Compact desktop line mixer?

[OneRoomStudio]

All connections should be on DB25...this isn't 1983. All modern patchbays and most 8 channel preamps, 500 racks and everything else is on DB25. There should be very few dedicated individual in/outs. Cheaper, easier manufacturing , easier hookups.

DB25 was invented in 1952….so I don’t know what the year has to do with it. Personally, my interface and patchbay are ¼” TRS.

 

[Brian Roth]

I might be a strange example because I have a Dangerous Source that acts as both the D/A for my main outs and my monitor controller. The rest of my hardware goes through my other AD/DA converter (a MOTU).

You bring up a good point though. I guess I had been thinking that I would monitor off the board while I was mixing, then print the mix to the DAW, and if I wanted to listen back afterwards, I could just patch back into the stereo return and listen through there. I have meters to know how hot I’m hitting the DAW, and digital doesn’t alter the sound enough that I feel like I need to monitor the returns while printing. I know that’s not how things were done in the tape days though.

OK, your workflow is similar to some folks I know who don't have a desk of any type.....using an external monitor controller. I only have a vague idea about one of my friend's setup, but there is a UA monitor controller of some sort along with other UA digital interface gear. No analog desk; a 500 rack that somehow ties into A/D and D/A convertors.

But, with this project, the mixer IS the monitor controller. CR level, solo listening, speaker select, etc.

Bri

 

[Brian Roth]

All connections should be on DB25...this isn't 1983. All modern patchbays and most 8 channel preamps, 500 racks and everything else is on DB25. There should be very few dedicated individual in/outs. Cheaper, easier manufacturing , easier hookups.

I had thought about that. The x-desk used multiple DB-25's. OTOH, the LILO used XLR and TRS jacks. But, it was a much larger mixer.

DB-25's pretty much eliminate the possibility of a DIYer "easily" doing their own metal work. Chassis punches are incredibly expensive, and drilling a bunch of overlapping holes and then spending a ton of time with a small file is very tedious and the results look crappy. I can easily make a panel with a drill press and some Greenlee punches, but draw the line at manually "chopping" odd-shaped openings. Shrug....

Bri

 

[Brian Roth]

@OneRoomStudio I have an UNfeature Creep idea. <g>

Instead of the multi-segment meter on each channel and the peak indicator, instead use a "three-step" indicator for Signal Present (-20?), Normal (0) and Clip (+20?). Either a single tri-color LED or three individual LEDs. There is a way to add a pre-fade sample into the readout circuit to catch clipping of the input buffer as well.

Perhaps a single multi-segment meter could "watch" the Solo audio bus?

As best as I can see, the x-desk and LILO have NO metering or clip indicators on each input.

Deleting the meters on each channel greatly simplifies the circuity and reduces required panel space.

Bri

 

[MidnightArrakis]

I can't seem to access the file this way.

[I can't seem to access the file this way] -- Since this forum is essentially "an engineering forum", I would think that the creators and/or moderators of this forum would allow it to be more accommodating with it being able to attach the many types of CAD-design files that all of us commonly use. This would then allow all of us to freely exchange our various types of CAD-design engineering files amongst one another without the need to "trick" the system into believing we are attaching an allowable file-type, when in reality, we're not!!! Is there a reason why CAD-design files are not allowed to be attached to messages here, but MP3's and WAV files are? HMMMmmmmmmmmm......

In any case, recently when I uploaded an -- STL -- file for RuffRecords to review which was renamed in the manner he has detailed, he afterwards made no comment about having any problems downloading and importing my file to him, other than that he was able to import my file and use it. However, and perhaps similar to your own experience upon accessing RuffRecords' attached FPD file, I did initially receive a "Black Message" as you have indicated. But, it's an easy fix to do.

Just place your cursor over the attached file and do a "Right-Click". You'll get a pop-up menu. Scroll down, select "Save Link As" and name the file to whatever you want.....>> BUT!!! <<.....just make certain that your file has an -- .fpd -- filename extension and then click on "Save". You should be "GOOD-TO-GO"!!! It worked for me!!!

GOOD LUCK!!!

/

 

[ruffrecords]

[I have just designed a rough front panel] -- I have two minor suggestions for your front-panel design:

1. Add another "fixing" slot above Channel-8 (primarily for a more symmetrical look, not necessarily for mechanical reasons).

