Hi,
I've got 2 pairs of input transformers which I'd like to use for some upcoming projects (Baby Huey EL84, Tubelab TSE)
I need some help with wiring and mounting for unbalanced input, into an unbalanced circuit.
They are:
- Hammond 140UEX (https://www.hammfg.com/files/parts/pdf/140UEX.pdf)
- Jensen JT-11P-1
To my understanding, the case on the Hammond is the same as the white wire on the Jensen.
I understand that I should change the input resistors on the PCB to 10K to give the proper load resistance to the transformer.
Taking the 140UEX for example, the wiring seems straight-forward, RED-YEL to the RCA jack, and GRN-BLU to the PCB input terminal.
However, I am not sure if the transformer chassis needs to be isolated from the amp chassis, and where to tie the star-ground of the PCB (directly to chassis as without the transformer or otherwise?)
The Jensen introduces 2 extra wires (white and black) which are related to the above questions.
Thanks
I've got 2 pairs of input transformers which I'd like to use for some upcoming projects (Baby Huey EL84, Tubelab TSE)
I need some help with wiring and mounting for unbalanced input, into an unbalanced circuit.
They are:
- Hammond 140UEX (https://www.hammfg.com/files/parts/pdf/140UEX.pdf)
- Jensen JT-11P-1
To my understanding, the case on the Hammond is the same as the white wire on the Jensen.
I understand that I should change the input resistors on the PCB to 10K to give the proper load resistance to the transformer.
Taking the 140UEX for example, the wiring seems straight-forward, RED-YEL to the RCA jack, and GRN-BLU to the PCB input terminal.
However, I am not sure if the transformer chassis needs to be isolated from the amp chassis, and where to tie the star-ground of the PCB (directly to chassis as without the transformer or otherwise?)
The Jensen introduces 2 extra wires (white and black) which are related to the above questions.
Thanks
Jensen recommend (for unbalanced devices) tie the black (case) and white (shield) to output "cold" (orange) wire, which is connected to the device "ground".
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Thanks euro21.
My preamp has both balanced and SE outputs so I'm considering whether to wire the input of the amp as XLR or RCA.
If I were to do so, it seems like the wiring is the same on the secondary, with the primary either tying pin 1 to ground or lifted.
My preamp has both balanced and SE outputs so I'm considering whether to wire the input of the amp as XLR or RCA.
If I were to do so, it seems like the wiring is the same on the secondary, with the primary either tying pin 1 to ground or lifted.
To take best advantage of the input transformers, you would use only three conductor (XLR) input jacks. For single-ended sources, both signal hot and signal return would be carried back to the source device's output jack, and shield would be connected at one end only, normally at the terminating end.
An exception would be in a really terrible RFI environment, where the shield might need to be connected at both ends. Jensen has lots of excellent white papers about these issues; highly recommended.
All good fortune,
Chris
An exception would be in a really terrible RFI environment, where the shield might need to be connected at both ends. Jensen has lots of excellent white papers about these issues; highly recommended.
All good fortune,
Chris