Hi guys, I’m an absolute beginner on this. I want to use my SQ6 in a studio only with a pc. I have figured out how to hook up Cubase but all my Standard keyboards use 1/4" leads L/R. Stereo inputs are few on the back and was looking for a way to use the XLR inputs, but do I need a DI box running stereo for each keyboard? ( I have 8 keyboards in stereo to hook up- ouch!) What in your opinion is the best solution? Thanks for any suggestions for this beginner.
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Hi,
If your 1/4" cables are not very long (max 25’) then you can use an adapter. Longer cables are more susceptible to noise (EMI, etc…) and can attenuate the highest frequencies in the case of very long cables.
Search Amazon or your favorite online retailer and search for 1/4" female to XLR Male adapter. I found on Amazon, adapters from Cable Matters ($9.00/pair), this times eight stereo keyboards ($72.00) is a lot less than one good quality Direct Box
Just remember to engage the PAD in the preamp because the keyboard output will be a lot hotter than a typical microphone and absolutely ensure the Phantom Power is OFF on each channel before plugging in. One other note, make sure you set the input levels for stereo channels before you link them.
I hope you get lots of enjoyment from your SQ-6, I really love mine!
All the best!
To the moderator of this forum…
Please move this from the AHM to the SQ category
[Moderator: Done!]
I echo the above post.
You can use 2 adjacent XLR inputs (with a pad setting for line signals) as a stereo pair meaning you can control both the left and right channels simultaneously with one control.
As already stated, make sure Phantom power is switched OFF before connecting your keyboards!
Also check the leads or adaptors for balanced/unbalanced configuration.
The SQ has balanced (mono) inputs on the XLRs. You need to make sure the wiring/adapters are correct for your keyboards.
If in doubt, post the manufacturer and model/make of your keyboards and we can check.
Dave
Go for this: Behringer | Product | DI800
You will need two of these to have all the keyboards in stereo 
I echo (or should that be delay?) using XLR to jack leads, you can use adapters if you prefer.
Depending on what synths you have, they may even have balanced outs.
I would however make sure that phantom power is not used on any of the channels connected to your synths, I doubt they would enjoy having 48V DC applied to thier output circuitry.
Many thanks many thanks…can you kindly suggest the best jack to XLR Adaptor for this purpose. Sorry to be a Luddite but we all have to learn!
Cheers Neil.
I will consider this option closely ty for your help it’s really appreciated Neil.
The best option would be to get a Radial Stereo J48 DI. It’s an active 2 channel DI box, designed to convert your unbalanced keyboard signal into a balanced signal suitable to input into the SQ’s XLRs. It uses phantom power to power some active devices inside of the box. They’re really robust, and roughly $380.
While a good choice in DI box, they would need 8 of those to enable all keyboards to be plugged in simultaneously. That would be about $3,000 in DI boxes!!!
Would be more economical to get 2x 8-channel DI racks for the purpose. Pick up 2 decent ones for maybe $600 total.
Something like this would be my suggestion if needing to stay on a budget:
https://www.thomann.de/ie/palmer_pan_16.htm
Since every unneeded Component is a potential source for noise and problems I would suggest to avoid the usage of DI-Boxes if they are not necessary. So:
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A 1/4" Stereo Jack can mean there is an unbalanced Stereo Signal on it or a balanced Mono Signal. So if in doubt check each of your keyboard manuals what you really have there.
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switch off Phantom Power on your SQ6 for any Inputs you use for the keyboards. They will not need it and there might some weird cases in which that could cause damage - not very common but can happen.
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For a balanced Mono Signal you might be able to use a simple balanced male XLR to 1/4" Adapter to connect your keyboard to a single Mono Input of the SQ6 That is the most easy variant. Beware: unbalanced Mono Connectors may or may not work with balanced (“Stereo”) 1/4" Jacks depending on the design of their contact parts.
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For unbalanced Stereo you need at least an unbalanced Stereo 1/4" to 2 male XLR Connectors Adapter or Cable that connects your Keyboard to two XLR Inputs on your SQ6. You may then define your keyboard Channels as Stereo on SQ6 so you have only one Fader for that (and Balance instead of Pan when mixing).
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Now check your keyboard signals Use Gain and Pad Controls to get a good Signal Level. The SQ Inputs normally offer enough range to “eat” line levels without a problem. If the signal is reallly too high for the sq, try to lower output volume of your keyboard a bit.
