[ADUHF]

I would better use the 2 line outputs of the Focusrite for that. Dunno if you can do balanced->SE without a converter?

This seems like another obvious alternative. Imo though, you shouldn't go from a balanced output to an unbalanced (aka single-ended) input, or vice-versa, without an appropriate line level converter/transformer.

Some pro audio devices can support both types of signals on the same input or output, with appropriate connectors/cables (e.g. TS->TS, or TRS->TRS). But I don't think you'll generally see that in consumer audio gear. And it's not something I'd try, unless you are absolutely certain that the connectors on the device are compatible with both kinds of signals and cables.

There are differences in grounding, signal levels, connectors, pins, etc. that just generally make balanced to unbalanced connections a bad idea. And something to be avoided. It's just better, and also more convenient to use components with compatible signals and connectors, imho.

 

[pevsfreedom]

So this thread is way off the rails, which is OK,

but so on the back of the S501 are Line level inputs (unbalanced). The output off the back of the Focusrite are... mono balanced? I have two mono 1/4" TS going to RCA into the S501 now (I got my 'music' room set-up yesterday without the Heresy).

As I said in another thread I got my electronics degree many beers ago and forgot most the basic stuff

 

[pevsfreedom]

(I got my 'music' room set-up yesterday without the Heresy).

And a picture, because why not?

 

[helloh3adfi]

The output off the back of the Focusrite are... mono balanced? I have two mono 1/4" TS going to RCA into the S501 now (I got my 'music' room set-up yesterday without the Heresy).

No, they are TRS. I don't know if it's a good idea to use TS instead...

 

[pevsfreedom]

"LINE OUTPUTS: LEFT and RIGHT – 2 x ¼” (6.35 mm) TRS jack sockets; +10 dBu output level (variable), electronically balanced. Either ¼” TRS (balanced connection) or TS (unbalanced connection) jack plugs can be used." With the S501 amp the TS cables are better because they are now unbalanced, and the cable downgrades the balanced connection to unbalanced to better interface with the amp.

It appears that though 100% not technically ideal, in the real world this balanced > unbalanced set-up just results in an unbalanced signal, which the S501 is designed around. I don't see any downside besides theoretical arguments that they aren't a mated pair, but I have read extensively this type of set-up is very often used, and with a cable run of 3' shouldn't have any issues whatsoever.

 

[ADUHF]

"LINE OUTPUTS: LEFT and RIGHT – 2 x ¼” (6.35 mm) TRS jack sockets; +10 dBu output level (variable), electronically balanced. Either ¼” TRS (balanced connection) or TS (unbalanced connection) jack plugs can be used." With the S501 amp the TS cables are better because they are now unbalanced, and the cable downgrades the balanced connection to unbalanced to better interface with the amp.

If the documentation on the Focusrite interface says that the 1/4" outputs can be used with either balanced TRS or unbalanced TS cables, then you're probably ok.

The unbalanced inputs on your S501 amp are most likely designed for a somewhat lower signal level than +10 dBu though. And I'm not sure how using the TS cable might effect that. You can read a little more about the different signals here though...

https://en.wikipedia.org/wiki/Line_level

I believe that balanced pro audio connections normally us a +4 dBu line level. And unbalanced consumer audio connections use -10 dBV line level. Which is one of the reasons it's not generally a good idea to try to interconnect them without an appropriate signal converter or transformer. The volume control on your interface may be sufficient for that though. (?)

If the 1/4" outputs on the interface support TS, then you could probably also try connecting them to the unbalanced RCA inputs on the Heresy amp as well, using unbalanced 1/4" TS to RCA adapter cables. Just be aware that your Heresy amp may also be expecting a lower signal level than your interface is capable of putting out. More on the order of -10 dBV.

It appears that though 100% not technically ideal, in the real world this balanced > unbalanced set-up just results in an unbalanced signal, which the S501 is designed around. I don't see any downside besides theoretical arguments that they aren't a mated pair, but I have read extensively this type of set-up is very often used, and with a cable run of 3' shouldn't have any issues whatsoever.

I can't explain the differences in a way that an engineer could understand. I just know from using alot of different gear that going balanced <-> unbalanced is generally a bad idea. And that there's more involved than simply dropping a wire or pin. If the docs for your device says it's ok though, then you're probably in the clear.

The balanced connections that are sometimes used on consumer audio gear are also not well standardized. Which would make me even more cautious about the type of cabling I'd use with them. When in doubt, RTFM. (And say a little a prayer to your favorite audio deity!)

 

[ADUHF]

Article on the subject of +4 dBu vs. -10 dBV, and balanced vs. unbalanced cables/connections that may help to explain some of the differences a bit more...

https://www.bhphotovideo.com/explor...humored-attempt-demystifying-10-dbv-and-4-dbu

One of the main uses of a pro audio mixing board is to perform conversions between all of the above signals btw. So if you're working in a studio, you generally wouldn't need a dedicated balanced <-> unbalanced line level converter, like the one shown in the above article. Or like these two devices made by Radial...

https://www.radialeng.com/product/j4
https://www.radialeng.com/product/j-iso

 

[ADUHF]

I generally try to avoid attenuating the volume on the source components in my setup, btw, because of the potential effect that can have on noise levels. If I'm using a PC to drive some other audio devices, for example, then I'll try to keep its volume at or close to maximum to keep the noise floor as low as possible. And will make only some minor negative gain adjustments with a preamp filter in my EQ software to prevent clipping.

If you have to attenuate the volume on your interface to bring the levels on the 1/4" outputs down to something that's more appropriate or manageable for an unbalanced consumer line level input, I wonder about the effect that might also have on the signal's relative noise levels, and the audibility of noise downstream in your headphones and other gear.

 

[pevsfreedom]

So far I've noticed zero distortion at any point. I did a full turntable set-up yesterday since moving and was kind of shocked at how good it sounded. With the Focusrite plugged in the source audio is bypassed (by choice) so it's maxed out there, at the DAC (Focusrite) and I just control volume thru the S501's. I will say the R820f speaker experiment in a small room did not work out.. I am gonna have to swap speakers between living room (Cambridge S30s right now) and music room, but that's probably more sensical regardless Besides that, I got my wife to try on the Sennheiser HD600s, and she typically hates headphones/earbuds, but she didn't want to take them off and kept listening to stuff. She loved em. Funny enough in this set-up I bought the Focusrite Solo 3rd gen, which I guess the 3rd gen's biggest upgrade is balanced output, so maybe the 2nd gen would have been a tiny bit better suited.

 

[ADUHF]

No distortion is good distortion imho.

Distortion is a bit different than noise though. And mostly effects the clarity of your signal. While noise will usually be heard as a subtle, but continuous hiss.

If you hear more of a hum, that's usually related to the ground or interference.