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Post by guitfiddler on Jun 15, 2018 21:14:16 GMT -6
My goodness! A mixer that sounds great in front of my interface for live tracking with all the basic necessities with a Pro sound? This is exactly what I've been looking for all these years. I just can't be satisfied with all the budget mixers, they all sound like dookie! Man I love your enthusiasm but unfortunately this isn't a complete mixer it's just a channel strip for my existing mixer, an Alesis X2. It's stealing a lot of the best stuff from other designs, so only some of it is my design. I have a Crest Century VX and it sounds pretty good already, but if I could design something like this, I would have done it already. I would love to make a small format mixer with all the best components, but be able to change the desk any size by the frame! Bums me out, maybe I didn’t read all the posts and thought you were building something would be available like your 4 channel 9098. I’m just curious if the VX has a design worth pursuing, or Just give it up. It has Jensen transformers in it. You can actually add them on each channel. It does have them on subgroups and main mix buss along with VCA’s! I like putting outboard preamps and going in line in, sounds much better to me, but the preamps aren’t too bad. |
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Post by svart on Jun 19, 2018 9:56:08 GMT -6
Thinking about the EQ some.. And yes I bounce around on ideas a lot.. If I use the CAPS EQ design for the mids, I need to come up with a log/antilog pair. I'll see if I can approximate this with linear pots and taper bending resistors!
if not, I think maybe I'll just do a full SSL "black knob" setup. It's the same amount of pots, but nothing exotic like a log/antilog pair, but I won't get the ridiculous Q of the CAPS circuit either.
Otherwise, using a combination of 9mm and 16mm pots I can get the EQ down to around 5-3/4" of length which is great so far. I think this is the way to go!
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Post by svart on Jun 20, 2018 14:59:00 GMT -6
So I've been trying to get my head around the log/Alog pot combo and there just isn't a good way to do this due to the configuration. The pots are set up in pseudo-rheostat setup, which makes it easy to get an Alog taper but impossible with a Log taper.
I guess I'm going with the black EQ midrange, which is kind of a bummer since it's not nearly as elegant as the CAPS style parametric EQ. I won't be able to get as narrow of a Q as I'd like and the skirts of the band will change with gain, also something not as desirable.
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Post by svart on Nov 30, 2018 14:58:41 GMT -6
So I'm getting back into this slowly. I've been working on the PCB layouts trying to get everything to fit with all the features I'd want to see in a channel strip. So I've settled on a mismatch of SSL pink/black/brown EQ trying to get the best curves and using available pots, SSL 4K/6K channel compressors with mods, and my own interface/fader/send/assign circuitry. The latest conundrums were getting all the pots and switches to fit on the PCBs in the length of the channels in my Alesis X2 console chassis. The chassis has an opening of 23.5" so the sum of the various boards can't be any longer than about 23.25" to fit. So far I've designed an EQ board that is 6" in length, a compressor board that is 5" in length, an I/O board that is 2" and a fader/send/assignment board that is 10.25" in length. I also added the ability to send the compressor sidechain pre or post EQ, use the compressor sidechain in feedforward or feedback mode and also send the insert signal pre or post compressor as well as bypass capability for both EQ and compressor. block diagrams:   Comp:  EQ:  I'll probably order the comp and EQ boards next week while I finish the I/O and assign boards. |
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Post by svart on Nov 30, 2018 16:12:39 GMT -6
BTW here's a mockup using 1:1 prints to check alignments and such:  |
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Post by svart on Dec 4, 2018 16:35:55 GMT -6
I ordered a few of both the EQ and the compressor.
The first rev of compressor worked, so I don't expect this one to be different overall, but the EQ is a big unknown, but if they both work I'll order the remainder of the boards I need to replace all the channels in my console.
