Dynavector XV1-S and step-up

You need to know the phono gain of the Shindo preamp and the total gain needed for the Dynavector. The difference between those two numbers (in db) will tell you what you need in terms of the SUT. Then select the best quality SUT that affords you the needed gain when interposed between the Dyna and the preamp. The turns ratio of the SUT will also determine the value of the load resistor needed.

Lewm, my technical understanding is cursory, but here are the details available:

Shindo MM input: Pnono MM（RCA Pin Jack ) Input Sensitivity/Impedance：3mV/47KΩ.

Dynavector: recommended load resistance of > 30 ohms; output voltage 0.3mV (at 1KHz, 5cm/sec.);

Do these details at all get us to difference in gain. Pardon my complete ignorance.

Cheers

So you need to step up the voltage by a factor of 10 (from .3mV to 3mV). You can select a SUT with that information. The reflected impedance is related to the square of the turns ratio. With a 10:1 transformer, the impedance seen by the cartridge will be equal to 47K divided by 100, or 470 ohms. Some might say this is a little high for the Dynavector. For best results, you would replace the 47K load resistors with 10K load resistors, so the Dyna would see 100 ohms (10,000 divided by 100). Or,if you don't want to remove the 47Ks, you can calculate the value of the parallel resistance needed to reduce the net resistance to 10K, if you want the Dyna to see 100 ohms. I get 12.7K ohms as the value of that resistance.

In my opinion, gain is not the most important issue in choose the right step-up; the difference in gain of a 1:10 (20dB) to a 1:20 (26dB) step-up are really not that big. 6dB is easily compensated by the volume control. Also, it really depends on what gain your line stage has, some have 6dB, some 10dB some as high as 23dB. Gain is important but it is not the central issues in selecting the right step-up.

When selecting step-ups I would rather focus on the correct loading - The XV-1 has an internal impedance of 6 Ohm and Dynavector recommends 30 Ohm loading which is about right. A 1:20 step-up achieves a reflected loading of 117 Ohm. With a 22 KOhm additional resistor on the secondary (i.e. 15KOhm total loading) you get 37 Ohm. Certainly in the same transformer with more taps, I most often preferred the tap that gives the right loading without using extra resistors, irrespective of gain.

Finally different step-up are designed with different secondary load impedance in mind, loading a 1:10 at 10 KOhm may not necessarily ideal. Instead loading on the primary (i.e. before the step-up) may be preferred. To make a long story short, a 1:10 may work or not and so may a 1:20. The best result is in trying.