Topping DX1 Gain: L or H for Sennheiser HD 560S?

[Sen]

Hi,

I have a Topping DX1 which has a "Gain" switch on the back with options: L and H.

I plan to buy Sennheiser HD 560S headphones tomorrow, which have the following specifications:

• Impedance: 120 Ohms
• Sound pressure level (SPL): 110 dB (1kHz, 1 Vrms)

While Topping DX1 has the following specifications:

• Output Impedance < 0.5Ω
• Output Power: 280mW X 2 @32Ω | 190mW X 2 @64Ω | 51mW X 2 @300Ω

As for the "Gain" switch, if I understand correctly, it should be set to "H" for high impedance headphones. What I'm not sure about is whether the HD 560S fall into that category, ie. would I have better results if:

• if the "Gain" switch is set to "L" and the knob is turned more, OR
  
• if the "Gain" switch is set to "H" and the knob is turned less?

By "better results" I mean that the sound in certain frequency ranges is neither weaker nor artificially louder than it should be (I want to maintain the neutrality of the sound as much as possible in accordance with the characteristics of those headphones).

 

[VMAT4]

Most likely low. High impedance in headphones is more like 250, 300, or 600 Ω. In general use the lower/lowest gain setting possible to suit your need for loudness.

 

[Jimbob54]

Use the lowest gain setting that gets you as loud as you like to go and/or the most usable amount of play on your volume knob. No point using low gain if max vol is only just loud enough, no point using high gain if you never go above (say) 11 o clock.

I suspect unless you EQ heavily or listen very loud, that low gain will be enough.

In half decent modern headphone amps, they are that clean that there is negligible noise penalty for using high gain, its more about usability.

 

[AnalogSteph]

Relevant DX1 specs:

Output level:
2.2Vpp @ G=L
11Vpp @ G=H

That's about 0.78 and 3.9 Vrms, respectively. Low gain would thus put you at about 108 dB SPL max. That is close enough to the rule of thumb of 110 dB SPL that I'd say 99% of people should be more than fine in low gain.

And should you ever find yourself in need of digging into the lowest noise floor of demanding classical recordings, 14 dB more gain is just one flip of a switch away.

 

[Sen]

Thank you!!!

 

[Sen]

One more question, if it's not a problem (and maybe it's a stupid question, but I have to ask )
Topping DX1 has two outputs: 6.35mm and 3.5mm.
Is there any difference/advantage between the two outputs?
Sennheiser HD 560S by default has cable with 3.5mm jack, but 3.5-6.35 adapter is included.

Probably there is no difference, I looked at the specifications but I didn't see anything that would indicate any differences between the two outputs:

 

[AnalogSteph]

My guess is they're just wired in parallel and both are present for convenience. Much like the 4.4 mm balanced outputs on some of their higher-end models (e.g. L50).

 

[Dunring]

I've had both, you'll be fine in low gain unless you equalize with a preamp reduction, then I had to use high gain. Also with replaygain, or pre volume war recordings like the extended version of Tonight,Tonight,Tonight by Genesis and you'll need high gain for the quiet parts of that song.
For day to day use, low will be fine on those. They're really nice out of the box. The Autoeq profile was ok, but I game so don't boost bass up much.