[newworld666]

Actually I use a Monolyth THX 887 for my Headphone by Hedd with a sensitivity of 87 db for 42 Ohms, which give me really good results and requires often to turn 75% of the volume knob or more for giving some nice instant low frequencies clear "impacts".
I am wondering, if could use a spare Sony TAN55ES for another place in my home and connect the headphone through
a Speaker amp to headphone box.
https://www.zynsonix.com/Speaker-Amp-to-Headphone-Converter-Box_p_36.html

I know this box is nearly as expensive as a little THX SMSL SP200 amp, which also has the benefit of using a balanced input (and not my Sony speaker amp), but, can a speaker amp theoretically do better job though?

Does some have any experience with such thing? I couldn't find a clear answer.

 

[guitargonaut]

Check out Vinyl Flat Can Opener for a quality, lower cost solution.

 

[beemerphile]

You don't need the box for a solid state amp. It does not mind the high impedance load the way a tube amp would. I am using a Marantz MM-7045 directly connected without a box to my Susvaras which are 83dB/mW at 60 ohms. The Marantz is 140 wpc v. your Sony which is 110 wpc. At 42 ohms, your 110w Sony is only putting out about 20 watts. If you were concerned, you could install a series 10-12 dB attenuator in the RCA inputs to the Sony. Something like this...

Harrison Labs 12 dB RCA Line Level Audio Attenuator

Not sure what you are doing for volume control, but you'd need a solution for that.

 

[newworld666]

Thank you for all your interesting answers .. I didn't have a look to this till now of such use of my amps !

Basically, There is a already volume attenuator on the amp.

But, my sources should be a Sony WM1A being used as DAC and feeded via Bluetooth LDAC by an a android smartphone or I will try also my Fiio M11 as dlna renderer (QOBuz+NAS). Depending if I can get a good result or not with one of those sources (though my M11 is a bit too much behind my WM1A to render DSD/Flacs).

 

[Rob the Comic]

Until it died recently I used a big old 70's Japanese Sony amp from the CD transport for all my Senns and it sounded absolutely fantastic.

 

[chesebert]

Careful with DC offset. Speakers don’t really care with some DC offset but a little will destroy your cans over time.