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Old 21st March 2009, 02:37 PM   #1521
flg is offline flg  United States
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You might double check the orientation of the JFETs. Some actually work backwards and some don't work the same at all backwards
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Old 21st March 2009, 04:03 PM   #1522
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Default Re: Soldering little bugs

Quote:
Originally posted by dcbingaman
Anthony - I like your suggestion - I've also heard folks use double-sided tape to hold the little devils in place on an SOJ-to-DIP adapter PCB.

In your experience, however, is it better to try this before or after a nice glass of Balvanie Scotch ??

Quote:
Originally posted by udailey
In pcb assembly houses they use a little dot of some special red glue. I dont know how special it has to be but a tiny dot of some adhesive on the back of each SMD part, put them in place and let it all dry, then go to work with the iron.
Uriah

Oh I don't know about the Scotch, depends on whether it will steady your hand more than it blurs your vision.

I actually manage the purchasing department in a large Electronics manufacturer. We have 3 SMT lines, Genisis, GSM and Panasonic. We use Loctite SMD Adhesive to hold parts in place, but it needs to be ordered over night delivery as it must remain refridgerated until use. If you have a lot of parts to put down the Toaster oven method works with a little practise, but for one offs I still prefer a steady hand and a bit of solder.

Anthony
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Old 21st March 2009, 04:22 PM   #1523
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Default tooling adhesives for SOIC's

I like the adhesive idea - I was thinking potting compound might work OK also, but I might try either super-glue or "Gorilla Glue" contact cement first. You guys have convinced me that this is doable.

And, Anthony, in my case, the hands steady before the vision goes with good Scotch....but that is only after one. After three, all bets are off. According to my wife, even my other appendages are of little use. I say its age !!
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Old 21st March 2009, 04:31 PM   #1524
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Default Re: tooling adhesives for SOIC's

Quote:
Originally posted by dcbingaman
I like the adhesive idea - I was thinking potting compound might work OK also, but I might try either super-glue or "Gorilla Glue" contact cement first. You guys have convinced me that this is doable.

And, Anthony, in my case, the hands steady before the vision goes with good Scotch....but that is only after one. After three, all bets are off. According to my wife, even my other appendages are of little use. I say its age !!
My wife is the Scotch aficionado, I am a beer snob, Spitfire Ale, Old Speckeled Hen..... anyway remember the point of the glue is only to tack while you are soldering. Most of the product you mention will ensure a permanent bond and heartache if you have to rework.

Regards

Anthony
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Old 21st March 2009, 04:37 PM   #1525
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Default Re: silent b1

Quote:
Originally posted by rob lenk
one question and one suggestion
check that you have voltage on the board- positive 18 or 24 volts at a transistor to ground- remember this buffer draws very little amps so if the positive volts are there you are probably ok
assuming you didn't burn the transistors soldering them(and from the photos it looks like you did a nice job), the my guess would be the volume pots- wired backwards or shorted out- by pass them with a 25k ohm resistor and, a small prayer if you are of that persuastion-
hope it goes better
rob
Glad I read this: I was wondering why when I played with the pots, there was no change in volume.

Duh! Wired things in reverse and no grounds whatsoever!
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Old 21st March 2009, 04:38 PM   #1526
labjr is offline labjr  United States
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Default Re: Re: tooling adhesives for SOIC's

Quote:
Originally posted by Coulomb


My wife is the Scotch aficionado, I am a beer snob, Spitfire Ale, Old Speckeled Hen..... anyway remember the point of the glue is only to tack while you are soldering. Most of the product you mention will ensure a permanent bond and heartache if you have to rework.

Regards

Anthony

Gorilla Glue expands while it's hardening. I don't imagine that would work well. Maybe loctite threadlocker blue would work if you can find a way to apply small amounts.
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Old 21st March 2009, 04:40 PM   #1527
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Default silen b1

score
one
for me
yehaaa
r
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Old 21st March 2009, 11:46 PM   #1528
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Default Volume....

I paid close attention to the plus/minus when I assembled the B1 but that seems the easiest place to start. There is no "star" ground to the chasis as the board is on nylon standoffs. The RCA input and output "G"rounds are all insulated from the chasis also. All wired connections to the RCA's, Pots, and Toggles are single conductor wire insulated. Wire insulation on all wires is not connected. I do notice that there is distortion after the volume is turned above 50% although volume is extremely low.
I don't understand "backkwards" FET's ???

-BP
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Old 22nd March 2009, 01:48 AM   #1529
flg is offline flg  United States
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The source and drain are connected where the drain and source should to be...
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Old 22nd March 2009, 12:51 PM   #1530
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Default b1-bfny response

Mr BFNY-
lovely reference to the texas instruments facts page-great reading!
I really need to go there more often- they have some great freeware on building sallen-key filters
thank you so much for the input
rob
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