Sowter 1090 Transformers

[mediumgrade]

Folks,

I have been running my Eros 2 with a Hana HOMC cart for a little while now. Generally, I am fairly happy with the results. Paul said I might want to look into adding some Sowter 1090 transformers as my Hana cart only pushes about 2mv. What do you all think? I mean, my TT rig does have a bit less drive/authority than my DAC output, would the Stower help? Anything else that it might improve? Any tradeoffs?

[Paul Birkeland]

You'll get more gain with the SUT and lower perceived noise floor since there's more signal going in.  You will decrease the loading on your cartridge to around 10,000 ohms, which is still about 10 times higher than it needs to be.

[mediumgrade]

You'll get more gain with the SUT and lower perceived noise floor since there's more signal going in.  You will decrease the loading on your cartridge to around 10,000 ohms, which is still about 10 times higher than it needs to be.

So... good?

Later, if I want to pair with a LOMC cart, do I need to remove these transformers or can I use an external step-up transformer with these?

[Paul Birkeland]

You would need completely different step-ups for a LOMC.  This is why I would tend to recommend the configurable 1:10/1:20 units, as they will work with a much broader variety of cartridges.  The 1:2 step-ups are really only effective for HOMC carts.

[mediumgrade]

But, if I leave the 1090 in, can I add an external one later if I want to use it with a LOMC cart? In short, can I use two transformers or can I only use one for some reason?

[mediumgrade]

I am trying to see if I can avoid having to remove the 1090s altogether in the future if I switch carts.

[Paul Birkeland]

I would not recommend using four transformers for this purpose. 

[mediumgrade]

Thank you.

[mediumgrade]

So, I just received my Sowter 1090 transformers and I was going to attempt to install them based on the guide posted in this forum, but the colors do not match the photo previously in the "Eros 2 Step-up Transformers" topic. In the picture, there seems to be a yellow/pink pair and a white/grey pair. My 1090 transforms only have white, yellow, orange, pink and black (no grey) (see attached images). Does anyone know how these are supposed to be wired up?

Apologies for my ignorance on transformers.

[Paul Birkeland]

Here's the datasheet:
https://www.sowter.co.uk/colours/1090.pdf

The white and yellow wires go to the RCA jacks and the pink and orange wires connect to the terminal strips in the same manner as the instructions posted elsewhere.  The black wire is an electrostatic screen and can connect to the ground buss wire wherever it's convenient.

[mediumgrade]

Here's the datasheet:
https://www.sowter.co.uk/colours/1090.pdf

The white and yellow wires go to the RCA jacks and the pink and orange wires connect to the terminal strips in the same manner as the instructions posted elsewhere.  The black wire is an electrostatic screen and can connect to the ground buss wire wherever it's convenient.

Thank you for that. When you say that "white and yellow wires go to the RCA jacks and the pink and orange wires connect to the terminal strips" does that mean the yellow and pink are "positive" and white and orange are "ground?" Does that make sense? I am basically asking which colors should be positive and negative on either end.

[mediumgrade]

Or should white line up with pink and yellow line up with orange? Sorry, I guess I don't fundamentally understand how to wire up transformers.

[Paul Birkeland]

You just need to be consistent between channels.  So either yellow and orange are your ground wires on both channels or pink and white are the ground wires; it's up to you.

[mediumgrade]

Thank you, Paul. Your patience is appreciated.

Unfortunately, in trying to remove the loading resistor, I broke it. Is this the type I need?

https://www.digikey.com/en/products/detail/vishay-dale/RN65C4752FB14/3338505?utm_adgroup=Resistors&utm_source=google&utm_medium=cpc&utm_campaign=Shopping_Supplier_Vishay&utm_term=&utm_content=Resistors&gclid=Cj0KCQiAyMKbBhD1ARIsANs7rEGhUHvmOgdcXIZ8CwqRPMzj88fyfpiP6Db9Q6MM_uIjm2BHu4BW4v0aAqvxEALw_wcB

Please let me know. Thank you again.

[Paul Birkeland]

The RN65 will be a bit bigger, while the RN55 is the same size.
https://www.digikey.com/en/products/detail/vishay-dale/RN55D4702FRE6/3336173