Last weekend I had the pleasure of working with several of the other trustees of the Klipsch Heritage Museum Association. There was much work to do to get the sale items ready for ebay. Several items in the museum that are being sold to make room for the PWK library and archives but some of these large historical items were very heavy. The move of these items was headed by Jim Hunter. I must say I was holding my breath while flying the 16A, 450lb 27" Cinaudagraph woofer, and extremely heavy K400 horn mold.
Brook 12A clone or imposter or nisemono. Just received the iron from the good people at Heyboer. The Brook wasn't built with fancy parts yet still had a great reputation. This is most of the parts for the Brook imposter except for chassis, tube sockets, and meters.
I had some of the parts, some were given and some were found on the ebay. I've been looking forward to this project for a long time. It will give me something to do while Chris and I work on the..... whatever the hell we decide to call the massive amp.
As the Klipsch Museum Of Audio History transitions to a non profit entity they are selling some items to make room and to raise funds to put the organization on sound footing. This means that this year you will be able to bid on items from the collection of PWK and some owned and tested by PWK. There are items in this collection up for sale that have never seen eBay and some seen once every few years. I will post here as the items come up for sale on eBay.
I bought this Knight stereo amp years ago at an auction. I tried to rebuild it to its original state but the voltage was soaring and the circuit boards were a brittle nightmare. They were not taking to the constant work. I called it quits. My good friend Chris Hornbeck was kind enough to draw up a fresh more modern schematic. The chassis tubes and transformers were great so that is all we kept.
Forget what I said fortunately Chris chimed in with a comment:
path is all push-pull, differential input with CCS, cathode follower
drivers, plate and cathode loaded triode connected outputs, separate
cathode resistors with 1000uF bypasses to 0 and 32 Ohm taps, 8 Ohm tap
to signal ground. No long-loop feedback, extensive decoupling to input
Power supply is dual GZ34's to 10uF Solen/ factory choke/
4x100uF to outputs, then 20Hy/C/R/C to inputs. Bottom of supply lifted
by 5V for CCS supply.
This amp was a kit and has never worked properly until now. The orginal builder just never got it to work so I got all nos tubes with it. That is four EL37 and two GZ34 rectifiers. All mullards except the 12AX7 amperex and 12AU7 also mullard are just from my stash.
If I ever get the schematic corrected I'll post but it was very challenging getting everything to fit in the snug chassis. I'll always afford myself more room than this... I don't like rebuilds but prefer scratch...
Anyway it is quiet on my 107db1w1m Klipsch Jubilees so what else could one ask for but just a few easy mods and it be done lol....
“I like big horns and I cannot lie, those little horns make me cry” Tom Danley "Simple. A horn is just a reasonably rigid boundary for an air column. Now all you have to do is figure what shape to make it." PWK