Cordial CIW-1 DI Box - Quick Review

[Jack]

Hello all,

In an effort to curb my gear addiction I recently sold a few things off. (The clearout is ongoing if anyone fancies a couple of guitars or a White of Sunderland 4x12”!!) Anyway, one of the things that got the chop was my Triton Audio BigAmp. It was a great DI, small enough to keep around at all times, great sound, etc etc. The problem was, I find phantom power quite hard to come by in some situations. It’s no problem when it’s our PA system but sometimes other engineers get weird about it. The two most common excuses are that the desk is all or nothing with phantom power and that other devices won’t like it, or that the snake from FOH won’t pass it. Both strike me as various degrees of excuse, but the fact remains that passive DIs seem to suit my situation better. Besides, I have a Countryman Type 85 so other active DIs are sort of unnecessary anyway.

This leads me on to our subject. Whilst browsing Thomann for new cables I stumbled across the Cordial CIW1. Like the BigAmp it’s a DI in something not much bigger than a jack to XLR adaptor. Unlike the BigAmp it’s passive, so it should suit me better. I was (and still am) very sceptical about the quality of the transformer that you can fit into a device this size, but I couldn’t not buy one for less than £50.

The unit is TINY. TINY. Like, really small. In terms of features: none. There’s an input, a transformer and an output. No pad, no through jack, no nothing. It's good to know that the jacks that are there are Neitrik and locking. It's a solid little thing. Input impedance is roughly 50kR so it’s really not designed for passive instruments but it should work great with pretty much any buffered or active source. It works well with my Stingrays and after me pedal boards, but it does round off the top end of the passive P-bass quite noticeably.

It’s a difficult thing to test objectively and properly. I tried just playing into it (with a Stingray) but then any kind of comparison has to deal with the vagaries of my playing. In the end I came up with quite a good test platform. I played a bassline into my Helix and set that on an indefinite loop using the looper. I then fed one 1/4" output into the Cordial and the other to either my Countryman or my Radial SB-2. I could then use my XR18 mixer to match levels and solo/mute channels to hear the difference between boxes. Please note, this setup obviously has 2 AD/DA stages (helix and mixer) and a few too many cables to be a perfect testing platform. I don’t have the technical nouse to properly scope it out, Cordial say it’s flat across its frequency range and I believe them. I’d be interested (if anyone was more technical than me) to compare its distortion and clipping characteristics compared to something more industry standard. My brain tells me that a transformer that small has to have limits.

In terms of sounds, it sounds fine. I mean, actually it sounds really good. You do have to be careful not to clip the input as it doesn’t like really hot signals (and there’s no pad) but other than that it’s pretty honest representation of what the bass sounds like. Sometimes, I think the lower frequencies are ever so slightly blurred or smeared compared to the Countryman but I wonder if it’s psychosomatic because I know that the Cordial is less 25% of the size and price of the other box. It’s also quite a lot quieter than the (active) Countryman, and ever so slightly quieter than the (passive) Radial.

I still believe that if you can only have one DI box it has to be
1.    Able to handle any input, which really means an active box
2.    Not reliant on phantom power, so it has to have the option of being ran from a battery or external PSU
3.    As ‘clear’ and flat as possible. There are so many ‘character’ DI boxes, but you don’t always want the same character all of the time.

In short, you really have to have something like the Countryman as your only DI box. Or the nicer, active Radials. Or even the Orchid DI box if you’re on a budget. But realistically the Cordial won’t be your only DI box, it won’t be an integral part of your main gig rig and you won’t take it into the studio to record with. You’ll buy it to chuck in the bottom of your gig bag and have it there to save your behind when something else breaks. And for that it’s absolutely perfect.

 

Edited August 3, 2018 by Jack

[rmorris]

Interesting post. A few points come out of it for myself.

re Phantom Power and the "Sound Guy" - some desks do indeed have 'global' Phantom Power switching.

But it's typically only on Mic inputs (or XLRs that can be switched Mic / Line) whilst there are separate 'Line Only' inputs on TRS Jack and these don't get Phantom. There would be an issue if Phantom were applied to the output of a piece of kit not 'expecting' it.

