adding headphones on DOZ power amp

[tiagor]

Finally got the first channel of the DOZ working(problems I was having were due to a transistor not working as it should the damn thing could just have stopped working and saved me hours of troubleshooting), and though I haven't made any measurements yet, the sound is really good, fluid and not fatiguing at all. I expect to post some pictures soon. I hardwired everything using perforated boards so it still has a rats nest look into it.

Though I know Elliott also has a DOZ project for headphones, I'd very much like to keep the headphones option on the same amp. Is there an "easy" way of doing it? As far as I can see from the schematics the only differences are on the output transistors, and the extra output resistors. As for the resistors, I can use a switch to change between the headphone/normal amp mode. Is there a problem in using the 2n3055 transistors with the suggested 300mA of quiescent current?

Tiago Rodrigues

PS: Just a word of appreciation to Rod Elliott for sharing his great designs and knowledge.

[Freddie]

Have you seen this?
http://sound.westhost.com/project100.htm

/Freddie

[tiagor]

Thanks for the link Fredie, I understand the solution presented in the link, though I think it's an awful waste of power(not to mention the gratuitious heating) drawing 1.5A continuously while using the headphones unnecessarily.

Still, it may be a fair solution as backup, if i can't manage it in a more efficient(economic) way.

Regards,

Tiago

[Tube_Dude]

Originally posted by tiagor
Is there a problem in using the 2n3055 transistors with the suggested 300mA of quiescent current?

Olá Tiago!

Of course not...you only need use a heatsink and some thermal compound!!


Um abraço!