I’m currently using a pair of headphones rated at 24ohms input impedance with a 10w practice amp rated at 8ohms output impedance. It sounds absolutely terrible (hissing like crazy) through headphones (fine when used with just the amp).
I’ve read some websites that state to avoid distortion you should multiply the output x8 (so in my case headphones with 64ohms).
Is this about right? I was looking at the Sony MDR7506s which have 63ohms but wasn’t sure if I need something lower.
Typical headphone impedance is 32 ohms. 24 is on the low side but not as low as (say) earbuds. So your phones are in the normal range.
I have a pair of MDR-V6’s (the pro version of the 7506) and they are fine headphones with most sources I have used them with. If you want to buy the 7506 and try them, it won’t be a bad buy. They are also relatively inexpensive.
This might or might not be relevant to your case but I’ll throw it out there anyway.
I went through a tonne of research trying to understand impedance matching with gear and headphones, and trying to work out technical specs of headphones and just generally how to get the best sound quality… Only to find that the headphones weren’t the weak point!
I eventually found that for a lot of amps (not sure if it’s common across the board or just on cheaper combos) the headphone circuit seems to be separate and actually skips some of the amps shaping so it sounds completely different.
You can get some combos such as the Orange Crush which has a cabsim feature that emulates the full amp speaker tone through headphones.
However I did buy a couple nice Sennheisers during this process because I needed to upgrade my general listening cans anyway, and I learned some things so it wasn’t a complete waste of time
I was thinking along those lines too - the headphone output probably being an afterthought for amp manufacturers (afterall its not really the main selling feature for most customers) and with mine being a cheaper entry level model (cheap Ashdown) this issue being “amplified” (pun intended).
