Headphone half-kit

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PatOMalley

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Re: Headphone half-kit
« Reply #20 on: 16 Jul 2007, 12:32 am »
Narrow and deep.

No more sodas on that table!!!

hagtech

Re: Headphone half-kit
« Reply #21 on: 16 Jul 2007, 03:35 am »
Which of these two styles do you prefer?



or



jh

IronLion

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Re: Headphone half-kit
« Reply #22 on: 16 Jul 2007, 03:36 am »
Top by far; the black parts on the bottom one look tacky to me. 

dnewman

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Re: Headphone half-kit
« Reply #23 on: 16 Jul 2007, 04:22 am »
Top

WGH

Re: Headphone half-kit
« Reply #24 on: 16 Jul 2007, 05:57 am »
The top, but...
why not a Lansing case a wee smaller than the Cornet2, narrow and long? Keeping the case design similar through your product line would define the Hagtech look. Kit builders can substitute their own case designs if they like.

flatmap

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Re: Headphone half-kit
« Reply #25 on: 16 Jul 2007, 06:07 am »
Top style is the better of the two.  What lights my fire is the idea of having something, pretty compact, that I can use at work playing music from my computer.  There aren't so many products out there that combine USB->DAC->volume-control-Amp, but that's exactly what I'd want for the office.  I don't want to have to lug a bunch of boxes around or commit a lot of desk space.  Something where I could come in, flip on the computer, get the headphone amp and headphones out of the locked drawer, turn on iTunes and start to work. 

Having this as a halfkit would be terrific.

PatOMalley

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Re: Headphone half-kit
« Reply #26 on: 16 Jul 2007, 05:28 pm »
Top. I know that takes us to a wider front or so it looks.

I vote top.

Much cleaner style. More sell-able.

Will the kit come with an option for a drilled chassis? That is a big draw.

Sidebar: You should get some more pre-drilled chassis for the cornet and sell it at the higher price. People are willing to pay for the convenience of having that pre-drilled chassis.
« Last Edit: 16 Jul 2007, 10:27 pm by PatOMalley »

hagtech

Re: Headphone half-kit
« Reply #27 on: 16 Jul 2007, 05:46 pm »
Top is the clear winner today.  Don't know what they were thinking when they made that bottom bezel.  The bottom extrusion is really nice though, with card guides in the perfect spot.  Mechanically, it is near ideal.  But maybe all for naught, as perhaps neither comes large enough to fit all of the parts.  As you said, third option is to use the Lansing, which is much more expensive.  I'll keep looking.

jh

Jade East

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Re: Headphone half-kit
« Reply #28 on: 16 Jul 2007, 09:57 pm »
Great idea for a new product. :drool:

Jon L

Re: Headphone half-kit
« Reply #29 on: 16 Jul 2007, 10:26 pm »
I'm wondering if just having one of those RCA-to-2.5mm cables will work for the iPod.  Use the headphone output jack?  Or maybe they make a cable that connects to the line outs on bottom?  That would be better.  Trying to DIY a clean and professional looking dock by hand might be asking a bit much.  Or does somebody sell such a thing?  A panel mount dock?

jh

For iPod users, there are many commercially available line-out adapters. 

Sik Ram Din is cheap and good-sounding:
http://www.sik.com/ram_din.php

If you want to go all-out, ALO makes some nice adapters:
http://www.aloaudio.com/Cryo%20X%20Silver/cryoxsilver.html

Jim, most of us hard-core headphone guys over at Head-Fi want awesome sound quality first and foremost.  Most of us do NOT use iPods for serious home headphone listening, so unless you are designing a portable amp to be used with iPods, I would market a home amp with real RCA input jacks and 1/4" headphone output jack. 

And we would rather the $ be spent on parts for ultimate sound quality, not things like built in USB-input and/or DAC.  We already have nice sources, and we want our headphone amps to be Class-A, discrete (no op-amps) tube or SS designs.

