Supplier for DI Transformers

[Tele]

I had the idea of building in DI transformers into the stage box/multi-core to save setting up time and clearing the stage of DI boxes and link cables.

Can anyone recommend a supplier of passive DI transformers?

[Brian]

Canford.

[boatman]

I had the idea of building in DI transformers into the stage box/multi-core to save setting up time and clearing the stage of DI boxes and link cables.

Can anyone recommend a supplier of passive DI transformers?

 

I'm curious to know why you think this is a good idea. The purpose of a DI box is to match the unbalanced output of a high impedance instrument pick-up to a low impedance balanced line. To minimise potential interference, this should happen at the earliest possible point in the signal chain. Moving the DI box into the stage box or multi-core will almost certainly cause signal degradation.

[revbobuk]

I guess a lot depends on the layout of the stage. I use a rackmount 8-channel DI box, and use good quality jack cables from acoustic instruments and a short 8-way loom from DI box into the multicore; never yet had a problem, and it saves on boxes. But if the stage was bigger, it wouldn't be such a good solution.

[ramdram]

I would surmise that the distance from the instrument to the stagebox is the deciding actor for the technical reason and cost as another.

 

I gather too that it is de mode to use Jensen audio txrs, but, they are not cheap.

 

I suppose you could have the stagebox tricked up with txrs if the distance tween "instrument" and s'box was not too great otherwise you might just as well use a "normal" DI box.

 

However if you wanted to build ground lifts circuits into the stagebox you might find it was a bigger job/headache that you had at first anticipated. And, where would you find the space to mount several txrs and ground lift switches? Short of starting from scratch with a new box, doing the cutouts, etc etc. it is possibly the easier option just to set up separate DI boxes in the first place.

[Sound Man]

These from Rapid Electronics would be suitable.

 

David

[ramdram]

They may well be the answer ref the physical size but then, presumably, you would need to mount them on a PCB. Doable certainly but a fair amount of effort and a lot more cobbling if you wanted to fit ground lift switches as well as.

 

My money would be on the separate DI boxes.

[brainwave-generator]

Making DIs up is quite economical. Just buying a DI transformer, however, is not. You need to choose one to suit what you're doing.

 

Jensen transformers are usually considered the best, as found in Radial DI boxes. These aren't too easy to come across in the UK, I group bought 100 and had them imported. It cost thousands. I had about 10 and I think it was about £250-300. Maybe more. I then bought some Behringer passive DIs for about £25 each and re-fitted them with the Jensens. They do not sound any worse than our Radial boxes now. Huge improvement.

 

However, I then discovered Crimson transformers. I bought 10 of them from a US dealer on eBay and had them sent over. They're not as flat response as the Jensens but they definitely have a far fatter tone for things like bass guitars or dirty synths.

 

Head over to the Prodigy Pro DIY-audio forums to see what people have been tinkering with, and partake in group buys to get US-stuff sent over here at trade price.

 

As for cable run distance, that's pretty petty on the most part. Whether you have a DI after 1 metre or 5 metres doesn't change much. If I were you, I'd be tempted to buy an 16-way stage box with lots of room inside, such as the one here:

http://www.vdctrading.com/images/products/279.jpg

 

and fit it with 8x Jack Inputs and 8x Jack 'Link' outputs (just parallel wired to inputs). Ground Lift switches could be fitted on one the side of the box, pad switches the other. Fit the end with a multipin connector and you have a simple solution that you can put anywhere on stage for 8 DIs straight to a patchbay. Quite practical and will save people nicking your DI boxes. Much easier at festivals for patching too. Also ideal for bands with a lot of keys / FX, or just sticking up on stage for a DJ set.

[audiomik]

You can get transformers from Sowters which have wire tails so you won't need to look at making a PCB....

http://www.sowter.co.uk/#

 

However, also think you are better off with separate DI boxes as these keep the unbalanced High Impedance instrument leads short.

 

hope this assists

Mik

[Sound Man]

Thinking about this, I remember making a 12 channel stage box 15 - 20 years ago for a churches new sound system. Channels 1 - 6 had XLR sockets and channels 7 - 12 had XLR's and jack sockets for guitars/keyboard via an active DI circuit. The input for the mixer was selected via a small DPDT toggle switch, either direct from the XLR or from the output of the active DI circuit. All six DI circuits was built onto a piece of veroboard along with the mains power supply and the whole lot put into a metal dicast box. All 12 inputs to the mixer was via a 25 pin D connector.

 

With the set up they had, the unbalanced jack lead was never any longer than 6 meters for any of the high impedance inputs and it was in place for a number of years. The only fault with it was that one of the toggle switches started playing up causing a channel stop working intermittantly.

 

David

[Tele]

Canford.

Thanks Brian. Canford is the answer to many things, I first used them over twenty five years ago, my most recent order arrived this morning. I've had a nose through their site and can't find a DI transformer, can you please post a link.

 

I'm curious to know why you think this is a good idea. The purpose of a DI box is to match the unbalanced output of a high impedance instrument pick-up to a low impedance balanced line. To minimise potential interference, this should happen at the earliest possible point in the signal chain. Moving the DI box into the stage box or multi-core will almost certainly cause signal degradation.

I intend to DI electro-acoustic guitars for 'pub gigs'. The stage area tends to be very tight, so keeping what little space there is clear is important and use of long (5m+) jack leads unnecessary.

 

'Will look into Stower and Rapid transformers.

 

Thanks all.