how to build a pre using S&B TX-102 transformers

[krishu]

Hi,

so I start this thread now without having much to tell.

Some links which may be helpful first:
S&B TX-102 official page
Hifi NEws (UK) Review
Hifi World (UK) review
audiotweaks bent kit review
audioasylum t.Loesch review
Bent audio ... some schematics etc.

Cheers
Christian.

[krishu]

Bent audio NOH preamp Assembly Photos
Bent audio download page .... schematics
Bent audio: TX-102 primary wiring schematic .... about +0dB and +6dB
bent audio: complete schematic with RCA and XLR inputs and outputs ... everything else

Cheers
Christian.

[Badge]

Thanks for the info. I am still interested in a remote control for volume. Perhaps one using FET switches for each step.

[krishu]

Hi,

easiest in my opinion is to use a rotary switch and a standard remote control kit in combination with a small DC motor and belt instead of motorized pot. A solution using relays is too big I guess.

Cheers
Christian.

[wytco0]

Great to see a build thread up for the TX102's, thanks krishu.

I got mine yesteday but I wont be able to start to build anything until later in January. At the moment I am not sure how I will approach my Pre Amp. I am looking forward to seeing other builders ideas.

I would also love a remote control solution but I dont want to do anything to compromise the sound quality.

Is there such a thing as a motorised multi position switch that we could use, I like the idea of a switch driven by a belt as it should be possible to keep the control system almost completly removed from the passive volume control. However I dont like the idea of making such a thing!! unless someone else could work out how to do it ;-)

PS I notice my transformers have different coloured wires, one has mostly black the other mostly white, is that significant?

[Stocker]

Krishu, relays can be had with exterior dimensions of less than 2cm on a side.

[ThorstenL]

Konnichiwa,

Originally posted by wytco0
PS I notice my transformers have different coloured wires, one has mostly black the other mostly white, is that significant?

That is intentional. One transformer is for L the other for R. Using different colours makes the wire spagetti a little better to work through.

Sayonara

[wytco0]

Thanks KYW, from speaking to JB yesterday I know you know a lot about these designs ;-)

[mcs]

Originally posted by krishu
A solution using relays is too big I guess.

What's too big for you? I got everything to fit on a single euroboard (16*10cm) using standard sized relays, or you could use squadras layout using four 8*5cm boards.

You can see the layout of my board here: http://electronics.dantimax.dk/Kits/11021716092.html

The price could get lower with a groupbuy...

Best regards,

Mikkel C. Simonsen

[Gregm]

Originally posted by Krishu
use a rotary switch and a standard remote control kit in combination with a small DC motor and belt

Have you found sourcing for the motor & remote? It seems that there's also a matter of torque involved...
Otherwise, the "mechanical remote" seems indeed to be a simpler solution.