It's very difficult to optimize one amp to be great with both low-impedance 'phones (like 32 Ohm Grado's) and high-impedance 'phones (say 600 Ohms of Senn or old AKG), so perhaps you can choose one camp, or build 2 versions  :green:

PatOMalley

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Re: Headphone half-kit
« Reply #30 on: 16 Jul 2007, 10:38 pm »
from the blog:

"One power switch, one volume control.  Two headphone output jacks, so the power signal does not have to pass through a
switch.  Really, the jack costs the same as a switch, so may as well just have two jacks.  One for low impedance, one for high, different taps from the tranny.  Or maybe I'll have two power switches, so I can dispense with the B+ delay?"


following this closely and it's fun to see this developed. Where will the power switch be? In the back? Becuase if it's in the back and there's two then it may be an issue. Rather a 3 position toggle for power with center = off.


slwiser

Re: Headphone half-kit
« Reply #31 on: 16 Jul 2007, 11:30 pm »
How hot would this one run?

hagtech

Re: Headphone half-kit
« Reply #32 on: 16 Jul 2007, 11:37 pm »
I have yet to come up with anything reasonable for the B+ delay.  Could be normal relay circuit, maybe photo-MOS, maybe reed relay.  This will change how power switch is implemented.  For this machine I think one switch on front is best, at least from a consumer's standpoint. 

So I did a mechanical fit check, the trannys are pretty hefty, so I have to go with the biggest chassis in that lineup, or about 9x9x3.  That's still pretty compact for what we are fitting inside.  I worked out an internal configuration where circuit board has parts on both sides.  It's the only way to make things fit.  Tube socket and iron on top, everything else on bottom.  I can take advantage of ground plane to then implement self-shielding from power supply and other interference.  With 2" tall trannys, the board slides into the bottom groove on the chassis extrusions.  No standoffs or drilling needed.  One big hole drilled into top, and then the normal holes and cutouts on front/rear panels.    Here's pretty much what it could look like, with enough of the tube sticking out top for easy removal.



jh

hagtech

Re: Headphone half-kit
« Reply #33 on: 16 Jul 2007, 11:42 pm »
Quote
How hot would this one run?

It's only 10W total dissipation.  Most of that in the tube.  It will be hot, of course.  The box will warm as most of the radiation from tube is captured inside.  Top cover will end up conducting most of that 10W into the environs.  Knobs and jacks will remain cool.  For comparison a CORNET is 30W.

jh

slwiser

Re: Headphone half-kit
« Reply #34 on: 17 Jul 2007, 12:04 am »
10 watts is not bad at all...so it would not be to hot at all.

hagtech

Re: Headphone half-kit
« Reply #35 on: 17 Jul 2007, 12:14 am »
Prices can add up quickly.  Chassis have always been difficult for use in half-kits.  They need to be in stock, purchasable in quantities of one, and customizable.  DigiKey does not have much for choice.  This one is from Mouser, at $61.  Not bad.  It comes already painted and is very machinable.

So I looked at the option of frontpanelexpress, for those who like a professionally cut finish.  The panel below comes out at $33.  Rear panel would be about the same.  That's $130 for an almost finished chassis (you still have to drill the 1.125" hole in top cover).  Kinda pricey. 



But hey, that's still under $400 total out of pocket for raw parts.  Probably $300 if you drill the chassis.  Bring Your Own Solder.

jh

PatOMalley

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Re: Headphone half-kit
« Reply #36 on: 17 Jul 2007, 03:03 pm »
That looks likes a good way to budget the chassis in; costly but can be done in stages.(budget consumer consideration) I can give a shot at drilling the chassis myself and if it fails, punt.




anumber1

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Wooo HOO!
« Reply #37 on: 18 Jul 2007, 01:50 pm »
I am drooling over this whole concept!

I need a decent headphone amp and have both Grado cans and Senn 580s!

Thanks Jim!

dnewman

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Re: Headphone half-kit
« Reply #38 on: 19 Jul 2007, 09:23 pm »
So I looked at the option of frontpanelexpress, for those who like a professionally cut finish.  The panel below comes out at $33.  Rear panel would be about the same.  That's $130 for an almost finished chassis (you still have to drill the 1.125" hole in top cover).  Kinda pricey.

Jim, should you "productize" this as a 1/2-kit, please also consider making the Front Panel
Express files for the panels available online.  Saves us some work and allows us to order
them in our favorite designer colors (and 5mm thick as we all know that sounds better than
4.5mm thick ;-).

As an aside, I too like 1/4" head phone jacks but I have a love-hate relationship with
the locking ones.  Some of them lock really well and are a great way to accidentally
pull the unit off of a shelf, dangling it from your head phones (e.g., Neutrik).  Just another
reason to have online any FPE files: to accommodate our tastes in the hardware.

Regards,
Dan