Behringer Phara-O Mini Analogue Synthesizer - Output Connectivity limitations

[ssimlai]

I got myself this synth and later found it had no output jacks except for headphones output. And the manual says not to connect to balanced line input of a mixer.

This is baffling because this synth does not have any audio out. It is similar to the Korg Volca Keys which also doesn't have any analogue out. I have not come across this situation earlier where a synth has no audio out other than headphones Out.

Quoting straight from the manual:

"6. HEADPHONE SOCKET – use this 3.5 mm jack socket to listen to the PHARA-O MINI on a suitable pair of headphones. Not suitable for feeding balanced line level inputs on mixing desks."

​While they wrote this in the manual, they also gave two hookup drawings in the same manual, one showing the Headphones Output directly connected to an Audio Interface, and the other showing the Headphones output directly connected to a Keyboard amplifier for Band Practice System.

God only knows what this guy who wrote the manual was smoking!

The Headphones Jack specs say 3.5 mm TRS, stereo, 5 mW 32 Ω!! No mention of voltage, so not sure if an attenuator of some sort, or a DI Box or nothing is required.

Also, if this output is to be connected to another synth input, what kind of input is safe for this signal. All I am being told, that too by AIs, that the signal is hot, be careful.

None of the limited YouTube videos on this product talks about connectivity, but they all are loud sounding so it means something.

A serious limitation - not on the product (perhaps) - but with the contradiction in the manual and lack of information on connectivity.

If anyone can throw a light, shall be greatly appreciated.

[BertKoor]

In my humble experience I found not much issues with headphone outputs used as line outputs. The reverse (plug a headphone into random line output) works less. Nothing breaks, but there's hardly any sound.

Weapon of choice: a 3.5mm stereo to dual male RCA cord (as used to connect an iPod/mp3Player to home hifi) plus two female RCA->1/4" TS male adapters. This works even well with balanced inputs, since the 1/4" jacks are mono.

Going straight from the 3.5mm stereo to 1/4" stereo and plug that into a balanced input gives an interesting effect: you get only L-R difference. On mono patches that renders silence.

If you want to know what kind of voltage to expect, here is a calculator:
https://bertkoor.nl/VawoCalc/
And chatbots are bad sources of technical detail.
Go here instead:
https://en.m.wikipedia.org/wiki/Line_level

[ssimlai]

Thanks. My main concern was the words “balanced line level” as used in the manual. So “balanced” will be taken care of with your advice as above. What about line level? I believe headphone outs are somewhat higher voltage than line? Is that why Behringer wrote it in their manual?

The calculator tool looks interesting. Will use it. I assume it is for DC voltages only.

[BertKoor]

I believe headphone outs are somewhat higher voltage than line?

Not all headphone output drivers are equal. This one delivers about 0.4V I think, so that's lower than the textbook 1V for line levels. Still same ballpark, this is why you have voltage gain and trim knobs on inputs.

Is that why Behringer wrote it in their manual?

Beats me. It's very often totally unspecced.

[ssimlai]

I agree. On the one hand they say do not connect to balanced line input of mixer. And on the other hand they show hookup drawings doing exactly that.

[BertKoor]

They did say "balanced". I think their intention is to stop you from hearing only a dash of reverb.

[thecontrolcentre]

I've used a Korg - MONOTRON-DELAY by connecting it's headphone out to a channel or auxillary input on a couple of mixers. Never had any issues (using this kind of lead.)



Just have be careful with the gain structure.

[ssimlai]

Alright mate. Understood.

[ghettosynth]

They did say "balanced". I think their intention is to stop you from hearing only a dash of reverb.

Exactly this. It will be fine if you connect it to unbalanced inputs, that is, what you will get if you use a TS, not TRS, 1/4" plug on a 1/4" channel input on nearly all mixers and audio interfaces. While Behringer manuals are among the worst in the industry at the moment, the manual is pretty clear in showing you a TS cable, AND, specifying that balanced inputs are the problem. While I get that this isn't that helpful for a beginner, it's not actually wrong.

[ssimlai]

Noted and thanks to all friends for listening patiently and helping me out.