24 channel mixer the "Stereotype"

[hakanai]

so I made a quick audio file using pink noise and flipping through the pan. I think most people would want a 9 position, adding a wider option before hard pan. This works for me, but here is a reference to see what my values result in.

http://hakanairecording.com/mixerpics/Output%201-2.mp3

 

[hakanai]

So I had my first 'from scratch' mix session with this thing, and I am very happy. The bottom sounds great and it just bring a little life to the mix. I't nice to be OTB again, I have always enjoyed the workflow more.

Just a quick update. I'll keep you posted on the PCB's

Don

 

[baadc0de]

Always good to hear that it sounds better

 

[stitch-o]

lookin good!

 

[0dbfs]

Yeah, this is sweet and it's really moving my electrons just watching!

 

[hakanai]

just got an email from the PCB fab. boards should be to me either friday or monday. Just an update


don

 

[rrs]

I've been looking at building 16 channel active mixer incorporating the Jeff's boards so an extremely interested in this.
Just wondering the cost of a 16 channel version??

 

[baadc0de]

I've been looking at building 16 channel active mixer incorporating the Jeff's boards so an extremely interested in this.
Just wondering the cost of a 16 channel version??

I guess 110$ for main PCBs and 170$ if you want pan PCBs as well. Plus the DOAs, grayhill switches...

 

[hakanai]

So the boards Just got here! I have a few parts coming from digi/mouser to confirm the fit is fine. Once I have that sorted out I will send an email around to everyone who contacted me. Anyone else interested let me know, as I ordered a few spare boards. I attached a pic from my phone but I need to bring the good camera into the studio tomorrow.


As for cost, doing a 16 channel version could be pretty reasonable. The two big things you can do to save yourself money are use toggles for LCR panning instead of Grayhills, and solder your own DOA's. When I ordered my GAR's from Jeff I got them at $13 (or something like that) a pop because of the quantity I ordered. It is an investment in time however. Once I did a few I could get one 2520 done in just under an hour. So at my fastest, I spent 24 hours soldering my DOA's, it was probably more like 28 though. One thing for the cost conscious is to remember that you don't have to do everything one way. Meaning 8 grayhills and 8 LCR toggle's would be pretty damn good for most applications. 24 pans are nice though.

don

 

[baadc0de]

Congratulations!

That looks b'dass it will be nice to see them in person.

 

[hakanai]

boards are in, and ready to ship. Shipping is a little spendy based on current quotes but I'll try to get that down if possible.

thanks
don

 

[indigom]

Very nice Don!  I sent an e-mail to you asking if you still have a few of the 8-channel PCBs.    I'm going to may hard wire the LCR per channel, so I don't see using the pan PCBs yet.    If you were to design a PCB to take a two-deck Grayhill though, I'd buy some of those for stereo output attenuators.

Cheers~
J

 

[hakanai]

Hey all, I am out of town until next week so while I have tried to answer all email/pm's if I missed yours I will get to it when I am back in the office. Thanks

Oh and just quickly on the stereo attenuators front. The pan board can be used for this. I designed the boards to accompdate the grahill 2pole 6position switch which would work in this capacity. You will only have 6positions but that may be fine for an attenuator. If you look at the photo in last post you will see holes labelled "B". That is for the 2nd pole. You just use what would be the holes for pins 6 and 7 as the ends of the two poles (that's the pair labelled 67 right near the other wire holes).

Don

 

[indigom]

Got it, thanks.  Sorry I didn't notice the 2 pole action going on there in the photo.

Hey all, I am out of town until next week so while I have tried to answer all email/pm's if I missed yours I will get to it when I am back in the office. Thanks

Oh and just quickly on the stereo attenuators front. The pan board can be used for this. I designed the boards to accompdate the grahill 2pole 6position switch which would work in this capacity. You will only have 6positions but that may be fine for an attenuator. If you look at the photo in last post you will see holes labelled "B". That is for the 2nd pole. You just use what would be the holes for pins 6 and 7 as the ends of the two poles (that's the pair labelled 67 right near the other wire holes).

Don

 

[hakanai]

Quick update. I'm hung up out of town a few days longer than I expected so all boards will ship and questions answered either Wednesday or Thursday of this week (instead of today).

Don

 

[hakanai]

Back in town and a bunch of boards shipped. I am going to get an email with the BOM out to everyone soon, but for now here it is. The only thing missing is the diode part#. I think it was a ina4004 but need to confirm.

don

 

[funkmuffin]

Don -- Quick question on the BOM.

For C2, C5, C6, you show the quantity of 18 -- looking over the boards, I only see 10 total in those positions - 1 each channel, and one each V+/-. 

Thanks!

 

[hakanai]

AHH! good catch. That is meant to be 10. I updated the file. thanks. I kind of rushed it out so people would have the part numbers I designed for, sorry for the mistake.

don

 

[hakanai]

Ok, so all the main boards are sold and I have a couple sets of switchboards left. Here are the final details for the boards:

the diodes I used were these:
http://www.mouser.com/ProductDetail/Fairchild-Semiconductor/1N4004/?qs=sGAEpiMZZMtEwUVCuofpuI3LdHjUmCjoTdyfWZhQ5ME%3d

the board mounting holes are setup for an easy fit with 4-40 hardware. I used these:
http://search.digikey.com/scripts/DkSearch/dksus.dll?vendor=0&keywords=1450bk-nd

Also some instructions. If you don't want to use the dc blocking caps (not used in my version) simply jump the holes with a resistor leg. If the trim resistor R9 is not to be used, then jump the two holes with the white line between them. Other than that I think everything is exactly as it seems. It's a pretty simple circuit and I tried to keep things clear with the labeling.

oh yeah the diodes are labeled to go ring to ring, meaning the cathode goes to the hole that is circled.

Hopefully no one minded my company slogan in the ground plane! Did anyone notice? There are three little extras there. My logo, the revision number and the slogan.

I have also attached both the updated BOM and the schematic in one zip file for easy download here:
http://hakanairecording.com/mixerpics/STE2docs.zip

don

 

[hakanai]

As for the switch boards. There is a link earlier in the thread to the switches that will work, but essentially it's a Grayhill series 71 single deck switch with either 1 pole/10 or 12 stops OR a 2 pole/5 or 6 stop switch. the resistors I designed for were Vishay CMF55's but I oversized the holes so if you can fit the parts on the board the holes should be adequate. If a 10 position switch is used then simply jump the unused resistor positions (a 10 position would not use 12 or W). As for labeling, it was tight but I tried to make it clear. The resistors are labeled as such: 12 = the resistor between positions 1 and 2 that system continues until you get to the last three, then it's 90 = 9/10, 01 = 10/11, and W = 11/12 (Why "W"? I have no clue). The positions for 6 and 7 are located right next to the flying lead holes for 1 and 12. This makes it easy for a 2 pole switch. 6 becomes the last stop for pole 1. 7 and 12 become positions 1 and 6, respectively, for pole 2.

I think that's it