This is a "feature" of front panel designer. I use the "add system holes" option to place the fixing slots. Unfortunately this only works properly for panels up to 84HP wide (the maximum that fits into a 19 inch rack). This panel is 104HP wide so when you ask it to add system holes it throws up an error and offers to resize the panel! The panel is the right size so I ignore it and the result is what you see in the file I posted. I didn't bother to move them because all I was really interested in was the price.

In fact I found it very hard to create a 104HP panel in front panel designer. The up/down arrows on the width selection box will only go up to 100. I had to type in 104 to get it to work. However, I have not checked the width of the panel so I am not sure it it actually came out as 104HP.

Cheers

Ian

 

[MidnightArrakis]

This is a "feature" of front panel designer. I use the "add system holes" option to place the fixing slots. Unfortunately this only works properly for panels up to 84HP wide (the maximum that fits into a 19 inch rack). This panel is 104HP wide so when you ask it to add system holes it throws up an error and offers to resize the panel! The panel is the right size so I ignore it and the result is what you see in the file I posted. I didn't bother to move them because all I was really interested in was the price.

In fact I found it very hard to create a 104HP panel in front panel designer. The up/down arrows on the width selection box will only go up to 100. I had to type in 104 to get it to work. However, I have not checked the width of the panel so I am not sure it it actually came out as 104HP.

Cheers

Ian

[I found it very hard to create a 104HP panel in front panel designer] -- Well.....Alrighty NOW!!!.....I think there could be an easy "work-around" to resolve this little issue of yours!!!

Provide me with a -- DETAILED -- mechanical sketch of your desired front-panel. Include -- ALL -- holes, slots, cutouts, etc. with EVERYTHING clearly dimensioned!!! I could then create your front-panel in SolidWorks to be however and whatever you want it to be and then I could do a "Save As" and save the design as an -- STP -- file. From there, I could import the -- STP -- file into Front Panel Designer and turn right around and do another "Save As" as an -- FPD -- file.

Once I have all of that created and saved, then I could send you a ZIP-file containing both the FPD and STP files so you can then add-in all of your graphics and text. I just ask that you include the -- +11 -- for a chuckle!!! (And, I'm assuming that you are aware of the "This Is Spinal Tap" movie, which is where this came from).

How does this sound to you?



/

 

[studio1117]

DB25 was invented in 1952….so I don’t know what the year has to do with it. Personally, my interface and patchbay are ¼” TRS.

There simply isn't enough real estate to allow all of the inputs and outputs this console will require to be useful to anybody. If it was such a great idea to have a ton of XLR and 1/4" inputs on the back....why hasn't anybody else done it on these modern small mixers? Why didn't the X-desk ? You can buy some DB25 to 1/4" to fit your studio and the rest of the world can use DB25 like every other modern piece of audio gear. Next thing you're going to be arguing to bring back cannon balls and horse drawn buggies.

 

[studio1117]

DB25 was invented in 1952….so I don’t know what the year has to do with it. Personally, my interface and patchbay are ¼” TRS.

Oh and BTW the DB25 audio standard (Aes59) wasn't even adopted until 2012! https://www.soundonsound.com/glossary/aes59

 

[kags]

I agree that DSubs are the way to go, but I also would love at least 1 or 2 pairs of TRS inputs for convenience. Sometimes you have a floater piece of gear or a visitor wants to plug their device in, so some TRS connections that override the Dsub on, say, channels 1-4 would be welcome.

I understand the expense of dsub cables turns some people off, but they are ubiquitous these days. I also agree it’s difficult to hand cut a db25 hole in a chassis. I trace the cutout from a middle Atlantic panel and use a Dremel to cut and smooth and it works fine and takes about 10 minutes.

Another idea that I employ is to simply cut a rectangle and mount a Middle Atlantic db25 plate to the chassis of a device with screw or rivets . This creates a nice finished look. This is what it looks like.

 

[MidnightArrakis]

There simply isn't enough real estate to allow all of the inputs and outputs this console will require to be useful to anybody. If it was such a great idea to have a ton of XLR and 1/4" inputs on the back....why hasn't anybody else done it on these modern small mixers? Why didn't the X-desk ? You can buy some DB25 to 1/4" to fit your studio and the rest of the world can use DB25 like every other modern piece of audio gear. Next thing you're going to be arguing to bring back cannon balls and horse drawn buggies.

[Next thing you're going to be arguing to bring back cannon balls and horse drawn buggies] -- Hey!!!.....WHAT A GREAT IDEA!!! Less overall pollution, even if it does take you longer to get where you're going!!! YA-A-A-A-AY!!!.....

