- 485 Posts. Joined 5/2013
- Location: Oregon
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I agree with your thought: design, implement, listen, post. BUT you gotta get through design, first! If you can't finish the design, you can't implement, you can't listen, so, you post to get help with design!
OK, so with an amp with 8 ohm load impedance connected directly to headphones with 600 ohms impedance how would you calculate the attenuation?
How would you calculate it with a 4 resistor network?
Sorry, I'm afraid I don't understand the first question... What is the configuration?
If you have 600 ohm headphones, your attenuation calculation will be much less dependent on having the load there versus without it (in the 4 resistor configuration).
The full blown calculation is in post #1580
For all practical purposes, you can ignore the output impedance of the amplifier. The amp, at some volume setting, is going to output some voltage at the speaker taps. That appears across R1. The only thing you care about is what happens after that.
Let us know how it sounds, Mr Eddy!
And soon, the only brand in the world will be ThermoFisherHuntingtonMitsubishiCokaCola!
I was thinking of posting a wheatstone bridge with the headphone in the middle... but I wouldn't want Mike's head to explode
I have been talking to the person who designed my amp about begin able to adjust the resistance. here is what he suggested (planned for january when i send my amp in for some updating)
I think using a 6 position rotary switch and install various resistors on the switch is a better way to go in term of having different resistance between the amp and the headphone. I have spent a couple of night trying to find the suitable variable resistor. The major issue is there isn't any suitable dual gang unit out there. There are a lot of precision single gang unit which is not suitable in stereo operation. So here is my suggestion.
Using one 6 positions rotary switch and a bypass switch. Steps for the resistance is going to be 5 ohms, 10 ohms, 15 ohms, 20 ohms, 30 ohms, 50 ohms plus bypass.
there also would be an 8 ohm resistor (on/off) for use with tube amp.