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i'm on a roll... the kgsshv


kevin gilmore

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So I ordered some LSK389A in TO71 packages directly from Linear Systems' Canadian sells representative. It was pretty hassle-free. I was told they will be shipped in 2 weeks; so it really shouldn't be too hard for people to source these parts, if they do decide to use them. There is a question I want to ask though. The input stage of the kgsshv is a common source amplifier, is this correct? What would be some desirable characteristics for the jfets in this configuration?

The reason is that I found an thread by EUVL recently: A Compact, High-Performance Source Follower Module - diyAudio

Where he describes desirable characteristics for jfets in CS loaded source follower. So I am wondering the same thing about the circuit in the kgsshv. :) He also blasted the 2SK170 on its actual noise level, and distrust LSK389s' manufacturing tolerance. (how's that for hyperbole?) The article he linked down in a few posts shows that the manufacturing tolerance for these device was on the rise from 2006~2007 though, but that was three years ago, so I am also left wondering what their manufacturing tolerance is like now...

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I'm not sure, this is not a field that I am an expert in. But I wanted to understand the circuit a little better, that's why I asked. I'd guess differences between the individual jfets within the dual fet? But they are on the same die, so the difference should be minimal, and because they are on the same die, thermal drifting should be minimal... Would the difference between the dual fets be a problem between the channel? I have a feeling that it would not.:palm:

Jesus, I felt like I'm taking a test. :P

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  • 3 weeks later...

Due to busting up my foot a while ago, i have had to slow down a bit.

I want to get the next 5 x T2 chassis out the door first which

should be about 2 more weeks. That will leave only 3 left.

I have shipped the board files to someone that is going to make me

a small run of prototype boards for a rational price.

Someone else has the board files for the KGITSOJC so that is moving

along too.

I'm installing hid lighting over my workbench at home today to make it

easier to build stuff.

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Due to busting up my foot a while ago, i have had to slow down a bit.

I want to get the next 5 x T2 chassis out the door first which

should be about 2 more weeks. That will leave only 3 left.

I have shipped the board files to someone that is going to make me

a small run of prototype boards for a rational price.

Someone else has the board files for the KGITSOJC so that is moving

along too.

I'm installing hid lighting over my workbench at home today to make it

easier to build stuff.

What'd you do, drop a T2 Heatsink on your foot!

J/k

Can you describe the lighting? I'm looking at lights presently for a few work areas as well.

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See i injured my foot pretty good, stress fracture... Now if i had stayed off it for about 3 weeks

then (like my doctor told me) i would not have injured it 3 more times in the following 2 weeks.

Finally it got to the point that i just plain had to slow down, and be much more horizontal much

more of the time. Great for listening to music. (with headphones of course). Lousy for just

about everything else. (queue dr. wood)

Anyway, most people would be happy with 2 or 3 of these. These really are great, and cheap, i have 2 in cans lighting the fireplace.

EcoSmart PAR38 18-Watt (75W) LED Flood Light Bulb (E)* - ECS 38 WW FL 120 at The Home Depot

but i went a bit overboard with 2 of these.

Miletus PAR-38 Dimmable LED Light Bulb (20-Watt, High-Power Nichia LEDs) : PAR Series : Ultimate : LED Light Bulbs

(warning this company is a bit hard to deal with and lies about delivery times like you would not believe, fake tracking numbers and all...)

(neutral white/spot)

I get about 6000 foot-lamberts at the work surface with the bulbs about 4 feet above the work area.

I already broke the cheap home-depot fixture as it really was not designed for this amount of weight and

after adjusting it, one of the two swivels broke. Should be fixed shortly. I'm going to have to put a dimmer

on them, because this is more overkill than i need.

