Radial JDI or J48?

[Bob_Ross]

Use another cable. Bad xlr won't be any better with a passive di

Actually, depending on how the XLR cable is bad, that passive DI may very well continue to work where the active one would not:

I was specifically thinking of cables with a faulty shield or an intentionally-lifted pin 1, where the JDI will happily continue to work while the J48 is dead in the water, since phantom power is no longer passed. You only need to encounter that snafu once during a critical show before it becomes an important consideration on every subsequent gig.

Don't get me wrong, I love active DIs; I just love the ones that don't rely exclusively on P48 more. I was a huge fan of Radial's original JDV active direct box because, among other things, it came with an optional outboard power supply. The Countryman Type 85 with its onboard battery is another good solution.

But the JDI is 100% badass. No soundman worth their salt will ever turn their nose up at a JDI.

 

[matante]

Absolutely false. Yes it does.

(Face palm)

Nope. Look it up. The JDI does and everyone assumes the j in j48 stands for Jensen, but it doesn't have one.

 

[darwin-bass]

Ok...
Now I'm thinking people don't "get" the 48v thing......
They seem to think of it as a hassle or negative feature. Every mixer on the planet (99.9999999%)
has phantom power.....so what's the problem.....????

1. Not all amps with a DI are phantom protected. Hit it with 48v and you may blow out the DI's op-amp.
2. Phantom creates HUGE pops in the PA. This is an issue when connecting/disconnecting cables or when a mic cable has a bad connection. It happens. The risk is blown tweeters in the FOH speakers.
3. Phantom can cause noise in otherwise quiet sources (Line6 Helix).
4. Some devices that run on phantom require a ground connection. You can't lift the ground to fight ground loops or you lose the phantom power that the device is using.

 

[Rice]

I run the JDI atthe end of my pedal board, and as such, I've never noticed a difference between my actice and passive basses by the time the signal gets through all the other pedals. #ignoranceisbliss??

 

[Wasnex]

Use another cable. Bad xlr won't be any better with a passive di

FYI: A JDI will work with a lifted ground and a J48 will not.

 

[matante]

FYI: A JDI will work with a lifted ground and a J48 will not.

A j48 has its own ground lift. You don't need to lift ground at the mixer. From what I've seen j48 are more common in pro concerts, popular with guitarists as well as bassists, so any perceived negatives don't seem to bother the pros.

 

[ugly_bassplayer]

Nope. Look it up. The JDI does and everyone assumes the j in j48 stands for Jensen, but it doesn't have one.

You're right. Only the stereo one ha the Jensen

 

[hbabels]

I own both JDI and J48 DIs. I use both with active and passive guitars and basses and both sound and work fantastic. Can’t go wrong either way and sonic differences are very very small.
As with most things you May prefer one over the other with your setup and typical gigging needs but I think it’s safe to say you’d be well served by either one.

 

[Wasnex]

Anybody compare the PZ DI to these? The variable hpf and push button lpf onboard is so tempting.

Powered only by 48v phantom power though. Any idea how to keep one always on for a pedalboard?

I chose the PZDI instead of the J48 in case I need to buffer a piezo for upright bass. The PZDI is supposed to be a J48 with different features. One of the different features is variable input impedance 220K, 1Meg, 10Meg. The J48 input impedance is fixed at 220K. I tried my active bass in the PZDI and slightly prefer the 1Meg setting, but you may like 220K better. The difference is fairly subtle with an active bass.

Another cool feature the PZDI has is the Thru can be toggled from parallel to buffered. This isolates your amp's impedance, so it does not load down the pickups. On most DIs, the Input and Thru are simply parallel connections, so you can plug your bass and amp into either jack and it would be electrically the same.

The PZDI also has a variable HPF (5-500hz) and a 3khz LPF.

 

[Wasnex]

A j48 has its own ground lift. You don't need to lift ground at the mixer. From what I've seen j48 are more common in pro concerts, popular with guitarists as well as bassists, so any perceived negatives don't seem to bother the pros.

Correct but you missed the point. If the mic cable has a bad ground, anything that requires phantom power will not work. I have seen this trick up audio techs before. Often when a channel is dead the first thing you do is swap the signal source. But if you swap a passive signal source for an active signal source, you may miss that the mic cable is the problem, and assume you have a bad DI.

FYI, the J48s ground lift does not lift the ground from the DI's internal power supply, but it does lift the ground from the signal path.

 

[ugly_bassplayer]

Meh..

Both are good.

