[robinje]

I am currently running an AT 150MLX moving magnet cartridge with my AVA Ultra SL preamp phono section.  It sounds great!  I am, however, considering trying out a low output moving coil cartridge, which would necessitate an external phono preamp, or using some sort of "step up" device and continue using the phono section in my AVA Ultra SL preamp.  I've looked at the K&K step up transformers (highly regarded) and the Hagerman Picollo (active battery-powered JFET step up device).  Are these options, which don't cost an arm/leg, worth it?  Are there others I should consider?  I like the idea of continuing to use the built-in phono section in my preamp because it does sound very good indeed, plus I already paid for it!  Buying a complete external phono stage when I already have an excellent built-in AVA MM phono section kind of rubs me the wrong way.  Would using a step up device and necessary cabling in front of my preamp add too much circuitry/complexity to the phono signal path and negate any potential for sonic benefit from using a low output moving MC cartridge?  Curiously, Frank, why don't you make a phono section that has enough gain for low output MC's?  Please don't perceive this as a complaint.  I do really like the MM phono section in my preamp, and I'm sure you have a reasons.  Please share them.  Thanks!   

[oneinthepipe]

I am currently running an AT 150MLX moving magnet cartridge with my AVA Ultra SL preamp phono section.  It sounds great!  I am, however, considering trying out a low output moving coil cartridge, which would necessitate an external phono preamp, or using some sort of "step up" device and continue using the phono section in my AVA Ultra SL preamp.  I've looked at the K&K step up transformers (highly regarded) and the Hagerman Picollo (active battery-powered JFET step up device).  Are these options, which don't cost an arm/leg, worth it?  Are there others I should consider?  I like the idea of continuing to use the built-in phono section in my preamp because it does sound very good indeed, plus I already paid for it!  Buying a complete external phono stage when I already have an excellent built-in AVA MM phono section kind of rubs me the wrong way.  Would using a step up device and necessary cabling in front of my preamp add too much circuitry/complexity to the phono signal path and negate any potential for sonic benefit from using a low output moving MC cartridge?  Curiously, Frank, why don't you make a phono section that has enough gain for low output MC's?  Please don't perceive this as a complaint.  I do really like the MM phono section in my preamp, and I'm sure you have a reasons.  Please share them.  Thanks!   

I might be incorrect, but I think that I recall a recent thread in which Frank discussed a phono stage modification to accommodate low output cartridges.

[avahifi]

I have been working with the Insight+ phono section and I can easily increase the gain.  However, unfortunately, the background noise level goes up as the gain in increased.  The result, a low level soft broadband hiss is audible near the speakers.  It is swamped by the music, and sounds great with my Denon, but not quiet enough for production.

If you want to try it yourself with an Insight+ phono section, all you have to do is change the 1.1K ohm resistor next to the IC socket to a smaller value.  Cutting the value in half will double the gain, and so on.  There are two resistors on the board, one per channel.  This only works with a new PC-608 Insight+ circuit board, with the new OPA627AP chips installed.

Caution, it is easy to remove the plated through holes when you are removing parts and that can ruin the board.  You need a hot small tip solder station, and patience..  A sharp wood toothpick end is useful for reopening the holes to install the new resistor values.

Regards,

Frank Van Alstine

[Dan Kolton]

robinje,
DB Systems makes a budjet head amp (DB-11) that might be what you want.  It's reputed to be very quiet, and can be supplied with whatever input impedance you need.  It's price is even less than building the Hagerman.  Loading with step up transformers can be tricky (pretty much impossible if you need 47k for a low output Grado).

I wish Frank would make a stand alone head amp. with about 20db gain and adjustable input loading.  I'm pretty sure it would eat other head amps lunch based on Frank's other work; but it probably wouldn't be cost effective because of low demand.