SCA Preamp DIY Build

Wolfeman

I Prefer EL-34s. So What?
Feb 21, 2006
4,375
0
36
Cleveland
Figured some of you would enjoy following along as I build this preamp.

I'll start off by saying that Seventh Circle Audio is an amazing company from what I've seen so far. I just got my box of goodies today, and was very surprised with how this company handles themselves. The packaging was AWESOME on my stuff. Double boxed, double bubble wrapped, paper wrapped, all parts in sorted baggies, and they threw in lots of extras for me that I wasn't expecting to get.

So here are some initial pics. I'll explain as I post them.

This is the box that I took out of a box. This one was wrapped in bubble wrap all the way around and fit perfect in the outer box.
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The chassis itself was wrapped in plastic and brown paper, and also in bubble wrap. I was amazed at how meticulous even just the brown wrap was- it was all tapped up and the corners were folded perfectly... Whoever works at SCA is very OCD about shipping. Which is a good thing.
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So I took the cover off and was not surprised to see all the individual components I ordered perfectly wrapped in bubble. I was also impressed that the power supply and chassis was already fully assembled for me. Judging from the instructions I've seen online, I thought I was going to have to but it all together myself.
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Here's all the individual components. Everything was sorted in bags based on where it goes. Good job here too SCA.
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Ahhh the good stuff!
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The envelope you can see in the other pic contained the schematics, BOM, and PCB. The PCB is very stout, whoever did the layout knew what they were doing. Better than a lot of high end gear I've seen.
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And this pic shows why I now love this company. They sent extra stuff along with my order that I wasn't expecting. Snap on ferrite bead for the power cord, lead bender for resistors, tons of hookup wire, heat shrink tubing, and a bunch of zipties and cable routing clips. All these things are usually never included in kits like this.
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That's it for now. I'm going to start assembling the pre later tonight. I have to clear all my amps off the workbench and then I'll be on it.
 
Yea Ive been wanting do buy into this but I'm afraid of my soldering skills. I don't want to spend all that money and totally fuck things up with some botched soldering. Anyways Keep posting pics please and let us know how it goes!!

Btw what preamps kits did you get?

Never mind i see the A12 on the bag now :)
 
Yea Ive been wanting do buy into this but I'm afraid of my soldering skills. I don't want to spend all that money and totally fuck things up with some botched soldering. Anyways Keep posting pics please and let us know how it goes!!

Btw what preamps kits did you get?

Never mind i see the A12 on the bag now :)

I'm sure you would do fine with the soldering. If you look at the SCA forums, there are guys on there that have never even touched a soldering iron before, yet they end up building them fine.

Yep I'm starting with an A12. Eventually I'll add another A12, two N72's, and four T15's
 
Badass dude, I'm now a lot more confident I could build one of these since they apparently take so much of the guesswork out of it! :D
 
The build and the instructions are very straightforward. Not really a learning experience if you have built stuff before. Almost like paint by numbers. Just follow the instructions, take your time, and you will be fine. Soldering technique would be the main thing. But work clean and you will be fine.

Things get a little tricky when you start adjusting the bias and such, but if you follow the directions, it isn't a big deal.

For a set of really killer preamps at a stupid price, the SCA stuff is amazing. Reviews and comparisons to their inspirations have all been very positive.
 
All done. This was a bit too easy for me, as has already been said it's a straight up paint by numbers.

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Was the board completely blank when you got it, or were those little resistors/caps/other doohickeys already soldered on?
 
Impressive, that vertical row of like 12 blue things (resistors? total shot in the dark there :lol: ) looks like it could cause a headache, at least for me :D
 
Curious - are these stepped inputs or is it just a standard spinning pot?

Shit... one night? This is definitely my next big audio purchase.

Gain control is stepped. Trim pot is a standard pot.

Only took 2 hours total. The money saved just for 2 hours of work is unbelievable. Time to run your KSE DI's through it now.
 
wow, these look savage- once you've you're first one bought and built it seems pretty cheap to add more units considering what they are. I can definately see myself picking up a few down the line
 
Yeah you can do a T15 with the chassis and power supply for $399. The T15 and A12's are the easiest to build. Also you can use the SC10 OpAmp for a more Pacifica-esque pre as well.

The N72 isn't too bad, but it has a few more parts and the input transformer requires some finesse. The C84 has a lot of parts. The J99 looks like the hardest. But the instructions are so well written and the parts are laid out in order.

Not to mention the customer support is excellent.

They are by far the best deal in pre-amps.