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[New Module] nw2s::io Balanced line transceiver
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Author [New Module] nw2s::io Balanced line transceiver
scottwilson
Now available for order!

http://nw2s.net/product/nw2s-io/



I've had a lot going on these days, with finishing up 1.0 version of the firmware and doing my best to support those of you actively working on the 'b, but I did manage a little time to work on this.

It will be different in that I won't offer a kit. It will be almost 100% SMT and I'll be having it assembled by robots as much as possible.

It's still in the prototyping and tuning stages, but it's far enough along to know that it will work, and I certainly need something in my studio like this.



For far too long, your modular has lived in its own world. Crazy signal levels, Unbalanced connections, Odd cables, Disconnected sleeves? Or is that ring? Or should it be grounded? The nw2s::io lets your modular integrate with your studio just as if it were another well-behaved piece of rack gear.

The nw2s::io is electronically balanced using precision THAT Balanced Drivers and Receivers. It is designed with SMT components and stacked PCBs, resulting in an extremely high-density module.

Record directly to your DAW at optimal levels

Even with a padded DI, the signal coming from your modular can be too hot for the internal circuitry of the DI or the mic-pre. When padded enough, you're attenuating it down to mic levels just so it can be re-amped to balanced studio levels.

The nw2s::io has enough headroom to directly convert your high-voltage modular audio signals (over 22V peak to peak) to line level +4dBu balanced signal that can be reliably routed through your studio so that your modular can be treated just as any other pro audio device.

Record Rich Patches with a Minimum of Hardware

With 8 channels per 10hp module, you will reduce the need to pre-mix signals before recording, giving more flexibility at mix-time.

Integrate pro audio gear into your patches

Reverbs, delays, dynamics, EQ, distortion, anything else you can think of. Integrate your +4dBu studio gear into your patches with no special cabling or compromising unbalanced cables.

Treat your modular as a hardware insert for your DAW

Process audio with your DAW just as you would any other external effects processor. Along with a MIDI to clock converter, you can even get tempo synchronized processing, all at studio levels with balanced cabling.

Interface CV with your DAW

The nw2s::io is DC coupled, so you can integrate Silent Way into your studio without the need for special cables that defeat the noise-cancelling properties of balanced interfaces.
dadek
one for me please! Guinness ftw!
really great.
L.C.O.
When this is out: I am getting one.
Very cool
suboptimal
This would radically improve the way my studio is wired. I'll be keeping an eye on this. I suppose my question is how gain staging is managed - I've never used a DB25 connection, and the cost of those cables alone is going to make this a bit of a stretch for me . . .but man, the advantages are probably worth it!
scottwilson
Yeah, the most affordable way to get the cabling is either Pro-Co from one of the online retailers or custom from Redco for some US-made ones. They are not that expensive when you start doing the math. Mainly depends on how far you need to run them.

And yes, it's a bit selfish on my part for studio wiring purposes. I hate having to have so many DIs and to not have a permanent wiring solution. It seems like by the time I'm ready to record, I have to find cables, find DIs, figure out how I'm going to use the only 4 DIs I have, and by then I get demotivated cause all I wanted to do was hit record. This will make it so I can just have 8 in and 8 out wired permanently to my DAW interface and not worry about it again.

I was a bit surprised to find there were no true-balanced options available. Yes, most folks can just go straight in with an unbalanced cable or disconnected ring and never have an issue, but as I'm primarily an engineer, it's one of those things that I'm just not comfortable with. When it comes time to mixdown or record and something is wrong, the time spent dealing with it is just not worth the shortcut.

