Responses from ghostrider45

Can 12AT7 be a substitute for 12AU7 tubes?
The tubes are electrically pretty similar, so you won't smoke anything, but as previous posters have noted the gains of the tubes are quite different, so there would be sonic change. 
Stereo sub out to mono, is it safe?
If the sub outs are not buffered and high pass filtered, and are merely connected in parallel with the main L/R outs, then when you connect the sub outs to a y adapter you will also mix the main L/R channels and make the whole system mono. 
Do I need BOTH amp and pre to be sonic holography?
The reason for the delay is that you want the out-of-phase right channel signal injected into the left channel to arrive at the left ear at the same time as the (in phase) acoustic right channel signal arrives at the left ear, resulting in cancell... 
Do I need BOTH amp and pre to be sonic holography?
Magfan Pehara and Zydo have it right. The Sonic Holography circuitry took a band limited (mostly midrange) signal from each channel, delayed it slightly, and injected it in reverse phase in the opposite channel. Carver built the circuit into their... 
audiophile rockers
Katy Lied was one of the first albums recorded with dbx noise reduction. Unfortunately the encoder malfunctioned, and they were never able to recover the original fidelity, even when dbx tried to hand tweak a decoder to complement the flaws in the... 
HDMI dembedder option for DAC use?
For your scheme to work you need a device that will extract the DSD datastream from HDMI, convert it to a PCM datastream (perhaps 24/96) and output it on connection compatible with your DAC. From its description the device does not appear to suppo... 
One Monoblock or Two?
If you bi-amp, you probably don't want 2 - 300 watt amps instead of one 600 watt amp. The high frequencies need much less power than the lows, so it usually makes more sense to use a fairly large brute force amp on the bass half, and a much smalle... 
Yamaha PX-2 Cartridge
I wanted to try a MC cartridge on this table. The 304 is a low output MC cartridge that seems to mate well with the arm. It has higher compliance than the DL 103, which is why I chose it. I think it is a solid performer. It is very detailed and ha... 
Yamaha PX-2 Cartridge
I have one with a Denon DL 304 mounted. 
Wadia Remote Control
Which remote? They have many... 
Rogue Audio M 180 fuse upgrade
The purpose of fuses is to protect your gear. Using a larger value fuse will allow more current to flow before the fuse blows in case of a problem, and other expensive parts like output transistors may be damaged instead of the cheap fuse. As othe... 
Getting New Panasonic ST30 Plasma TV
Don't know about the Panny in particular, but almost all sets come out of the box in "torch mode", with brightness and contrast set high to make the set look good in a showroom. You will want to dial back the settings, especially on a plasma, sinc... 
ST optical to TOSLINK cable... & good ST cable?
They operate on different wavelengths and are not compatible. 
What is your source for discovering new music?
WWOZ over the air or cablePandora 
Looking for a silver lining
Pass XVR-1 is an all analog programmable crossover with balanced ins and outs. I use one in place of the stock electronic crossover that came with my Apogee Studio Grands and it is much more transparent.