Speedball success! But notes..

efp · 3572

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Offline efp

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on: May 30, 2013, 08:24:37 AM
Ok, it's taken me a couple of days and some profanity but my speedballed Crack is now up and running, and it's hard to wipe the  sh**eating grin off my face as I lie back with my HD650's and a large single malt. Thank you big time Doc  and everyone else on here whose advice has been invaluable. I suspect a large part of my satisfaction is down to having built the beast with my own hands as you say, but there is no denying the sheer quality of the sound I am getting, leagues ahead of the Little Dot 2 it is replacing.
A couple of caveats: Despite never having soldered or built anything like this in my life, I whizzed through the Crack build without issue, other than my stupidity in continually reading the word "attach" as "solder".  Hence I kept I kept having to go back to a nicely made joint and undo it to attach another wire.
May I humbly suggest that next time you rewrite the instructions you make it a bit more clear for morons like me, that Attach means fix, but don't yet solder?
Secondly, my instant success with the Crack, which fired up first time, made me complacent with the Speedball.
Again, I can only blame my incompetence, but the Speedball does require another level of finesse and precision which I was not prepared for. In particular, my clunker of a soldering iron was way to big and hot for the smaller pads and components here, and made for some ugly joints. Some of the closely spaced solder pads could be safely bridged (inadvertently or not..) but others, equally close spaced, could not. Perhaps this could be made more clear?
My other issue was with the finer wire. The finer gauge solid wire and incompetent stripping led to several scored cores and subsequent breaks. And as each time the A and B boards were unscrewed to fix one connection more flex was applied to the other wires, break followed break and the E and I pads became quite a mess. I'm sure there is some valid reason but perhaps you could explain why braided wire is unacceptable here?
And finally, there are are numerous solder pads and legends on the A and B boards unused. R3, R4, 432, Cc,'K, Rc.  I'm guessing they are leftover from some prototyping but I'm curious as to what they are or if the voltages/ resistances across them could be useful in troubleshooting? I've read this forum quite far back and have yet to find anything on this.
But again, despite my whinging. a superb product and support, my profound kudos.
Best regards



Offline Paul Birkeland

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Reply #1 on: May 30, 2013, 08:44:04 AM
May I humbly suggest that next time you rewrite the instructions you make it a bit more clear for morons like me, that Attach means fix, but don't yet solder?
Page 16, at the top, in red, with your specific detail both in red text and bold type font.

Some of the closely spaced solder pads could be safely bridged (inadvertently or not..) but others, equally close spaced, could not. Perhaps this could be made more clear?

It is good practive to assume that no pads can be bridged with solder. 

I'm sure there is some valid reason but perhaps you could explain why braided wire is unacceptable here?

If you shove stranded wire through a small hole, the strands spread apart and bridge to nearby traces.  Stranded wire also does not stay where you put it.

And finally, there are are numerous solder pads and legends on the A and B boards unused. R3, R4, 432, Cc,'K, Rc.  I'm guessing they are leftover from some prototyping but I'm curious as to what they are or if the voltages/ resistances across them could be useful in troubleshooting?

Those pads apply to implementations of this board in other products.  Nothing is connected to them, and they are not connected in the circuit, so there are no useful voltage or resistance measurements to be taken on these pads.

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline efp

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Reply #2 on: May 30, 2013, 09:11:21 AM
Lol. That's me told then..
And in punishment for my smugness, between it working fine on my bench and plugging it into my hifi downstairs it's died again.
Ah well, back to the workbench tomorrow.
Thanks for the info anyway



Offline adamct

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Reply #3 on: May 30, 2013, 09:55:50 AM
May I humbly suggest that next time you rewrite the instructions you make it a bit more clear for morons like me, that Attach means fix, but don't yet solder?
Page 16, at the top, in red, with your specific detail both in red text and bold type font.

Paul,

There is no question that the manual alerts you to this. But as a practical matter, when you're in a groove and going through the build, it is easy to forget the note on page 16 and overlook the distinction between attach and solder. From memory, the number of instances where you are only supposed to attach a wire without soldering it in place within a step or two is fairly limited. In those few places, it might be worth reminding people not to solder the wires until Step (x).

Best regards,
Adam



Offline efp

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Reply #4 on: May 30, 2013, 01:34:47 PM
Thank you Adam. I feel slightly less dumb now.
Paul, I take note of your comments but do feel slightly condescended to. I have made no secret of my inexperience  here and had hoped for a rather more positive response. In particular, I've found a suitably tinned braided wire fairly easy to position, but I bow to your experience.
So be it.



Offline Paul Birkeland

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Reply #5 on: May 30, 2013, 01:41:18 PM
Tinned braided wire will indeed work a lot better, especially into the PC board holes, but it becomes kinda tough to bend around the terminal strips on the other end.

