Seventh Circle Audio

Hi, sorry about the dummy question but I'm a little confused about what jumpers to plant on the A12 (SC25 and Cinemag input tranny) I'm building. In the pictures on the instruction pages it looks like everything is jumpered but J6. And I should jumper L1 and L2, yes?
Thanks,
Oliver

If you're using the CMMI-8-PCA input transformer that comes witht he A12KF, you don't need to install J1 or J2. If you're installing the A12 in a CH01, jumper J3 and J4 as shown, and jumper J5 unless your tape machine has 600 ohm inputs. Don't jumper J6! If you're leaving out the load isolators, you must jumper across L1 and L2.

Thanks Tim! It's up and running, I just have to clean up the wiring a little before everything goes together.

I am leaving out the load isolators (I think) because I believe I don't need them for the stock A12. But what do I jumper with? There don't appear to be any parts included with the kit to make this jumper. The only possibility are two resistors that have a tan body and a single black stripe. I measured these and they have essentially no resistance at all. Are these what I use to jumper with?

The resistors you mention are 0 ohms. You CAN use these to jumper the traces for the load isolators.

I just used leftover transformer wire, but I guess Tim is including the 0 ohm resistors now. Both work fine.

Shane

so these 0 ohm jumpers are only installed to be used for tape machine loads? I installed them but I'm using a digital interface is this wrong?



V

No, it's not wrong. These jumpers are installed in lieu of L1 and L2, the coils that you can see in the assembly photos. The shorting jumpers at J3, J4, and J5 need to be installed for proper operation in your case.