How important is ext. adj. for cartridge loading


Hello Folks,

A New Phono Preamplifier will soon be introduced - MSRP around $1750 - $2000

A small "focus group" questionnaire - On a Phono Preamplifier how important is it to you that MC cartridge loading is adjustable from the front panel of the amplifier? How often do you "fiddle" around with loading ? Enough to warrant the cost increase, probably about $200 for the additional switches faceplate machining etc. pricing the preamp towards the higher end of projected price?

Same goes for MM/MC switching Would external selection be preferable to a internal Jumper setting ?

Is a MUTE function desirable on the front panel as well?

MC loading is at 100, 220, 330, 500 Ohms and 47K Ohms, do you think these are OK or would you like other values?

We have designed the unit so it can be used as a fully differential unit as well with one balanced input and one balanced output, you'd need two of them for stereo, do you find this desirable? Would you prefer this mode of operation to be selectable from the outside (switch on back) or would internal jumper selection be enough?

Thanks in advance for your thought on these questions

Peter
pbnaudio

Showing 1 response by viridian

Peter:

I don't change MC loading that much, though having it on the front panel would be nice. MC/MM selection on the front is not desireable to me as the first visitor or child that flips the swith to MC when you are running MM will cause an unfortunate increase in loudness. Just my take.

BTW, how does having loading on the front panel increase the cost of the front panel? Isn't it being machined anyway with holes punched in it? Don't you use a numerically controlled lathe for this operation?

Internal jumper is fine for choosing balanced/SE.

My preamp has mute, I don't need it on a phono stage.

You don't mention if loading is effectuated by transformer or active devices, so I will assume that it is actively achieved. Additional MC loading of 30 and 1K would be nice. In addition to 47K, 20K would be very nice for MM. Some MM cartridges, like the Grados, can sound better into this load and often it is not available.

You didn't ask, but I like a ground lift on the AC of a phono preamp. Sometimes it is the only way to make it really quiet.

While I'm at it, the more inputs for turntables the better. My preference is for three, switchable from the front. Two is still better than one.

These are just my personal preferences. Good luck with your new preamp. You didn't say what the tube compliment is, LOL.