Seventh Circle Audio

Hello folks. I have been having problems with noise and hum on my D11's. I am thinking about putting the transformers in them to see if the problem is corrected. My question is, do I need to install 1 or 2 trannies per D11? Also, there was some talk about the Cinemag trannies for PCB mounting some time ago, are there any news about these?

Thanks,

rey

I have been having problems with noise and hum on my D11's. I am thinking about putting the transformers in them to see if the problem is corrected.

Do you have noise problems when connecting the D11 to a preamp in the same chassis? The transformers will be useful primarily when connecting to other chassis.

Yes, when I'm connecting to the preamps in the same chasis.

Connect a spare 1/4 plug to the D11 input and short the tip to the chassis. Does it still hum?

Hi Tim. There is no hum when I short the tip to the chassis (the screws, not the painted areas).

Have you tried different guitar cables, changing your playing position, or the different input impedance settings on the D11? If the hum disappears when the input is shorted, the problem is most likely external interference of some kind.

OK. I have tried different cables, and some work better than others. Changing position also helps, but it's not practical when it's a keyboard, for example. I haven't played around with the impedance much, I usually keep it at the center position. Will the transformers help this issue at all? If so, should I install 1 or 2 in each D11?

Thanks once again, Tim, for your excellent tech and customer support. It's a huge added value to your outstanding products.

With line powered devices such as keyboards, try powering them from the same outlet strip as the D11. Most devices with an active output can drive a mic preamp directly, though you may need to pad the output.

OK. So the transformers won't help with this kind of noise/interference?

Probably not. The transformers isolate the outputs, not the inputs. The tests so far suggest it's more likely interference or grounding issues on the input side.