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Old 6th March 2013, 07:48 PM   #611
KWS1 is offline KWS1  United States
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Yes. Ohms
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Old 6th March 2013, 08:56 PM   #612
Itsmee is offline Itsmee  England
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Quote:
Originally Posted by KWS1 View Post
I am seeing 20 volts at R11 & R12....What is wrong? No smoke....
Could be nothing, depends what your voltage rails are.

Quote:
Originally Posted by KWS1 View Post
One probe..gnd the other at the resistor.
Measure the voltage across R11 & R12.

Red probe connected to +V, black probe to Q3 source/ R11 junction.
Black probe connected to -V, red probe to Q4 source/ R12 junction.

Marra pointed to this earlier.

Last edited by Itsmee; 6th March 2013 at 09:00 PM.
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Old 6th March 2013, 10:11 PM   #613
KWS1 is offline KWS1  United States
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The voltage ...R11 & R12 20 volts. I hooked it to speakers and drive and it sounds great....I do not understand. I built the Amp Camp.....worked right away.
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Old 6th March 2013, 10:17 PM   #614
6L6 is offline 6L6  United States
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What's the DC voltage on the speaker jack?
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Old 7th March 2013, 12:15 AM   #615
KWS1 is offline KWS1  United States
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1.3 volts right .95 volts left
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Old 7th March 2013, 06:21 AM   #616
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you have not measured correct. measure across the Source resistors(R11/R12) one probe on each side of the resistor. and do NOT hook up any speakers until bias and DC offsett is adjusted. you are lucky you did not blow up your speakers.
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Old 8th March 2013, 01:04 PM   #617
KWS1 is offline KWS1  United States
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On one side I have 4.85 & 0.80 on the other....the speaker output is...1.3 volts. I was using old speakers....I have been trying to get this going for along time.
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Old 8th March 2013, 01:13 PM   #618
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4.85V????? 4.85V/0.47ohm=10.3A. 10.85A*23V=250W dissipation. no way.
to get around 1.3A bias, you will want to see about 0.6V across the Source resistors. and close to 0mV offsett.
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Old 8th March 2013, 05:28 PM   #619
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Originally Posted by KWS1 View Post
On one side I have 4.85 & 0.80 on the other....the speaker output is...1.3 volts. I was using old speakers....I have been trying to get this going for along time.
Perhaps this is mV?

Russellc
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Old 8th March 2013, 05:31 PM   #620
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What about taking pictures of the DMM and the location of the DMM probes?
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