[JimK]

I finally started my Piccolo project today (please don't ask about the delay! ), and based on advice I received from "tubesforever" I soldered-in a socket for the  IC charge pump as seen here:



My question is this: Is there supposed to be continuity between the two sockets I have bracketed in red, or did I mess this up? With the exception of these two, none of the other sockets "ring out" to another.

I'll be starting on the resistors......now.

Thanks!

Jim

[dnewman]

My question is this: Is there supposed to be continuity between the two sockets I have bracketed in red, or did I mess this up?

When in doubt, check the schematic.  In this case, and assuming that that is U1, then note that according to the schematic both pins 3 and 6 of U1 are tied to ground.  And, those happen to be pins 3 and 6 of the socket you are looking at.  So, they should also show continuity to ground.

Cheers,
Dan

[dnewman]

P.S. In the future, you may want to solder the resistors in before the socket.  Theory being to put in the least tall components first so that when you turn the board upside down to solder them, they stay close to the board's surface.  When taller components have already been placed, the resistors will have a habit of sliding out of their holes a little and riding proud above the board.  Mind you, that's not necessarily a Bad Thing.  Just if you want the resistors close in to the board's surface, it's easier if taller components have not yet been soldered in.

And, of course, assemble things in the order Jim specifies: he's already worked out the sensible assembly order.  (Yes, the socket wasn't part of the directions and so you needed to figure out when to place it on your own and it falls outside of Jim's directions.)

Dan

[tubesforever]

Hey dnewman,

JimK is going to experiment a little with his build.  He visited Audio Research just a while back and they are putting the components up off the board so the passive components don't touch the board at all.  They claim they are getting better sonics.

Perhaps all the micro resonance of the passive parts actually feeds back into the board and pollutes the other devices near by? 

I don't have an opinion on this because I have always mashed my passives to the pcb on my projects hoping the pcb would eliminate the resonance of the passive pieces.

I do plan to try this on my next Hagerman build. 

So all Jim's passive parts will be free flying.  Jim Hagerman!  Did they cover any of this theory in college?   

I cannot wait to see it myself.  If it sounds as good as my Piccolo JimK will be a proud DIY guy for LIFE!

[Bill Epstein]

Morgan Jones, John Broskie, George Anderson and others tie premature failure of passives, especially resistors, to placement hard against the board and the resulting heat build-up.

[JimK]

Thank you all!

Response to "dnewman": Yes, I saw those two pins to ground on the schematic, but I didn't know the pin designator for the socket/charge pump. Is this a "standard" I don't know about, or did I simply miss it somewhere? Either way, thanks! And regarding your "PS", all I can say is this:



I've never done this before, and I was wondering how everyone got all of the resistors to stay in place for soldering!  What I did, both from ignorance as well as caution, is solder-in my resistors one at a time, inspecting and checking each joint as I went, and I can see (now) how this process could be sped-up and made much simpler.

And thus the learning curve keeps rising....

And "tubes" is correct in that I am keeping everything off the board just a bit. Will it make a difference? I don't know, and I have nothing to compare it with, but I figured, "Why not?" I'm using the paper ends of matches as spacers, and so far it seems to be going well. Also, I'm not using "stock" resistors, but rather PRP units sourced from Parts Connexion. For budget reasons the caps will be stock.

Response to "tubes": Thank you for answering my questions last evening, Jim! Hopefully my "hand holding" period is (or soon will be) over....

Regards,

Jim

[dnewman]

Thank you all!

Response to "dnewman": Yes, I saw those two pins to ground on the schematic, but I didn't know the pin designator for the socket/charge pump. Is this a "standard" I don't know about, or did I simply miss it somewhere?

For each IC package type -- and there are MANY -- there are standards (some de facto as in the case of a manufacturer introducing a new package design).  For the DIP package (dual inline package), on the top face of the package there is an orientation marker which marks the "front" edge -- a "U" shaped notch along the top face's vertical centerline.  There is often but not always also a dot indicating pin 1.  Regardless from the front egde, the left front pin is pin 1.  The pins then number COUNTER CLOCKWISE. So for your DIP-8 component you have pins 1, 2, 3, and 4 numbering down the left edge and pins 5, 6, 7, and 8 numbering up the left edge.

When ordering parts, you always need to check the package type as common parts may come in several packages: often a through-hole package meant for a board such as the Piccolo where the pins go through holes in the board, and then surface mount components such as Jim uses on the HagDac card.  They mount to the surface of the board and often have finer pitch leads (e.g., 0.05 inch spacing instead of the more typical 0.1 inch spacing on DIP packages).  These days, there's a much larger variety of IC parts available in surface mount packages than through hole packages.  Thus, depending upon what sort of circuits you like building, you may find yourself faced with using some SMDs.  (They're actually no big deal as long as they aren't the size of a grain of sand.)

I've never done this before, and I was wondering how everyone got all of the resistors to stay in place for soldering!

Insert, bend leads a tad, then solder.  Alternatively, you can solder one or both leads from the top side first and then, optionally, do the bottom side as well.   This assumes that all the holes are through-plated with pads top and bottom.  Not a safe assumption on home-made, etched boards but the standard these days for commercially manufactured boards.

Obviously, this strategy doesn't work well for some packages.

What I did, both from ignorance as well as caution, is solder-in my resistors one at a time, inspecting and checking each joint as I went, and I can see (now) how this process could be sped-up and made much simpler.

