LA3A 500 BUILD

[dmp]

you might need shielded wire going to the pots

 

[12volts]

Ok, I've got my matched opto cells in hand. Tonight I plan on smearing some silicon on the el panels and soldering them in place. Should be complete. Then run some electricity thru them! ;D

Nice pictures. However, those biscuits look very 'dry' and plain. Have you tried 'Custard Creams'?

 

[peter purpose]

Peasant.... Bahlsen for the discerning palate..!

 

[peter purpose]

Duantro... is that a bulge in the front panel, or are you just happy to see me?

File the bloody screw heads down.

 

[duantro]

Nice pictures. However, those biscuits look very 'dry' and plain. Have you tried 'Custard Creams'?

It would be rough, if fire bricks were the only thing to eat around here!
The temporary screw heads are too big. I was more concerned with finding out if this thing can sing. I'll get some smaller ones today.

 

[peter purpose]

I hear ya, but you can get away without fixings... that front panel hole is a tollerance fit.

 

[duantro]

Well... one of my pair fired up just fine, the other is shorting out on +16v rail somewhere. Dims the +16v led on my 51x nicely. I don't see anything obvious at first glance. I'll grab the meter tomorrow and see if I can find what I botched on this thing....

 

[kato]

Ah fuck.

Kit ordering brethren - Duantro e-mails me to say RV23 and RV31, the "underside" trimpots don't line up with the adjustment holes. A new hole must be drilled 1/8" to 1/4" to the left of the current hole. They're askew on my build too - I hadn't noticed; still waiting on transformers. Apologies for the added inconvenience.

Also, sorry for jacking this thread with so much minutia. I'll consolidate my posts into one for the long term.

 

[Winetree]

HAD THE SAME PROBLEM WITH THE UNDER TRIM POTS NOT LINING UP.
Placed them in the cuircut board and assembled front plate.
took a screwdriver and pushed the trim pot into alignment, bending the legs in the process. Disassembled and soldiered.
Where there's a will, there's a way.

 

[mulletchuck]

So, does anyone have a consolidated Build process for this?  Buy ___ from ____, ___ from ___, and then ____ from ____.  See ___'s thread for assembly photos.  This seems like the most complicated of all the 500-series modules to DIY.

 

[duantro]

So, does anyone have a consolidated Build process for this?  Buy ___ from ____, ___ from ___, and then ____ from ____.  See ___'s thread for assembly photos.  This seems like the most complicated of all the 500-series modules to DIY.

Actually, this build isn't super difficult to get together, and I'm pretty much a rookie. There isn't a lot of posted photographs for reassurance in assembly, but it's all labeled on the pcb's and schematics are listed in this thread also.
My advice would be to see if Kato has any parts kits left, order transformers from Hairball Audio crew, then find some el panels. I think there was a group buy on here somewhere. Now get to work!

 

[mulletchuck]

lol.  Easy there.  I've got a lot of stuff still in the pipeline waiting to be built.  Amazon hasn't even delivered my Iron yet!    All in good time!!

 

[peter purpose]

cough

 

[mulletchuck]

got a wee tickle in your throat there, Mr. Purpose? 

 

[imo]

did a number on the amp boards after realizing the diodes weren't gonna fit with the heatsinks. Definitely mastering the art of point to point wiring on pcb's<g
I was gonna point out that 'R14' was wrong in the BOM, but realized after looking around a bit that the sub is a mod to make it interface better. Nice!
I like the way everything is put together. I'm excited to finish it and A/b it against my old LA3A.
Thanks again for putting it together
Ian

 

[jensenmann]

Amazon hasn't even delivered my Iron yet! 

ARGH, I though that was a joke. But no, you can actually buy iron at amazon. Holy moly, wtf....

 

[mulletchuck]

ARGH, I though that was a joke. But no, you can actually buy iron at amazon. Holy moly, wtf....

LOL  whelp, all my amazon stuff except for my multi-meter showed up today    I think the best purchase is this little guy:

 

[kato]

Followup on those pesky trimpots - the two "underside" ones RV23 ad RV31 - I replaced them with Bournes brand as specified by Pete, and now the holes line up perfectly. They are behemoths compared to the Vishay/Sfernice so don't be fooled - same pin layout ≠ a direct replacement. I think I owe some of you some new trimpots. 

 

[sonic02]

hey Kato, do we have to substitute the RV23 ad RV31 (from the supplied kit) with bourns? do you have a link to which ones?

 

[peter purpose]

I think I owe some of you some new trimpots. 

You might owe someone a new front panel.