As to gain staging, the goal is simplicity and avoiding compromising the precision built into the balancing circuit. This means setting up the gain with as little in the way as possible, with as low a noise floor as possible, and as little chance of clipping as possible. At this point, I'm getting close to settling on -6dB from modular to DB-25 and either 0dB or +6dB going the other way. The problem going back into modular is primarily the 12V rail limitation. Have to play with the prototypes some more.

s
lintfresh
Scott, this is great. I've been looking for something like this forever.

thumbs up
L.C.O.
scottwilson wrote:
[...] I hate having to have so many DIs and to not have a permanent wiring solution. It seems like by the time I'm ready to record, I have to find cables, find DIs, figure out how I'm going to use the only 4 DIs I have, and by then I get demotivated cause all I wanted to do was hit record. This will make it so I can just have 8 in and 8 out wired permanently to my DAW interface and not worry about it again. [...]


This is so true. I will only add to it, that the thought of just recording the whole thing as a single two (or one!) channel piece never sits well with me. I know that there will always be things that need editing, balancing, adjustments etc.

I suppose there is a value in that, and perhaps an encouragement to perform live, but I think this module, will make it possible to "have it both ways".Looking forward to it!
akrylik
I have a DB25 to 8 x TRS snake cable that I bought to use with an ES-1 but then ended up never using. Would that work with this?
scottwilson
Yes, that's exactly what this would work with. DB-25 to TRS or DB-25 to XLRM/XLRF, DB-25 to DB25... DB-25 to patch bay? DB-25 to punch block!

I got the *ahem* acrylic panel prototype in to test the layout and I think it's a good fit. I was worried they'd be a little tight next to the DB-25s, but in practice, as long as you put it on the lower right of your rack, it's not in the way at all.

Also been rethinking the circuit a little bit. In order for the THAT chips to run optimally, they will require +/- 18V rails. +/- 12V rails are just too much of a compromise in that the unbal->bal is limited to about 20dBu and the bal->unbal is limited to less than 14dBu. Far from the 24dBu that is the standard full-scale audio level for most converters.

Doing a proper 18V rail off of 12V will mean that most of the circuit will be power supply, but really, the power supply is probably the most important design aspect of a module like this.

Setting them up this way will allow me to configure them as 0dB overall gain (+6dB/-6dB) and you'll be able to record -10 to +10 control voltage or up to +24dBu audio - really any signal your module will be able to generate, without a problem.

akrylik
If you are going to go through the trouble of deriving +/-18V from the eurorack supply then maybe its better as a standalone box with its own wall wart?
scottwilson
Most standard wall warts will still only give you a single positive voltage - which would need the exact same circuitry to get +/- rails.

Add the expense of an enclosure and that it's no longer integrated into your system, and it's hard to justify.

Also consider the scale: 16 channels of IO needs a little less than 60mA at 20V rails. A reasonably efficient DC-DC converter will require about 150mA of +12V to supply that conversion. Some reverse voltage protection, a few well-placed capacitors, a couple of regulators, maybe an inductor or two for good measure, and we're still talking about something that can easily fit behind a 10HP panel. I think it will be pretty tidy.

s
thresholdpeople
Nice! Looking forward to this module. Contemplating 3U of i/o modules just for this reason has been a drag.
ignatius
applause applause applause applause

yes please.
Fractaltctrl
Ohh man this is much needed!
ignatius
any news?
scottwilson
Got your earlier email, but my response must've gotten lost. I'll get back you you today. Wanted to get the 1.0 firmware out for the 'b and now that 's in the can, I'm back on this full-time.

I'll be pricing out prototyping shops this week - just finishing a couple of PCB tweaks before sending it out. (SMT pin header libraries are a lot harder to find than they should be!)

Thanks for the interest!

s
Ya-Neck
Man I love this invention of yours!
This is such a need in modular synthesis!
Thanks and keep up the good work! Can't wait to get my hand on this one!
scottwilson
Making some progress. Managed to fit 8 channels of balanced receivers, 8 channels of balanced transmitters, 6 channels of LED drivers, and a +/- 18V rail power supply. This thing is dense for 10HP.

ignatius
wicked!

that's a dandy.

didn't get your email though. can PM me here for starters and will see what the email hang up is asap.

can't wait for this thing. so handy.
HIMA
I think it's exactly what i'm looking for. But i'm not sure i understand it correctly. I'm about to get all noob...

