Mosfet Power Amplifier

[denny9167]

I found this design years ago,and wanted some input on the design,below is an attached schematic,I haven't added the resistor or capacitor values yet,I can do that if they are needed,Thanks

[srh]

Hi Denny,
The schematic appears to be a copy of the Australian ETI 5000 Series power amp. The TIP2955, 3055 should be BF469, 470 and the Fets 2SJ50, 2SK135. The source resistors should ideally be non-inductive. A good sounding 1980's design by David Tillbrook.
Cheers,
Steve.

[godfrey]

Hi all

If I've got this thing figured out right, there's a connection missing on the schematic, shown here in red.

I was scratching my head about the choice of transistors (tip2955, tip3055), but srh seems to have cleared that up.

Cheers - Godfrey

[srh]

Hi Godfrey,
The connection correction is correct.
Cheers,
Steve.

[denny9167]

Originally Posted by srh

Hi Denny,
The schematic appears to be a copy of the Australian ETI 5000 Series power amp. The TIP2955, 3055 should be BF469, 470 and the Fets 2SJ50, 2SK135. The source resistors should ideally be non-inductive. A good sounding 1980's design by David Tillbrook.
Cheers,
Steve.

Are there any IR or other equivalents to the 2SJ50,and 2SK135?

[srh]

Hi Denny,
This design is for Lateral Mosfets only. The modern equivalents are 2SJ62,2SK1058. These are readily available, including from at least one forum member. An extensive redesign of the bias network would be necessary to enable the use of Vertical Mosfets (IRFxxx etc).
Cheers,
Steve.