Step-up transformers. How much gain is too much?

Rocketman248 · 722

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Offline Rocketman248

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on: September 22, 2019, 01:51:26 AM
So I'm in the planning/saving stages of some system upgrades.  Getting a new turntable and cartridge in a few months, and I have some questions regarding step up transformers when paired with an Eros.  Current setup is an Ortofon 2M Black into an original Eros, which is then fed into a BeePre and Kaiju.  In a few months, I'll be upgrading my table to a VPI Prime Signature, and I'm shopping around for a suitable cartridge.  On the short list right now is a Hana ML or Lyra Delos.

I know both of those carts will require a Step-Up Transformer, and I do have one that I kind of accidentally bought a few years ago (dumb, unresearched purchase).  It's a Phasemation T-300, with 26db of gain, which after some reading, leads me to believe it's a 1:20 ratio.

I'm pretty much terrible at math, so could the wizards here let me know if that's too much gain to be paired with the Eros/BeePre?  Will it be ok, or should I look for a 1:10 transformer? 

Here's the specs for the two carts:
Hana ML:  0.4mV output voltage.  8 ohm impedance.  >100ohm recommended load impedance.
Lyra Delos:  0.6mV output voltage.  8.2 ohm impedance.

Thanks

Nick DeBrita
Yokosuka, Japan


Offline Paul Birkeland

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Reply #1 on: September 22, 2019, 05:15:27 AM
That step-up transformer is probably too much for the Eros with both of those cartridges, though in my experience that 1:20 will dip down a bit depending on loading.  For the 1:20, I would look for a cartridge that's no more than 0.3mV and plan to load the secondary down a bit to reflect an appropriate load to the cartridge. 

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline Rocketman248

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Reply #2 on: September 23, 2019, 02:35:56 AM
I'll probably just plan on getting a 1:10 SUT.  Although I'm not opposed to building one if anyone can recommend some decent plans.

Nick DeBrita
Yokosuka, Japan


Offline Paul Birkeland

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Reply #3 on: September 23, 2019, 04:23:32 AM
If you have the Eros 2, you can install a pair of Sowters right into the chassis with the holes we have provided.  I'd also recommend a 1:10/1:20 SUT so you have some flexibility.

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man