You're building just one and you want to have quality results.  So take your time and enjoy.  I double check the board and part placement after I place the part.  Solder it, check the joins under a magnifying glass with good light, clip the leads, recheck, and often reflow the solder.  Slow and careful is a Good Thing.

Enjoy,
Dan

[amandarae]

Hello Jim!  Remember me from Central?

Yes, pin 3 and 6 are tied together to ground.  You can check it out from the schematic.



As one poster already indicated, start from the dot on the IC and move to the right counting pin numbers (1,2,3,4) then across moving R to L (5,6,7,8).  Yep, mounting it with a socket is best if you want to try other OP amps (I did, but settled with the one pictured).



This second pic is for you as a guideline and if I can make a suggestion.  Look at the LED.  It is soldered not flushed to the circuit board but potruding (place teflon tubing or heatshrink on both legs) just enough so that it will reach inside the plastic dome which is mounted on the top cover.  This way, the LED can be easily seen when lit. 

And finally, my unused avocado colored Piccolo



Best regards,

Abe

[hagtech]

resulting heat build-up

OMG - there is nothing even remotely warm in this circuit.  Except maybe the input regulator, and that depends on supply voltage...

jh

[Bill Epstein]

OMG - there is nothing even remotely warm in this circuit

I was writing in general and generally, whether the Piccolo or an 845 amp, not a bad guideline to follow.

[JimK]

Abe:

Thanks for the fine close-ups, and yes- I recognize you from Central and VA! I trust all is well with you and yours!

A couple questions, if I may. First, do you recall where you sourced the C1R/C1L caps? Jim/tubes sent me a pair for my build, but I don't think they are going to fit in my box (and Jim- if they don't fit I'll send them back to you). Secondly, the "shield" between the inputs and C4 through C8 caps- what is that made of, and how is it installed? Jim/tubes mentioned that he did something similar with his "Piccolo-zilla", and seeing that yours is similar has gotten me all sorts of curious...

And another thanks for the advice on the LED! My plan is (or, "was") to get this part of the build completed this week sometime, and your timing is perfect.

Regards,

Jim

[amandarae]

Abe:

Thanks for the fine close-ups, and yes- I recognize you from Central and VA! I trust all is well with you and yours!

Hello Jim,

Thanks, I am doing well.

do you recall where you sourced the C1R/C1L caps?

C1L and C1R caps?  That is the Sprague right?  I had some in my caps stash.  Do you need a pair?  I can take a look and see if I still have some spares.  If not, does a Russian 0.1 uF (Green case) sounds okay to you?  They look liike this

Secondly, the "shield" between the inputs and C4 through C8 caps- what is that made of, and how is it installed?

Honestly Jim, I do not recall ordering that and I am positive that Jim Hagerman included that on the half kit when I ordered my board.  The manual call it as ""terminal shields" but I look it up on Digikey and Mouser and cannot get a hit.

Let me know about the caps.  You can email me directly at arevz@msn.com

regards,

Abe

[BobM]

Just finished my Piccolo build and I noticed a funny thing. I left the board out of the case and plugged it in to see what it sounded like. I got lots of hum and became very concerned. After searching frantically for the source of the hum, on a fluke I sat the board w/ top plate attached into the case itself.

Whallah - the hum disappeared. Apparently somehow the case helps ground the circuit and got rid of the hum. I still don't know how that can be since the case isn't grounded to anything.

Strange but true.

I've also used those big silver Russian teflon caps and they are just ever so slightly too large. They are running in now, but I'm also feeling that they may be light on bass over a set of Sonicap II's that I tried in a friend's Piccolo. Transparent on top and holographic, but the bass and bottom end dynamic may not be there.

Enjoy,
Bob

[tubesforever]

Bob,

I sent him some FT-2 0.10uf caps to use as coupling caps.  They are much smaller than the FT-3 caps and they actually have excellent bass response.  They are as clear as the CineMags and have less sibilance and less noise.  I am very pleased with them.  I am using the ultra quiet FK Black Gates at all the 100uf 25 volt points and these have noise levels -160 db.  From what I know about electrolytics, these are the quietest caps ever built on the face of the earth. 

I want to try the Mundorf SIO 0.10 caps but they are pricey and huge.  At least the teflons are just huge.

Did you use FT-2 or FT-3 caps?  I agree that the FT-3 cap would be a mistake for the Piccolo circuit.   I like these bypassing the 1.0 uf coupling cap in my Clarinet and Cornet 2.  They give me clarity and clear highs while the Mundorf SIO plumb the bass lines.

[BobM]

I used the FT3's. They do have the deep bass thing going on, but I can't help but feel there's a hole in the midbass somewhere that they're just not filling in. I did run them in for about 100 hours befiore I installed them and these caps do break in quicker than the V-Caps or Sonicap Platinums, so they should be OK in that regard.

I have another set of Sonicap II's that I know sound very nice. I also have a set of RelCap RT's that should qork quite well in there. I may put those in and see what happens.

Update: Well the RelCap RT's went in and yes, they had more bass and midrange warmth. But they also had a top end forwardness and glare that I just couldn't take. So I pulled them out after about a half dozen sides and put in the Sionicap II's. These are really nice caps for the Piccolo. Small and very good sounding, with all the attributes I look for (or listen for) in good vinyl.

Enjoy,
Bob