[pocomo]

I'm pretty thick when it comes to electronics, but here's my question. I'm thinking about what amp to use to drive a pair of HD580s, and I realized that I have a decent 300B-based single ended triode amp sitting unused at home in the basement. It does not have a headphone output, only loudspeaker terminals. Is there any way I can use it to drive the Senns without blowing them to bits?

 

[eric343]

Moderator, can we get this moved to the DIY forum? It might get more answers there...

 

[jopi]

You want to get some high wattage resistors (couple of watts) and put them across the speaker binding posts. Try to match your power amp speaker impedance setting (4, 8 or 16 ohms). This will fool the power amp into seeing 4, 8 or 16 ohm speakers instead of headphones.
Next you would want to put 120 ohm resistor in series to your headphones. This will fool the headphones into seeing a standard 120 ohm load on the amp side.

Make sure you get high wattage (Frankenstein) resistors and you can try different values to see which combination you like best.

Another (possibly) better approach would be to use a different winding tap off the output transformer, but you would have to check out which ones are available and it would render your amp useless with speakers.

 

[pocomo]

Thanks - I'll post this query to the DIY forum and see if anybody there has additional input.

 

[darkclouds]

I've been using my 300b with the ASL UHC signature with good results. You may want to check it out. Although, with my current preamp (AE-3), the sound is bit warm and some loss of control. It may be a case of too much of a good thing (too much tubes).