Phono 1:1 Input Transformers - info sought...


I was looking at the Brinkmann Edison Mk II and their site refers to a 1:1 input transformer... What is the purpose of this and when would you utilize it? I understand about Step-up's but this isn't really that... one can turn on/off apparently...

I have searched abit and have not run across this on the web... does another manufacture employ this? Searching the forum did not provide me with an answer... maybe I am poor at searching...

Here is an excerpt..

Three Balanced RCA inputs, two of which also feature XLR connection, accommodate the most elaborate systems. Each input is independently adjustable for gain (16 steps from 49 - 73 dB) and impedance (12 steps from 50 - 47k Ohms). Adding selectable mono/stereo, phase/invert and a 1:1 input transformer of superb quality, Edison provides a level of fine-tuning unsurpassed by any other phono stage. A remote handset maximizes user convenience.

Thanks,

Steve

sc2

Showing 3 responses by lewm

You’re correct about cartridges but most have cartridges wired single ended at the phono stage. I puzzled over this myself. In certain circuits there can be DC offset at the input stage. Resulting DC current across the coils of an LOMC cartridge could damage it. The transformer would protect the cartridge from DC. Ask Brinkmann.

The 1:1 input transformers might also be used to invert phase at the input of the phono stage. (I notice that the ad copy mentions phase inversion as a feature.) Actually, by using the transformer input, you can do both: convert an SE input to balanced and add a phase inversion function. If the transformers are indeed at the inputs of this phono stage, there would be no effect on the output of the phono stage, but the unit does seem to claim a balanced output.

Most likely they are using input transformers to create a balanced input from what is internally a single ended circuit.