[tcristy]

Finished moving it over. I like this much more than the plastic Pactec case I was using before. Although it is a little wider and longer, the thinness (0.75") makes it more pocketable.

The complete amp (with quarter for scale):

Full res pic

Innards:

full res pic

Before someone points out that the input caps are overkill, let me explain. The long but small diameter shape of these make them the only 1 µf metallized polypropylene cap I could find that would fit in this slim case. I'm too paranoid about my $350 headphones to skip the input cap, and they are not that expensive ($7).

Tim

 

[till]

Looks good

Where did you get those black-rimmed jacks?

 

[tcristy]

They are the Kubicon jacks available at Mouser.

 

[walangalam]

its it the part # 161-7300 ?

 

[tcristy]

Yup.

 

[aeriyn]

Where'd you order that case? I like it better than the smallest Hammond case...

Are those kubicon jacks isolated?

Oh, and how long did you get the case... 3 inch or 4 inch?

 

[PeterR]

Beautiful, nice job. Looks like you did the PCB yourself?
What opamp is that and what phones do you use it with?

 

[Syzygies]

Quote:

Originally Posted by aeriyn Where'd you order that case?

Lansing Enclosures

(For anyone using search on this forum, don't overlook the "Show Results as Posts" option.)

 

[jerb]

awsome it looks really nice in that case, nice alternative to a hammond.

 

[Syzygies]

This also looks like a great case for MINT amps, with room to play, e.g. with charging circuits. No cutting the board or contortionist acts required, someone who figured out the drill could churn these out:

I think that various 9V batteries will fit fine, reports elsewhere to the contrary notwithstanding.

So when we buy a 5" case, is there 5" of usable space inside? I couldn't decipher their site on this.

 

[tcristy]

The jacks are isolated (the entire exterior is plastic).

Yes, I made the boards myself. The case I used is the 4 x 2.75 x 0.75 version. If I were to omit the input caps, I could get it in the 3" version.

The opamp is the LMH6622, a low voltage (+-2.25V to +-6V) design capable of putting out quite a bit of current into low-impedance loads (rated at 90mA into a 100 ohm load with a +-6V supply). I use low-impedance, high sensitivity canalphones (Westone UM-2), so current is more important to me than high voltage.

I run it on a single Powerex 9.6V 170mAH NiMH battery.

The standard 9V batteries I tried were just barely too thick to fit. You could force one in, but it would be hard to get back out again. The rechargable one I'm using fits ok with the labels removed.

The length of the case listed is the tube without the endcaps, so it is all usable. The endcaps you chose add to the length. Interior height measured by my digital calipers is 0.635" and the interior width at the narrowest point (between the screw rails) is 2.285".

Tim

 

[Syzygies]

Quote:

Originally Posted by tcristy The standard 9V batteries I tried were just barely too thick to fit.... Interior height measured by my digital calipers is 0.635".

Interesting, I tracked down a datasheet rumored to be the actual manufacturer of my Ray-O-Vac NiMH 9V batteries, and they specified a range of 15.5 to 17.5 mm. This could actually be a standards specification, I don't know. 0.635" = 16.19mm, and my particular Ray-O-Vac batteries are under this. This could be serious "your mileage may vary" territory, too bad if it is. The case looks worth the trouble to me...

 

[n_maher]

First off, nice job tcristy!

Second, Syz why would you bother going chancing the height of the case when it's basically the same outer dimensions as the Hammond J12 (the lenght could be cut 3/4" to match). It has plenty of height for any 9v battery and has enough width (3") to get them comfortably in side by side. If you want a cleaner looking case just take the bezels off the Hammond.

Just a though.

Nate

 

[Syzygies]

The outer cross-sectional area of the Lansing DN1 is 63% of that of the Hammond J12, by my calculations. Anyone using a J12 case should put a PIMETA in it.

What drives me crazy about the Hammond C12 is that two 9V just miss side-by-side, and fixing this requires contortionist tricks with the MINT board, or grinding aluminum, rather than just cutting off a battery label.

iPower NiMH 9V batteries, e.g. the iPower 9V 250 mAh sold by Thomas Distributing, have a nominal thickness of only 16.5 mm, as opposed to the most frequently seen 17.5 mm. With two, I'm more concerned about mAh than volts, one could hope that removing the label does the trick here.

 

[n_maher]

Quote:

Originally Posted by Syzygies The outer cross-sectional area of the Lansing DN1 is 63% of that of the Hammond J12, by my calculations. Anyone using a J12 case should put a PIMETA in it.

Hey, it just seems to me that you've been driving yourself nuts in the search the perfect case over the past couple of months so I figured I'd just throw it out there. As far as putting a PIMETA in there goes, doesn't make any sense to me to build a stripped down PIMETA with the panny pot just so I can shoehorn it into a small case. But that's just me. I think the MINTs that I've built in J12's have come out quite nicely and don't take a degree in engineering (even though I've got one) to figure out how to put together. Could they be smaller, yup, do they need to be, not for the people I've built them for.

I don't know what your endgame is with finding the smallest, mass-produced case that can be used for a MINT but you've spent so much time drawing scenarios that you don't end up building that I'm tempted to take up drinking

.

Nate