In a few days i will probably start a thread on the lutron radio ra2 setup i'm installing, complete with about

$1500 in led light bulbs. Combined with a few other items, this is slick on a stick :D

(and yes i broke loose a copy of the software without having to spend 2 days in a class with a bunch of blue collar electricians)

Edited by kevin gilmore
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In a few days i will probably start a thread on the lutron radio ra2 setup i'm installing, complete with about

$1500 in led light bulbs. Combined with a few other items, this is slick on a stick :D

(and yes i broke loose a copy of the software without having to spend 2 days in a class with a bunch of blue collar electricians)

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Any recommendation for something I can mount under a cabinet that would be effective for soldering and what not? It will be about 3-4 feet from the light to the work area. Something that is a flush mount with cords that come out of the side would be best.

There is nothing really suitable on the LED front for under cabinet mounting like the 2 foot fluorescent lights. The few LEDs in that size work at a very white color temp and are pretty expensive. There are some nice LED desk and work lamps out there.

JHellow

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There is nothing really suitable on the LED front for under cabinet mounting like the 2 foot fluorescent lights. The few LEDs in that size work at a very white color temp and are pretty expensive. There are some nice LED desk and work lamps out there.

JHellow

I've got a long work bench in my Garage. It's 16' x 32". Ceiling is 9 1/2'. Would these Can lights KG mentioned above be good for workbench illumination?

If so, how many?

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Anyway, most people would be happy with 2 or 3 of these. These really are great, and cheap, i have 2 in cans lighting the fireplace.

EcoSmart PAR38 18-Watt (75W) LED Flood Light Bulb (E)* - ECS 38 WW FL 120 at The Home Depot

are there switching supplies in every bulb? my experience w/ CFLs has been the switching power supply starts to die long before the specified lifespan of the bulb

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yes of course there are switching supplies in them. Which is why the cfl's die because they

have a big electrolytic cap, and boost the voltage to about 300 volts. The led's are way

different, the good ones don't have any electrolytic caps of any kind and the latest

nat semi chips do a great job of dimming all by riding the ac input power.

i'm not doing this to save power or save money. this is clearly a money loosing

proposition at this point. i don't believe the bulbs will last 30 years. i want them

because of the color and intensity of the light, and bunches less heat.

Edited by kevin gilmore
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yes of course there are switching supplies in them. Which is why the cfl's die because they

have a big electrolytic cap, and boost the voltage to about 300 volts. The led's are way

different, the good ones don't have any electrolytic caps of any kind and the latest

nat semi chips do a great job of dimming all by riding the ac input power.

i'm not doing this to save power or save money. this is clearly a money loosing

proposition at this point. i don't believe the bulbs will last 30 years. i want them

because of the color and intensity of the light, and bunches less heat.

what color are they? my CFLs are 2700K and it was close enough to incandescent for me. they only save money in the summer. but they paid for themselves in 2 months. dropped my electric bill about $15/mo for 6 bulbs.

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various different color temperatures available

warm white 2500k-3200k

neutral white 4700-5700k

home depot bulbs are at 2900k (i actually measured these)

cfl's and most of the led bulbs are within about 1 watt of each other.

the ledwaves bulbs are put together with screws and come apart easy

and i will have no trouble repairing them. the cfl's in the basement as

they die will be replaced with led bulbs.

dimming the cfl's really shorten their lives.

if i actually save money on electricity, thats just a bonus.

The basement was a total of 1320 watts of incandescent

now its about 100 watts. plus the difference due to the heat.

Edited by kevin gilmore
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I've got a long work bench in my Garage. It's 16' x 32". Ceiling is 9 1/2'. Would these Can lights KG mentioned above be good for workbench illumination?

If so, how many?

Check this light out. Park Avenue High-Power LED Outdoor Light Bar : Wall Washers I just ordered one for the work area in my garage. Its available in warm white, which could be anything from 2700k to 3000k.

If you can throw two 6 inch can assemblies up, the Cree CR-6 or LR-6 would be great and half the price. The quality of light from the Crees is astounding. I have six in my kitchen and its just unbelievable how comfortable the light is.

John

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