The most modern ancient design, Doctor Self, maybe Curl , teenagers that time...

[destroyer X]

I think... maybe not...but this is a very old heathkit amplifier, a 200 watt each channel, powered by symetrical supply, 91 volts each rail.

Observe the differential, the CCS to the differential, the CCS to the drivers, the triple darlington, the double transistor VAS.... all very modern, we have amplifiers beeing published in our forum, now a days, with all those circuit features.

So, observe, see, and realise, modern is not so modern, was Doctor Self that has created such kind of circuit?

Maybe, but in my imagination he was very young those early days...sorry if i am wrong with dates.

But see, this is an excelent amplifier, a top modern idea used now a days...observe with a critic eye, are really modern the modern ones?

Also the old ones remains the good ones... is this a truth?

Am i wrong?.... how old is Doctor Self and Mr. John Curl?

regards,

Carlos

[burbeck]

hi Carlos,

i would like to see a full circuit of this, do you have one?

i dont think Doug Self claimed that he invented or created these things, just that he made a study of the subject and came up with the "blameless" which incorperates some of the ideas here.

Both Doug and John are so old that they would have forgot anything recent that they have worked on, at least the last 30 years.

[destroyer X]

here is the link, this amplifier and much more:

Heathkit Schematic Diagram Archive

regards,

Carlos

[destroyer X]

You see, old folks used to make good things too.

The schematic is also provided in link posted into the previous post.

I think those amplifier were made during the seventies... between 1975 and 1980, but i am not sure about that.

regards,

Carlos

[Mooly]

Hi Carlos,
Yes there is nothing really new "under the sun" is there. Just refinements and better understanding.
I once had a discrete circuit (late 1960's !!!!) for a Class D discrete power amp (self oscillating)

I used to dream of building something like a Heathkit once.... they were always so expensive.... to a young lad anyway and settled instead for a "Harversonic" kit. AD149 classic Lin type... and that was the start of it all... and I bet it would sound pretty good even now.

[Allen Wright]

THere are some new things: Wireless World 1972 The Blomley Class A amp with only 10mA standing current.

We built this and with some work it turned into the best sounding SS amp we have ever heard - then and now. Kinda tricky to stabilise all the Dc parameters though.

Regards, Allen

[destroyer X]

I had once a Heathkit, excelent amplifier, all aluminium enclosure..very interesting plates attached using bolts and nuts.... the nuts where already into the aluminium panels.... lovely sound.

Also i had a Heathkit Transceiver, a tube one, once again, all aluminium enclosure.

I think i have this digital circuit from the sixties, somewhere, recorded into one of my backup Cds.

.................................................. ................


Allen Wright

Do you have this one you mentioned?... the schematic?.... please, send me, i do not remember this one.... in 1972 i was 21 years old....maybe i have watched, maybe not.

Having the schematic, please send me:

carlos.eugenio1951@yahoo.com

regards to both, Mooly and Allen

Carlos