How about a Marantz HD-AMP1 Integrated Amp/DAC.
Use the USB for a direct connection to you iPhone, or add an Airport Express with a Toslink cable to go wireless into your Amp/DAC.
Includes headphone amp as well as 35w/ch for some small speakers.
https://www.musicdirect.com/integrated-amp/marantz-hd-amp1-integrated-amp-dac
As an aside, I don't think the iPhone 7 has an internal DAC - no headphone jack at all. It uses a tiny external headphone dongle which I believe includes a DAC?
Use the USB for a direct connection to you iPhone, or add an Airport Express with a Toslink cable to go wireless into your Amp/DAC.
Includes headphone amp as well as 35w/ch for some small speakers.
https://www.musicdirect.com/integrated-amp/marantz-hd-amp1-integrated-amp-dac
As an aside, I don't think the iPhone 7 has an internal DAC - no headphone jack at all. It uses a tiny external headphone dongle which I believe includes a DAC?