/

 

[ruffrecords]

There simply isn't enough real estate to allow all of the inputs and outputs this console will require to be useful to anybody. If it was such a great idea to have a ton of XLR and 1/4" inputs on the back....why hasn't anybody else done it on these modern small mixers? Why didn't the X-desk ? You can buy some DB25 to 1/4" to fit your studio and the rest of the world can use DB25 like every other modern piece of audio gear. Next thing you're going to be arguing to bring back cannon balls and horse drawn buggies.

I think it is horses for courses (pun intended). I have done both on mixers I have built. The last one I delivered was a 4 channel tube mixer that had a rear panel with 27 XLRs on it. The reason it was done this way is the customer does not uses a patch bay and all his other gear has XLRs. The one I am building right now, in the identical enclosure, is a 12 channel line mixer and has a rear panel with just four DB25 connectors. Three do the inputs and direct outs and the fourth the bus outs and AUX returns and the reason it was done this way is the customer intends to wire them all to his patch bay.

Cheers

Ian

 

[MatthewF]

Hi all,

Long time X-desk user here, been following this thread with interest!

A couple of X-desk features which I don't think have been mentioned:

The alt inputs can be routed directly to the stereo cue bus while the main inputs continue to feed the main mix - great for creating e.g. a drum submix on the cue bus which can then be routed on to the main mix or out via a stereo bus compressor and back into the main mix via a stereo input. In this way you can kind of operate the desk in a 16:4:2 arrangement during mixdown (with some limitations).

The main mix features an insert point, the return from which can either be switched in place of the pre-insert signal as usual, or can be summed with the pre-insert signal, thereby allowing parallel bus compression.

The mix buses themselves are exposed on one of the DB25 connectors, allowing further channels to be added in a separate chassis. (Still hoping I'll find a used X-Panda one day!)

The X-desk does have basic signal input indicators on each channel by way of a bi-colour LED (green for signal present, red for clip).

Not suggesting these features ought necessarily be incliuded in this design, but thought them worth a mention!

Cheers,

Matthew

 

[Brian Roth]

Me bad <g>.....I didn't easily spot the level indicator in the x-desk block diagram, but it's discussed in the owner's manual.

Bri

 

[Brian Roth]

Returning to the module front panel and its cost for a moment, there might be some money to be saved by separating the slider faders from the rest of the panel so for example there would be a 4U high panel for faders and, say, 3U or 5U for the plug in module. A single panel holding all the faders will be significantly cheaper than a dozen or more individual fader panels. Normally I would avoid large panel like this because they can be a nightmare for servicing but as long as there is little more than a fader per channel this objection does not apply.

So, I have just designed a rough front panel with 13 faders and their legends on a 4U panel which is 105HP wide (13 x 8 = 104 which is a "standard width in the synth world). The cost comes out at 171 Euros which is basically 13 euros per fader. (fpd file attached using @MidnightArrakis patent method of simply adding .pdf to the whole file name.

Cheers

Ian

Hi Ian. How did we end up with 13 faders? All the block diagrams posted by @OneRoomStudio have 8 mono faders for the inputs and 1 stereo fader for the master 2-mix bus. IIRC, that is one more than the SSL x-desk.

I'm obviously missing something! But the "one panel for faders" makes a lot of sense.

Bri

 

[Brian Roth]

@OneRoomStudio I just noticed what I think is a signal flow mistake. The Aux "Post" signal is indeed Post fader, but Pre mute. Hence, if a channel is muted, the send signal will continue into the reverb, whatever.

Bri

 

[OneRoomStudio]

There simply isn't enough real estate to allow all of the inputs and outputs this console will require to be useful to anybody. If it was such a great idea to have a ton of XLR and 1/4" inputs on the back....why hasn't anybody else done it on these modern small mixers? Why didn't the X-desk ? You can buy some DB25 to 1/4" to fit your studio and the rest of the world can use DB25 like every other modern piece of audio gear. Next thing you're going to be arguing to bring back cannon balls and horse drawn buggies.

I already established that there would be plenty of room for all the ¼” jacks on the rear panel. Three rows of 10 jacks only take up 2.5” x 7.5”. There’s plenty of space, it’s easier to DIY, and it doesn’t require rewiring/buying new cables. If you want to design a DB25 rear panel though, feel free.

