# DI for recording synths?



## spacedout (Dec 17, 2007)

Hi all,

Following a recent change in my studio setup, I've become aware that my synth's outputs are a little noisy - not a deal-breaker by any means, but something I'd ideally like to get rid of for recording purposes. Would a DI box help with this? At the moment I've got the (unbalanced) outputs of my synth connected directly to my interface's inputs using balanced cables. I'm aware balanced cabling won't do anything to reject noise in this situation, but I assume they won't make the problem worse. Is that correct? And lastly, a general question about DIs - I see they come in both active and passive flavours. Which is preferable, and why?

Thanks


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## tonyvdb (Sep 5, 2007)

As my limited knowledge of the difference is between an active and passive I cant be sure but Active requires phantom power or a 9v battery to operate and in most cases tends to be better for quality. I've used both and find that either will do the job well. 
Over short distances going unbalanced should cause no issues, how far is the distance between the keyboard and the mixer? When your saying your using "(unbalanced) outputs of my synth connected directly to my interface's inputs using balanced cables" is the inputs on the mixer balanced? Then I would say yes a DI box will most defiantly help as the signal your getting to the mixer the way you have it now would be too low causing you to have to boost the gain in the mixer to a point where the noise floor is raised to high.


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## marco_ktl (Sep 6, 2009)

Hi spacedout!
Before going out buying DIs, first check if there are ground loops between your keyboard system and your DAW/mixer. Then check if the audio cables run parallel to power cables. If all this is checked and nothing changes, go for DI boxes and fiddle around with the ground switch. DIs should be closest to the keys than to the DAW/mixer, the closer the better.
As for passive vs. active DI, it's all a matter of quality. Radial Engineering or Palmer passive DIs are better than Behringer active, for example. But with active (most of them can be phantom powered) you should have a tighter bass and high frequency response.

Hope this can help!
Cheers,
Marco


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## spacedout (Dec 17, 2007)

Thanks guys 

Some clarification: I'm using reasonably short (approx. 2m/7') cables. The inputs on my interface (RME Fireface 400) can cope with either balanced or unbalanced cables, so no issue there. There's also no ground loop as far as I'm aware - everything is run off a single mains outlet in a star formation. Power & audio cables running parallel to each other... not really, but can't give an unqualified "no" :huh:

Like I said, it's really not a deal-breaker - I only became aware of it because a slight change in my DAW configuration has meant that my synth's not permanently connected to my monitors (it used to be), and I became aware of the silence when it's disconnected :dumbcrazy: I was wondering if it might be worth trying a DI sometime, and I guess... it might :bigsmile:

Thanks again!


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## jonathanm (Mar 24, 2010)

Worth a shot...

What type of synth is it? an oldie? are the jacks in decent condition?


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## spacedout (Dec 17, 2007)

Hi Jonathan,

No, not an oldie at all - it's a Yamaha S90 ES  It's in perfect nick as well - only ever been in my studio, so no problems with the connectors...


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## jonathanm (Mar 24, 2010)

I've never used a fireface, but don't they have an impedance switch on the inputs? Is it set right?


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## PepAX7 (Mar 11, 2008)

Spacedout,

I have an RME Multiface and it handles bal/unbal 1/4" TRS. Also, each analog input can be confiqured for -10db or +4db but this requires you to get to the RME PC board and do a modification.. I believe a couple of jumpers. Not sure if possible w/Fireface?

I would try a test... first... don't run your audio cables in the same path as your AC power cords. Keep 'em separated! Sometimes just a foot can make a difference in hum/noise. Keep all wall warts(transformers) away from audio cables as well. There are better quality cables with 90%+ braiding or denser braiding/shielding. I would use those for your unbalanced S90ES outputs.. no longer than 10-15 feet right into the Fireface.

Second... I have a couple of Ensoniq kybds and I go unbalanced from them to my mixer (15ft) and take a Direct Out(DI) from mixer channel TRS(balanced) to the RME TRS(balanced)... or if I want a little EQ, I'll scrap the DI and just use a SubMaster out to the RME(All balanced).

Third... get a D.I. box. You get what you pay for but both types can be found for fair pricing. With the passives, it's all in the transformers inside. The best use Jensen Xfrmrs or Lundahl but you'll pay top dollar. The cheaper passives will tend to roll off the highs and some lows and add a little distortion, which in a synth situation and recording, may not be a good thing! See this thread: http://www.proaudioshack.com/forums/power-grounding-accessories/28056-cheap-d-i.html

Hope this helps w/your problem!

Pep


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## immortalgropher (Feb 16, 2010)

Anything that uses a battery gets a passive and anything that doesn't use a battery gets an active...Keep that in mind too.

That being said: ahem...RADIAL


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## DrGeoff (Dec 27, 2007)

spacedout said:


> Hi all,
> 
> Following a recent change in my studio setup, I've become aware that my synth's outputs are a little noisy - not a deal-breaker by any means, but something I'd ideally like to get rid of for recording purposes.


What kind of noise are we talking about here? Is it really mains hum or buzz? Or is it HR noise from nearby sources or is it from the S90 itself? 

Does moving the cables about change the amount of noise you hear?

Also, how did you wire the unbalanced outs to your balanced inputs?


