kevin gilmore

if that is one of the 2 sections in one section things, those are awful.

some future boards, probably the dynaloss would be 3 or 4 layers if i go completely surface mount. not really possible on the kgsshv boards

it is a dc amp, however the servo's will cause issues measuring dc. of the 5 pots i bought for this, i was only able to use 2 of them the others had problems either at low volumes and high volumes

its the same heatsink as the krell klone. (can't find it at the moment) the 2sc4686a parts are insulated, so just thermal washers both sides, screw and nut

those are insulated parts, so just regular thermal washer,screw and nut.

yep, how I did that I do not know. it was still possible to build that board, you had to bend the pins and solder all the parts that were not the output devices standing up and backwards. a lot of clean up and various traces on both sides the same exact length just for extra fun. and some ground plane on the bottom. new version http://gilmore.chem.northwestern.edu/kgdynalobal7.jpg

another of the active bias cable nonsense anyone recognize the manufacturer?

major error in the surface mount version of this board, fixed I think, someone please check http://gilmore.chem.northwestern.edu/boards/kgdynalobal7.zip

yep fully differential input. balanced or unbalanced. for unbalanced in, you tie the - input to ground.

there is no way he could have been that good of a shot.

actually i did one amp this way with multiple taps off the zeners... worked fine and all the parts were already there, just add one output resistor caps in parallel with zeners usually is a bad thing

actually WAY back then there were ceramic spacers for doing that. speaking of knobs, got in a piece of ebony, completely coated in wax. took the wax off and turned it round. completely black. then 3 days later 4 major cracks due to the wood being very wet. so pissed off. a piece of kiln dried ebony on the way. another vendor says there is no such thing as kiln dried ebony. precious metals are so much easier... want r-core transformers so bad...

wow, all the holes on the bottom in a straight line. good job. resistors really did not have to be that far off the board, but looks nice, all even. I'm sure birgir has a picture of a particular persons build (cough cough henyo cough cough) where the bottom of the thing was attacked with a hand drill and he should post it.

there is no hum whatsoever in either of mine, but I'm using power supplies that are probably 15 years old. most of it I would expect is radiation from the transformer. so with a really good torroid, you should be able to make it absolutely quiet.

you really want to use the dual linear supply, or something like amb's supply. Works much better at 16+ volts

absolutely no artic silver. The stuff is electrically conductive.

if that schematic is correct, the moron is reverse biasing the diaphragm. massive bad

the mpsa parts cannot handle the 1W for the output devices. everywhere else they are ok. same silicon, smaller package

that is slightly excessive, plus its not in stock. building up a parts order now. getting tired of $5 in parts and $7.50 in shipping

use plenty of heatsinking... 320ma on each it should be noted that the distortion figures above are unbalanced in, unbalanced out. balanced out reduces the second harmonic by about 6db resulting in a thd of less than .002% at these levels its silly and very expensive to go any further. singlepower squarewave into 50 ohms is .055% (no matter what Mikhail said, never designed to drive 50 ohms)

finally updating my test equipment... with a 30db attenuator and 50 ohm load... http://gilmore.chem.northwestern.edu/ssdynalobalthd.jpg surprisingly close to my 30+ year old antique

kgdynalobal7 is the all surface mount version. no one that I know of has made this one yet, so maybe check for errors. will look at the current mirror later, but the board would probably have to get bigger as its stuffed.

identical. pzta56 silicon exactly the same as mpsw56 only difference is package and heatsinking the silicon to the tab

for the surface mount version which can handle a bit more heat, 20ma per transistor 160ma on each rail per board

the current sources see the tails of the differential inputs. So really its very close to a dc level that does not change with input signal. maybe microvolts if that much, so the current sources really have very little difference. changing the current sources may change the current a bit which changes the output stage current, so you may be hearing that.