800ohms output

 

Mais alguns circuitos para esclarecer o leitor

 

Com duplo triodo 6AS7 /6080

 

Click the image to open in full size.

 

Jon Idestam-Almquist "Radio & Television" April, 1964

Acima circuito para uso direto em flantes de 800 Ohms

Abaixo adaptação para transformador para aplicação com qualquer impedância de falantes.

 

 

Fonte para ambas as versões.

 

 

 

Unidade de Potência.

 

 

 

Fonte.

 

 

 

 

Duas sugestões de pré amplificadores para ambas unidades de potência

 

 

 

 

Pré amplificador Philips

 

 

 

 

Teste do amplificador Jon Idestam-Almquist

 

We tested three amplifiers and all had different test values.
Here is a summary of our test. The reason for different output levels on the channels is that the gain was not the same on both channels. An asterisk * means that the signal was clipped . We did not test the tubes for conductance or anode current.
THD measured with 1 kHz
IMD measured with 60 Hz and 8 kHz 4:1
DFD measured with 10 and 11 kHz

 

 

Amp 1 before
changing ECC83s

Amp 1 after
changing ECC83s

Amp 2

Amp 3
Tested above

THD

 

L

R

L

R

L

R

L

R

0,5 W

20 V

-58 dB

-80 dB

-73 dB

- 74 dB

-73 dB

- 72 dB

-78 dB

-79 dB

2 W

40 V

-52 dB

-73 dB

-65 dB

-67 dB

-66 dB

-66 dB

-70 dB

-73 dB

8 W

80 V

-43 dB

 

-58 dB

-60 dB

-58 dB

-58 dB

-61 dB

-65 dB

9 W

85 V

 

-64 dB

 

 

 

 

clipped

clipped

13,8 W

105 V

-35 dB*

 

 

 

 

 

 

 

15,1 W

110 V

 

 

-45 dB*

-50 dB*

-48 dB*

-48 dB*

 

 

18 W

120V

 

-56 dB*

 

 

 

 

 

 

IMD

 

 

 

 

 

 

 

 

 

0,5 W

20 V

-47 dB

-65 dB

-60 dB

-60 dB

-60 dB

-60 dB

-62 dB

-61 dB

1,5 W

35 V

-41 dB

 

 

 

 

 

 

 

2 W

40 V

 

-58 dB

-52 dB

-54 dB

-53 dB

-53 dB

-54 dB

-54 dB

4,5 W

60 V

 

 

-47 dB

-49 dB

 

 

 

 

5,3 W

65 V

 

 

 

 

-48 dB

-48 dB

 

 

7 W

75 V

 

 

 

 

 

 

-41 dB

-45 dB

8 W

80 V

 

 

 

 

-57 dB

-57 dB

 

 

10 W

90 V

-30 dB

-47 dB

-42 dB

-45 dB

-41 dB*

-41 dB*

 

 

DFD

 

 

 

 

 

 

 

 

 

0,5 W

20 V

-60 dB

-77 dB

 

 

 

 

- 75 dB

-75 dB

2 W

40 V

 

 

 

 

 

 

-70 dB

-71 dB

3,8 W

55 V

-54 dB

-70 dB

 

 

 

 

 

 

5,3 W

65 V

 

 

 

 

 

 

-64 dB

-64 dB

8 W

80 V

-45 dB

 

 

 

 

 

 

 

10 W

90 V

 

-65 dB

 

 

 

 

 

 

Tubes

 

 

 

 

ECC83

Philips

other Philips

One Philips
One Telefunken

Siemens

EL86

Telefunken

Telefunken

Telefunken

EI

 

The Telefunken tubes are probably quite used since the data are out of original specs.
Test values will probably be much better with new Telefunken tubes, which we did not have.

 

  

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