Radial JDI or J48?

[keatz]

There is a nice spare spot on my board for a DI. Am definitely leaning towards JDI

 

[lowfreqgeek]

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.

The J48 uses an isolated switching supply to convert from single-ended 48V to approximately +/-15V. Power and signal grounds can be fully isolated with the ground lift, without disrupting power. The original J48 was the first to do this and the only one for a long time that could run on phantom power with the signal ground fully isolated. I may be wrong, but I believe that the Countryman Type 85 requires the battery to operate with the ground lifted.

 

[lowfreqgeek]

I owned a JDI and J48 at the same time and ended up keeping the J48 for life. The JDI is great, but there is a -22dB attenuation from the transformer, which means that the mixer has to boost the signal by 22dB to get back to unity. While that's not an issue for any decent mixer, there were times that I ran into problems with low-output instruments and poor quality, noisy mixers. Not an issue if you always run a preamp in front of the DI, but if you use a low output passive bass, you'll have to rely on the mixer for all the gain.

The J48, OTOH, has a +6dB output (if I remember correctly). Low output bass into a noisy mixer is usually no problem, as the mixer isn't making up that additional gain. I've had my J48 for over 10 years and it has performed flawlessly. I have also used one at church for just about as long and can't say enough good things about them. Plenty of experience with the Countryman and others, but the J48 is smoother sounding and less harsh in the highs, IME. The J48 was also Anthony Jackson's go-to DI, FWIW.

Still, if you have a high output bass and/or preamp in front of it, the JDI is a fantastic DI, as well.

 

[bass12]

I owned a JDI and J48 at the same time and ended up keeping the J48 for life. The JDI is great, but there is a -22dB attenuation from the transformer, which means that the mixer has to boost the signal by 22dB to get back to unity. While that's not an issue for any decent mixer, there were times that I ran into problems with low-output instruments and poor quality, noisy mixers. Not an issue if you always run a preamp in front of the DI, but if you use a low output passive bass, you'll have to rely on the mixer for all the gain.

The J48, OTOH, has a +6dB output (if I remember correctly). Low output bass into a noisy mixer is usually no problem, as the mixer isn't making up that additional gain. I've had my J48 for over 10 years and it has performed flawlessly. I have also used one at church for just about as long and can't say enough good things about them. Plenty of experience with the Countryman and others, but the J48 is smoother sounding and less harsh in the highs, IME. The J48 was also Anthony Jackson's go-to DI, FWIW.

Still, if you have a high output bass and/or preamp in front of it, the JDI is a fantastic DI, as well.

One of my active basses has fairly low output and I had a few sound guys (pros, not hacks) express some frustration with my output level when I'd use my JDI. I've had no complaints since switching to the J48.

 

[hbabels]

I have also noticed that the JDI does have a lower output than the J48. Its not a problem at all with quality mixers but if you’re using lower quality mixers you might have some noise issues or lower than ideal levels.

 

[keatz]

Is the thru out attenuated as well or just the DI out?

 

[Krisfield]

I was using the J48 after a preamp and thought there was a bit noise with this configuration.

Edit: concluded the JDI might be a cleaner option.

 

[Wasnex]

The J48 uses an isolated switching supply to convert from single-ended 48V to approximately +/-15V. Power and signal grounds can be fully isolated with the ground lift, without disrupting power. The original J48 was the first to do this and the only one for a long time that could run on phantom power with the signal ground fully isolated. I may be wrong, but I believe that the Countryman Type 85 requires the battery to operate with the ground lifted.

Pretty sure both the Countryman Type 85 and BSS AR116 used isolated DC to DC converters long before Radial was even a company. The BSS converter is a separate module called the AR117. So I don't think this is accurate.

 

[Wasnex]

Is the thru out attenuated as well or just the DI out?

The Thru on most DIs is simply a parallel connection with the Input. The one exception I can think of is the Radial PZDI, in which the Thru can be configured as parallel or buffered.

 

[hbabels]

Is the thru out attenuated as well or just the DI out?

The thru is parallel no output change

 

[okcrum]

Let me get this straight:

Allow me to clarify for you.

