Welcome Guest! To enable all features please Login or Register.



Go to last post Go to first unread
#1 Posted : Friday, December 17, 2010 10:17:12 AM(UTC)

Rank: Member

Groups: Member
Joined: 12/17/2010(UTC)
Posts: 1
Location: Lawrence, KS


Before I purchase my Sympatico kit, I have a few questions.
1. I will be running 4 Ohm speakers, and don't know what heat sink to get. I know in the "heat sink" thread it was suggested that one use Brian's recommendation. But I have not been able to find a post by anyone named Brian recommending a heat sink value. What is Brian's recommendation? Can he recommend a specific vendor and part number?

2. Also, the photo of the Sympatico shows the OP Amps bolted to the heat sinks. Does this mean I need to drill and tap holes in the heat sink myself? Can I buy heat sinks with properly-spaced holes?

3. Finally, I'm making a list of all the additional stuff I'll need to buy. If I make my case out of plexiglass, I'll need:
plexiglass and glue for case
heat sinks
circuit board spacers/risers
thermal paste
power cord (3-pronged, I assume)
thing put where the power cord passes through a case
on/off switch
2 RCA phono inputs
2 pairs of speaker wire terminals
internal wiring & cable ties

Can anyone think of anything else? Are there any suggested modifications specifically for driving 4 Ohm speakers? As you can see, I've never built an amplifier before.

Thank you,

#2 Posted : Friday, December 17, 2010 11:25:52 AM(UTC)

Rank: Member

Groups: Member
Joined: 5/23/2010(UTC)
Posts: 719
Location: Netherlands

Thanks: 2 times
Was thanked: 48 time(s) in 45 post(s)
1. I'd recommend a case with built-in heatsinks.
2. Yes, but that's pretty easy. Most heatsinks are made of aluminium, so drilling and tapping holes is easy.
3. Plexiglas may sound nice at first, but it's far from ideal to build an amp with. It tends to keep the heat inside the case, and it's a great source of static electricity. Also it's soft, so it can scratch quite easily.

It's not clear what your source is, but since the Sympatico is a balanced amp I'd use XLR input connectors. That way you would be able to connect both balanced and single ended sources. The conversion would be done using the connection cable.

As for the IEC (the thingy for the power cord), I'd suggest a Schurter or similar unit. Those can be ordered with a fuse drawer, (optional) on/off button and (optional) filter. This saves quite a bit of work. The fuse and a fuse drawer should be added anyway. To mount it one would need a pair of fi. M3 nuts and bolts. I'd use crimping connectors to connect the wires to the IEC, those are needed also for connecting the wires to the board. Use a proper crimping tool.

Use fi. heat shrink tubing to create double isolation from the IEC to the transformers. Twist the wires from the transformer to the board.
Rss Feed  Atom Feed
Users browsing this topic
Forum Jump  
You cannot post new topics in this forum.
You cannot reply to topics in this forum.
You cannot delete your posts in this forum.
You cannot edit your posts in this forum.
You cannot create polls in this forum.
You cannot vote in polls in this forum.