I have a ton of outboard gear I want to run through the modular, reverbs, delays, drum machines etc. and i'm on the verge of buying a patchbay to make my life a bit easier. But till now I've been overdriving line gear signals running through my desk and then bringing them into the modular with 1/4 to 3.5 mm cables. Or using a PTG to raise levels. That obviously sucked.

In my future set-up, I'd imagined to buy multiple Gozinta's to pump signals coming from the patchbay. But if i understand, I'm not sure i do, this module would make this unnecessary? It would, for example, take the space's reverb signal from the patchbay (TRS) in to the module (DB25) and have it's levels elevated to modular? Else i'm just integrating a very quiet signal and still need to pump it with the Gozinta...

once again, excuse what i'm sure is a stupid question. But enquiring minds want to know.

edit: all this talk of 12V vs 18V rails is going over my head. Could a uZeus power this?
CF3
I'm super excited for this. FINALLY a legit I/O set up for Euro (that's more than stereo!). Eagerly awaiting pricing and a release date. hyper DB25 is perfect for keeping it nice and neat. w00t
ignatius
i have space in the case and two snakes at the ready smile
scottwilson
@HIMA: I don't think those are silly questions at all - it's a bit confusing if you're not used to thinking about levels, but in reality, it's pretty basic as long as you know what standards everyone is speaking and take the time to work out how they interact with each other.

This module is made to be powered from a +/- 12V rail. The chips I'm using require a +/- 18V power supply for optimal headroom. I'm using the same ICs that are in countless pro-audio consoles, summing mixers, DACs, and ADCs. Most of these aren't limited by an existing power rail as we are in the eurorack world.

I'm fulfilling the voltage requirement using an on-board DC-DC power supply. I'm waiting on a production prototype of the SMT circuit to make sure that the theoretical noise performance will carry through into practice. Knock on wood.

Bottom line, yes, the uZeus will be able to power it.

As to the gain staging, I was first considering an overall unity gain model which would optimize headroom for the chips, but makes the input signal a bit low, as you are describing. As such, I'm pretty sure I will be settling with a +6dB input gain (from balanced to unbalanced) as well as a +6dB output gain with an optional pad on the output that can be used to tame the signals a bit if you expect your levels to be much more than 10V p-p or if you have particularly sensitive outboard gear without input gain knobs.

I'll provide a few more details and some specific examples once I confirm the production run and get some units in that don't look like glorified breadboards. Looking forward to it. Working all these details out in my head is a bit stressful - I'm ready for the assembled SMT boards to arrive!

-s
HIMA
Thanks for clearing this up. +6db gain isn't much. The extra +6 will help a ton. Is more possible? I like the fact that Gozinta has jumpers for each channel to configure gain to 12, 24, or 36dB.
scottwilson
This is primarily meant to be an interface - balanced to unbalanced and back. It's designed to be as simple as possible with a pristine signal path. At this point, the only thing in the signal path is just the 1246 or 1646 IC (input vs output). Adding more gain circuitry, particularly adjustable gain would increase the cost and compromise the signal path for the whole device rather than only those channels that need it.

If you have something that's particularly low level that you need to interface, you'll still need to provide some gain - either in the modular realm or prior to patching into the modular. The Gozinta is a great looking module that seems like would be great to have a couple on hand for when the need arises. Hopefully, of the things you're interfacing, you wouldn't need one for each channel.

6dB gain is actually just about right for the difference between pro audio and modular audio. I'm assuming that +4dBu is the nominal voltage level for balanced pro audio and 10V p-p is the nominal voltage level for modular signals. (Note: nominal = ideal compromise between headroom and noise floor)

Here's an example: you have a 0VU (+4dBu) signal coming from your console, sampler, synth, or effects processor. You're going to want that to end up being about 10V p-p. 6dB of gain gets us close without needing any extra circuitry.

