2. analog
  3. 1273516085

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
viridian's avatar
viridian
4,184 posts
 
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.
swampwalker's avatar
swampwalker
5,132 posts
 
Hi Peter-
I pretty much agree w Viridian.
Front panel switchable loading for MC would be great.
If X-former MC, then I would recommend post for easily
insertable resistors to set loading precisely.
Internal jumper for balanced/SE (or maybe rear panel
toggle switch)
I personally do not need nor do I envision needing 2 or
more phono inputs, but a rear panel switch for
mm/mc OR separate input jacks for mm and mc is good.
Hopefully we have not blown the budget ;~)
dgarretson
2,394 posts
 
Peter,

At that price point I would prefer the money invested in higher quality piece parts. However front panel or even remote control adjustable loading is becoming de rigueur at higher price point(e.g. Manley and ARC Ref phono.)

For MM/MI consider load options 47K>100K. These higher-than-spec values can sound much better with some MM-- and very few if any manufacturers understand this.

Regards,

Dave
More to discover