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Post by wiz on Dec 4, 2018 18:27:40 GMT -6
You are amazing Chris
cheers
Wiz
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Post by jdc on Dec 4, 2018 19:13:00 GMT -6
This is madness. The comp looks like a NYC subway map. I'm very intrigued
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Post by svart on Dec 5, 2018 8:57:22 GMT -6
This is madness. The comp looks like a NYC subway map. I'm very intrigued It is. It's been 2 years in the making already according to the dates on my files! It's a great learning experience, but it's also horribly time consuming. I'm spending more time figuring out how to make the mechanical portions fit, and how to flow the signal through the systems than I am actually doing electrical design. Granted, most of the basis is from the 4K console at this point, but I am adding and subtracting portions to suit my needs and to make it fit within the Alesis X2 chassis and bussing schemes. |
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Post by jdc on Dec 5, 2018 9:40:47 GMT -6
Given how much time you're spending trying to make every everything fit, would it have been more time/cost effective to design a chassis from scratch? (the thought being every hour you work on this project is an hour unpaid and therefore money lost)
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Post by svart on Dec 5, 2018 10:03:40 GMT -6
Given how much time you're spending trying to make every everything fit, would it have been more time/cost effective to design a chassis from scratch? (the thought being every hour you work on this project is an hour unpaid and therefore money lost) Well, I don't intend to sell these, so every hour is unpaid anyway! I guess I could make a new chassis, but that's just more cost. I already have two of these Alesis X2 consoles, so I figured I'd just use the chassis and save the time and costs. I guess in the future I could design my own chassis if I ever needed to expand, but I doubt it. Even then, building each channel isn't going to cost much in cash money, just time. I figure each channel will be around 100$ in parts, mostly the cost of the pots. I bought about 1000 NE5534 opamps in a lot on Ebay for roughly 0.08$ each, so I have plenty of those. The PCB's in quantity will be only a couple dollars each, but it'll likely take me 2-4 hours to stuff and assemble each PCB and cut, paint and print the panels for each channel. But another big cost will be making a drilling/cutting jig for exact drill placements. it's a large aluminum bar with hardened steel drill guides installed where the holes would go. You can just clamp them together and run the drill through quickly. Makes perfect copies of each panel. Then I need to make a silkscreen so I can screen print the markings on the panels. It's not expensive, but it's super time consuming to get it all right. Many tests are needed to ensure perfect alignment since I'm not using a full featured Autocad program to design all this stuff. |
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Post by matt@IAA on Dec 5, 2018 12:37:29 GMT -6
Svart, I have AutoCAD. Be glad to draw your stuff for you with dimensions, to scale.  |
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Post by jdc on Dec 6, 2018 7:24:36 GMT -6
Svart Desk! Svart Desk!
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Post by svart on Dec 6, 2018 7:47:38 GMT -6
I appreciate the vote of confidence, but I don't think it'll happen! Nobody buys the other stuff I've made, and SSL might get a little pissy with me if I sold a mixer that has their DNA. I'm good with building one for myself. |
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Post by svart on Dec 6, 2018 15:44:29 GMT -6
Here's a 2D mockup of the panel with all the holes in the right places. What I'll do is adjust the holes to fit the drill guides and have this machined. I'll press in the drill guides myself.  |
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Post by notneeson on Dec 13, 2018 8:55:28 GMT -6
Damn, dude. Mad respect.
And for what it’s worth, I know a guy who sold his Amek and got an X2 with an SSL sticker on it. He won’t tell anyone it’s an Alesis, calls it a “highly custom job” but I think you win on that front.
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Post by svart on Dec 13, 2018 9:15:28 GMT -6
Damn, dude. Mad respect. And for what it’s worth, I know a guy who sold his Amek and got an X2 with an SSL sticker on it. He won’t tell anyone it’s an Alesis, calls it a “highly custom job” but I think you win on that front. That's hilarious. I mean the boards sound great for what they are. They sound better stock than most of these modded cheap boards that everyone is raving about, and for a lot less cost. It's just the quality of some of the components that really hurt them at the time and plague the older boards still in service. If they had just spent a little more on better pots and connectors in the mid 90's, they could have probably given SSL a run for their money on the mid-sized mixer market. But honestly, very, very few clients even look at the mixer. They're just impressed by the size and professional look of it and only care that it sounds a ton better than their behringer they've been doing demos through. I did have one guy ask me about it after he muttered something about "Alesis.. don't they make cheap stuff?" To which I just said "they used to make high end gear back in the 90's" (which is partially true) and he just said, "Oh ok".. Which is funny because this guy was born a year after Alesis stopped making these boards. |
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Post by svart on Dec 13, 2018 9:25:24 GMT -6
So two quick updates. I got the EQ and compressor boards back and have been test fitting the panels with the pots and such. I found that my original offset for the metalwork and the PCB was a bit too tight, so I was able to figure out how much I needed to move it. The knobs I had planned on using are a bit too wide at the base to use how I intended and I'm having a very hard time finding knobs for splined shafts that are more narrow at the base while still extending down to the nuts. There seems to be a ton of knobs with narrow bases for D shaped pot shafts but very few for splined. Go figure. So I need to find knobs that are for splined shafts that are at MOST 12mm wide at the bases. 10mm would be perfect as it would allow me to have at least a little room on the sides of the knobs. At 12mm, I have no room on the front panel for print on the right side of the pots that side on the bottom(right) side of the PCB. 10mm would give me a little room, although I don't know exactly how the print would look. I printed out a drill drawing and used it as a guide to drill holes to make sure the EQ lined up:  And here's my mockup for the EQ markings for 12mm knobs:  As you can see the knobs on the far right have no space for print to their 3 o'clocks. I'm not sure when I'll get around to electrically testing these. I do have the parts to build them, but I suppose I still need to make sure the mechanicals can be satisfied before I go building a few boards in case I need to do another version of boards fixing mechanical issues. |
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Post by wiz on Dec 15, 2018 19:59:32 GMT -6
3D printer
?