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

Completely arbitrary, non-useful info. Discard.

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

Radial did originally (in 1996), until Jensen couldn't supply enough transformers starting in 2005, and they used both Jensen and Eclipse for awhile. Then Radial invested in Jensen and they're all Jensen again since at least 2014 or so.

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

Not all cables correctly deliver phantom power from the mixer to the user. The more important the application, the more likely the cable will be at fault, by Murphy's Law.

 

[okcrum]

Not all cables correctly deliver phantom power from the mixer to the user. The more important the application, the more likely the cable will be at fault, by Murphy's Law.

...or the more likely the phantom power in the mixer has failed.

 

[FirewalZ]

I keep a Radial Pro DI (passive) in my gig bag as a “just in case”, I wanted something super simple and failure proof so went with a passive. However, since switching to Mesa I don’t use it, as the onboard DI they have is as good or better.

 

[Jerry Ziarko]

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.

Did a side by side by side comparison of the ProDI, JDI and J48 with three different basses. If there was a difference, we couldn't hear any. The ProDI is a great little box at a every reasonable price.

 

[Woofenstein]

I own both JDI and J48. I play passive Fender basses and will always choose the J48 over the JDI - especially with a low output passive Jazz Bass. If someone needs to use a DI at a gig, I’ll always give them the JDI because of the simplicity of not having to ask for phantom.

 

[brianrost]

if a DI is used.....there is a mixer.... therefore....48v.... always./

Wait until you play that venue with a broke down PA with no functioning phantom. Passive DI or an active that takes a battery for me. Always. One less thing to worry about.

 

[GreyBeard]

I use a Mesa Subway pre-DI but I keep a JDI just in case. I also have a Whirlwind passive DI in the bag too. I keep it in there in case I need to loan it to someone on a gig like the KB player. I think I paid like $20 for it used and it works like a charm too. The JDI is an industry standard and is about as good as it gets for a passive DI. Heck, from what I heard, the cheap Behringer passive DI works well too.

 

[ugly_bassplayer]

Wait until you play that venue with a broke down PA with no functioning phantom. Passive DI or an active that takes a battery for me. Always. One less thing to worry about.

Wow....I envy that gig.




I'll take my Radial pro di to that one.....
No PA...... then why use a DI????

 

[ugly_bassplayer]

I owned a JDI and J48 at the same time and ended up keeping the J48 for life. The JDI is great, but there is a -22dB attenuation from the transformer, which means that the mixer has to boost the signal by 22dB to get back to unity. While that's not an issue for any decent mixer, there were times that I ran into problems with low-output instruments and poor quality, noisy mixers. Not an issue if you always run a preamp in front of the DI, but if you use a low output passive bass, you'll have to rely on the mixer for all the gain.

The J48, OTOH, has a +6dB output (if I remember correctly). Low output bass into a noisy mixer is usually no problem, as the mixer isn't making up that additional gain. I've had my J48 for over 10 years and it has performed flawlessly. I have also used one at church for just about as long and can't say enough good things about them. Plenty of experience with the Countryman and others, but the J48 is smoother sounding and less harsh in the highs, IME. The J48 was also Anthony Jackson's go-to DI, FWIW.

Still, if you have a high output bass and/or preamp in front of it, the JDI is a fantastic DI, as well.

Got enough fo AJ.....more than good enough for little old me

 

[Deleted member 271037]

I have extensive experience with both. They're both great!

No phantom: The J48 isn't even an option unless you want to add a dedicated phantom supply (and the cheaper ones often struggle with powering DI boxes). Get the JDI.

If you know phantom power will always be available:

If you ever plan on going straight from a passive bass into the DI you should get the J48. The output from the JDI can be on the weak side in some situations with a passive bass plus you risk loading the pickups with long cable runs. It won't be useless though, just not ideal.

If you use both basses with the SV-pre I would probably get the JDI though. It's my favourite DI for anything active/powered. The J48 will also work great with the SV-pre as long as you don't crank the output TOO much but for anything active/powered the JDI is hard to beat IMO.