Radial J48 no phantom power

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soss

New member
Just got a used Radial J48. It should receive the 48v phantom power from my TC Konnekt 6 but the LED on the DI does not blink like it should. Also no sound coming through the input on the interface. First time I have used an active DI like this. Any ideas?
 
Do you or a friend have a live/studio console that provides phantom so as you can be sure that the Di works to begin with?
 
Okay . . . I looked the Konnect up on Google.
See here: TC Electronic Desktop Konnekt 6

There are a couple of interest points in there:

1 It looks like not all 'scenes' will deliver phantom power.
2 You need external power when using 4 pin firewire to a laptop

Have you checked that out?
 
I was somewhat disappointed when I saw an open J48 at NAMM a couple years back.
They use cheap, no-name Chinese caps in a premium priced unit.
I'm in the computer business, and have no end of service calls replacing bad craps.

Reapping the J48 is a simple job, but no doubt invalidates the warranty.
Pity.
 
bgavin said:
I was somewhat disappointed when I saw an open J48 at NAMM a couple years back.
They use cheap, no-name Chinese caps in a premium priced unit.
I'm in the computer business, and have no end of service calls replacing bad craps.

Reapping the J48 is a simple job, but no doubt invalidates the warranty.
Pity.
Click to expand...

That's not necessarily a problem in (very low power) audio--computer caps live fast and die hard. Temps are much higher next to the CPU; I've seen swollen and burst Nichi PWs. That is probably not the fault of the cap, it's a design problem on the mobo. Bulk capacitance should have a bit more space whereas MLCCs can be relied upon for the close up dirty work.

A DI box is going to live its life at 25C or below for the most part, so the relevant question in small-signal audio is the contribution of the cap to system THD, which you can't tell just by looking. There is a lot of voodoo in DIY cap swapping and very little actual measurement. And of course first you need to know what the cap is doing in the circuit.
 
Agreed.
However, cheap is still cheap.

Yes, it is the fault of the cap.
There was a huge stink raised because the Chinese obtained a partial paste formula from Rubycon, and it was defective.
ABit was sued into oblivion because they refused to deal with this.
Dell has entire product lines with chronic capacitor problems.
I have replaced hundreds of bad caps in both VRM and in the field at large.

There is very little extra cost is incurred using a premium cap instead of no-name junk.
This is Engineering By Accountant, where a quality design takes a back seat to Cost.

The J48 is not a cheap product, and I expect it to not use cheap components.
As with so many made-in-china products, I suspect the component spec was left to the OEM, who went ultra-cheap.
 
That's great except where you ignored my observation of name-brand caps that have failed. Again, computers are cap hell. A modern CPU has to dissipate over 60W. Making a cap live next to the heat equivalent of a light bulb is going to test it to its extreme. Sometimes they fail as a result. Some fail sooner than others, and yes, some sooner than they should. All of them will fail within the useful live of the mobo for the simple reason that their life is measured in thousands of hours (and according to the ambient temp). Of course, the mobos are generally obsolete by the time the better brands (and mobo designs) would normally fail, but still, the caps will usually be the first point of failure. Go to that "bad cap" forum or whatever that was, and you'll see failure reports of every brand.

None of this has anything to do with an audio device where total power in the circuit is measured in milliwatts and which has a long reputation of stageworthiness . . . so, please stop scaring the poor newb into thinking he's bought a POS.
 
You have ignored my comment that "cheap is cheap".
You also ignored my comment about numerous field caps blowing, none are near the VRM heat concentration.

My comment is not intended to scare anybody, nor is it intended to present a platform for the pompous to spout off and increase their post count to impress the newbs.

I am simply disappointed that premium priced gear is using cheap caps.
Low quality, cheap caps and components are a fact of life and pervasive.
Where they are applied does not change the fact they are low quality and cheap.

You can have the last word.
 
Sweet! Yesterday I got the last piece of pumpkin pie (well half a piece, one of the kids took a bite out of it, but I got the rest! Good thing I'm not choosy about germs), and today I get the last word! It's like an Advent miracle!

So, in the spirit of the season, how about you offer to recap OP's box in exchange for me donating $20 to Toys for Tots?

Marine Toys for Tots Foundation
 
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