LA3A 500 BUILD

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Okay, this stuff clears (nearly) everything up, what i meant:

D1 -D4 are named in the main PCB, those are 1N4003,
D1 and D2 are also named on one of the addon PCB, so i am asking which type ? 1N4148 or 1N4003 as well.
And i mentioned that CR1+2 is named in the parts list, but i also cannot find it on board, hence my question
if D1 and D2 on the addon == CR1+2.

But on the schematics this can be seen, so thank you for this additional.


 
I have some spare OA91s, pm if somebody want some

also found this https://www.studioelectronics.biz/sunshop/index.php?l=product_detail&p=1217 but it doesn't seem that attractive price wise 
 
just putting together a parts order, and am suddenly aware of just how little I know about relays...
this looks good to me, but if anyone can spot a reason not to order it, or knows a better option, it would be much appreciated.

http://ca.mouser.com/Search/ProductDetail.aspx?R=G5V-2-H-DC12virtualkey65300000virtualkey653-G5V-2-H-DC12
 
About how the relay is powered... I was just going to stick some 12v relays in that I had pulled from something else, but I don't know their current draw.  I'm wondering if RRL or anything else has to be changed if the relay draws more / less current? It appears like the relay coil is in series with RLL, which sees the positive voltage (16v minus two diode drops... ~14.6v).  I'm not sure how the relay is seeing 12v with RLL only 10 ohm.
I think you would want to calculate RLL so that the Relay sees 12volts. So, for JABs relay, the current draw is I_relay=.0125 amps. You want RLL to drop 2.6 volts, so RLL=2.6/.0125 = 208 ohms.
 
Any guidelines for the heatsink on the output transistors? Do they need to share a heatsink like in your pic for temperature stabilization? Do you have a part number for the one you used so I can compare specs?
 
No special requirements for the heatsink except if using just one... insulate the cans... as 2 voltages don't mix.
I used part of an old chipset heatsink and sticky pads.

RRL as required.
 
Short question regarding the EA-11184-500 Autoformer: Which colors do align with what pos on the PCB ?
I'm not able to find a datasheet or color coding outlining this. 
 
From the picture on the hairball site it looks like black-5 red-2.5 blue-.31, but don't take my word for it.
BTW... I had to dress the wires from the standard part quite strangely, but think that these will need to be tightly twisted.
 
Hey guys,

I think there is an error in the BOM.

For RV23 & RV31 you actually need 3299P type trimmers. The ones listed in the BOM currently appear to be SMD, not through-hole.
 
I brutalized an innocent T4B for the guts.

t4b-opened.jpg


Seems like such a waste for 2 opto cells and one light emitter. But it had to be done...
 
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