DIY Mic Pre Kits, Lunchbox Mic Preamp Kits, Power Supply Kits

SC1-mk2 Mic Preamp Kit


Now, with optional Input Transformer option!
Improved design, improved performance, design refinements.
Uses the same "footprint" as the original SC-1, so you can use this new kit in our 1u SC-1 Rack Case.
Have 2 channels of clean/uncolored preamp and 2 channels of "flavored" preamp
Local PSU regulation for a 2nd-level filtering of power supply.
DC Servo, Dual Buffered design
THAT and Burr-Brown chips
Using uMetal shielded Input Transformer for excellent magnetic shielding
6dB gain steps in the lower range, and 4db gain steps in the upper range for more precise control
Using standard 0.1" pitch pads for power and XLR connections, Molex 0.1" compatible
Bourns, conductive plastic potentiometers
Grayhill, mil-spec selector switches
0.079" thick PCB with 2 oz. copper, Solder mask, silkscreen, plated-through holes, Lead-free Rohs

More ordering choices, more package deal combinations for better discount!
Flexible ordering with or without PSU, Rack Case, Input Transformers, etc... to fit your DIY budget.

More photos:

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Looks great! I can't wait to try them out.

Got a few questions if you don't mind:

Is the transformer-less version the same design as the original sc-1?

How do they compare to the TS-2?

Got any sound samples yet (particularly of the transformer version)?

Keep up the good work!

>Is the transformer-less version the same design as the original sc-1?

In the whole overview of things... I would say "Almost equal, but not really." If you'll notice, there are (4) chips on the new mk2 version. And the new chips se are dual-opamp version chips too. (not like the single opamp chip on the original SC-1.)

The big capacitor laying on it's side is also gone. I would call mk2 a more refined and improved product.

Connection pads are standard pitch, so any off-the-shelf 0.1" headers can be used on the board.

The PCB is thicker, now using 2 oz. copper weight, solder pads that retain their shine and clean appearance, more help and labeling on the board, etc.

Also, some changes in the gain setting resistors, so at the higher gains, you don't get big jumps in gain.

Plus new local supply regulation... just because... people asks for them.

It's a bunch of little improvements.

>How do they compare to the TS-2?

At first glance, the TS-2 is actually more closer to the SC-1... but generally, the TS-2 is in-between the SC-1 and SC-1mk2. Some of the things I tried in the TS-2 I incorporated into the SC-1mk2.

No samples yet... will come later. Thanks!

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current projections indicate I may be able to buy two of these by this time next month.


thus, i can barely contain myself.

I just bought a SC-1mk2 kit without the input transformer. Is it possible to buy the input transformer from you at a later date?

Also, have you done any experimenting with different kinds and brands of resistors and capacitors? I have numerous parts lying around from previous hi-fi projects I might be tempted to use.

Thanks for your order!

Yes, you can get the trafo at a later date.


Not really. All resistors I used are metal film 1%, C0G NPO for the ceramics, Panasonic electros, and lots of IC power supply bypass capacitors used.

Somebody did some mods though and used big bulky caps for the input coupling caps. But he had to mount his caps outside the PCB.

But whatever you do, do not bypass/remove these capacitors as they also serve as phantom power blocking caps.

If you remove these caps and apply 48V phantom power, you'll fry your chip.

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Does the SC-1 have a -20 dB pad like the other designs you offer? If not, is it possible to add one? Thanks.

No, it doesn't have a built-in pad.

But yes, it's possible to add one. Just need one DPDT switch and (3) resistors.

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