PH16XW NoiseFloor/Hum

deepee99 wrote:

cci1492 wrote:

Peter W. wrote:Three, as it happens.

Yeah? Spill the beans, which ones?

Until Peter W. comes off with his mysterious three, I can recommend the phono pre-amp built into the old Hafler DH-101 line pre-amp, at least for 47 uF MM cartridges. I was AB'ing it with the tube phono preamp I have and was pleasantly surprised. Also, there are lots of little tweaks you can do to this and other early Hafler gear to make it run like a $2,000 preamp.

As it happens, my Hafler is one of them.
Signal to Noise, weighted (3.12): 87 dB
Unweighted comes to well over 100 dB

My HK Citation 17 is another, as specified, 80 dB, as tested, 97 dB (on the hand-written test sheet that came with it) which I am figuring is close enough.

The last being the Dynaco PAT-5 biFet. As specified, 90 dB. Actual is again, about 97 dB, close enough.

The Revox A720 has relatively poor written specs, but I will state that it shows the least audible noise from the phono section at full volume.

Then, there is pretty much everything else.

cci1492 wrote:If they offered one with that walnut case, the wires on the rear panel and no hum, I might buy one!

Roy did mine that way with the RCAs, ground lug, and IEC/combo switch on the rear.  He also cut slots in the top cover to access the DIP switches.  

He probably will charge a bit extra for the cutting of the steel, but not much.

You could wrap it with wood but cut the rear piece so as to clear the wires/switch.  Or just wrap 3 sides.

Sorry about the fuzzy picture.

I love this preamp and there's no hum!

Looks good, I wonder if there's any benefit to using the toroidal ta instead.

the standard "flat-pak" transformers are extremely quiet, no advantage to going with the toroidal in this case