Partridge 977 mc transformers good match for this?

[hawkan2580]

Hello all,

I am not really a techie but know how to solder well (musician by trade and you either learn to solder or go broke quickly lol)... IE, I can do the work but flunk the math

Anyhow. I have a Benz Micro ace medium output cartridge on the way and only a fairly standard mm phono input...

Here's the data...

Cartridge
Benz Micro ace Type moving coil
Output Voltage 0.8mV
Load Impedance 200-47k ohms
Output Impedance 24 ohm

I've read that the "best" load for this cartridge is 250ohm.. but you know, you read one thing from someone who has a one type of amp/speaker and someone else chimes in and states the opposite based on their system... but more then one has stated that its optimal load is 250ohm..

The MM inputs sensitivity is 2.5mV (but obviously, one can run it with a bit hotter signal such as 5mV .. max input is 300mV but thd would go up to 0.5%

ohm is switchable between 30 komh /50 kohm /100 kohm

so I thought I'd buy a pair of partridge 977 and build a SUT for this with:
6 : 1 step up ratio.
26 ohms input DC resistance.... 300 ohms impedance.
250 ohms output DC resistance.....10k ohms impedance.


Would this be a good match??? I can work out the mv signal strength but get terribly lost in the rest of the math.. reflective, primary& secondary load etc..

So basically, if I build a SUT using these transformers, would I need to start playing with resistors and the like or will it be a good match straight in the Box??? Just thought I ask before buying them to do my first DIY hifi project

Thanks,

Hawkan

[merlin el mago]

This link help you: mh-audio.nl - Home

According with your specs and the calculators:

Min. gain: 11,5dBs (Partridge 977 have a gain of 15,56 dBs enough for your cart)
Cartridge load: 1.305,6 ohms
Resistor tuning: 11.131,6 ohms
Closest standard resistor tuning value: 11.100 ohms

Cheers
Felipe

[hawkan2580]

Thanks for that, appreciated!!

[merlin el mago]

I also own a couple of Partridge 977, good stuff

[hawkan2580]

Cheers, I just ordered a couple.. will be fun to see if I can make it work.. looking at what others have done, it doesn't seem to hard of a thing to make.. the resistor tuning the only "new" thing, haven't pics of how they are wired up but from what I gather, it is just a resistor on the 'out' on the transformer, right? IE, cartridge - 6:1 transformer -resistor- mm phono stage...

As I pre-warned, I'm not good at this sort of stuff but we all have to start somewhere haha..

[merlin el mago]

Yes: cart+res load+tx+res tuning+mm=enjoy

[dady]

Originally Posted by merlin el mago

I also own a couple of Partridge 977, good stuff

HI Merlin el mago, I saw you have one pair of this stuff transformers. Did you have you compare with another similar one? Please your answer could be important to me.
Best Regards

[merlin el mago]

I compared vs AudioTechnica, Partridge no hum vs AudioTechnica with hum.