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Components and Circuits For discussions about component types, alternatives and availability, circuit configurations and modifications etc. Discussions here should be of a general nature and not about specific sets.

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Old 16th Jan 2013, 1:59 pm   #21
kalee20
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Default Re: UY85 UL84 Amplifier

It is negative current feedback, taken from the cathode resistor and fed back to the input. So no it won't correct any non-linearities in the O/P transformer. Also, the damping on the loudspeaker will be nearly non-existent.

There are tone controls, but they are within the feedback loop which consequently will try to nullify them!

An interesting circuit, but not what I'd call a 'good' circuit.
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Old 19th Feb 2013, 10:55 pm   #22
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Default Re: UY85 UL84 Amplifier

Back to UY85 - UL84 amplifiers - If for safety, an isolation transformer was fitted to one of these record players from which the BSR motor was also supplied, what current/VA rating would the isolation transformer need to be?
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Old 20th Feb 2013, 12:23 am   #23
Herald1360
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Default Re: UY85 UL84 Amplifier

The motors don't take much power though they may need rather more VA.

Heaters are about 9W, HT maybe 12W or so, allow 25VA for the motor and a 50VA transformer should do the biz. Go for 100VA if you want it all to stay nice and cool.
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Old 20th Feb 2013, 5:45 pm   #24
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Default Re: UY85 UL84 Amplifier

Ok thanks.
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Old 30th Sep 2013, 7:15 pm   #25
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Default Re: UY85 UL84 Amplifier

One post about the Radio Constructor articles moved to the Websites section for information.
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