Why No Gain Control on Adcom Amp?
On 6/06/2018 6:34 PM, Phil Allison wrote:
geoff wrote:
Phil Allison wrote:
Quad 405, home-built mega-Quad 405,
** A Kiwi service tech working in Sydney ( Brain someone ) told me how popular it was to build your own Quad 405 if you lived in NZ. Good copies of the original PCBs were available and clones of metalwork & other parts too. This was in the early/mid 80s when buying a genuine example was impossible or crazy expensive.
Started (not by me) at NZ Railways where I was a comms tech . The main
enthusiast even went to the extent of getting heatsinks cast !
** That is very much like what Brian was telling me.
Like to know some details of you "mega-Quad 405".
Twin c-core transformers, larger reservoir caps, MJ15003 outputs,
TIP42(?)C drivers and 55VDC rails. Better electro's and poplyprop caps
throughout where appropriate.
** So about 150W @ 8 ohms per channel ?
The Quad 405 must be the most cloned, modified and re-engineered home hi-fi amp ever. I recapped one for a friend a few years ago, new main and PCB electros, ( all the Roederstein ones had gone high ESR ) plus a few other bits that looked ratty. Fitted gold RCA inputs and binding posts for outputs.
.... Phil
I wonder if the few ZTX304 and 504 I have lying around somewhere are
worth mega-bucks on Ebay ?
My mega-wquad was in a 4U rack case and bought heatsinks on the front.
All the best connectors etc too. And heavy solid rod ground wiring, and
heavy stranded pos/neg/output wiring.
Quite often the original phenolic pcbs get baked by the 560R 2(?)W
resistors.
geoff
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