If the PA runs with only Dynamics mics - say the workhorse SM 58 / SM57 - or back-electret mics then Phantom isn't required. Means can't use 'proper' externally polarised condenser mics - well not without dedicated power supplies for them -  but probably not using those for live in a lot of situations.

The '50k Ohm' input impedance figure is a nominal figure only - generally related to a load impedance on the secondary side of 600 Ohm. But 600 Ohm is just a 'standard' used for basically historical reasons from telecommunications. It indicates that the impedance is 'transformed' by x83 (to integer approximation). Along with an attenuation of approx 19dB. It really a bit more complicated due to winding impedances and stuff but it's in the ball park. Of course there may be some loading built into the DI already to suit the transformer.

Typically you'd might feeding a Mic input with something like 2 kOhm Input Impedance so that would end up looking like 166k Ohm to your bass - not too bad but still significantly les than the usual 470 kOhm or 1 MOhm at the front of a bass / guitar amp.

The 'problem' I see with the test set up is that the sources will all be relatively low impedance. The impedance of the source will affect the transformer response and a passive pickup has a very significant complex impedance from the Inductance and winding resistance.

Yes - it's hard not to wonder about the bass response of a small transformer. It's essentially down to the inductance characteristics and it's not usual to find them properly stated even when the transformer is a known one. There are ways to get a flat response from some small transformers but that typically involves active circuitry on the secondary side.

Anyway I guess the proof's in the playing 😊

Nice Photos btw.

Edited August 9, 2018 by rmorris

[Jack]

On 09/08/2018 at 11:16, rmorris said:

Interesting post. A few points come out of it for myself.

re Phantom Power and the "Sound Guy" - some desks do indeed have 'global' Phantom Power switching.

But it's typically only on Mic inputs (or XLRs that can be switched Mic / Line) whilst there are separate 'Line Only' inputs on TRS Jack and these don't get Phantom. There would be an issue if Phantom were applied to the output of a piece of kit not 'expecting' it.

If the PA runs with only Dynamics mics - say the workhorse SM 58 / SM57 - or back-electret mics then Phantom isn't required. Means can't use 'proper' externally polarised condenser mics - well not without dedicated power supplies for them -  but probably not using those for live in a lot of situations.

The '50k Ohm' input impedance figure is a nominal figure only - generally related to a load impedance on the secondary side of 600 Ohm. But 600 Ohm is just a 'standard' used for basically historical reasons from telecommunications. It indicates that the impedance is 'transformed' by x83 (to integer approximation). Along with an attenuation of approx 19dB. It really a bit more complicated due to winding impedances and stuff but it's in the ball park. Of course there may be some loading built into the DI already to suit the transformer.

Typically you'd might feeding a Mic input with something like 2 kOhm Input Impedance so that would end up looking like 166k Ohm to your bass - not too bad but still significantly les than the usual 470 kOhm or 1 MOhm at the front of a bass / guitar amp.

The 'problem' I see with the test set up is that the sources will all be relatively low impedance. The impedance of the source will affect the transformer response and a passive pickup has a very significant complex impedance from the Inductance and winding resistance.

Yes - it's hard not to wonder about the bass response of a small transformer. It's essentially down to the inductance characteristics and it's not usual to find them properly stated even when the transformer is a known one. There are ways to get a flat response from some small transformers but that typically involves active circuitry on the secondary side.

Anyway I guess the proof's in the playing 😊

Nice Photos btw.

Cheers man.

 

What actually 'sets' the impedance then? I'm aware the transformer is a passive step down device, so what sets the impedance in the system? The output of the bass? The input of the console?

 

Yes, I tried to keep everything low impedance on the testing. I have tried playing the DI with a passive bass and it sounds ok with two caveats. Firslty, both of my passive basses have flats, so there's already a reduction in HF content. Secondly, I've only got a couple of short XLR cables in my music room. I don't have anything longer than 10m up here so I can't really fairly say how the DI would react on a normal passive bass driving hundreds of metres of cable.