Part Sourcing Assistance/Advice Thread

[johnwmclean]

Looking for a name/supplier for these connecting metal joiners?

[luvdunhill]

I just make them myself. The usual suspects won't do them because the piece has to be turned to a 90 degree side. There is a special countersink bit for socket head screws that makes it pretty easy.

[Kerry]

I user them all the time. They are called counter bores.

I made these.

[kh90123]

Could anyone recommend a source for TDK 4CP-601 quad pot? Or Alpha quad pots?

Or any other good quad pots recommendation? I only know that Justin carries the RK50, the last time I asked him.

[Pars]

18 hours ago, luvdunhill said:

Ok, ordered. Interestingly, I ran it through OSH Park to see if they would kick anything back, and their board rendering showed the increased pin mask swell on the top as exposed copper, even though under the solder mask swell on the top there isn't any copper. That's odd.

I ended up ordering from PCB Way, as I got better lead-time and 2 more boards. Chose immersion gold, next step up in board thickness and 2 oz copper, and blue - the last three options best OSH. The FR4 spec that OSH uses was considerably more, not sure the what the Tg difference really entails. Shouldn't matter for my use.

I was tempted to have them delivered to me in China, but didn't want to risk mail routing issues.

I couldn't use Elecrow or Seeed because I exceed their width for their prototype (my boards are 12.5" wide) options. I still will use Elecrow for assembly though and maybe for another daughter board I need to whip up next.

Cool. Interesting to see how this turns out, though I'm not sure I ever knew why you needed or wanted these done this way.

[luvdunhill]

The right way to mount a TO-3 package is with a shoulder washer on the bottom and then using a ring connector to attach the case to the circuit. I am trying to do it another way. It will make more sense when I post some pictures

[johnwmclean]

Thanks Mark and Kerry, those custom pieces look terrific!

[luvdunhill]

Placed an order for a board with Elecrow (used PCB Way for a mating design) that looks something like this. The two odd sets of connectors on the far left are board-to-board connectors that I'm trying out from Mill-Max

 

[UFN]

Looks great - what is it?

 

//UFN

[luvdunhill]

It's a front end. BJT cascoded JFETs with MOSFET voltage gain. The relay is for switchable feedback loop.

[luvdunhill]

The right way to mount a TO-3 package is with a shoulder washer on the bottom and then using a ring connector to attach the case to the circuit. I am trying to do it another way. It will make more sense when I post some pictures [emoji4]

Ok, so strange. They interpreted the swell as negative board "cladding" (whatever the term is)? Anyways, it will work fine, but didn't expect the large non-blue areas around the TO-3 pins on the top layer. Next need the gage jack parts from Mouser for my next demonstration.

[Kerry]

Looking good Marc!

I owe you some part numbers.  I'll get those out to you tonight.

[luvdunhill]

Received and ordered!

[luvdunhill]

These look mighty cute

[luvdunhill]

Cool. Interesting to see how this turns out, though I'm not sure I ever knew why you needed or wanted these done this way.

Or,

Where the entire pin is in the bottom of the board, it's slightly press fit due to a small flange visible in the first picture

For the later example, it would have been nice to have a solder pad on the bottom, but kept the top as close to min annular ring so that we don't introduce a larger gap around the pin, which hurts thermal performance.

[Kerry]

I'm looking for some options for a good encoder to use with the digital attenuator.

Thanks

PS. Very nice looking Marc

[kh90123]

I missed the GB for the KGSSHV carbon boards, does anyone has spare amp boards to spare? 

[brazilnut79]

Suddenly I'm yearning of a speaker stand. Adjustable, and some marble, quartzite, or granite goes on top of a welded steel plate...  Crank needs to be kind of wide-base, much like this.

Don't know if anybody else is quietly itching to death for something like this...

In case I was unclear I intend to remove any tabletop should one already come with the crank-shaft, and-dubbed "Über-weld" a muscular 3/8 or 1/4 steel plate (no commercial TIG-station setup, so I will convert uberamp for appropriate duty) that ~21' or therabout tile or stone will bond with or rest-on, so it's adjustable at command, even to different speakers or room layout. Yet all coupled fairly well, not to mention (largely, rather) stable, with the floor! 

  Secondly, does anyone know if there's play [any oft-looseness] in such a crank-stand shaft idea wherein weight is on the stand? Say 150lbs? TICE advice? 

[Tinkerer]

I have a general potentiometer question. Anybody ever use one of the giant old milspec helipot potentiometers for volume control? I found a 20k quad for fifty bucks that I figured was worth a shot. The tolerances are good on paper but it's massive, like bigger than an RK50 quad massive.

 

EDIT: I got this in today for anyone who needs a laugh at the size of it. Turns out it was 5 gang but I only needed the 4 20k and not the single 30k.

 

 

So good and bad.

Good: Pulled out my multimeter and gave it a once over. 5% tolerance on each gang is actually within 2% at max resistance and each gang is within 2% of each other at almost every point. Still tracks exceedingly well.

Bad: sin/cos 360 pot so you only get a fraction of the manual adjustment for volume and would have to mark the volume indicators carefully. Old pot so old pot problems are likely.

Still really impressed all things considered. For fifty bucks it was worth a gamble. I'll try hooking it up to my kgsshv at some point and get a listen.

 

 

Edited February 27, 2016 by Tinkerer

[luvdunhill]

any suggestions on how to order copper bars and have them actually arrive? first order, got 1 of 2 (nice of UPS to patch the box) and second order both bars were missing.

 

 

[UFN]

Not sure if that was a rhetorical question, but if not: Ask the seller not to put them in a box so they rattle around. Tape them together and then just cover with a (thick) outer layer of bubblewrap and cardboard/paper/duct tape.

 

//UFN

[gepardcv]

I'm looking for a volume knob that would work with an RK50 on my Carbon build, with the pot mounted on the front of the case. A 48 or 50mm diameter knob, 25 or 30mm deep with an 8mm shaft would work well, in plain black anodized aluminum with an indicator dimple. Does anyone have a good source (or have some available)?

[Laowei]

http://m.ebay.com/itm/221765958085

You can drill to fit the 8mm shaft. 

 

[Pars]

http://www.vt4c.com/shop/program/main.php?cat_id=6&group_id=2

http://www.thlaudio.com/indexE.htm

Usually have some nice offerings. And yes, you are most likely going to need to drill to 8mm, and possibly retap the setscrew hole.

Edited March 7, 2016 by Pars

[johnwmclean]

http://www.viljomarrandi.com/gallery/

Vilts will make any custom knob to your liking.