Should I buy XLR cables?

Am I understanding correctly that you have both rca and xlr, at the same time, going into your parasound amp? With A21 and A23 you can not do this! Well, you can actually, but it will degrade sound in a big way (I tried with my A23). You can have only one connection at the same time. Is the Hinto different in this ?

 

"Harmonics" is completely wrong way to describe this effect. Melody or melodics is phisical vibration transmitted thru medium made out of single frequency per unit time, harmonics are multiple melodics transmitted thru same medium at the same time, it has all to do with vibration and nothing to do with electrical. What you're describing is electromagnetic induction.

 

Maybe I wasn't totally clear - I was talking about power line harmonics (which manifest as a buzz rather than a hum). It has nothing (other than extremely obliquely) to do with musical harmonics. And coupling between shield power line (and harmonic) currents and the twisted pair in balanced cables is due to magnetic coupling through minor asymmetries in the cable construction. Like the difference in insulation thickness and dielectric constant of different coloured wires (seriously). They are extruded on different machines, and have a different dielectric constant as a result of the different coloured dyes used, these effects lead to a difference in capacitance between the cores and the screen of a few percent. And use of foil and drain wire shielding which inherently distorts the magnetic field seen by the wires.

 

I believe Kristofa is using both the XLR and RCA inputs of the Parasound Hinto. That's totally different than having both XLR and RCA cables connected to the inputs of an amp such as the Parasound A21 and A23. The Hinto is a preamp and amp where the A21 and A23 are just power amps.

 

Ok, roger that !

 

I've peered at photographs of the parasound amps on the web, and it is not clear what chips they use, apart from them being 8-pin DIL. There are a few that are in that package, including the THAT devices. Which would be good if they did. It is less clear what they did with pin 1, because they use circuit board mounted XLR's. So pin 1 could go anywhere. It is a bit of a dilemma what to do as a designer in that case. You want the connection to chassis to be as short as possible to prevent a radiating loop inside the chassis. But it has to be done via a circuit board trace somehow. I hope, since John Curl is often responsible for some of their designs, that things are done properly.

Anyway, Parasound is a well respected brand. It is a pity that the specs miss lots of detail out - I guess because Joe Public would tend not to understand what an extended spec (like CMRR with a 10 ohm imbalance) actually meant.

 

FYI some of the gear (mostly high end pro stuff) that I have worked on, has electronics (signal) ground and chassis grounds separated, aka chassis is connected to earth ground, but electrical (signal) ground is generated by power supply and not connected to chassis or earth ground.