 

[Wasnex]

You're right. Only the stereo one ha the Jensen

It depends on the model of JDI and when it was made. The original JDIs had Jensens. Then they stopped using Jensens in the Duplex because they could not get enough transformers. At this point Radial started using Eclipse transformers that were supposed to meet the same spec. At some later date Radial bought Jensen transformers and AFAIK, started putting them in all JDI models again.

From the JDI Duplex FAQ

I understand that the Duplex went from using a Jensen to an Eclipse ET-DB1, and now back to a Jensen. Can you explain if this is true and the difference?
This is true. Due to short supply from Jensen, we had no choice but to have transformers custom made in order to fulfill demand. The Eclipse used were carefully designed to meet our spec. When Radial purchased Jensen, we injected a significant amount of money into the company to that it could increase production. Because Jensen is now delivering, we have shifted back to using the Jensen JT-DBE.
​

I believe there are currently three models of the JDI: JDI, JDI Duplex, and JDI Stereo. All three list the Jensen JT-DBE transformer.

 

[sstillwell]

I keep a mix of JDI, J48, ProDI, and ProD2, because there's always SOMEONE that needs a DI somewhere, and the ProDI series are just as rugged as their more-expensive brethren, if with lesser transformers and lower input impedance than the mighty Jensen in the JDI.

 

[bass12]

I have both the JDI and the J48 (as well as a PZ Deluxe). If I could only have one (and I play strictly active basses) it would be the J48.

 

[C Niz]

Active and passive do have nothing to do with active and passive basses. All di boxes do the same thing(balance outputs and lower impedence) and expect the same type of input signal ( hi z and unbalanced). The only difference is that active used a circuit to do this passive use a transformer. If you use both types of basses get one with a pad on the input. Other than that either works the same

 

[FunkyYeti]

Let me get this straight:

Passive DIs are for active basses and active DIs are for passive basses... but not really.

The JDI and J48 are relatively expensive because they have Jensen transformers... but they don't.

The J48 requires phantom power, which can be problematic... but not really because all PAs have phantom power.

 

[Wasnex]

Active and passive do have nothing to do with active and passive basses. All di boxes do the same thing(balance outputs and lower impedence) and expect the same type of input signal ( hi z and unbalanced). The only difference is that active used a circuit to do this passive use a transformer. If you use both types of basses get one with a pad on the input. Other than that either works the same

In general I believe this is true.

But some passive pickups are loaded down excessively if you use a passive DI. The passive DI does not in itself determine the impedance that is presented to the bass. The transformer basically has a ratio that converts voltage, current, and impedance based on the turns ratio. So the input impedance of whatever device you are driving with the DI ultimately determines that load presented to the pickups. I believe the ratio in most DI transformers is on the order of about 12:1.

Another factor is the length of the cable run between the DI and the driven device. A passive bass with weak pickups may not be able to generate sufficient voltage for a long cable run if you use a passive DI.

 

[Mannyinnewyork]

I found it all a bit confusing myself. I called Radial a few years ago, told them all my basses were passive, they said a ProDI would be a good choice. Opinions may vary and probably will, but this is what the particular sales person told me on that day. I bought a ProDI and it works just fine.

 

[Frenchy-Lefty]

On the DI side the Rupert Neve RNDI1 is exceptional for $250

 

[Wasnex]

I found it all a bit confusing myself. I called Radial a few years ago, told them all my basses were passive, they said a ProDI would be a good choice. Opinions may vary and probably will, but this is what the particular sales person told me on that day. I bought a ProDI and it works just fine.

A passive DI will definitely work with a passive bass; some better than others. It won't always sound great, but it is not a problem with most basses in most situations. In rare circumstances you actually need an active DI with a passive bass or it will sound like .

IMHO, people with a tendency towards OCD would be better off to follow the general rule. This is straight from Radial Comparing Direct Boxes - Radial Engineering Click the question "What kind of DI box should I get?" and you will see

A simple rule of thumb:

1. If the source is active, use a passive DI box
2. If the source is passive, use an active DI box

Radial gives the same advice on multiple pages throughout their website, but IMHO this advice is really to ensure maximum compatibility across the maximum number of situations. There are lot's of situations where you can break these rules and no one will notice or care.

I own both active and passive DIs and I have played an active bass for decades. The DI's I have used most are the Countryman Type-85, BSS AR116, and Radial JDI, so I used a mix of both active and passive DIs with my active bass. Some of my audio techs greatly preferred the BSS AR116 on bass over the Countryman. When we got new audio techs, they bought Radial JDIs and my bass still sounded great, but I would still use a Countryman in a heartbeat. For the record, I really love the way the Radial Duplex sounds with electronic keyboards. The Duplex seems to smooth out some of the digital nastiness so piano and string patches sound a bit more authentic.