kevin gilmore

extraordinary this is how they should be built.

ceramic insulators with white thermal grease and the appropriate bushing and screw

you want to use one of the linear isolators to drive one side of the bias circuit.

reverse engineering a product has been declared to be legal in the usa. see landmark rulling Emulex vs digital equipment corp. publishing a schematic that you have done is also legal. If you have an original copy from the manufacturer it is not legal to publish it. I don't know about copying an exact circuit board layout. Likely if you have the original gerber files and modify them, probably not a great idea. But if you layout a board from what you see, probably acceptable. lifting code from on board microprocessors may be an issue.

120ma thru 10 ohms is... 1.2 volts at least that is what I remember

got a scope and signal generator? pics of the 2 phases please at about 1vpp

an early version of that board had the ground missing from one of the capacitors. put the opamps in and see if there is any sound change. without the opamps there is an additional feedback loop

if you sds xlr breaks down you ship it to me. With a bottle of scotch. Dead output caps are a problem, but rare, usually the power supply does evil things. Can't imagine anyone else stupid enough to touch it.

i am pretty sure i never had the gerbers for that but i will look. Those are the original circuit, not balanced differential, and use hard to find jfet inputs. best to build one of the new boards

in the usa bdp 80fd, $300 and free shipping. If you have as many discs as I do, works out to 10 cents a disc way cheaper than anything else at the moment

gerber file alpsquad3 in my boards directory. birgir may have extra boards to sell. there were similar things on ebay a while ago.

most of us use the circuit board for the alps quad, so 6 wires including grounds to the pot board, then the pot boards to the amplifier boards, the pot board keeps the left and right grounds seperated

general rule of thumb is that peak unregulated capacitor value is 1.4 x rms output of transformer for a full wave bridge. so 22*1.4== about 30 volts unreg input the regulator needs 4 volts, so you still have 6 volts of overhead to compensate for low line etc. issues with how stiff the transformer are (how much it sags under load) lower the voltage a bit.

has to be the connector you used getting too close to that trace. I can move the trace a bit, in fact I just did, but better to pick a different connector. (not posted yet)

i'm thinking of 2 x 30V but you also might get away with 2 x 28V which I have used in the past, depends on the transformer manufacturer

fancy transformers AND fancy capacitors. unlikely anyone could tell the difference between the 3 models. The red label transformer is silver wire.

lots of different ways for different reasons, which is why i keep the original iso's around should i need to rip into a different format.

this is the first, and definitely not the last r2r discrete compensated dac https://kitsunehifi.com/product-category/audio-gear/dac/ i'm sure others will be duplicating these ideas soon, market is about to make a major change again absolutely insane (as in waste of money) to spend more than $2500 on a moving target.

foobar with sacd plugin or korg software from iso direct or sonore ripping iso to dsdiff then dff file to memory card for fiio x5ii etc or (when you rip to dff you might as well strip away the multi-channel stuff to save on storage) copy/map to any number of streamers/music boxes (like sony) your choice of pure dsd, or dop

better yet, do what i did, get 2 and stack them. rip 2 disks at once. could probably do 3 at the same time before the network slows down.

probably does not matter on this amp, but soldering the tabs on those transistors on the ssdynalo makes a fairly big difference to getting the heat into the heatsink plane

so that actually looks like an overheated pin due to poorly tinned wires (or no tinning) or not screwing down the wire tight enough. Seen this on too much expensive lab equipment. So the pin overheated, then all sorts of bad. The trace it was shorting to is the feedback line and is close to 0 volts

grlv boards will run perfectly without any load

one bridge if you are running a 3 wire transformer, 2 bridges if you are running a 4 wire transformer

you just had to point out the yellow chair... i'll bet it stinks too.