Help required to finish a valve project - please

If they glow, this is the place to be
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Blues45
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Joined: Sun Nov 12, 2017 2:08 pm

#1 Help required to finish a valve project - please

Post by Blues45 »

Hi, Friend of mine had a go at building a Headphone Amplifier. He lives in London and I live in Oldham, Lancs - the amp is currently with me. It is built but has a couple of issues - one being MONO when it should be Stereo, and the other issue being HUM.

Any kind soul out there who might be able to assist????


Thanks.
RhythMick
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#2 Re: Help required to finish a valve project - please

Post by RhythMick »

Is there a circuit diagram ?

How far did the build get ? Does the one channel work ?
Firebottle
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Joined: Mon Jul 21, 2014 7:50 am
Location: The Black Country

#3 Re: Help required to finish a valve project - please

Post by Firebottle »

Does the amplifier have floating heaters, i.e. no connection to the signal ground at all? This can cause hum issues.

If the output is in the form of a cathode follower then a raised bias voltage is probably necessary to avoid excess heater cathode voltages on all the valves.
Don't you just love valve phono stages 8)
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