Headphones and PP-amps

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Headphones and PP-amps

Postby soundbrigade » Sat Jun 06, 2015 3:32 pm

Hooking up headphones to a SS-amp is pretty simple. Just solder together a voltage divider and plug your phones to that one and your exclusive 10k phones and ears will live a while longer. But when it comes to tube PP-amps, how to do it?

I and many before me has been arguing with a guy who hooks up his 60 Ohm phones to the output of a PP-amp. We try to explain the simple fact that the output transformer not only transforms the load impedance of the tubes to a much lower impedance that fits the speakers better, but it also transforms the output impedance to the load impedance of the tubes and that may cause new and interesting problems.
I may, however be wrong, but considering the fact you never turn on a PP-amp without load also indicates that hooking up a load that is far too "wrong" will also cause problems. So what does the forum say? How wice is it to connect your headphones to the speaker connectors of your tube amp?
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Re: Headphones and PP-amps

Postby Geek » Sat Jun 06, 2015 8:19 pm

8R, 5W dummy load, 330R, 2W series into the headphones.

Just like any commercial amp, just use the 8 ohm dummy load so the tubes don't freak. Good for SE tubes as well.
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Re: Headphones and PP-amps

Postby soundbrigade » Sun Jun 07, 2015 12:18 am

That is what I would suggest, but my friend wants to run the headphones directly to the speaker connectors.

What will happen, or to be more precise, how will the tubes react when seeing a much higher impedance on the anodes?
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Re: Headphones and PP-amps

Postby Geek » Sun Jun 07, 2015 10:39 am

The tube amp will likely break into oscillation, redplate and die.

Maybe your friend needs to stay away from tube amps.
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Re: Headphones and PP-amps

Postby soundbrigade » Sun Jun 07, 2015 1:38 pm

Unfortunately he won't or cannot understand this or just provoke people who are trying to help. I have tried a lot to explain basic electronics but then, after a month or two, he starts to ask the same questions again. He also claims that it is good to have a power reserve of 60W when listening to headphones and the idea of purchasing a dedicated headphone amp is out of the question.
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Re: Headphones and PP-amps

Postby Geek » Sun Jun 07, 2015 2:59 pm

We have countless customers like that in the store :/

Boss and I think they have some mental issues, so we try and be patient *)
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Re: Headphones and PP-amps

Postby DeathRex » Tue Jun 09, 2015 8:21 am

I thought the headphone connector would be right before the phase splitter, and cut the output to the phase splitter. Then maybe a low powered tube to a very small output transformer. You shouldn't need anymore than 0.2 watts.
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Re: Headphones and PP-amps

Postby LW1DSE » Mon Apr 18, 2016 9:49 am

50W into a headphone directly coupled to his ears? Oh, my god...
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