Code:

4dBu + 6dB = 10dbU = 6.9V p-p


So if you have something that needs 12, 24 or 36 dB of gain, you're talking about something that's probably 150mV to a volt peak to peak which would be about -24dBu.

Hope that helps clarify a bit more.

Scott
HIMA
scottwilson wrote:


Hope that helps clarify a bit more.



It does, and i've made space for one in my rack! thumbs up
scottwilson
Progress update...

https://www.muffwiggler.com/forum/viewtopic.php?p=1667436#1667436
Stant
Looks like a great module, cant wait wink
SirSickSik
want!
thanks, I was just looking for such a module!
scottwilson
Prototypes are on their way back to me. Keep your fingers crossed!

s
botstein
scottwilson wrote:
Prototypes are on their way back to me. Keep your fingers crossed!

s


Exciting! This is definitely a module that a lot of us need.
ignatius
so ready for this! super awesome thing that will be problem solver for me smile
CF3
scottwilson wrote:
Prototypes are on their way back to me. Keep your fingers crossed!

s


Ready and Waiting. I so need this module. This will allow me to process shit thru the modular like a gentleman. SlayerBadger!
SirSickSik
isn't there some DIY kit to incoorporate stompboxes into your module?
in the sence that you take your stompbox apart and combine that circuit with an in&out circuit and maybe some CV possibilities?
scottwilson
You might be thinking of something different. This is specifically for integrating modular gear with balanced studio gear.


...And speaking of, the mainboard prototypes are waiting for me at home!


s
visible cow
Sorry, I realize this has been brought up but I didn't fully understand. Does the unique power requirement of this module mean that it is going to be especially power hungry? I'm hoping to stick this in my enclave flight case which has a sufficient but far from robust power supply.
scottwilson
It's a good question. Now that I have the prototypes, I can move beyond the theoretical and into the practical. I'll be taking measurements as part of the testing.

The reason behind the requirement is to be able to run the line drivers at their optimal voltage level of +/- 18V so that they can reach an output of about 22dBu.

To generate a reasonably clean DC supply from another DC source, you're going to consume a bit more power than you produce. Multiply that by the fact that you're increasing the voltage, so you require a bit more current even above the inefficiencies inherent in the system.

The power module consumes between 30mA to 300mA depending on its load.

I am hoping for something around 50 to 100 as an average and 150mA as a worst case... but you never know... Maybe you're running 8 channels of +20dBu audio into your WWII 600Ω radio microphone preamp through some zip cord you found on the side of the road with a couple of intermittent shorts? That will consume a lot more current than wiring it to a new Avid HDIO with some pristine Mogami studio cabling.

s
goiks
tascam pinout?
scottwilson
Yes. Tascam.
CF3
scottwilson wrote:
Maybe you're running 8 channels of +20dBu audio into your WWII 600Ω radio microphone preamp through some zip cord you found on the side of the road with a couple of intermittent shorts?


lolspew
Ya-Neck
Omagad!!! hyper hyper
Realy can't wait for this one!! thanks for all your work!!
rhizomatik
This looks just perfect for my workflow! applause
djthopa
Scott, would this be a good setup to use with my allen heath zed r-16?

Mostly for multitrack recording.

Lots of wires going from the modular to the mixer at the moment.

Dead Banana
seank
i'm planning on doing the same with an a&h wz4 16:2 mixer. 8 channels from the modular to the inserts with a snake, 6 fx sends to and from the mixer with two more snakes. so much easier!

would db25 to xlr or db25 to 1/4" snake be better for this situation? or does it matter?
ignatius
It's balanced I/o so 1/4 try's or Zoe are both fine. I'm guessing. So whatever you need to patch into... use that type of connection.
scottwilson
Looking at the shot of the inputs of the wz4, the mic inputs are on XLR and the line inputs are on TRS, so you're going to want DB-25 to TRS for that specific mixer.

