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Old 17th Jan 2008, 4:29 pm   #13
mastermanx2001
Retired Dormant Member
 
Join Date: Jun 2007
Location: London, UK.
Posts: 366
Default Re: Quad 2 Valve power amp questions

Quote:
Originally Posted by mastermanx2001 View Post
Hi GJ and anyone interested, I have done the tests suggested by GJ. On my completely standard Quad II (GEC KT66 and GZ32, used valves but probably good) The HT is 337 V before the smoothing choke and 332V after the choke. The voltage across the 180 Ohm cathode resistor (actually measures 193 Ohms) is 25 Volts.

I put in the new pair of GE 7581A/KT66 valves (and did the same measurements: HT before smoothing Choke is 343 V and after the choke is 338 V and the voltage across the cathode resistor (measured valve 193 Ohms) is also 25 V.

I hope that this is if interest. Would you please explain the significance of these results, regards, Paul.
Quad II diagram and voltages uploaded
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