rocketscientist, are you going to release the maxxed desktop version anytime soon?
Define "soon"?
I really don't know. I think I said "this fall" and I still hope to achieve that. Right now I'm still spending time on the O2.Speaking of the O2, the proto PCBs are "out for delivery" and I'm expecting them today if all goes well. I'll be building one up ASAP once they arrive.
No thanks!
But one other semi-related suggestion. If you happen to use adjustable regulators on the desktop version (LM317/337 etc) an idea would be to bring a rail voltage adjust pot out the front panel. The control could be labeled something like "600 ohm" for 16V or whatever your favorite high(er) voltage is, "80 ohm - 250ohm" for the 12V and "16 ohm" for 6V or so.
On the upper end that would provide more voltage for 600 ohm cans, however nutty the idea may be, and on the low end provide even more protection for low impedance cans.
That's an interesting idea. Are the adjust voltages/currents symmetrical between the 317 and 337? A switch might be a better solution. There's still the chance for "operator error", however using the high rails with say AKG K701s or planars and the O2 might die.
I know there are several headphone amps that use a DC-DC converter that can run at 2 or more rail voltages. It's pretty cool idea to help further adapt the amp to your headphones (especially where battery life is an issue).
It might be worth doing a "Group Buy interest check" to see what level of interest there is.
I myself would be in for at least 25 of the "portable" front panels.
I'm also wondering how many of the builders are going to do the "desktop" style case, which would require both front and back panels, with RCA's added to the existing "front" panel, but without the volume control(which would go to the back), and a simpler new desktop front panel with the volume control, 1/4 jack, LED power light(that's what I'm planning anyway), and a logo.. If we get enough interest in those as well, it would save everyone some money (and I would need about 19 sets of them..)..
We could discuss the finer details of the logos, etc, until the alignment issues have been resolved. Hopefully in the meantime, we'll get critical mass on the GB interest list that will save everyone some serious money
JD
I have the boards and I'm building one up now. So far I can report the pots, both the 15mm and 20mm shaft Alps and 15mm and 20mm "star" (T16) shaft Bourns work exactly as designed with the desired clearance between the knob and front panel.
Two different FPE front panels have been confirmed to fit. But the 3.5mm jacks don't quite live up to their drawing by a tiny fraction of a millimeter. It seems the 3.5mm jack openings need to be a tiny bit higher on the panel.
I'll let everyone know once I get the board done if I encounter any fit or performance problems after testing it on the dScope analyzer.
I'll also report back on modifying the battery terminal footprint to accommodate the Keystone as well as the existing Eagle parts.
Two different FPE front panels have been confirmed to fit. But the 3.5mm jacks don't quite live up to their drawing by a tiny fraction of a millimeter. It seems the 3.5mm jack openings need to be a tiny bit higher on the panel.
I'll let everyone know once I get the board done if I encounter any fit or performance problems after testing it on the dScope analyzer.
I'll also report back on modifying the battery terminal footprint to accommodate the Keystone as well as the existing Eagle parts.
As reported in post 697 in the group buy thread, the new PCB works great. I'm still researching the panel fit. I think the existing file is very close to correct and the jack issue might be related to the jacks not being fully seated in the PCB. It's also possible all the panel openings (except the screw holes) need to move up a few thousands of an inch.
Define "soon"?
Speaking of the O2, the proto PCBs are "out for delivery" and I'm expecting them today if all goes well. I'll be building one up ASAP once they arrive.
1 month starting from today, perhaps?
Define "soon"?
Speaking of the O2, the proto PCBs are "out for delivery" and I'm expecting them today if all goes well. I'll be building one up ASAP once they arrive.
Just say "Friday" ..
Something interesting about the Eagle Plastics Devices battery connectors. EPD appears to be a registered trademark of Mouser:
EAGLE PLASTIC DEVICES Trademark Details
Probably made under contract by some plastics company. So they are Mouser's baby.
EAGLE PLASTIC DEVICES Trademark Details
Probably made under contract by some plastics company. So they are Mouser's baby.
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@agdr, you're correct. Mouser has several "house brands" as do some of the other big distributors (i.e. Multicomp at Farnell/Newark, etc.). Other companies have exclusive relationships with distributors like CUI and DigiKey which creates essentially the same single-source situation.
I've modified the board so hopefully both the Eagle and Keystone battery terminals will now work. I'm just double checking everything but the new files should be available today.
I've modified the board so hopefully both the Eagle and Keystone battery terminals will now work. I'm just double checking everything but the new files should be available today.
That's great since Keystone happens to be a real company that sells to multiple vendors.
For those in countries with 220 - 240 VAC line voltage please see post 712 in the PCB Group Buy thread. It appears 12 VAC transformers won't work. I'm revising the BOM and have already revised the O2 Details article.
The final PCB files, an updated documentation PDF and revised spreadsheet (BOM/partslist) have been posted under O2 Resources! And yes, STM, the 3.5mm jack footprints were slightly revised to help the jacks seat easier.
The final PCB files, an updated documentation PDF, and a revised spreadsheet (BOM/partslist) have been posted under O2 Resources!
That's great news! The parts are sitting on my work table waiting for the PCB!
Something interesting about the Eagle Plastics Devices battery connectors. EPD appears to be a registered trademark of Mouser:
EAGLE PLASTIC DEVICES Trademark Details
Probably made under contract by some plastics company. So they are Mouser's baby.
Actually the trademark was abandoned in 2009.
se