Testing MC step up transformers

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Re: Testing MC step up transformers

Post by lejonklou »

Yes, some MC stages use an RCA jack where you can plug in the resistance of your choice. Internally, that will be presented as a load parallel to the cartridge.

I contemplated adding this to my Entity MC phono stage, but my experience is that there's a loss of quality when the load is applied like this instead of being soldered directly at the input on the circuit board. So I would actually prefer a slightly suboptimal load to an optimal one that's connected externally. This is a tricky matter, as there's a compromise no matter how you do it. Except in the case where you actually open the unit and solder the optimal load to the board (as you do in SINGularity).

When using a step-up transformer in front of an MM stage, the load on the input of the MM stage (47 kohms) will be transformed into a much lower load. How low depends mainly on the ratio of the transformer. Do you know the ratio of the transformer? If so, we can calculate the load as seen by your Denon MC cartridge.
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Re: Testing MC step up transformers

Post by FalseMetal666 »

Yep, I'm running a Denon AU-103 transformer with 1:10 windings, so I believe the Gaio is seeing a 470 Ohm load.

I recently replaced the Bellari transformer I was running, which was wound at 1:12.

I've been considering messing around with some parallel resistance jacks in the transformer outputs, like the one from my previous post.
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Re: Testing MC step up transformers

Post by lejonklou »

FalseMetal666 wrote: 2019-09-27 04:48 Yep, I'm running a Denon AU-103 transformer with 1:10 windings, so I believe the Gaio is seeing a 470 Ohm load.
Correct.
FalseMetal666 wrote: 2019-09-27 04:48 I've been considering messing around with some parallel resistance jacks in the transformer outputs, like the one from my previous post.
You could do that, using a 13 kohm resistor. But you will likely get even better results by adding a 130 ohm resistor on the primary side of the transformer.
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Re: Testing MC step up transformers

Post by FalseMetal666 »

Fascinating. Looking like I'll be placing a parts order momentarily.

Planning on getting matched pairs of tantalum resistors...any suggestions to the contrary?
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Re: Testing MC step up transformers

Post by lejonklou »

There are many fancy resistors out there. All the really expensive ones I've tried have sounded weird. Everything labeled "Audio" is just crap - that seems to be a rule with very few exceptions. High precision metal film is good. Every brand and model sounds a bit different.

Just like with HiFi, the fanciest stuff is usually terrible. The good stuff is hidden somewhere and it takes a while to find it.
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Re: Testing MC step up transformers

Post by FalseMetal666 »

Makes good sense to me.

Thanks again!
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