jackinnj said:I have built a dozen and a half of these amps, inverted, non-inverted, bridged and paralleled -- you can't under-rate the heat sink. National's recommendations -- albeit a bit on the conservative side -- will prevent heartbreak.
Anecdotal evidence appears to indicate that the chips do not heat up as much with gainclone type designs where the feedback resistor is soldered at the chip pins. Perhaps this explains varying experience.
Although mounted on a fairly conservative heatsink, mine has never seemed above room temperature.
Franz, are this tubes PL 509 ?
Upupa: This are PL519 (running in enhanced triode mode eg. grounded grid) and the circuit is some modified Danielak design (DC-coupled).
Franz
Hi Bartek,
Looks ruely impressive. Simple but elegant.
Beginner question to you: I see 4 resistors in 3875 kit-guide on chipamp.com. But I can see onl 3 in your circuit. Is one of them hidden somewhere? If not, what is your layout? Thanks,
Murat
Looks ruely impressive. Simple but elegant.
Beginner question to you: I see 4 resistors in 3875 kit-guide on chipamp.com. But I can see onl 3 in your circuit. Is one of them hidden somewhere? If not, what is your layout? Thanks,
Murat
Halo and many thanks for good words.
This is strictly Peter Daniel"s circuit with 22K Caddock input shunt ,680R Riken and 22K Caddock feedback resistor that is hidden underneath the chip and is soldered stright to the chip pins.In some versions there was also series input resistor but it is not actually needed, at least in my (and not only mine ) expirence.
Bartek
This is strictly Peter Daniel"s circuit with 22K Caddock input shunt ,680R Riken and 22K Caddock feedback resistor that is hidden underneath the chip and is soldered stright to the chip pins.In some versions there was also series input resistor but it is not actually needed, at least in my (and not only mine ) expirence.
Bartek
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Hi Bartek,
your amp looks fantastic - I personally like the p2p inside. I love copper, should give myself a push an start working with it for another amp...
BTW: Did you check up my p2p (a little hidden by all those cables though...) on my last documented chipamp? I did use those subminiature carbon resistors, they are a bit smaller than Caddocks and Rikens (like in my last, PD "reference chipamp").
Klaus
your amp looks fantastic - I personally like the p2p inside. I love copper, should give myself a push an start working with it for another amp...
BTW: Did you check up my p2p (a little hidden by all those cables though...) on my last documented chipamp? I did use those subminiature carbon resistors, they are a bit smaller than Caddocks and Rikens (like in my last, PD "reference chipamp").
Klaus
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