In this article Ufuk Onen shares his recommendations for something every engineer needs. Adaptors to get you out of unexpected connection incompatibilities, otherwise known as “bodge leads”!
If you work in your home or project studio by yourself and exchange audio files with your collaborators only over the internet, provided that your setup meets your needs, you are pretty much done. Most likely, you will not be faced with unexpected and odd connection requirements. However, if you have people showing up in your studio with a variety of audio equipment, or if you go out and do recordings, live sound or any audio work, chances are you'll probably need to make some unorthodox connections. This is especially true for places that have 'Frankenstein' systems. Some schools, bars, sports facilities and similar places have old and poorly maintained audio systems that have newer equipment added on over the years. Often the maintenance and add-ons are done by electricians or other tech people, not by qualified audio professionals. Consequently, they end up with these 'Frankenstein' systems with "highly creative" connections and cablings.
It's fun to mock these 'Frankenstein' systems but not so much fun when you have to integrate your equipment into them! You must be ready to make some unorthodox connections. Not only when you go out, but sometimes in the studio as well. I have had many instances in which clients brought special equipment to my studio, such as a journalist-type cassette tape recorder or a consumer-type old reel-to-reel machine, to record audio from.
Below is a list of cable adapters that come in handy on those occasions. You might not need them all the time, but they certainly make your life much easier when you do.
Not all of these cable adapters are readily available, so you either have to make them yourself if you are good at soldering, or have them done by someone else if you are not.
Before the list of cable adapters, here's the list of cable-mount connectors used for them:
XLR male
XLR female
1/4" TRS male
1/4" TRS female
1/4" TS male
1/4" TS female
1/8" TRS male
RCA male
Balanced Mono Connections
XLR Male - XLR Female
While this seems like a regular XLR to XLR cable, it is not because of the way it is wired! Although not often, I occasionally come across cables or jacks on panels wired in reverse by mistake. That is, pin 2 is soldered to negative (-) instead of positive (+). In stereo recordings with two microphones, if one of the cables' pinout is reversed, you might get phase problems if you later convert the stereo recording into mono. Of course, the easiest way is to replace the cable or use another jack on the panel, but sometimes you cannot. In that case, the cable adapter that I'm going to recommend comes in handy.
The purpose of this XLR - XLR cable adapter is to swap the pinouts. You need to solder one of the connectors (it doesn't matter which one) with the standard pinout [pin 2 to positive (+) and pin 3 to negative (-)], and the other one in the reversed order [pin 2 to negative (-) and pin 3 to positive (+)].
XLR 1 > pin 1: shield / pin 2: positive / pin 3: negative
XLR 2 > pin 1: shield / pin 2: negative / pin 3: positive
This is a dangerous cable! Please make sure you mark it clearly, preferably with bold letters on a red or an orange tag.
XLR Male - 1/4" TRS Male
This cable adapter is to make balanced connections between two pieces of equipment that has a TRS output on one of them and an XLR input on the other. A typical example would be connecting the outputs of an audio interface with 1/4" TRS jacks to the inputs of audio monitors with XLR jacks. Another example would be connecting the parallel/link TRS jack of a power amplifier to another power amplifier's XLR input to distribute the same signal to multiple power amps.
XLR Male - XLR Male
XLR Female - XLR Female
Ideally, you should not need these, but, as I previously discussed above, sometimes things are far from being ideal. A common occasion when you might need these cables is when you run out of tie lines in an installed wall panel. If you have run out of returns for headphone mixes but still have unused mic lines running in the other direction, these cables can quickly temporarily convert one into the other.
Unbalanced Mono Connections
1/4" TS Male - RCA Male
This cable adapter is mostly for connecting consumer-type equipment to an audio interface or mixer. It is a cable with a 1/4" TS male plug on one end and an RCA male plug on the other. A must-have for any audio person.
1/4" TS Male - RCA Female
As an alternative to the one above, you can buy a small adapter without a cable, like the one in the photo below, to convert one of the connectors to 1/4" TS male on a cable with RCA male plugs on both ends.
1/4" TS Female - 1/4" TS Female
I love standard microphone cables (with XLR connectors) because you can extend the cable length by combining several of them. You cannot do it with cables that have 1/4" TS male plugs on both ends ('guitar cables' or 'instrument' cables, as some people refer to as). Well, with this adapter, you can. Make a short cable with 1/4" TS female plugs on both ends and use it in the middle of two 'instrument cables' to combine them.
1/4" TS Male - 1/4" TS Female
This cable adapter is an alternative to the one above. However, with this one, to extend the cable length, you need to make this adapter cable longer compared to the previous one.
RCA Female - RCA Female
You can use this one to combine two cables with RCA connectors on both ends. As an alternative, you can buy an adapter without a cable, like the one in the photo below.
Balanced Mono or Unbalanced Stereo Connections
1/4" TRS Female - 1/4" TRS Female
1/4" TRS Male - 1/4" TRS Female
You can use these for the same purposes as the 1/4" TS female - 1/4" TS female and 1/4" TS male - 1/4" TS female adapter cables. Male to female ones especially comes in handy for extending headphone cables.
Unbalanced Stereo Connections
1/8" TRS Male - 2x RCA Male
I always carry this cable in my MacBook bag. I also keep a pair of 1/4" TS female - RCA male converters. This way, when I need to hook my laptop to a mixer or a pair of powered monitors to make a presentation or to give a lecture, I'm ready to roll! It doesn't matter whether they have RCA or 1/4" TS inputs in their sound systems.
1/4" TRS Male - 2x RCA Male
For this one, you can make a cable (with 1/4" TRS male plug on one end and two RCA male plus on the other), or you can buy an adapter, like the one in the photo below, that converts 1/4" TRS male to two RCA female connectors. I refrain from using adapters with 1/8" connections because the jacks on the equipment tend to break easily. However, as 1/4" connectors are more sturdy, I don't have problems using adapters for those.
1/4" TRS Male - 2x 1/4" TS Male
Sometimes you need to split the stereo signal from a 1/4" TRS connection into two mono channels. For this, you can make a dedicated cable (1/4" TRS male - 2x 1/4" TS male), or you can use a combination of the adapters and cable adapters I suggested above.
Balanced to Unbalanced Connections
XLR Female - 1/4" TS Male
Occasionally, you need to connect the output of a balanced equipment to the input of an unbalanced one. For that, this cable adapter comes in handy. Pins 1 and 3 on the XLR should be soldered to sleeve (S) on the TS plug.
XLR 1/4" TS
Pin 2 Tip
Pin 1 & 3 Sleeve
1/4" TRS Male - 1/4" TS Male
This one is similar to the previous one, except instead of an XLR, a 1/4" TRS male plug is used. Ring (R) and sleeve (S) on the TRS plug should be soldered to sleeve (S) on the TS plug.
1/4" TRS 1/4" TS
Tip Tip
Ring & Sleeve Sleeve
Conclusion
I shared the cable adapters that come in handy in my line of work with you. I hope you find this article helpful. Are there any other ones that you use or think of which are not on this list? Please let us know in the comments.