The reply wasn't meant to be condescending, only highlighting what is available in the manual and just some observations I've made having done a fair amount of repair work to kits (especially to those wired with stranded wire). 

In general, if you have some intermittent issues with the Speedball, I would look to the voltages at terminals 1 and 5 when you experience the problems.  If one or both of these should drop to 0V during operation, it is often the case that the center leg of the MJE350 needs some extra heat from the soldering iron, as this leg is connected to what would be considered the heatsink of the device.

Since you had your Speedballed Crack in operating order, your culprits are well narrowed down and your troubleshooting should be fairly minimal.  As always, voltages are a great place to start in terms of looking for issues.

-PB

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline Doc B.

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Reply #6 on: May 30, 2013, 02:12:17 PM
Just to clarify, when you say braided do you perhaps mean stranded? They are different. Stranded wire is a group of very fine wires inside a single insulating cover. Braided implies either several individually insulated wires braided together, or a group of bare wires braided into a shape like a tube or a ribbon.

The stranded wire has two strikes against it. It is difficult to form into a shape in the tight confines of an amp, as it wants to spring back to its original shape. And there is a real issue with "whiskers" - when one or two of the fine strands don't get attached and soldered with the others and then have a tendency to bend around and short to neighboring terminals. It's fine to use stranded wire from an electrical standpoint. We just try to recommend materials that we think will make the process as painless as possible for those who may be new to the hobby.

Dan "Doc B." Schmalle
President For Life
Bottlehead Corp.


Offline Laudanum

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Reply #7 on: May 31, 2013, 12:42:57 AM
A note on the wire included with Speedball.  And this assumes that it is still teflon insulated.   The Teflon insulation is tough stuff.  That's the price paid for a very high heat/solder resistant insulation, thin insulation and , arguably,  better sonics.   Wagering a guess here, stripping the teflon insualtion is what is causing you grief with the broken speedball wires.  PVC insulatation doesnt actually have to be scored 100% of the way through in order to strip the insulation so you dont have as much chance of scoring the wire.  That teflon is thinner, so easier to get the stripping tool accidentally down to the wire as well as the insulation being tough as nails ... and slick, so also can be a pain to remove from the end, especially with the short lengths of wire.  A dedicated tool that is made for teflon insualtion is the best solution but obviously not something everyone would have on hand, especially a first time DIY'er.   The insulation can be stripped with a standard tool, with a little finesse and extra care.  But that's easy for me to say I guess considering what I did for a living.   Anyway ... extra attention is definitely needed for those teflon insulated wires.   And now you know   ;D

Desmond G.


Offline efp

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Reply #8 on: May 31, 2013, 06:42:52 AM
Thank you all for your helpful comments, my lessons are hard earned for future projects.
Paul, I took on board your point about the center leg of the  transistor but surprisingly I had got that right. The problem turned out to be more prosaic. After painstakingly working my way back from the speedball connections and wires for continuity (rather assuming the fault would be there)  and then back through the Crack circuits, the issue turned out to be, yes, a scored wire fracture at the very first  joint on the fuse-holder. Duh..
 Being such a short wire it appeared solid and of course was just at the end of the insulation so hard to spot and intermittent. The fact that it worked on the bench wrong way up but failed when inverted into the case should have given me a clue that gravity was a factor here..
Naturally, I've mis-filed the surplus lengths of the original wire, so I replaced it, and a few other suspect ones, with stranded (not braided, thanks for the clarification Doc..) equivalents with tinned ends carefully checked and bent onto the terminal lugs. It seemed a fairly simple operation in this case and being on the 240v side of the transformer I think even the sonic purists couldn't object, but I see your point on other uses.
Laudanum, thank you for that information, news to me, and interesting. In hindsight I do recall  reading a note somewhere  warning of the danger of scoring the wire cores with sloppy stripping, but I obviously didn't pay enough attention.
Whatever, I'm now a happy, and more experienced, owner and I thank you all again for your help and a great product.
Best rgds



Offline Paul Birkeland

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Reply #9 on: May 31, 2013, 07:20:46 AM
Awesome!  I'm glad you found the source of your problem.  I have a persistent habit of not installing the fuse when I'm finished building, I think it has happend on at least the last four projects I've built.

With the stranded wire, you can build some beautiful gear that sounds great with such wire, but as you noticed, it takes a great degree of care and patience during the process.

On the amps that I have seen where this worked out, liberal use of plastic wire ties and wire tie anchors played a critical role in keeping everything in place.

Back by the IEC inlet and switch, you can make the wires as short as possible to keep just a little tension in them. This alone is sufficient to keep things in place.

For stripping teflon insluated wire, these really make life easier. 

-PB

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man