I agree for the most part. But after integrating the SGCD/Preamp with my Sony AVR’s true differential XLR output’s (volume control bypassed), the gain is about 6 dB down (expected) between my center channel versus my front L & R speakers. It’s a pain every time I play 5.1 discs and have to reduce the center channel every time to match the front L & R. I expected this when I first set this rig up. While the RCA’s are fed into my Bose Series 2 “Dog’s Breakfast” EQ and it’s RCA’s fed out to the two M700’s. Things are super silent but 6dB down. So I bought two adapter boards from China ( I know…I know). These things have what I assiume to be fake “Nichicon” power supply capacitors and no name yellow 100nF bypass caps. The “TI” opamps are look alike 5534 knockoff’s (I think). I plugged it in running 17VDC + & - fed from a Toroidal transformer/full wave bridge rectifier and two 100uF made in the USA Vishay Aluminum Electrolytics ($$) bypassed with two 100nF SMT ceramics 0805 size (cause I’m old). As expected, the mids & high’s are a bit shrill but I have better Bass extension (WTF ?). One would think running two of these adapter boards (differentially going in from the SGCD then single ended to and from the Bose EQ box and then converting back to differential out to the M700’s with the second PCB) would increase my systems noise level using the crappy components they came with. I will say that the actual PCB fit and finish is pretty damn good for China. Gold flashing on the PCB and gold plated XLR pins/RCA jacks and 2.54mm holes to direct connect single ended bypassing the RCA’s.
No additional noise issues but I have ordered more 100uF Vishay’s, 100nF WIMA’s, along with genuine OPA2134’s, NE5534, and SMT to thoughole adapters for fitting some OPA627’s onto.
The resistor’s however appear to be (measure) as 1% metal film type resistors (they must be… they are blue in color…LOL).
Here’s a link to the the boards I bought. Took about 1.5 weeks to get here.
As Elk mentioned. One has to really understand what they are doing or else you can make things worse and lose all that glorious sound of the Stellar Stack.!