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## Darnstrat (Jan 9, 2010)

spacedout said:


> Hi all,
> 
> Following a recent change in my studio setup, I've become aware that my synth's outputs are a little noisy - not a deal-breaker by any means, but something I'd ideally like to get rid of for recording purposes. Would a DI box help with this? At the moment I've got the (unbalanced) outputs of my synth connected directly to my interface's inputs using balanced cables. I'm aware balanced cabling won't do anything to reject noise in this situation, but I assume they won't make the problem worse. Is that correct? And lastly, a general question about DIs - I see they come in both active and passive flavours. Which is preferable, and why?
> 
> Thanks


The S90 is a really good instrument and it's pretty quiet (noise-wise). My suggestion is to get a dual preamp for it, take your line outs from the synth into the preamp, then into your RME. That way you can get a better S/N ratio, have balanced lines, and with the right preamp, get some tube warmth. You don't need to spend of ton of money on the preamp, in fact, you can get one for about the price of two Radial DI boxes and you'll have something that you can use with mics, etc.


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## spacedout (Dec 17, 2007)

jonathanm said:


> I've never used a fireface, but don't they have an impedance switch on the inputs? Is it set right?


Two of the inputs have an impedance switch, but I'm not using those, just ordinary line inputs.



PepAX7 said:


> Spacedout,
> 
> I have an RME Multiface and it handles bal/unbal 1/4" TRS. Also, each analog input can be confiqured for -10db or +4db but this requires you to get to the RME PC board and do a modification.. I believe a couple of jumpers. Not sure if possible w/Fireface?


Not as far as I'm aware... will check though.



> I would try a test... first... don't run your audio cables in the same path as your AC power cords. Keep 'em separated! Sometimes just a foot can make a difference in hum/noise. Keep all wall warts(transformers) away from audio cables as well. There are better quality cables with 90%+ braiding or denser braiding/shielding. I would use those for your unbalanced S90ES outputs.. no longer than 10-15 feet right into the Fireface.
> 
> Second... I have a couple of Ensoniq kybds and I go unbalanced from them to my mixer (15ft) and take a Direct Out(DI) from mixer channel TRS(balanced) to the RME TRS(balanced)... or if I want a little EQ, I'll scrap the DI and just use a SubMaster out to the RME(All balanced).


Could try the first one... don't have a suitable mixer to try the second though



> Third... get a D.I. box. You get what you pay for...


Indeed... :spend::spend: ...and I've been following that thread :nerd:



gswan said:


> What kind of noise are we talking about here? Is it really mains hum or buzz? Or is it HR noise from nearby sources or is it from the S90 itself?
> 
> Does moving the cables about change the amount of noise you hear?
> 
> Also, how did you wire the unbalanced outs to your balanced inputs?


It's a high-pitched noise - what do you mean by HR?

I just put a balanced cable between synth and interface... :huh:



Darnstrat said:


> The S90 is a really good instrument and it's pretty quiet (noise-wise).


Indeed - I'm in love with it!  The noise is _very_ quiet - I only became aware of it when it suddenly wasn't there :rubeyes:



> My suggestion is to get a dual preamp for it, take your line outs from the synth into the preamp, then into your RME. That way you can get a better S/N ratio, have balanced lines, and with the right preamp, get some tube warmth. You don't need to spend of ton of money on the preamp, in fact, you can get one for about the price of two Radial DI boxes and you'll have something that you can use with mics, etc.


Yes, could do that - only thing is that at the moment it's directly integrated into Cubase using Studio Connections (which allows for recall of synth patches within projects, like a VSTi). This has the side-effect of Cubase reserving the inputs for the exclusive use of the synth. If I wanted to easily reconfigure a preamp for use with mics and such I'd be looking at adding a patchbay as well... :spend:

Some great suggestions here - thanks to you all! This is a bit of an education for me - I'm going to have to think about this for a bit now... Cheers :T


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## PepAX7 (Mar 11, 2008)

You said you are using a balanced cable between synth and the Fireface...... I'm assuming you're using 1/4" TRS (tip-ring-sleeve) jacks on that balanced cable.

I looked up the specs (Yamaha web site) on the S90 and they are NOT balanced outputs. I'm wondering if your getting a ground loop from the ring connection.

Try using a non-balanced 1/4" cable (tip-sleeve) from the S90 to the Fireface. I believe the Fireface will take either/or without any grounding issues.

Pep


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## jonathanm (Mar 24, 2010)

PepAX7 said:


> Try using a non-balanced 1/4" cable (tip-sleeve) from the S90 to the Fireface. I believe the Fireface will take either/or without any grounding issues.
> 
> Pep


Well spotted....

You could also disconnect the ring at one end....


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## spacedout (Dec 17, 2007)

PepAX7 said:


> You said you are using a balanced cable between synth and the Fireface...... I'm assuming you're using 1/4" TRS (tip-ring-sleeve) jacks on that balanced cable.
> 
> I looked up the specs (Yamaha web site) on the S90 and they are NOT balanced outputs. I'm wondering if your getting a ground loop from the ring connection.
> 
> ...


Now this is an eye-opener... you're correct, I'm using TRS cables. I was under the impression that while there's no benefit to be gained in using balanced cables in unbalanced sockets, there also wouldn't be any problem in doing so. I didn't realise it could actually be detrimental to the sound as well :rubeyes:

I'll obviously be trying this as a first course of action - not right away though. Some stuff has just come up which is going to involve a relocation of my studio pretty shortly, so I'll leave it until then... can't be bothered faffing around trying to reach awkwardly-placed connectors when I'll have to dismantle them before long! You're also right that the FF won't mind 

Thanks! :T


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## PepAX7 (Mar 11, 2008)

You are most welcome!

That's what makes the Pro Audio Shack work..... multiple heads... solve problems. :sweat:

Keep in touch,

Pep


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