Final cu auto defazare...

[feri.visky]

Credeţi într-o aşa schemă? O fi ea americană, tehnică, economică, etc., dar cum stă la parametri de tip, distorsiuni, sensibilitate, randament, etc. Vedeţi ce putere este afişată acolo... (la consum, desigur...).

 

Schema de pe FB...  , doar nu o fi de 1 aprilie...

Editat Aprilie 2, 2018 de feri.visky

[Kosmin]

Daca arunc o privire doar la filamente: 5y3 5V@2A+ finale [email protected]+ 12ax7 [email protected]. Si finalele or avea un [email protected] ies vreo 44W si cu un randament de 85-87% al tr. de alimentare ne apropiem lejer de 50W asadar nu cred ca e umflat consumul acela. (asta ar fi pretul lampii redresoare ;-) ).

Daca are finalele imperecheate la sange ar trebui sa functioneze cat de cat etajul de iesire.

Mai multe despre configuratia respectiva se gasesc in tubecad_Journal 2-3 randuri:

Citat

Now, let’s look at some bad ideas. A trick used in cheap amplifiers was to forgo the expense of an input transformer or phase splitter circuit that used an extra triode, which makes a circuit more than casually similar to the SRPP. In the amplifier at the right we see the top EL34 being driven by the input signal, but the bottom EL34 receives its drive signal from the signal developed at the top pentode’s screen. What’s wrong with this amplifier? The degree of balance between tubes varies with the load impedance and both the first pentode’s distortion and bandwidth limitations are just cascaded into the bottom pentode. Furthermore, power supply noise does not cancel, as it would normally. Still, while the results were not perfect, they were good enough for many applications, such as cheap phonographs