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Post by svart on Nov 12, 2019 9:33:47 GMT -6
I'm getting back to this a little since I had some time to finish the layout on the last of the PCBs. I mocked up a whole panel and used my drill guide to cut the holes which verified that everything will fit OK through the front panel. I'm in the process of stuffing a couple EQ and compressor boards to test out while I wait for the I/O board and the bus interface board to get here.  Overall the BOM cost for the channel is around 100$ if I reuse the main faders from the X2 and use really cheap knobs. I haven't chosen the color I'll paint the strips, but I'm thinking a darker grey background with white lettering would be easier to look at than a lighter background with dark lettering. |
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Post by cyrano on Nov 12, 2019 10:48:52 GMT -6
Nice project.
I had something similar in mind, but decided to leave my desk as is. It was sold to me as "needing lots of TLC", so I counted on modding in stead of repairing. Turned out the only TLC needed was the removal of some layers of sticky tape. Doing what you're doing would probably take me decades... :-)
When I bought it, I had a look at an Alesis X2 too. Nice desk. Rare in these parts. Decided not to buy that one because of weight. Price and condition were very similar, but I can't lift an Alesis X2 on my own. The DDA is just under 40 kg and I can lift that if really needed.
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Post by svart on Nov 12, 2019 11:51:09 GMT -6
Nice project. I had something similar in mind, but decided to leave my desk as is. It was sold to me as "needing lots of TLC", so I counted on modding in stead of repairing. Turned out the only TLC needed was the removal of some layers of sticky tape. Doing what you're doing would probably take me decades... :-) When I bought it, I had a look at an Alesis X2 too. Nice desk. Rare in these parts. Decided not to buy that one because of weight. Price and condition were very similar, but I can't lift an Alesis X2 on my own. The DDA is just under 40 kg and I can lift that if really needed. The first X2 I got, I removed all the channels from it so I could lift the chassis. Without the channels it was only maybe 70lbs. |
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Post by cyrano on Nov 13, 2019 7:09:47 GMT -6
It's a bigger desk, for sure. But I wouldn't call 70 lbs "portable"...
My DDA travels in it's flight-case. The last time I used it live, I needed to move it a bit after setting up. That's possible, even with all cables attached and even doing it alone. With an X2, I wouldn't be able to do that, I presume. I would have needed a few roadies. And usually, these are not around when I'm setting up.
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Post by svart on Nov 13, 2019 8:21:54 GMT -6
It's a bigger desk, for sure. But I wouldn't call 70 lbs "portable"... My DDA travels in it's flight-case. The last time I used it live, I needed to move it a bit after setting up. That's possible, even with all cables attached and even doing it alone. With an X2, I wouldn't be able to do that, I presume. I would have needed a few roadies. And usually, these are not around when I'm setting up. Ah I see, you wanted a portable mixer, not just one you could move if you needed to. Yeah it's too big for moving around on a regular basis. |
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Post by svart on Nov 14, 2019 15:15:51 GMT -6
So here's the printing for the front of the channel strip. I'll remove the layer that shows the buttons and knobs so it'll just be some lines and text when I have a silkscreen made.  |
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