Correct XLR cable type for Mixer to Amp?

[SeventhStar]

Hi guys! It’s been a long time since I’ve been on the forum. I’m just getting back to using my synths. They have been dormant for while.. I used to plug them directly into a single keyboard amp via 1/4” mono instrument (TS) unbalanced cables. Just this month I bought my first mixing console. I got different conflicting advice from a few people, so I thought I’d ask on here. The XLR cable selection has got me a bit confused..

This is the setup I’m attempting to wire up.

One Peavey PV-14 non-powered (no amplifier) mixer. Main Output jacks described in the manual as follows: Two fully balanced XLR, left and right. Two 1/4” TRS Z balanced jacks, can be used with Tip, Ring, Sleeve (TRS) balanced or Tip, Sleeve (TS) unbalanced cable connectors.

Two Peavey KB100 keyboard amps. Each amp only has an XLR input jack on channel 1. Channels 1, 2 & 3 have 1/4” inputs. The input jacks are described by the manual as follows: XLR unbalanced (Low Z, for use with low impedance microphones or low level sources equipped with a male XLR connector). 1/4” (High Z input, provided for extremely wide dynamic range. This input will accept very high level signals generated by synthesizer keyboard systems or very low signals generated by practice or home keyboard units.)

Each Mono Synthesizer keyboard’s 1/4” out to a Mixer channel 1/4” input via 1/4” mono instrument (TS) unbalanced cable.

Sequential Multi-Trak’s Mix A & B outputs to Stereo 1/4” input jacks on the Mixer’s channel 11/12 stereo input, via two 1/4” mono instrument (TS) unbalanced cables.

Mixer’s Main XLR Left channel out to Keyboard Amp #1’s channel 1 XLR input via XLR Microphone balanced shielded cable.

Mixer’s Main XLR Right channel out to Keyboard Amp #2’s channel 1 XLR input via XLR Microphone balanced shielded cable.

Is an XLR Microphone balanced shielded cable the correct XLR cable to use to connect the Mixer Main XLR outputs to the KB100 XLR channel 1 inputs? There is no microphone being used in this setup. But I was told, by one person, to use an XLR Microphone cable for the Mixer to Keyboard amp connections.

I am also concerned about the KB100 XLR input jack being described as unbalanced in the manual, versus the Mixer Main XLR outputs being described as fully balanced, in its manual. Should both ends of the XLR connection either be balanced or unbalanced?

As a second question, to use the Mixer Main 1/4” left and right outputs to do the same connection to each 1/4” channel 1 keyboard amp input, would I use 1/4” mono instrument (TS) unbalanced cables to do this?

[madtheory]

I can see that what is confusing is that the connector type does not tell you the signal type. So let’s try to look at it as signal type.

The mic input on the amp will be overloaded by the line output of the mixer. You can avoid that by using TS cables. That effectively forces you to connect to the line input of the amps.

Put simply, a balanced line is better at rejecting interference than an unbalanced line. Either one can carry low voltage mic signals roughly 50mV, or relatively high line level signals, roughly around 1V. If you send a 1V signal into a mic input, it will distort because it’s about 20 times louder.

I’ll let you digest that before explaining synth out to mixer in.

[SeventhStar]

Thanks for your reply.

So I should just use 1/4” TS unbalanced cables to go from Mixer Main outs to 1/4” amp line ins. Which is what I was going to do before the kids working at Guitar Center suggested differently.

After doing this and testing the setup, I have determined that channel 11 of 11/12 (stereo input) has a problem and is not working correctly. Stereo input pair channel 13/14 work as expected. So I bought a used 14 channel mixer with a bad channel 11.. Just discovered this today, 3 weeks after I bought the mixer for $200 and brought it home. I did test the mixer, but not with it connected to two amp/speaker cabinets at once.

I just brought the 2nd Peavey KB100 home last night, also bought used. I just realized that the tweeter in the 1st KB100 is dead, not a peep comes out of it. The working tweeter in the 2nd KB100, alerted me that something was wrong with Amp #1. I was amazed at how much better the highs sounded from Amp #2.

I’ve had Amp #1 for 5 years! And just thought the highs were lousy on it because it was a Peavey.. Then I come to find the highs are lousy on it because the tweeter isn’t generating any sound at all.. It doesn’t even give off a hiss when the amp is turned on and the input pot is turned all the way down to zero. It’s just dead silent. In contrast, I hear a hiss coming from both tweeter and woofer on the 2nd unit when input is zero.

Come to think of it I now believe #1 KB100 tweeter has been dead for the entire 5 years I’ve owned it. That one was bought untested from Craigslist for less money. I paid $100 for that one. The one I got yesterday is the same mid 90s vintage, looks identical, and I paid $189 out the door from Guitar Center for that one.

[madtheory]

You're welcome. It's easy to replace the tweeter.