mypasswordis

Job interview tomorrow for me, currently studying up in preparation.

I hope someday you'll get past your gear OCPD.

But they advocate fire safety through stop, drop, and roll. Minus the stopping, plus shooting randomly.

http://www.youtube.com/watch?v=1pD53MfS7SQ&feature=youtu.be fucking video tags, how do they work

Do your research and learn some spelling and grammar before your next inane tirade, it'll help you seem less idiotic.

F1 with K1000 is not gm amp, it's just a poor voltage amplifier. F2 also isn't, and the others most definitely aren't.

I think Beyers just suck because they suck. I also think if headphone manufacturers used more science and less voodoo to design their headphones, there wouldn't have to be crazy amp designs suited for a particular esoteric driver or type of speaker that sound like crap on the majority of amplifiers. But I guess some people find that fun. Was going to type out a long response but Firefox decided to go nuts on me so I had to restart. Basically I can see where Doug and others are coming from. From the viewpoint of a (former?) orthodynamic enthusiast, in which there needs to be a lot of damping involved, electrical damping is much preferred to acoustic damping. Less issues to deal with, and less fiddling around with felt and vents and whatnot. Granted, there still usually needs to be some form of acoustic damping, but less is better. I wouldn't say the impedance of the HD800 is that linear, but it is better than crossovers which then can have phase issues, etc.

Meet impressions other than aforementioned issue: Listening between the SR-007 Mk1 and the SR-009, I'm pretty sure I prefer the SR-Omega to both. Would of course have to have all three side by side to make a conclusive opinion. BHSE still sounds good. K1000 still sounds good. Pico Power can drive K1000. That's all I listened to, too much talking not enough listening done.

Yeah I figured the channels weren't swapped after you played the left right channel test clip. Glad you figured it out in the end.

Output impedance and impedance matching is a lot more complicated than that. Decreasing output impedance usually increases the bass, but it may also increase other higher frequencies and make the frequency response very uneven, depending on both the impedance of the amp and of the headphone (they both vary with frequency). Damping factor is a measure of how well the headphone load is electrically damped by the amp, as opposed to mechanically damped through physical construction of the drivers and surrounding parts. Drastically decreasing damping will be especially apparent at the natural frequency of the driver, which is usually somewhere in the bass. Would be interesting to make some CSD plots at different output impedances. 170kohms/5.3k is still 32+ damping factor, and it's mainly a reactive load anyway. Of course, you could try going in the opposite direction and make a transconductance amplifier like the F1 except with much higher output impedance for headphones. Also the HD800 is a mediocre headphone IMO, the K1000 is much better if you want a dynamic.

I'm about to receive the Raspberry Pi I ordered. First OS I'll try is of course Raspbian, and learn Python while I'm at it. Seems GPIO is limited, there are only 8 pins and only one of them can support hardware PWM. Will probably end up using my other ARM development board for hardware prototyping and control, but definitely interested to see what the large and enthusiastic RPi community comes up with in the meanwhile.

2SK389 I mean.

Sounds fun, it would have been nice to take a class like that but I'm learning everything on the spot, from construction to operation of the machinery, motor and motor drives, open source CNC software, and even started reading up on writing and modifying OSes. Specifically RTOSes for microcontrollers, I'm somewhat comfortable writing basic round robin/simple state machine type stuff in C and assembly for microprocessors but OSes are on another level. Context switching, semaphores, HAL, drivers, the works. I'm even learning legal stuff, pertaining to formation of a company, liability, contracts, etc. Found a 5HP single phase motor that might just be in need of a new start cap, that I might be able to swap in to the machine.

Hah, knew I should've checked diyaudio first, didn't see anything about it on his site. I'll email/message PD about if he has any J-X boards left when I get the time, thanks. Can never get away from those JFETs. Noticed there's a bunch of 2SK170/2SJ109 pairs on ebay, I wonder if they're fake.

Yup it's for the 'stats. Something tells me I don't want to try tackling a 5000Vpp direct coupled 'stat amp project just yet. Cool, I'll look into it. Might just wait until the F6 design is released, for yet another option to choose from.

Thanks Al, much appreciated. I hope I'm not biting off more than I can chew, also currently trying to apply to some actual engineering jobs in various places across the nation, based on the loactions of teachers I want to study with.

I might be there for the last two hours. Don't really have anything to bring, though.

Didn't see a thread topic relegated specifically to automated machinery specifically so I thought I'd make one. I'm working with another person in starting up a company that offers consulting services to optimize parts and layout production efficiencies, which includes a machine shop of our own. We're starting with conventional subtractive machining, but are looking to expand later with plasma/lasers, casting, plating, PCB layout and fabrication, etc. Currently we have a (cam operated) B&S screw machine with an old Bridgeport CNC coming in soon. We'll be looking to retrofit them both with open source CNC software and the proper motor drive modules pretty soon. Currently we'll be operating the screw machine for our first client as-is, machining/buying the necessary cams and tooling as needed. As most of the heavy duty machinery runs on three phase power and we're starting off our business in our garage, ie on residential power, the options as we see it are to swap out the motors for single phase, or buy a VFD/inverter, or have PEPCO install three phase, probably with a separate meter. We'll move to renting out an industrial space later on but money doesn't grow on trees. Thoughts? Also any info on good places that sell cams and tooling would be great. We pretty much have what we need already but it wouldn't hurt to expand or replace.

Necro bump, is the Rigol DS1102E still the best entry level DSO to buy? I looked into some of the other Chinese OEM stuff but they're not as well documented or supported, it seems, and some people had issues with glitches. Currently using Tektronix 455.

Anyone here try building or upgrading to F5 Turbo V2 or V3?

I think I'm more of a hookers and blow kind of guy, but it could be a fun warm-up.

I'm trying to make it, will find out by September.

Drinking is fun.

It's usually more trouble than it's worth. Better to find a good hobby, or better yet, a sense of purpose in your life. Actually, those two things aren't mutually exclusive.

Nice one John And glad to hear of your recovery.