s
seank
nice. thank you! can't wait to run all my euro fx as sends. this rules. do you have an eta or estimated price? mark me down for two.
scottwilson
For subscribers of this thread, I've updated the other one with some new info:

https://www.muffwiggler.com/forum/viewtopic.php?p=1729456#1729456

s
scottwilson
Just a heads up - it's available for order now!

http://nw2s.net/product/nw2s-io/

s
Noha
Hi, I have a question about this module:

It's stated that it can be used to send audio or CV out of the modular, but that the modular audio levels are attenuated -6dB as they leave the system through this module. So what happens to CV? Does it get attenuated as well? I would be interested in sending CV/Gate from the modular through this module to rack gear that takes CV/Gate, but I don't want the CV to get attenuated as this would screw up tuning.

thanks!
scottwilson
It's primary purpose is to improve audio-path workflow between your modular and your digital multitrack, mixing console, or effects. That it's DC coupled makes it _possible_ to use it for CV/Gate, but doesn't mean it's perfect out of the box.

Even the expert sleepers software which is output only needs to be calibrated. If you want this to be pitch-perfect in and out, you'll need to do some calibration as well... For instance 0.5dB which is a very very small amount when it comes to audio, is the equivalent of 100mV in the CV world - that would be horribly out of tune.

Rather, you'd want to create a loopback, figure out what the overall gain is, and adjust that track's output by that much. Personally, I haven't yet tried it, but it's on my TODO list to be able to document what the process would be and to see if you can get the tuning to work well.

-s
Noha
thanks Scott, that answer makes total sense. I think the module is a brilliant idea and one I am very seriously considering integrating into my workflow, but it sounds like for my purposes I'd be better off using it only for audio. Perhaps for things like LFOs or more chaotic modulations it would be fine to route the CV through attenuation, but for precision CV I'll stick with direct cabling.
Noha
le double
7C
you probably have it on the far right in your case, which is not possible because of the big cables on the right side of the module. it´s just a minor problem, but you loose 2 to 4 hp and this is quite frustrating, when you´ve spent ages to setup a case very specifically and it doesnt work out with the hp´s wink

and: my unit´s first two ins were buggy, most of doepfer patchcables would just come out again, confused does work with other cables though.

apart from that - sound and built quality is nice!
thresholdpeople
So I've had the :b for a while now, but I'm a bit shamed to admit I haven't used it so much as things have been changing around in my studio...

At the moment, I'm looking to set up a computer to interface with some hardware, I've got a motu 828mk3 on the way.. I believe the MOTU puts out a max +/-2.5v.

Does the :b convert line level to modular level? I'm interested in both audio and CV applications.
scottwilson
You mean the 'io? (not the 'b)

Yes, the active version of the IO will increase the signal coming from your MOTU by 6dB - doubling the output voltage.

-Scott
thresholdpeople
d'oh! yep the io!

Great! Thanks Scott.

Is it possible to run the io at +/-15v?
scottwilson
Yes, it is possible with one caveat... I know of one customer who is doing it and customized the panel to fit in a Buchla (or Serge?)

The LED bias voltage is only correct when running at +/- 12V, so if you want to run at +/- 15V, you will need to swap two resistors on the power PCB.

I'd be happy to do that for you if you like.

I did correct this on the second run of the power supplies. I haven't tested them at 15V yet, but in theory, they'll run without any modifications.

Scott
thresholdpeople
Thanks Scott! Let me think about it.

I have an unused +/-15v power supply laying around at the moment, that's why I asked. I need to figure out how much current it can provide, I'd like to run some Expert Sleepers hardware with it as well. If it can indeed power everything, I'll get in touch -- I appreciate it! -- otherwise, I'll just get a +/-12v power supply, and keep things simple.
scottwilson
7C wrote:
you probably have it on the far right in your case, which is not possible because of the big cables on the right side of the module. it´s just a minor problem, but you loose 2 to 4 hp and this is quite frustrating, when you´ve spent ages to setup a case very specifically and it doesnt work out with the hp´s ;)

and: my unit´s first two ins were buggy, most of doepfer patchcables would just come out again, :confused: does work with other cables though.

apart from that - sound and built quality is nice!


