Amp/Headphones Impedance

Hi, the amplifier i have for my speaker setup only supports up to 50ohm headphones (according to the manual and website) but im buying 60 ohm headphones and a proper headphone AMP/DAC later on, what are the downsides in doing this without the AMP/DAC, cant afford the AMP/DAC right now, any help in telling me what might happen will be VERY much appreciated, THANKYOU!

Use the 1/8 rule of impedance for the best sound quality.

Most headphones work best when the output impedance is less than 1/8th the headphone impedance. So, for example, with 32 ohm Grados the output impedance can be, at most, 32/8 = 4 ohms. The Etymotic HF5s are 16 ohms so the max output impedance is 16/8 = 2 ohms. If you want to be assured a source will work well with just about any headphone, simply make sure the output impedance is under 2 ohms.