Phase Linear 2000 op-amp upgrade

Gepetto said:
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When I worked at Siemens Automotive I was a failure analysis engineer. I specialized in root cause analysis for anti-lock brakes and air bag deployment modules. We did a lot of SMT soldering too, and I don't miss it one bit. If you don't have the tools, don't try it! We used a preheat plate and that made things easier, but it's definitely a different process than regular through hole soldering.
We had Metcal equipment too, Joe. Good stuff.
 
frhodes said:
Installed the new dual op-amps with Brown Dog adaptor. Easiest upgrade I've ever done.
Couple of taps with the hammer and success. Sounds great. Now to find the mylar caps.
Thanks Lee
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Hello there,

I received oday my little browndog thing : I am maybe missing something obvious, but, I can't figure in wich direction I'm supposed to insert te adaptator as I can't see any kind of poka yoke to help with ...

Any tip?

Thanks a lot in advance
 
I should have said buy the "mounted" option.... as I have never surface mount soldered I really have no help to offer here...
 
Coldsmoke said:
Hello there,

I received oday my little browndog thing : I am maybe missing something obvious, but, I can't figure in wich direction I'm supposed to insert te adaptator as I can't see any kind of poka yoke to help with ...

Any tip?

Thanks a lot in advance
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Send some photos Florian to help explain what you mean please.
 
Florian there is an indicator on the mounted option. Did you buy the adapter with the op-amps mounted?
 
Pin number 1 is a square tinned hole, the rest are round...on BOTH options, there is that square hole indicator....
 
laatsch55 said:
Pin number 1 is a square tinned hole, the rest are round...on BOTH options, there is that square hole indicator....
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Hello Lee, I bought the mounted option of course as advised : I hadn't noticed the little square thing, thanks for that. I am more used to the rounded footprint at one end of the body of the OPA.


BTW, a quick update on my 'restoration':
- I'm almost done with replacing all the resistors with 1% ones
- I read on a Joe's comment that the use of the 33k resistor on the volume pot could cause some troubles, so I won't replace it
- I couldn't find .0027uF 150V so I'm planing to mount .03uF 220V on the top pot ends
- Last thing : I couldn't find any low intensity white led so I'm trying to figure the value of the resistor that I should place between the TIS97 and the led to lower its insentity, say of 50% or so... Any clue?
 
Not offhand no, but Ohm's law still works. If you want to cut the current in half, I would double the resistance...
 
laatsch55 said:
Not offhand no, but Ohm's law still works. If you want to cut the current in half, I would double the resistance...
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Ah ah Thanks Lee you probably think that I'm such a goat with the ABC's :)

My point was rather : Can I assume that the instnsity is a direcet linear function of the amperage ....? I think I just have to try .... I'll start with doubling the resistance (122 O if I'm correctly applying my ohm law for a 2.2 V 18mA) : ))
 
laatsch55 said:
Not offhand no, but Ohm's law still works. If you want to cut the current in half, I would double the resistance...
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Trial and error to your liking. LED light output is not very linear with current especially at the low end. Clip on a jumper and try various higher resistor values until you find one you like and then perform the solder replacement.
 
If one was to make an assumption that's as good as any.....is illumination linear? Good question...
 
laatsch55 said:
If one was to make an assumption that's as good as any.....is illumination linear? Good question...
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Yep sorry, sometimes I just write what I have in my head without realy thinking... It wasn't really a question, let's try, :]
 
Coldsmoke said:
Yep sorry, sometimes I just write what I have in my head without realy thinking... It wasn't really a question, let's try, :]
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I know it wasn't really a question, I took it as rhetorically.....




Joe, Thank you!! Now we know. I imagine optics and illumination has it's own can of worms to deal with...
 
Sounds like a good use for a variable resistor with 1/2w or so dissapation rating. Adjust until it looks right, measure it, stab in the closest standard value fixed resistor. Bit of a hack way to do it, but "cheat to win" as they say.
 
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