You must consider to use DI Boxes in the following cases:
a) if you hear Humming or much electromagnetic distortion noise on the keyboard signals that may be reduced with balanced signals or by the ground lift
b) if you cannot get a good and clean signal level with the available controls (DI Boxes provide at least a PAD switch, active ones may even level up too low signals a bit)
c) if you have to be mobile with your Setup and might use different power lines for SQ and Keyboards (so you might get phase difference/humming loop noise and therefore need a ground lift - beware that there might be “ground-free” Connectors on some Keyboards and Mixers that normally should not need this).
d) if you need long cables. What “long” really means is a bit subjective - I personally would say more than 5-10 Meters but YMMV.
For a first check, a cheap passive DI Box will at least show up if Ground Lift / balancing the line can help you. If you need to level up your signal or if you have high demands on signal quality especially in treble Range, you have to consider an active DI Box instead.
When using active DI-Boxes check how they can be powered. Some might be able to use Phantom Power, some need batteries, some use or can use Power Adapters. Passive DI Boxes do not need Power at all.
This is bad advice. Use a DI. The DI not only balances the inputs and isolates the devices from damage if phantom power is switched on, but a DI also matches impedance. A mic pre will want to see 600Ω or less. a very low impedance. I am not sure what your keyboard outputs are, but they are likely a lot higher than that. You will lose tone with a mismatched impedance. Maybe not a lot, but something.
If you have ever used a ¼" unbalanced cable to XLR with an acoustic guitar pickup, the you will understand better. An acoustic guitar bride pickup is arouns 10,000Ω and plugging that directly into a mic pre is awful. It is very thin with no body to the tone. This is the result of a mismatched impedance.
Although your keys are likely nowhere near as mismatched, there will be tonal difference that is likely not as full.
A DI is a device to assist you to deliver a full tone with isolation at an impedance that is matched to a mic pre.
Bottom line…get a couple of DI’s. Even the cheap Behringer DI100 is not bad. Just plug in the keys you are using each time. Otherwise, get a line mixer and add the line mixer to the front end input of the SQ6.
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This is not a bad advice. A Keyboard or other line level Source is no Hi-Z low voltage Guitar Pickup which is very sensitive to disturbing capacities and inductivities (what is the real reason for the massive influence of cables to their sound).
Impedance is normally no Problem in the Case of a Keyboard Lineout since SQ6 Inputs are (linke most modern “professional-targeted” Mixer Preamps) absolutely designed to handle Mic and Line Signals. That is also the reason why you find “Line” Jacks on cheap Mixers - their Mic Preamps are too limited to handle a line signal well. Those of SQ are not, they can do that perfectly.
Due to the SQ Datasheet:
Mic/Line Inputs:
Input Sensitivity -60 to +0dBu. Switchable -20dB Pad
Maximum Input Level +23dBu
Input Impedance > 5kOhms
THD+N, Unity gain 0dB 0.002% -92dBu (20Hz-20kHz, AES Direct Out, @0dBu 1kHz)
THD+N, Mid gain +30dB 0.003% -91dBu (20Hz-20kHz, AES Direct Out, @-30dBu INPUT 1kHz)
The Preamps in the Stage Boxes may have slightly different values but that difference is academic for a live stage. Overall those values are more than absolutely ok for Line and Mic Sources.
In fact, even the Impedance Mismatch of a Mic with 600Ohm to the 5 kOhms of the Input (which is 1:8) is no better Match than that of 75 kOhms (which is a typical line out of a keyboard and leads to a Mismatch Factor of 5:1). Just the direction is the opposite, the result is nearly the same.
For comparison:
The Stereo Line Inputs (ST1/ST2) have an Input Impedance of > 7kOhms and a maximum Input level of +22dBu/+18dBu. Thats a little bit nearer to the optimum for line signals, but not so much that a reasonable Number of People will be able to distinguish it in a double-blinded Hear Test.
In worst case you get 0,001% additional THD between minimum and maximum Gain of the XLR Ins. That is also not really audible (and whole system THD is at least twice as high anyway).
In most Cases you can definitely connect line sources to the XLR Inputs of a SQ or one of the common A&H Stageboxes without any real Problem as long as you keep your cables short, do not have much magnetic distortions, have all Devices on the same AC Phase and do not build a humming loop. Been there, done that many times. Nothing breaks, nothing sounds bad with that.
