Using flea powered amps for headphones

[kazap]

Brains needed:

I wonder if a 300B speaker amp pushing 8W to 4ohm and 8ohm trannie outputs could drive a Senn HD800 headphone with 350ohm average impedance direct without a resistor?

1. DC it is said can damage headphones, but would there ever be any DC on a trannie output?
2. the power seems safe: 8w at 8ohms should be 180mW at 350ohms (for +120dB) and the HD800 can take 500mW so should be OK?
3. would it cause any harm to the output transformers to not use a resistor?
4. would the freq linearity or amp operating parameters be destabilised pushing 350ohms?

Thanks 🙂

 

[anibal]

It looks like it will work OK provided your amp has very low hum or noise.
Probably it will be safe to also use a resistor of 8 ohms in parallel with the output of the amp to properly load it.

 

[Kay Pirinha]

The attenuation of 8 and 1 is 19dB (-19dB).

That ist the voltage attenuation. What really matters is the power attenuation, which is -38 dB in this case. To be even more precisely, we'd need to regard the headphone impedance in parallel with the lower divider resistor.

Best regards!