Hi all,

Long time X-desk user here, been following this thread with interest!

A couple of X-desk features which I don't think have been mentioned:

The alt inputs can be routed directly to the stereo cue bus while the main inputs continue to feed the main mix - great for creating e.g. a drum submix on the cue bus which can then be routed on to the main mix or out via a stereo bus compressor and back into the main mix via a stereo input. In this way you can kind of operate the desk in a 16:4:2 arrangement during mixdown (with some limitations).

The main mix features an insert point, the return from which can either be switched in place of the pre-insert signal as usual, or can be summed with the pre-insert signal, thereby allowing parallel bus compression.

The mix buses themselves are exposed on one of the DB25 connectors, allowing further channels to be added in a separate chassis. (Still hoping I'll find a used X-Panda one day!)

The X-desk does have basic signal input indicators on each channel by way of a bi-colour LED (green for signal present, red for clip).

Not suggesting these features ought necessarily be incliuded in this design, but thought them worth a mention!

Cheers,

Matthew

All worth mentioning, but I purposely eliminated those to decrease I/O, complexity, and front-panel controls. The simplified peak/level indicators could work, but proper metering was one feature I wish the X-Desk had.

@OneRoomStudio I just noticed what I think is a signal flow mistake. The Aux "Post" signal is indeed Post fader, but Pre mute. Hence, if a channel is muted, the send signal will continue into the reverb, whatever.

Bri

Good catch! I’ll update the block diagram tomorrow.

…and yes - there should only be 9 faders - 8 mono faders and a stereo mix bus fader.

 

[Brian Roth]

My metering suggestion was merely to reduce complexity and panel space. I had noted the lack of channel meters on the x-desk and LILO which I've been constantly studying.

OTOH, the many recording desks I've used over the years typically provided "per track" metering, typically by reading the output of the multi-track. If recording, the recorder would loop-back the track's input signal to the desk or feed repro back to the desk and thus be metered. But, if several mics were submixed I don't recall many (if any) desks had an easy method to meter each individual input channel before they were submixed. But, not really relevant in this design!

Many mid-tier FOH PA desks I've used also lacked channel meters but often had metering on the Solo bus to check an individual channel(s).

Just musing again as I typically do! <g>

Bri

 

[Brian Roth]

While the feature set is being tweaked, I decided to look around at fader options. Of course I thought of P&G, but they are no longer being made and would be a budget-buster.

Next I thought of TKD. I've seen them on various consoles, like the Neotek Elan at a studio here in town. They've always seemed quite reliable and "feel good".

https://www.tkd-corp.com/en/product.html#manualfader

I did a little bit of searching and found this:

https://wheatstone-store.ecwid.com/TKD-CPA-9101-UNC-Fader-p195011493

Yippee! 421 in stock for $30.00 each. Uh-oh! Linear taper.

TKD does not appear to have have stocking distributors so I guess they would be factory ordered with a minimum quantity.

I decided to look around at Mouser. Only filter was 100mm and audio taper. So it will include special order.

https://www.mouser.com/c/passive-components/potentiometers-trimmers-rheostats/slide-potentiometers/?taper=Audio&travel=100 mm

Not a lot of choices. I seem to recall these nice ones:

https://www.mouser.com/ProductDetail/Alps-Alpine/RSA0K12A1013?qs=YMSFtX0bdJDDCro05rKppg==

...but that one is stereo. I attached an Alps catalog sheet and plan on "assembling" part numbers with a reasonable selection of Ohms value options and do web searching.

The remainder are PCB mounts from BI (conductive plastic tracks ) and Bourns (carbon). Mouser seems to have the BI faders in both mono and stereo. I will assemble parts numbers for alternate resistance values and do web searching.

Digikey doesn't list tapers (!!) on their selection page nor on a few random part numbers I opened to read specs.

I need to do a deeper dive into Alps choices.

I am not a fan of the little cheap sliders. They usually feel wobbly and rough and seem to break easily. But, next Mouser order I place I may add a fader or two just to see.

As I mentioned, the PC mount choices will require a PCB behind the front panel. My instinct is to have a "strip" board for each fader vs one giant card.

IMHO the mono and stereo faders should be from the same manufacturer and "series". That way the handle height (and fitted knob) are the same, and they will all "feel" the same.

Enough searching for me tonight....the floor is open for discussion!

Bri

PS, I looked at Alibaba...lots of "Ten for a Dollar" type crap. <g>