SOLD Step-up Transformer w/Cinemag 3440As and ground-lift switch

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mike_p

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Courtesy of Wojiech over at the Asylum, a pair of Cinemag 3440A transformers in a nice cast aluminuml case (sorry, I thought it was steel), w/decent RCA's and a ground-lift switch. Good starter for someone (like me) getting started with low-output MC's. Works great at the 1:18 (150 ohm) tap for a Denon 103 or 103-R (and most LOMC cartridges) into a phono stage looking for an approx. 5 mv signal, give or take.






Cinemag lists only the load impedance of their transformers, rather than listing the transformers' turn ratios. A Cinemag 3440A phono transformer has taps for load impedances of 37.5, 150 and 600 ohms. Those figures are the load impedance that the phono stage 'sees' from the cartridge. The stated cartridge load impedances of 37.5, 150 and 600 ohms are measured in reference to a hypothetical 50k ohm MM phono stage impedance. Dividing that 50k ohm reference input impedance by the square of the turns ratio for any of the 3 taps gives one of the stated load impedance figures. When solving for the turns (step-up) ratios, you get (approx.) 9:1, 18:1, and 36.5:1. If you need less gain, try the 9:1 (600 ohm) tap. [I wouldn't imagine you'd use this transformer for the 36.5:1 tap. If you can afford one of those wonderful, really pricey, super-low output MC carts and need more gain, you're probably going to buy a Bob's Devices 'blue' Cinemag step up if you use a SUT. (Wojciech would rather have a Hashimoto . . .)
« Last Edit: 30 May 2014, 11:33 pm by mike_p »

loving_it

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Re: Step-up Transformer w/Cinemag 3440As and ground-lift switch
« Reply #1 on: 21 May 2014, 01:46 pm »
what gain and cartridge loading its configured for at this time.

mike_p

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It's currently strapped to the 1:18 tap. With the (standard) 47k input impedance of my Seduction phono stage, that works out to 145 ohms load impedence and about 25 db gain.  The Seduction w/C4S has 40 db gain. My 0.25 mv Denon 103-R with the combined 65 db gain works well into (the 100k input of) a Stereomour 2A3 amp (no line stage in the chain).