Walnut Hi-Fi V2 WAV (& MP3) Player by wt - :ok_hand: screenless budget killer combo DAP/Amp :ok_hand:
Aug 12, 2017 at 6:14 AM Post #3,272 of 3,631
Anyone getting the F1 planning to mod the input to accept balance input?

I wonder if they could just make it balance input with an adapter to do se.

That would have been brilliant, a true balanced amp with balanced input...

Highly doubt a interconnect cable that terminates at 2.5mm balanced at both end exist................. well at least I had never seen one before..............
 
Aug 12, 2017 at 7:56 AM Post #3,273 of 3,631
Highly doubt a interconnect cable that terminates at 2.5mm balanced at both end exist................. well at least I had never seen one before..............
Well I'm sure has seen one somewhere. Anyway, it's not like hard to do one by yourself :)
 
Aug 12, 2017 at 3:16 PM Post #3,275 of 3,631
Anyone getting the F1 planning to mod the input to accept balance input?

I wonder if they could just make it balance input with an adapter to do se.

That would require re-engineering the input stage of the amplifier, to "float" the L(-) & R(-) signals, since they're currently both connected to the common GND of the F1 - and they would be separate on the Balanced output of the source device.
Once the circuit etches are modified for the input wiring, you'd need to find and install a 4-pole volume control, in-place of the 2-pole unit.
You would then have to modify the circuitry around the Op-Amp socket, so that you can install a differential output device, in-place of the single-ended Op-Amp that's currently in the circuit.
The gain structure of the Balanced vs Un-Balanced input stage may also need to be modified.
 
Aug 14, 2017 at 4:38 PM Post #3,277 of 3,631
This kind of reminds me of the time they soldered the opamp.
Which do you prefer se input or balance input?
at Walnut F1 amp's price point, its target customers are probably "commoners" like myself, curious about balanced drive, but doesnt have the finance to dive into a balanced DAP or balanced drive amp. and so us "commoners" prefer SE input and Balanced drive output in the F1 to get our feet wet =P
 
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Aug 14, 2017 at 10:56 PM Post #3,278 of 3,631
Someone is hacking on my ipad. It feels like they are bufferring my keystrokes to get a head start on what Iam about to say.
I heard facebook monitors keystrokes before you even enter the message.

Anyway I saw Penon selling a 3.5 to 2.5 trrs adapter so if the input is balance I think it shouldn't matter.
Though a se to balance adapter probably is something else altogether.
But a balance input should accept se converted to balance. It just might cost more.
 
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Aug 15, 2017 at 12:26 AM Post #3,279 of 3,631
Someone is hacking on my ipad. It feels like they are bufferring my keystrokes to get a head start on what Iam about to say.
I heard facebook monitors keystrokes before you even enter the message.

Anyway I saw Penon selling a 3.5 to 2.5 trrs adapter so if the input is balance I think it shouldn't matter.
Though a se to balance adapter probably is something else altogether.
But a balance input should accept se converted to balance. It just might cost more.

The F1 has a Single-Ended Input, driving an OPA2134 dual Op-Amp, which can be swapped, like the ones in the Walnut v2 and Zishan Z1.
From looking at the photos of the amp, it looks like the Op-Amp then drives a pair of TI Burr Brown DRV134PA single-ended to balanced drivers [ http://www.ti.com/product/DRV134 ].

The issue with trying to connect a Balanced source to the Single-Ended input of the F1 - is that balanced outputs are four separate signals (L+),(L-),(R+),(R-).
Since the (L-) & (R-) signals can't be shorted together, without damaging the output amps in the Source, they have to be kept separate.

So, while you can drive balanced loads with a single-ended output - you can't (easily) drive a single-ended load with a balanced output.
 
Aug 17, 2017 at 1:29 AM Post #3,282 of 3,631
Can someone tell me if the Walnut V2 can use a 2.5 tttrs jack?

Sorry if this is a dumb or nonsensical question, I'm new to this audio tech stuff.

The Audio Input and Output of the Walnut V2 is Single-Ended 3.5mm TRS.
You can connect a 3.5mm TRS Plug -to- 2.5mm TRRS Jack Adapter, which will allow you to listen to Balanced Earphones from the Single-Ended output.
But, you can't connect a Balanced (TRRS) source to the Single-Ended (TRS) input, without shorting the (L-) & (R-) signals to GND.
 
Aug 17, 2017 at 2:29 AM Post #3,283 of 3,631
The Audio Input and Output of the Walnut V2 is Single-Ended 3.5mm TRS.
You can connect a 3.5mm TRS Plug -to- 2.5mm TRRS Jack Adapter, which will allow you to listen to Balanced Earphones from the Single-Ended output.
But, you can't connect a Balanced (TRRS) source to the Single-Ended (TRS) input, without shorting the (L-) & (R-) signals to GND.
Thank you, I'll just get the standard edition VE Monk SPC to listen to it, then :)
 

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