Piccolo build update, and a question.

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JimK

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Piccolo build update, and a question.
« on: 1 Jan 2010, 04:25 pm »
I spent a few hours on my Piccolo build last night, and......well.....here's where I'm at right now:



Although it doesn't look like it, all of the resistor are in place with the exception of R5R/L (I used-up all of my 4.75K ohm resistors with the R6R/L "issue" I posted about previously, and I haven't re-ordered them yet). I will need to trim the inside flanges of the Lansing case for this to fit (the board is sitting on the flanges in the picture), and although it will be "tight" in there, this will make for an almost perfect match, cosmetically speaking, to my re-cased phono preamp.

Underside shot showing the receptacles for the loading resistors, as per Jim Howard's suggestion:
 


Here's the question: In the first picture you can see a polypropylene cap standing-up against the case, and I'm afraid to install them until I know: Do these have a polarity, and if so, what is it/how do I know?

Thanks everyone, and Happy New Year!

tubesforever

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Re: Piccolo build update, and a question.
« Reply #1 on: 1 Jan 2010, 05:16 pm »
Hey Jim, the film caps you have there are non directional.  Its ok to put them in any way you want.  Directional caps are nearly always marked with either a polarity signal or the ends of the leads will be long and short.  The longs are nearly always positive on any directional electrolytic I have purchased. 

If you drill the top plate now and then mount the board to the plate you will find that the board drops down below the flanges.  You might need to remove one side of the Lansing case work as you fit it together but the board should float freely below the flanges. 

Remember you can solder in any component from the bottom up.  I did this on mine where the Black Gate caps were so big they would not fit side to side on the board.

The orange drops are non directional. 

On the bottom of the board I marked the position of the loading resistors as 1 through 6.  That way I have an easy way to know I am not messing up and doing the resistors right on one channel and wrong on the other.   Jim marked these A to F.  Just mark them now so you don't have to refer to the schematic when you want to try some different values later.

I use a super fine permanent marker to indicate what goes where.

Jim, that Lansing case will look totally cool next to the George Wright Signature phono preamp.   Isn't DIY the best! 

Happy New Year!

JimK

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Re: Piccolo build update, and a question.
« Reply #2 on: 1 Jan 2010, 05:31 pm »
(Dangit, Jim! You edited that on me!  :lol: )

Thanks for the reply Jim, and Happy New Year to you!

To jump ahead here, I'm not really certain if those caps will fit or not. The plan for today is to get these film caps installed and then get the cover drilled so I can get a better "feel" for the space left inside the case. Right now I'm trying to find a decimal to fractional conversion chart to see if I have the correct drill bits. (Yes, I plan on using step-bits...)

RE: "Isn't DIY the best!"

Well, I'm still quite leery about those weird readings I was getting, and even though everyone here said to go ahead with the build, can I withhold answering that until this thing is up and running? :? (And if it doesn't work, I don't know that I'll be able to troubleshoot it. I've spent a considerable amount of time looking it over, and I can't find a single thing I installed incorrectly...)

I have some extra parts I don't know what to do with, so I may have to give you a call this weekend. 'Zat ok?

Off to solder in these caps and drill some holes....

tubesforever

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Re: Piccolo build update, and a question.
« Reply #3 on: 1 Jan 2010, 05:42 pm »
Hey Jim, I revised my post so you might want to re check my advice to you on the caps.  BobM found the Teflons to be too two dimensional for him.  I think he ended up using some paper in oil caps.

The key is to just solder in some wires to the board at the final coupling cap position and then connect that to the film, oil, or teflon cap that best delivers the magic in your system.  I tried 5 or 6 caps and chose the teflons because they were the closest to the frequency response and clean clear signal as my Cinemags. 

What I need to constantly remember is that while Teflon works so well in my system it might sound 180 degrees different in your system.  System matching is everything in diy. 

I don't mind making recommendations for parts that cost under 20 dollars to try yourself, but I also need to remember that these recommendations might sound terrible in some systems. Diy is not a one size fits all hobby.

Call me today Friday or Sunday if you want to chat.  I am working Saturday the 2nd.

JimK

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Re: Piccolo build update, and a question.
« Reply #4 on: 1 Jan 2010, 06:18 pm »

Jim,

Thanks for the smack upside the head regarding the case flanges! Why didn't I think of removing the sides?  :duh: You just saved me some time and grief!

Caps are installed, but I installed the "stock" final coupling caps (C1R/L) upside down for future possible replacement. I don't know if you told me to do that earlier, or if it was my own idea, but without a baseline against which to compare to, I would be fumbling around in the dark were I to install something else...

Time to drill!

tubesforever

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Re: Piccolo build update, and a question.
« Reply #5 on: 1 Jan 2010, 06:29 pm »
Dang Jim, some people think outside of the "box".  My saving grace is that when I undertake a diy project I always think from inside the "box".

Now be easy with those stepper drills.  They are very fast and sometimes too fast!  A drill press makes the hole sizes a lot more predictable. 

Cheers!

JimK

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Re: Piccolo build update, and a question.
« Reply #6 on: 1 Jan 2010, 10:34 pm »

Jim, or anyone else,

What are these parts for?



I know where the little plastic "globe" goes, but the nylon washers, screws, and black ring have me scratching my head.

And while I'm at it, am I supposed to bolt-down tag "U2", the LM2941 regulator, shown on the corner of the board? 

Any help?

Thanks.

Bill Epstein

Re: Piccolo build update, and a question.
« Reply #7 on: 1 Jan 2010, 10:59 pm »
I think, think, that the washers are to keep the live heat sink of the LM thingy from grounding if you were to use the corner holes to mount the board on stand-offs.

Back in olden times :green: we didn't use standoffs, only the stems of the switches holding the board to the chassis. I wonder if that's why my switches keep failing! :duh: :duh: :duh:

Maybe you should e-mail Jim for the correct answer?

BTW, I received this pic in regard to talking about Auld Lang Syne and want to share it, it knocks me out. Francis Langford and the Glenn Miller Orchestra:


analog97

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Re: Piccolo build update, and a question.
« Reply #8 on: 1 Jan 2010, 11:10 pm »
The plastic washers are for stadoffs for the battery pack case.  The 2 screws are used for this as well. The screws are threaded into the bottom of the battery pack case.  Be VERY careful not to over torque. The plastic dome is for the LED hole and the rubber washer holds it in to the case lid from underneath.   :D

JimK

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Re: Piccolo build update, and a question.
« Reply #9 on: 2 Jan 2010, 03:05 pm »
Thanks! That's exactly the info I was looking for!

Well, here she is, almost done, and submitted for your inspection:



I still have to cut-off the shafts, secure the knobs, and run power to it, but until I receive the replacement R5R/L resistors, this is as far as I can go....



Loading resistors have yet to be installed.

She should look really nice next to my JH-modded Wright AG  Phono:



Speaking of that, note to Jim Howard:Those teflon caps are too large to fit inside this casing, by about 1/8". I'll send them back to you, along with the log pot from the Wright. 

Thanks all! I'll let you know how she fires-up. Hopefully I won't let the smoke out of anything....