bosoz PSU help!?

[cowanrg]

kilowattski,

i have one. i dont think i had one when the PSU boards were first built though... i do have one now though.

jleaman,

last time i checked, a variac wasnt exactly cheap. not terribly expensive, but not cheap. and its not something ive found surplus either.

how exactly would a variac help me out here though? with the light bulb thingie i dont seem to be blowing anything anymore. ive heard that a variac is a good thing to have, and i know what they do, but im just not sure what exactly their benefit is...

edit:

thanks for the compliments though

[jleaman]

Variac's ca help yo slowly bring up the power in your psu : O ) not full power and let it smoke : O )

Variac's are cheap look on ebay and stuff. .

[kilowattski]

Jason,

The lightbulb idea works just as well, maybe even better and costs a whole lot less.

[cowanrg]

i bought a ceramic light bulb base and a pack of lightbulbs for like $4.

i chopped two power cords and spliced them all togehter. now i have a power cord with a light bulb in series with it, so i can plug in anything and test for shorts. it works very well.

although, it doesnt tell me what exactly is going wrong. if there was a little tip that could do that, i would be all over it!

i think i might just buy all new 610's and 9610's. they are pretty cheap and i have a few things i need to buy from digikey anyways... ugh.

[cowanrg]

i didnt want to start a new thread, so ill just continue this one...

after getting very frustrated and messing with this thing for days, i couldnt find anyting wrong with it. i individually metered each part and everything tested just fine. so, as a last straw before i rebuilt the whole thing, i just hooked it up again. it worked. i tried the other one, it worked. i tried both, they both work. i stopped thinking about it and just went on working

i have NO clue what happened, but it works like a champ now. i have it on and off all the time to test and measure, and its never given me a problem, and the PSU is mounted in there for good now:

http://www.cowanrg.mesanetworks.net/...z/preamp10.jpg

i also took extra caution to shield things and keep the transformer as far away from the preamp circuit as possible. unfortunately, its a small case to fit an 800va transformer and all the other junk in, so i was limited. but i just ended up doing a "firewall" in between the preamp and power supply section (cold-rolled steel) and also putting a piece of steel around the transformer itself for further sheilding. i learned my lesson with my aleph3's.

http://www.cowanrg.mesanetworks.net/...z/preamp11.jpg

so its getting close to done. thanks to a donation from Synergistic Research cable, i have some decent wire to hook up the signal path with. they have been following my projects for awhile and like what i do, so they donated some alpha sterling hookup wire.

i basically just have to hook up the volume control and its pretty much done! here are two more pics of the front panel. its just a mock-up, so things will be different in the end. the shafts for the knobs are too long right now, so the knobs stick out way too far in my opinion. they stick out 1" now, i want them to be about 0.25". that will look nice and clean.

the wood front panel is a mirror reflection in the right light and without patterns in front of it (little jab to bill). the lights could be brighter, but would look awesome at night in a dim room.

http://www.cowanrg.mesanetworks.net/...z/preamp12.jpg

http://www.cowanrg.mesanetworks.net/...z/preamp13.jpg

this is going to be one sexy sexy preamp. i dont brag much, but im really proud of this one.

[AR2]

Awsome!
Great work on wiring. I like your mechanical pot.
AR2

[cowanrg]

thanks. i hope someone would notice the input selector. its a grayhill rotary that im using for input selection and LED selection.

its also the on/off switch. you can see the gears and the spring. right behind the shaft there is a DPDT switch that turns the unit on and off when the left knob is pressed in. this keeps the front panel free of awkward looking on/off switches.

that is the 4th version of that. the first version was the concept switch and it had the rotary switch enclosed in a track inside a small project box and the whole assembly slid inside the box and activated the switch. it was VERY complex and hell to wire.

this is by far the most elegant of all the designs i had. it works very well and is bullet-proof. its easy to adjust the push strength with just the one set screw on the collar. in addition, it helps align the shaft with the more tension you add. i used end mill bits to cut the holes so they are actually quite smooth and there isnt much friction. a little WD-40 makes it work just fine.

[steenoe]

That sure is one nice preamp. Very well build
Hmm, that faceplate is just a beauty..

Steen

[cowanrg]

the thing i like most about the faceplate is in lower light (aka, when light is not directly shining on it from flash or sunlight), you cannot even see the lights when its off. it just looks like a solid faceplate. and when it turns on, the lights just seem to come from nowhere. its exactly what i was looking for. simplicity.