DI Boxes are a powerful tool that should be used if it is really needed, of course. But if not needed, as any device on the planet they cost money and introduce additional complexity, failure sources an noise. “Don’t use things you don’t need at all” is always a good advice..
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Thank you @eschwenk, excellent post.
Let’s try to remember that @neilwatts is looking for a reasonably priced solution for his studio.
Everyone has made great suggestions but the original purpose of the post was to have someone recommend a budget solution that works.
I still think adapters are his best solution for under $100.00 USD
In time he can eventually upgrade to rack mount Radial Engineering Direct Boxes for when he is playing live… (fingers crossed!)
Best of luck Neil!
Disabling Phantom Power is right, but don’t hesitate too much on making mistakes with that.
Most Line Output circuits don’t have a problem with phantom power, they can just ignore it. Of course, there is no guarantee, so the advice to disable is generally right.
I would even bet this is a standard entry in circuit design criterias since no manufacturer wants dozens of customer reclamations due to that. There is no doubt that “phantom Power on line sources accidents” happen all the time on real stages. A product that gets damaged by this would receive not-so-good reputation very fast.
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I reiterate that in order to identify any suitable adapter will require knowledge of what the keyboard/synthesizers actually are.
Otherwise, we are all guessing…
Dave
Hi guys , Thank you all for your Sage advice.
In answer to Daver2’s response the rig I have consists of Korg Kronos x, Korg Krome, Korg Rk100, Korg M50, Roland D50 and Hammond Skx Also looking to populate my collection with a Yamaha Montage m6 soon.
pc plugins. Hope that clears things up. Once again Cheers guys, I got a lot of learning to do, and might even enquire about a local SQ user to help getting me set up for writing/ recording at home. BIG Thanks, Neil.
So, the manual for the Korg Kronos X identifies the audio output connectors as 1/4" TRS balanced.
The manual for the Korg Krome identifies the audio output connectors as 1/4" TS unbalanced.
Repeat for all of your other equipment…
However, it indicates that you will require both types of adapters for your equipment - both are wired differently.
You will require a 1/4" TRS balanced plug to a male XLR wired as balanced.
You will also require a 1/4" TS unbalanced plug to a male XLR wired appropriately.
If you are just buying adapters, or ready made cables, you can ask for what you want - and they should be made correctly by the supplier.
You will obviously need to use a pair of cables/connectors for each keyboard (for stereo), and use the correct cables/connectors for each keyboard type (balanced or unbalanced).
There is a very useful website here: Sound System Interconnection.
Their recommendation is:
7 for the balanced TRS connector arrangement and 13 for the unbalanced TS arrangement.
Dave
Hi Dave,
the adapter I suggested is TRS female 1/4" to Male XLR. The balanced signals will remain balanced with a TRS connector, the unbalanced signals will be unbalanced. In the TRS configuration when the female connector is presented with a standard unbalanced connector, the ring and the shield will both be connected (shorted) to the shield of the incoming connector and thereby create the unbalanced signal (Pin 1+3 as ground and Pin 2 as hot)
I not sure how to better define this, I have been using adapters like this for over forty years and have never seen a different outcome except when the the connectors have defect.
The only exception is when someone tries to plug in a headphone (stereo TRS connector) to one of these adapters…
I know you know, you know what you are talking about but in my experience I’ve never had any different outcome and I don’t expect that will change.
Best Regards!
I have the same ‘tools’ in my toolbox also!
I agree that (in the large majority of cases) this will work:
1/4" male TRS to 1/4" male TRS (with cable).
1/4" female TRS to 3-pin male XLR adapter.
If the OP buys these parts, they should be good to go, with the following exceptions:
Increased use of adapters and connectors over time introduces weak points within the system (ultimately noise generators due to bad contacts). I generally prefer a dedicated cable with the appropriate connectors on both ends (that are labelled as to which end goes where). But this is (perhaps) a pureist view!
Ground loops. Guitarists (well, their instruments) are high on my list of offenders followed by keyboards/synthesizers.
In order to correct for a ground loop, you have to ‘break’ the screen between the instrument source and mixer.
However, if all the equipment is located in a studio and in close proximity to each other, the chance of a ground loop is minimal (unless there is a really poor piece of equipment).
I suspect your proposal is the way to go and, if a ground loop is evident, a slight rethink.
The adapters will always come in handy anyway!
Dave