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Black Box Analog Design – The Ordeal in 3 Parts Effects Pedals, Units & Accessories
Old 19th February 2017
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rvwainscott's Avatar

Black Box Analog Design – The Ordeal in 3 Parts

Part 1 - The Butterfly Effect

So, my partner at Black Box Analog Design, Eric Racy, calls me to inquire whether or not I thought it possible to “whip up” the new microphone preamp so we can show it off at NAMM. Normally, I'd jump at the chance but NAMM is less than two weeks away and even though we have two working prototypes of what will be the new preamp, we have yet to have circuit boards made or the case or face plates manufactured. We have digital renderings of what the new preamp will look like both inside and out and Eric really outdid himself putting as much as possible in the smallest container possible – it really is an art. “I can custom order a one-off face plate and have it to you the Tuesday before NAMM.”

Well, call me foolish but I love a challenge so I told him I was gonna scout around the shop and see if I had enough bits and parts to put something together. Now, the drawings I've seen in Sketchup tell me that this is going to be a two space box with a cutout showing the tube through a grill which, I'm told, the face plate wont have and that I'd have to manufacture that as well as figure out a way to get it to stick to the back side of the face plate.

I found an old two space project box for an 1176 project I was gonna do but never got around to doing. Next, I gathered up the parts I figured I'd have to use and placed them in the project box to see if there were enough room for all of it. Bingo! Knowing that it will probably fit, I order all relays, switches, knobs, etc that I know I'm going to need. I know that these parts are going to take at least 4 days to arrive but I've got plenty to do.

The first thing I need to do is figure out how I'm going to build the structure that holds the tube sideways and it will also hold the circuit board for the triode and triode cathode follower and the two switches. What I need is a tiny table saw kind of a thing but I do not have such a thing so I went down to Harbor Freight and bought a Jig Saw and put it upside down in a vice clamp and used it as my mini table saw. I dug around in boxes until I found some copper clad board to cut and cut it to shape.

I found that the best way to put in standoffs is to drill the case and the the item that will be attached to these standoffs at the same time. This way I know everything will fit. Now, height is going to be a real problem as I have 6 switches that must fit in a setup with fairly tight tolerances. Because of this, I had to use threaded standoffs so that I could raise and lower these boards.

I get the standoffs put in place and the tube structure built and spray painted. There is going to be a lot of point to point in this so every bit of space must be looked at twice. I've glued in the LED bar that will light up the logo. I've also glued in some aluminum foil just in case I need some extra reflection to light up the logo - this IS NAMM after all

In parts two and three you'll see. . . well, you'll see.
End of part 1.
Old 26th February 2017
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rvwainscott's Avatar

Part II - The Calm Before the Storm

With the case drilled out, it was time to see if everything still fit and get an idea how this was going to look.

Seeing that everything was going to fit, it was time to focus on the sub-components and I immediately turned my attention to the dual triode/cathode follower section. I've drawn out a diagram how this should all go down given the number of solder lugs available. I also need to wire in a place for the blue led which will backlight the tube.

I've got to wire everything back from the pinout of the tube socket as well as think about the 6.3 volts I'm going to need so I put that on the copper as well. May as well keep the regulator close and use that copper as a heatsink.

So far, so good.

I need my pentode volume pot to do a few things so I glued a relay and wired its parts directly to the pot itself. Easy. Done.

Now it is time to turn my attention to the push button circuit board. I'm gonna need a rail for 12v to power the LED's in the switches as well as 12 volts to relay all around. I've also dropped a ground rail that all my noisy led's, relays and voltage regulators can drop to. I'm using this perf board so that I can move these switches around to fit the cutout on the faceplate that I haven't seen yet. If I remember correctly, there are 21 steps to getting a single switch hand wired and in position.

I need to wire up an EF86 but I do not want to do it by hand because I lack the room to do it so I decide I will re-purpose an old circuit board. It has switching for phantom power, phase, impedance and an air boost as well as the footprint that will hold the Cinemag input transformer so why not just “modify” the board and modify it I did. I modified it until I no longer knew up from down.

I've more or less got everything ready to go. The power supply is attached and working. The output transformer is in place and the input and output xlr's are wired as well. Time to start attaching sub-components. NAMM is now five days away and I've got plenty of time, right?

