Drip STA-Level Input Transformer wiring

[morls]

Hi,
I need some help with this stage of my build. Using Sowter 9062e input transformers, and the lead colour indicators on the PCB don't match the transformer leads. I'm also not sure whether to join the blue and violet leads of the secondary?
Here's the PCB:


And the transformer specs:


My current thoughts are to wire as follows (colours are transformer wires, ignore PCB):

PRI HI = Pink
PRI LO = Grey
SEC HI = Red
SEC LO = Yellow
CT = not sure. Join Blue and Violet and don't connect to this point? Connect both Blue and Violet to this point?
ISOLATE = White

Any help greatly appreciated.
Cheers
Stephen

 

[kazper]

What version of pcb?

Do you have the build guide and or did you look/compare to the schematic?

 

[schrobbelbop]

Hi,
I need some help with this stage of my build. Using Sowter 9062e input transformers, and the lead colour indicators on the PCB don't match the transformer leads. I'm also not sure whether to join the blue and violet leads of the secondary?
Here's the PCB:
View attachment 83178

And the transformer specs:
View attachment 83179

My current thoughts are to wire as follows (colours are transformer wires, ignore PCB):

PRI HI = Pink
PRI LO = Grey
SEC HI = Red
SEC LO = Yellow
CT = not sure. Join Blue and Violet and don't connect to this point? Connect both Blue and Violet to this point?
ISOLATE = White

Any help greatly appreciated.
Cheers
Stephen

That's correct, i've got it like this working.

I think now it's configured 1:4

 

[morls]

Thanks schrob

 

[Riinehart]

Thanks schrob

I'm in the exact same situation right now, so I was really happy to find this thread. Following up to see what you did with the Blue and Violet wires. Any insight? Thanks!!

 

[Riinehart]

Reframing this in a little more detail, in hopes maybe someone can help with the more general question of how to wire the secondary of an input transformer in series vs parallel.

According to the Sowter 9062 data sheet, with the secondary wired in series, the result will be "1CT:8CT or 1CT:4+4" ... and in parallel it will be "1CT:4".

From my understanding, the input transformer ratio in the original sta-level is 1:4, and somewhere in one of Gregory's video he mentioned he recommended a 1:4 ratio.

I think that, wired in the way morls and schrobbelbop suggested (connecting the Blue and Violet wires), the secondary would be in series, giving a 1:8 ratio.

If that's true, my question is: What's the appropriate way to wire the 9062 in parallel for a 1:4 ratio?

From what little I understand, I'm thinking to connect Red and Violet together at Secondary High, and Blue and Yellow together at Secondary Low.

Can anyone confirm if this is correct? Or help me understand the right way to do this?

Thank you!

 

[morls]

Hi Riinehart,

I'm trying to remember how I ended up doing this, and I'm pretty sure I connected blue and violet together, and didn't connect these to PCB. I can't be sure though, and it's a big job to get the STA out and take off the bottom of the case to have a look, as I've used hot glue to run a twisted pair from the power switch.

My guess is that it would be running at 1:8 ratio, as the input levels are very hot. I wouldn't mind trying it at 1:4, just to see whether a lower input ratio might give a different feel.

Sorry I can't be more definitive...

 

[Martan]

Hi,
I finished mine recently and wired the red and violet together and the blue and yellow together for 1:4. Should be right. I caution you: use your continuity meter to make sure the labels on your board are correct for the secondaries. I had the 2018 board and there was an error. Can’t remember what exactly, but one label was not in the correct place.

 

[morls]

Thanks Martan. It's things like the errors in labelling that make this a challenging build...

 

[Riinehart]

Thanks so much, Martan, it's extremely helpful just to know that's the right wiring configuration for 1:4 on the 9062. I'm new to this, so understanding where those wires should go (and whether there are errors on the board) will be a challenge. Fingers crossed!

 

[Riinehart]

For what it's worth, the 2020 boards I'm using appear to have been corrected. Just spent a little time following traces and testing continuity and all looks okay.