Amplifiers 4-5-6: Single Ended with quiescent current compensation
In the amplifiers 4-5-6 the tube B3 is changed into a pentode mode 50 mA constant current source. This compensates the quiescent current of B2. The OPT is no longer in saturation. Only the right side wire of C4 should be disconnected to change B3 into a constant current source. Now we can investigate how real SE amplifiers should sound.
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Amplifiers 7-8-9: Single Ended with quiescent current compensation plus cathode feedback
In these amplifiers the quiescent current is compensated by B3 in the primary winding of the output transformer. Also cathode feedback is applied by connecting the cathode of B2 to a tap on the secondary winding. This CFB changes the specs drastically, as I will discuss following. See the schematics for all the details and click 
here to download the specifications.
Lees meer …Amplifiers 7-8-9: Single Ended with quiescent current compensation plus cathode feedback
THE MATRIX
In de voorafgaande projecten 13 tot en met 26 heb ik twintig totaal verschillende buizenversterkers besproken. Deze kunnen alle gebouwd worden met de standaard universele uitgang GIT80 en de bijbehorende universele voeding POW80. Ook het versterkerschema is universeel. Alleen door het wijzigen van enkele verbindingen (draadjes anders leggen) kunnen alle versterkers gemakkelijk worden gerealiseerd.