I’ve not come across the Fromel before, I will enjoy looking into! I think I need to calm down on the hardware for a while, but what else is there to do during this never ending lockdown!
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It’s lovely, based on Scot Stites remake of the DC-2/SDD320, I bought a custom one from John Fromel about a decade ago. The newer DC-2W does something very similar for a bit less.
True, but not only that!
Balanced connections (studio and PA equipement, usually using 6.35mm= 1/4" jack or XLR plugs) usually are designed to use + 4dB signal level, while unbalanced connections (“home” equipement, usually using 3.5mm jack or RCA plugs) usually runs on -10 dB.
The Super 6 has 6.35mm jack plugs like studio and PA equipement, but uses them unbalanced AND on a signal level typical for unbalanced connections.
So, the connector sets simply the wrong expectation for signal level.
Next issue i recognized: The Master Volume knob label is a litte missleading.
The difference between 0dB and +4dB is nearly 10dB.
If +4dB is max Volume, than 0dB would be just in the middle between the 0dB and +4dB mark.
With the master volume knob in that position and ENV LEVEL at 0dB (to prevent clipping) the output level seems to me nearly perfect (for an unballanced connection).
Of course, i have to use the +4/-10 dB button on my mixer in respect to that.
The really good news (to me):
Unlike other equipement, the Super 6 has no electrical connection between power supply ground and audio out ground, so there is no risk of a ground loop, even if the output is unbalanced.
And to be honest: preventing the noise of ground loops is the only reason for balanced connections on higher signal levels.
Sorry but that’s totally inaccurate. If you study the history of audio connectors, you’ll see 1/4 inch jack plugs have mostly been used for unbalanced instrument and line level signals (think guitar and keyboard cables going back to the 50s), while XLRs have traditionally been used for balanced line level.
Check out the Rane notes for a good education on this stuff, particularly the article on Sound System Interconnection:
True!
It’s also worth noting that both Unbalanced and Balanced are Line Levels. For the most part the only type of audio devices that are not line level are microphones and guitars.
Also, Balanced audio doesn’t automatically means it operates at +4dBu.
And finally a TRS connector doesn’t have a better sound quality than a TS connector per-se…there are many other variables. For instance, you will get a much better signal using TS cables when interfacing with Unbalanced devices (like the Super 6). The biggest issue with TS or any unbalanced cabling is once they exceed 25 Ft. Then you start getting interference that you won’t get with a balanced cable.
That’s why, in my studio, I use short TS-TS cables from the UDO to a synth preamp that outputs balanced lines. I connect those balanced lines to my audio interface.
If you would know my education, you would find that funny too.
I wrote about my todays expectations, based on todays knowledge about the pitfalls of historic
design flaws. Sorry if i din’t express this clear enough.
And if i read the thread title rigth, at least one other expected some higher level too.
Sorry for my bad english, but i thought if i use terms like “usually” everybody knows that this means not “automatically”. So please help me out, what would be the right term?
But my technical skills are a little better than my english, so i could tell you, that (usually) only a balanced connection could drive +4dB, so if it’s unbalanced it must be -10dB and only if it’s balanced there are good chances that it’s +4 dB. Thats what i wanted to say.
Not any connector makes any sound quality! Connectors only connect.
But a TS connector forces -10dB line level while a TRS connector could have +4dB.
And the line level determines the SNR!
If you assume the same amount of interferences, a +4dB signal has 14dB more SNR than a -10dB signal.
And if it’s a well twisted pair cable, interferences mostly compensate, so the difference between balanced and unbalanced make definitely a difference on top (regarding SNR-influence of wiring).
AND: A balanced connection is less sensitive for side effects of ground loops (regardless of the length of cables!)
But to summarize the discussion:
For my humble opinion the developers of the Super 6 made a good compromise by providing unbalanced audio at -10dB with completely separated ground.
You only have to know it!
In a studio or home recording environment this is enough, it completely prevents ground loops and it prevents even low budget input stages from overdriving…
… and on stage (with longer wires) a well educated technician would take special care by converting this (like he does with historic instruments).
Converting the unbalanced signal to balanced in a short wired environment simply for the audio interface makes no sense to me. If you recognize any difference (except higher levels) this seems to me more like a design flaw of the audio interface (what is no surprise at all).
-10db, +4db, line level, instrument level, none of that matters. Modern equipment recognizes and automatically adjusts for differences in impedance and voltage and doesn’t care whether you you’re using balanced or unbalanced. The only thing you have to do is:
- increase the volume of your instrument (synth) to about 85%. You want the strongest signal level at the source because this will give you the cleanest, most noise-free signal.
- plug into a channel on the mixer that has a gain knob and adjust the gain knob until it registers a level signal
You can put anything you want in between the instrument and the mixer: pedals, DI boxes, whatever. Quality modern mixing boards like Mackie or Allen and Heath and quality pedals recognize however weak or strong the incoming signal is and automatically compensate. They accept line level, instrument level, +4db, -10db, and everything in between, on the same input ports. If you plug a hot signal into the mic preamp, the mixer knows not to activate the preamp.
The only caveats are:
- if you need to use long cables then you should use a DI box with an XLR (balanced) output. You don’t need to get Migami, a CableWorks cable is just as good. The only purpose of a balanced signal is to eliminate noise.
- if you plug a high impedance guitar directly into the mixing console, then you need to activate the high-Z switch on the console.
- if there are explicit switches on your equipment for things like -10db, low-ohms, etc, then of course you will need to set those to match what’s being plugged in. If there are no special switches, then you can assume it’s compatible with whatever can get plugged into it.
Pedals and DI boxes are already designed to accept high impedance, so you can plug guitars straight into them. Pedals and DI boxes also accept any other kind of signal you want to give them (line-level or weaker), so you can also plug synths or anything else.
Gain staging: you set the strongest signal you can at the source, you set the gain knob on the mixer, you set all the channels faders to 0db, and then adjust them downwards to achieve the mix you want. Quality boards like the Mackie ProFX16v3, DI boxes like Radial, quality pedals like Source Audio and Boss, quality XLR and 1/4" cables like Migami and CableWorks, and quality PA equipment like RCF, Meyer, and JBL.