Preamp 47K load. Cartridge needs 330 ohm


Experts!!!

Preamp is Conrad Johnson PV7.  Recently refurbished by Music Technology.

Cartridge is Miyabi Cello Chorale 0.35 mV and needs 330 ohm load.

How do I solve.  Preamp load not adjustable.  Any interface box like Puffin?

Or maybe a Andover SPINSTAGE PHONO PRE-AMP

Or a Lundahl or similar transformer?   I am not sure.

Thank you.

dcaudio

Nad used to make inexpensive electronic pre-phono box that boosts necessary gain pretty much for any cartridge.   Classe Audio NIL is probably higher priced pre-preamp.

lewm

I just wanted OP (or others following this) to know, 1:10 is not absolute, as a matter of fact anything up to 1:12 will be good, 1:12 might be best.

I agree 1:12 is limited; and 1:10 is more common, however, IF the OP searches, asks for help, and gets answers like above, he can end up with 1:12 or very close (my FRT-4 has 1: 10.55, who would look for that?

imhififan

Good find, seems like a very versatile unit. Independent Control of Gain and Impedance it ideal for current and future cartridges.

Allasso was on my chart, but I’ve never seen one, and never know if what I find is old or current.

I don’t see PASS for an MM, but it only has ONE input, so who needs PASS?

PASS would let you change to an MM cartridge or headshell with alternate MM pre-mounted/aligned and leave the cables Tonearm to SUT and SUT to MM Phono EQ (external or internal)  in place, that’s a big advantage IMO.

 

samssa

another good find!

 

 

I just wouldn’t perpetuate the myth that the OP needs precisely a 330 ohm load for his cartridge. If he goes away believing that then he won’t have learned anything.The Cello Miyabe is an MC cartridge with an internal resistance of 2.5 or 3 ohms, based on two different sources. (To the OP) Generally you want the input impedance of the phono stage to be about 10X the internal R of the cartridge. Therefore technically you could load your cartridge with any impedance greater than 30 ohms, on up to even 47K ohms. You could even go below 30 ohms load, but then you begin to sacrifice cartridge output. Many say they hear differences in tonal balance exquisitely related to input impedance with LOMC cartridges, but actual measurements usually don’t support this belief.