Seventh Circle Audio

For the spot C1, the item listed on the Bill of Materials is 220J C0G 50. I do not have this piece, instead I have a 220J C0G 100. Is this ok?


Also, the intructions for step 8 are:

If you need to drive extremely long cables (greater than 50m) or know that you'll be connecting the preamp to capacitive loads (you probably won't), add the "load isolator" inductors L1 and L2 now. Otherwise, solder jumpers in their place.

Is it neccessary to solder jumpers place of the load isolators, and are these jumpers included in the A12 package (if they are I don't have them)? This isn't specified in the instructions or Bill of Materials.


I'm also a bit confused about this part:

J5 connects a 604-ohm load resistor across the output. Unless you’ll be connecting the A12 to a piece of older gear with 600 ohm input impedance, connect a shunt across J5.
J6 - A separate, isolated output signal is available at this header. The amplitude at J6 is half the amplitude at the main output, CONN2.

I am given only one 2-pin header and am unsure in which spot (J5 or J6) I should place it, and don't know what this "shunt" that I am to connect across J5 is.


Apart from these questioned items my A12 is assembled. Thanks in advance for your answers.



Oops, I just noticed that I soldered on the 3 way pin headers upside down, making the part that sticks up too short to hold the jumpers it needs. Will this work ok if I cut the jumpers down in size, or find smaller jumpers to use?

For the spot C1, the item listed on the Bill of Materials is 220J C0G 50. I do not have this piece, instead I have a 220J C0G 100. Is this ok?

Yes.

Is it necessary to solder jumpers place of the load isolators, and are these jumpers included in the A12 package (if they are I don't have them)?

Like it says in the instructions, if you don't install the load isolators you must install jumpers in their place. If you have a pair of resistors with a single black stripe you can use those. If not, two lengths of hookup wire will work just as well.

I am given only one 2-pin header and am unsure in which spot (J5 or J6) I should place it, and don't know what this "shunt" that I am to connect across J5 is.

Install the header at J5. The shunt or shorting jumper is a small black plastic device that contains spring contacts. It is just big enough to bridge two pins on a 0.1" header.

Oops, I just noticed that I soldered on the 3 way pin headers upside down, making the part that sticks up too short to hold the jumpers it needs. Will this work ok if I cut the jumpers down in size, or find smaller jumpers to use?

No. You must remove the header and install it correctly.