Very sorry for the patch cables popping out. I'm getting new ones in stock finally, so if you wanted a replacement, I'd be happy to help you out.

Also, I had promised a photo of how to set up the cables if you wanted to align it right up against the edge of your case. I've got a couple of them and one is done like this - right against the Tip Top Z rails.

Done like this, the cables are completely within the panel dimensions and if you pinch them in enough, they don't push on the pinheaders at all.

fragletrollet
Am i right in that the balanced version is not available as a diy kit? Panel/PCB combo`s not available for the balanced version?
scottwilson
Correct - It's got a lot of small SMT to be able to squeeze everything in there. Goes down to 0402 for some of the stuff!

s
SamUK
I'm thinking of picking up a balanced nw2s::io, but I really don't get pro-audio terminology that well. I'm a clever(ish) chap but dBu, dBV, dBfs all drive me nuts. I'm okay with V, Vrms and Vpp.

So 10Vpp = -5V to 5V and 5Vpp = -2.5V to 2.5V.

If I take a 10Vpp signal from my Eurorack into the (balanced) nw2s::io, it will come out the DB25 as a 5Vpp balanced signal. Right?

If I then take that 5Vpp balanced signal put it back into the input of the nw2s::io it will come out the minijack as a 10Vpp signal?

Let's say I want to take a signal from Eurorack, via the nw2s::io into an Eventide Timefactor (it's unbalanced):
- 10Vpp into the nw2s::io comes out as 5Vpp balanced
- 5Vpp balanced into the Timefactor comes out 5Vpp unbalanced. Let's just assume that the Timefactor outputs at the same volume as the input. I'm also assuming that it's okay for the Timefactor to accept a balanced signal, it will either ignore the sleeve or short it to ground. What about the nw2s::io, will it be okay with that?
- 5Vpp unbalanced goes into the nw2s::io and comes out at....? This is the bit I'm not so sure about, is there some signal loss due to how the common mode rejection works?

Any guidance helping me get my head around this would be greatly appreciated!
C14ru5
SamUK, while most of the points in your proposed setup are okay, I'm concerned that your Timefactor may not handle a 5Vpp signal without clipping. So before anything, you should at least verify that the Timefactor has the headroom to deal with such signal levels. If it turns out that a 5Vpp signal is too hot for the Timefactor, a better option for i/o modules would be the Ladik A-520/P-520 combo which can be set to a -20dB/+20dB (10Vpp/1Vpp) attenuation/amplification. Note that the Ladik modules just use plain TS (unbalanced) minijacks.

I'd say that the typical intended scenario for the nw2s::io is to hook up your modular multichannel signal to your professional audio interface, which usually has significantly more headroom than guitar pedals.
SamUK
Thanks for the reply C14ru5, the main usage would be with my audio interface.

The Timefactor was really given as an example of an unbalanced device, though out of curiosity I did check just now, it copes pretty well, if you fiddle with some of the gain settings, it will output an almost 10Vpp triangle wave that's been fed in. Once you add feedback it gets a bit more hairy.. Pretty cool though.

Mainly I just wanted to get the maths correct, particularly with respect to the unbalanced signals, i.e. what happens if I put an unbalanced signal into the nw2s::io. Does anyone one know the answer to that bit?

Edit: Those Ladik modules look really useful btw.
scottwilson
There's a few things adding to the confusion...

Balanced signals aren't measured relative to ground, but as a differential signal - two inverted copies of the same signal relative to each other. When you're talking unbalanced (like with the time factor), typically you would only use one leg of the balanced signal and reference it to ground. This would cut your usable signal by half when going from balanced gear to unbalanced gear.

Also, the 'io doesn't just do a straight balanced to unbalanced conversion - It's got a fixed gain structure that makes the studio<->modular signals a little more natural.

