My Rogue RP-5 has all SE connections (I now wish I spent a tad more and purchased the RP-7 which is balanced). That aside, from all the reviews I’ve read on the Stellar and BHK amps, the RCA connections sound fantastic. Of course, full balanced connections will bring the most quality and quietness (especially with longer cables).
My question:
Does any advantage exist of running RCA out from preamp using an XLR adaptor and and using the balanced input of the Stellar/BHK amp?
None whatsoever. In fact, adding the adapter may be detrimental; avoiding unnecessary connectors is always wise.
If you want to stick to the RP-5 and are considering a BHK or a Stellar I would go for a SE-XLR transformer. Simple, cheap and (IMO) the best solution. Unless the BHK or Stellar have the ability to do that internally, by shorting pins 1 and 3 and ‘making’ it balanced.
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.!
Having gone that route before, using high quality Purist audio adapters, I can safely say adding any adapter, no matter how good, is a step backwards.
I know the whole backwards ideology and it’s true when the person doing the modifications doesn’t have a clue as to what their doing. But the reason I am doing the above is to get rid of a nasty low level buzz in my left channel while bumping up both front L & R to better level match (+6dB) my Center Channel . The above worked like charm. I removed all the crappy parts as mentioned in my previous post and for now I have 4x OPA2134 op-amps swapped in along with the WIMA & Visahy Caps. I also got some Brown Dog dual 8 pin SOIC to 4 pin standard IC adapters for trying out some OPA 627’s (I had 4 but fried two on another circuit I was working on - $$). I’ve read every damn OPAMP “rolling” post there is and prefer to figure it out for myself.
I had a problem…fixed it…now it’s time to play. When I crank the Stellar Gain Cell DAC/Preamp to 100 (no music), all I hear is glorious low level hiss from the amps and my Bose “Dog’s Breakfast” EQ. This is with my ear next to the front or rear 8 cones. Just for fun, I bypassed the EQ and did the same “100” test. Same amount of low level hiss. At normal listening levels, no hiss and no buzz at all EQ in or bypassed !
I agree with Elk and Gary M. Unless the components are designed as fully balanced, a single-ended RCA connection is likely to produce better sound than any combination of add-on adapters or additional circuits. There are some people who argue that single-ended connections often sound better than balanced XLR connections simply because the signal is not being fed through the additional circuitry needed for a balanced connection. The obvious exceptions are when you are running very long interconnects or experiencing significant noise on a single-ended connection; in those cases, a balanced connection should produce better sound.
In comparing the RCA connections to the XLR connections on my SGCD preamp feeding M700 mono blocks via 1m interconnects, both RCA and XLR are very quiet and have similar sound quality but the XLR is louder.
I ordered a BHK pre. Until I order new amps, in a couple of months, I’ll just use the SE connection to my amp and purchase RCA/XLR adaptors for my sub connection.