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Post by antonio on Oct 17, 2022 4:22:55 GMT
This morning I went to use headphones with my new Yaqin amp for the first time, unfortunately the left hand speaker did not cut off so I assume it is a fault with the amplifier. I then connected my unused Musical Paradise, and since I thought speakers must be connected before powering on, I disconnected the speaker leads from the Yaqin and put into the MP, plugged in my headphones and everything is ok. My question, would it have been ok just to have unplugged the speaker leads from the Yaqin since the headphones were plugged in, and again if using the MP with headphones do I need to connect my speakers?
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Post by firebottle on Oct 17, 2022 6:55:52 GMT
That's a good question Dave, unfortunately it all depends on how the speakers are 'cut off' when HP are plugged in.
Raises the question of whether the speaker output stage is shut off/headphones driven from another dedicated output.
Or whether a dummy load is switched in to keep the output stage loaded properly.
What are the model numbers and I'll do some research?
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Post by antonio on Oct 17, 2022 8:46:53 GMT
This is the model I purchased, don't know how much is on the net, but I will have a look as well aoshida-audio.com/products/-299The right channel cuts out, not the left, so I assume it's a fault with the amp, but as you realise the question is, am I ok to unplug the speaker cables. Thanks Alan |
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Post by mikeyb on Oct 17, 2022 8:57:43 GMT
I'm sure it tells me in the manual for my Primaluna valve amp NOT to run without speakers connected, not sure if that's true for all valve amps.
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Post by antonio on Oct 17, 2022 9:10:01 GMT
firebottle I have sent an email to the service dept at Aoshida Audio and hope they can give an answer. It really is a special sounding amplifier, so will not be the end of the world if I cannot use headphones with it.
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Post by antonio on Oct 17, 2022 9:38:13 GMT
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Post by firebottle on Oct 17, 2022 10:11:19 GMT
I have the full details of the amp and the way the HP are connected. On the -C version there is a relay that disconnects the speakers when the HP are plugged in.
Perhaps the relay wiring is incorrect, not disconnecting the left speaker.
With HP in there is a series 680 ohm resistor feeding the signal to the HP. This then presents a massive load impedance to the 300B output valves compared to driving 8 ohm speakers. I can only presume Yaquin are happy for this mode of operation?
Generally it is not recommended to run a valve amp without any load (speakers) connected as very high voltages can be developed across the output transformer primary winding.
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Post by antonio on Oct 17, 2022 13:38:28 GMT
firebottle Thank you Alan, exceptional detective work. I've just come to reply to this thread since I've sorted it. I have a REL sub that connects to the speaker terminals, 2 wires, one for the left and one right positive, and one wire for either negative, I have removed the negative wire and plugging in the headphones, cuts the speakers off. In future I will just have to remove the negative REL cable. Please accept my apologies everyone who has tried to help me.
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optical
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Post by optical on Oct 17, 2022 13:49:18 GMT
Glad it's sorted Dave, good news.
See Alan can fix things even when they're not actually broken.
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Post by firebottle on Oct 17, 2022 13:52:51 GMT
See Alan can fix things even when they're not actually broken.  Thanks Chris.. Yes the relay interrupts the speaker negative wire, hence the existing negative connection on the sub amp providing a path through to the speaker. |
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Post by antonio on Oct 17, 2022 14:00:34 GMT
Once again Alan, sorry for the inconvenience.
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Post by firebottle on Oct 17, 2022 14:21:13 GMT
No inconvenience Dave, I like to know how things work.
Plus it's part of the ethos of the forum to help and advise.
(Apart from the advice that you NEED a Denafrips Terminator II)
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Post by antonio on Oct 17, 2022 15:59:25 GMT
Terminator II - Too rich for my blood Alan.
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