Stay tuned for part III where sleep becomes a thing of fiction and miracles do happen.
Old 1st March 2017
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Part III – The Sum of all Fears

I've got five nice long relaxing days to finish this project. So, I drop in the main circuit board and wire it up. No need to hurry, right?

I drop in the push-button circuit board and fire up the power supply. The On/Off switch is in a heavy plastic ziplock bag. Live and learn.

The faceplate arrives tomorrow and I need to go to the hardware store and get a grill thing of some sort and I settle on the mesh used to hold stucco in place. Though I forgot to photograph it, I had to beat it with a hammer on an anvil to flatten it out and then I sanded it down, cut it to size with a dremmel and spray painted it.

Well, it is Tuesday mid day and the faceplate has arrived. I've decided that I'm going to epoxy the mesh first and then figure out how I'm going to color the exposed areas black. But wait!!! This faceplate wasn't made correctly and the letters on the logo are all broken. Panic.

Deep breath. The company that manufactured the faceplate is going to overnight me a replacement. With that in mind, I can experiment on this faceplate and try to figure out what will and will not work best. I try spray paint, markers and gun bluing to color the exposed metal. Next, I wire up some miscellaneous things.

The first thing I must do is somehow line up the two switches that are going to be resting on the visible tube display thingy. I figure out that Popsicle sticks is the best way to go and I will use that, a paper jig I made with a wooden spoon and silicone to hold it all in place.

This all needs to dry and there isn't anything else I can do at the moment as I need the real faceplate so I can wire it up. Tomorrow is Wednesday and Eric will be in Anaheim setting up our booth.


This is the first thing I see Wednesday morning which was all the motivation I needed to get busy. I have to wait for the faceplate. Cosmetically prepare the faceplate, wire up the faceplate, wire the faceplate to everything in the box, test and calibrate the unit. Package it up for transport.

The faceplate arrives right on time! I tape it off and spray paint the silver beveled edge. I glue in the mesh and I use this permanent marker to darken the edges.

Eric begins sending me images from Namm. The hole you see in the rack is where this pre is supposed to go.

Just in case I forgot.

I wire up the faceplate and I can begin to see where it may all come together. I've still got, I don't know, 20 or 30 loose wires that still have to be connected.

Not a glamour shot but it is alive!

I didn't just want a box with some light but an actual working unit. This is an actual working unit.

This is kinda fun as a one off but I am so glad that the “real” ones will be made in a commercial production facility.

We were right next to the Mix with the Masters guys. Fun.
Old 26th March 2017
Gear Addict
rvwainscott's Avatar

What does it do?


I thought I might upload a few response curves to show what this unit does.

Instead of using traditional additive or subtractive EQ which is something I find to be too destructive, I go for different responses by changing the impedance of different frequencies. After all, a vacuum tube amplifier is nothing more than an Impedance Coupled Amplifier and I can get a response that you could not get with a traditional eq and do so without any of the phase or comb filtering that comes along with it.

These images show the RESPONSE feature on this preamp. There are other features as well that shape tone and saturation but I'm just showing you the RESPONSE capabilities of this unit.

Here is a nice gentle slope where you can roll off 30db between 1.7k down to 20hz. From 1.7k on it is nice and flat.

Here I do the opposite and roll off the top end and have some aggressive low end.

Here I take away both the top and bottom and leave the mids. Keep in mind that I could, if I felt like it, also saturate or excite those mids as well.

The unit is capable of giving up a flat response as well. Notice that all of these response curves still have a -6db output into protools so I do not lose any overall gain by doing these curves.

Old 20th April 2017
Lives for gear
mattcollen's Avatar
I cannot wait to get my hands on one of the new preamps.

For my fellow slutz, BBAD is a great company. I have one of the prototypes of the first preamp, and it is killer. When it died a few weeks back, I sent it to Robert who offered great service and made it new again. Robert sent photos and videos during the repair and updating process.

Simply put, BBAD's service is unreal. They truly stand by their products, products that are overbuilt, works-of-art.
Old 20th June 2018
Gear Addict
rvwainscott's Avatar

Another Update


Have a look at this review. Also, it is a chance to hear the unit in action.

First Listen: Black Box MM-1 Mic Preamp - Vintage King Blog
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