Darling headphone jack

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Darling headphone jack

Postby coop402 » Fri Dec 06, 2019 6:49 pm

Darling headphone jack.
I am sure this has been addressed. Can't find it!
I understand that there are many ohm loads for headphones.I have High ohm Senns, and cheapos.
What would be the procedure for adding a headphone jack that is high quality to an existing darling amp.
Edcor 8 ohm Outputs. Antek PS. Just Curious what it would take to do it right.
Really standard build.
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Re: Darling headphone jack

Postby coop402 » Fri Dec 06, 2019 8:54 pm

Of course, I just saw that Tom has one on his last Darling amp.
I am always behind the learning curve!
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Re: Darling headphone jack

Postby jwhitmor » Sat Dec 07, 2019 10:12 am

There are far more capable people than me, to answer that. Just looking at Tom's photos, I would say the essential parts are the (front mounted) attenuator, an output selector switch, and a stereo phone jack. Looks like the signal is off of the speaker terminals. I think that would be fine for headphones up to say, 32 ohms. For headphones that are 600-2000 ohms, I would think that a small audio grade impedance matching transformer could be a worthwhile addition. Not sure what would keep you from smoking the phones, by having the volume set too high. I developed the habit years ago of turning the volume to zero, before turning my equipment off. That was in prehistoric days when the amplifiers could, and often did, "thump" when the power was switched.
If it is not making X-rays, your B+ is too low.
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Re: Darling headphone jack

Postby coop402 » Tue Dec 10, 2019 7:51 pm

Tom posted this.... "Typical Darling except with a switchable headphone jack with Shannon's 20 ohm attenuator", what is that, how do you wire it,and where do you get one. lol.
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Re: Darling headphone jack

Postby TomMcNally » Thu Dec 12, 2019 11:16 am

Look at the second page of the Budgie docs ... http://www.diytube.com/budgiese/budgie_se.pdf
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Re: Darling headphone jack

Postby Jeffytube » Thu Dec 12, 2019 11:26 am

It is just a voltage divider made of two series connected 20 Ohm 3watt resistors. The transformer speaker leads to a DPDT switch, in middle positions. One side of the switch go to the speaker terminals, the other side of the switch, each pole to ResistorA 20 Ohm resistor. The other end of ResistorA connects to ResistorB, also a 20 Ohm resistor. The other side of ResistorB is connected to ground. The headphone jack will be connected to the junction of ResistorA and ResistorB, therefore, the jack in series with ReistorA and parallel to ResistorB to ground.

You can also use a stereo switched 1/4 inch jack, with two sets of switches with 8 solder lugs. In the default position when the plug is not connected, the signal go to the speaker terminals. When the plug is connected to the jack the signal is routed to ResistorA, which then connects to the headphone contact and ResistorB. The other end of ResistorB will to to ground. When the plug is connected to the amplifier, the speakers will switch off automatically. This works well for low power amplifier like the Clementine SE 1626 and Darling 1626.
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Re: Darling headphone jack

Postby coop402 » Sat Dec 14, 2019 10:10 am

Thanks guys!
I am so glad I asked the question. This is my first amp in quite a few years. I have a bunch of things lined up.

Thus, I will be pestering you more! ha (banana)
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