20dB pads on the BSS are for speaker level outputs direct from an amplifier output. So unless you're planning on connecting to an amp's speaker terminals, I wouldn't worry about it. On thing the BSS has over the J48 is a transformer coupled output which will completely isolate the electronics of the DI from the mixer. It's rare, but occasionally with non-transformer coupled active DIs, I've had noise get through from that direct coupling which can only be eliminated with a transformer. So I have JDIs for those situations.
 
Re: Any reasons to get an AR133 over a J48?

I got the numbers for "signal to noise at max output" and "noise floor" from page 3 of the PDF posted. I calculated the max output using those two numbers, but like I said in the first post, I'm unsure that this is a valid way to calculate it.

IE: If the noise floor is at -140, and the signal at max output is 108.4 dB higher than the noise floor, the signal level at max output would be -31.6.

http://www.radialeng.com/pdfs/Radial-BlueReport-on-DIs.pdf

Feel free to tell me if I'm totally wrong. :razz:


Chris