So take modular to studio on the nw2s::io. There is a 6dB overall gain reduction.

If you put a 10V p-p signal (+5/-5) in the modular side, you will get two 2.5V p-p signals out - each one measured relative to the other is 5V p-p.

5V p-p is about 7dBu.

If you run that into a balanced studio interface that's calbrated to +4dBu = 0VU = -18dBFS, then your input meter would read about -15dBFS with a 10V p-p modular signal.

Let's say that instead of running that into a balanced studio interface, you run it into an unbalanced timefactor. The time factor manual gives no specific operating levels besides "line level" - Let's assume this means that 0VU = -10dBv and we don't know exactly how much headroom that gives you.

The eventide pedal will only see half of what the studio interface sees because we are dropping one leg of the balanced signal and measuring against ground instead of against a differential signal.

This will be 2.5V p-p. This means that the eventide pedal will get about -1 dBv at its input. Which is about +9dBVU for that specific pedal. Since they don't say what "clipping" is, then we don't know with absolute certainty without trying it out that the eventide pedals will take the "unbalanced" signal from the 'io, but signs would point to yes, it should be fine.

Running back into modular, there is a 6dB gain... which inverts all of the above... increasing the voltages by the same amount that we decreased them.

Hope that helps.

s
SamUK
scottwilson wrote:
If you put a 10V p-p signal (+5/-5) in the modular side, you will get two 2.5V p-p signals out - each one measured relative to the other is 5V p-p.


Perfect.

One final bit of confusion about inputting unbalanced signals. If I input a 2.5V p-p unbalanced signal, do I get 5V p-p out the minijack or 10V p-p?
scottwilson
Well, to take the same approach, let's say you put a balanced signal with two opposing 2.5Vp-p signals into the balanced input. This is a total differential signal of 5Vp-p. With the 6dB gain going from balanced to unbalanced, that will create a 10Vp-p signal at the mini jack.

Alternatively, if you put a 2.5V p-p unbalanced signal, that will be considered a total of 2.5V measured by the differential input. Add 6dB to that and you will get 5V p-p at the mini jack.

-s
SamUK
I thought that was the case, but thanks for confirming. So if I use an unbalanced effects unit I'll need to add 6db of gain (2x) on the euro side to maintain an overall unity gain.
Multi Grooves
scottwilson wrote:
This is primarily meant to be an interface - balanced to unbalanced and back. It's designed to be as simple as possible with a pristine signal path. At this point, the only thing in the signal path is just the 1246 or 1646 IC (input vs output). Adding more gain circuitry, particularly adjustable gain would increase the cost and compromise the signal path for the whole device rather than only those channels that need it.

If you have something that's particularly low level that you need to interface, you'll still need to provide some gain - either in the modular realm or prior to patching into the modular. The Gozinta is a great looking module that seems like would be great to have a couple on hand for when the need arises. Hopefully, of the things you're interfacing, you wouldn't need one for each channel.

6dB gain is actually just about right for the difference between pro audio and modular audio. I'm assuming that +4dBu is the nominal voltage level for balanced pro audio and 10V p-p is the nominal voltage level for modular signals. (Note: nominal = ideal compromise between headroom and noise floor)

Here's an example: you have a 0VU (+4dBu) signal coming from your console, sampler, synth, or effects processor. You're going to want that to end up being about 10V p-p. 6dB of gain gets us close without needing any extra circuitry.

Code:

4dBu + 6dB = 10dbU = 6.9V p-p


So if you have something that needs 12, 24 or 36 dB of gain, you're talking about something that's probably 150mV to a volt peak to peak which would be about -24dBu.

Hope that helps clarify a bit more.

Scott


150mV would be a very low level moving magnet stylus through phono amp stage i.e. a quiet signal from a turntable. Theres no way around it, it'd need another gain to be used with modular...


**edit I just saw the date- ignore this**
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