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What happend to 320K resistors ?
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asmi:

--- Quote from: Siwastaja on February 19, 2021, 04:32:27 pm ---What's wrong with the classic R2R DAC that uses a single value of resistor?

What's wrong in putting another resistor in series?

How are you driving your resistor DAC? From standard CMOS outputs of an MCU or logic IC?  :popcorn:

I think the problem isn't sourcing 320kOhm resistors; it's designing a DAC. Let's start by defining your requirements for the DAC.

--- End quote ---
I would add one more question - what's wrong with people designing in thru-hole passives in year 2021?
srb1954:

--- Quote from: nali on February 19, 2021, 04:26:03 pm ---
--- Quote from: Jan Audio on February 19, 2021, 04:09:40 pm ---Ofcourse i want the precision for a DAC,
because i could buy them some time ago i dont want those 316K.
They just disapear ?, someone has buyed them since they have nothing left.
Why not make a few to keep stock ?, is it so difficult ?

--- End quote ---

Just wondering, why do you need such precision when you only have 6 bits anyway?

--- End quote ---
And why get so concerned about a little bit of error in the resistor value for the LSB of the DAC? 

You are going to need some very precise resistors for the MSB of the DAC before the error in the LSB value is even going to be noticeable.
srb1954:

--- Quote from: Jan Audio on February 19, 2021, 04:09:40 pm ---Ofcourse i want the precision for a DAC,
because i could buy them some time ago i dont want those 316K.
They just disapear ?, someone has buyed them since they have nothing left.
Why not make a few to keep stock ?, is it so difficult ?

--- End quote ---
It is actually quite difficult for the distributors and manufacturers to deal with the demand for with rarely ordered values.

A distributor is not going to want to keep a reel of very slow moving resistors on the shelf just for the occasional low volume purchaser. The solderability of components deteriorates over time so the distributor is only going to stock items that can be turned over every 6 months or faster.

The manufacturer is going to have the same problem. They are not going to keep an obscure value on the shelf just in case some distributor orders it out of the blue. More likely they will manufacture the value to order and then they will want to manufacture considerably more than a one reel quantity to justify the set-up costs for that production.
coppercone2:
axial resistors kick ass

what suppliers get for stocking e196 is
1) people buying more parts in general in the first theme because they can get anything they need in the same kind for uniform designs, its not that much room considering the size of these places, give me a break. you need them for some engineering designs, stop forcing SMD on people for no reason other then its cheaper or desirable for YOUR process.. stop thumping the 'new testament' of SMD being better at everything, not everyone wants rice. People keep pushing vibration but there is also flex
2) respect

wraper:

--- Quote from: coppercone2 on February 20, 2021, 03:14:04 am ---stop forcing SMD on people for no reason other then its cheaper or desirable for YOUR process.. stop thumping the 'new testament' of SMD being better at everything, not everyone wants rice.

--- End quote ---
SMD is not only cheaper but also takes less space, is faster to assemble and have less of parasitic inductance. Not to say TH parts go away, you simply cannot find most of modern parts in TH.
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