What happend to 320K resistors ?

[Zero999]

The thing is i like to make a 6-bit DAC :
5K
10K
20K
40K
80k
160k
320k

Why do you need those resistor values in a DAC?

[ogden]

I personally do not like solderless breadboards, they are source of extra problems I don't want; even if you use highest-quality 3M breadboards and be careful not to damage them, they greatly limit the types of components you can insert.

Right. Breadboards are great for beginners to play and learn. That's main purpose of them. Professionals will find parasitics of breadboards and jumper wires limiting. Tho my usual approach of quick weekend prototype (if any) - use stm32 blue pill module together with prototype circuit board on perfboard/manhattan/custom_PCBa, use breadboard as carrier and interconnect for modules. If I need some faster signal between MCU on bluepill and prototype circuit - use soldered wire or TP or coax, maybe even remove corresponding DIP pin on bluepill. Hint: get more than single bluepill/arduino and acompanying breadboard. You may have multiple ideas in parallel

[Vovk_Z]

The thing is i like to make a 6-bit DAC :
5K
10K
20K
40K
80k
160k
320k

That can be made from three nominals: 5k is 2x10k in parallel.
Then 20k in parallel ( it is 10k).
Then 20k.
Then 20k in series.
Then 160k in parallel.
Then 160k.
Then 160k in series.
So we'll need only three popular values: 10k, 20k and 160k. Some of them exist in E24, some in E48, some in E96, and all are in E192.

[Jan Audio]

For SMD people its easy to advice something like that.

[Monkeh]

For SMD people its easy to advice something like that.

It's no harder with through hole. You could have fixed it easily by now.

[JohnnyMalaria]

For SMD people its easy to advice something like that.

Seriously, how hard is this?

[bdunham7]

Seriously, how hard is this?

(Attachment Link)

I don't know about the OP, but for the typical OCD-addled audiophile type that would trigger a meltdown that would require months of therapy.

"The soundstage is clearly bifurcated...."

[Jan Audio]

I only wanted to know why 100 resistors cost more then 50 euro without tax.

[JohnnyMalaria]

Why 100?

[bdunham7]

I only wanted to know why 100 resistors cost more then 50 euro without tax.

If you are referring to the ones I posted, it is because they are 0.1% 25PPM/C industrial-grade precision resistors.

What exact part number were you using previously that you can't get now? 

[Jan Audio]

I dont know.

Why 100 ?, i buy per 100 or 1000.

[TimFox]

For SMD people its easy to advice something like that.

Seriously, how hard is this?

(Attachment Link)

Similarly, decades ago when I started using SMD parts (beginning with 1206), we found it easy to put two components in parallel by soldering one above the other, when circumstances required (probably no longer allowed, especially with smaller parts).

[Zero999]

320k being a E192 preferred number, will be more expensive because fewer will be made and it will be a precision part, with a tolerance of 0.5%, or better.

I still don't see the reason for the values listed? Obviously they're powers of two, but I would go for 7k5, 15k, 30k, 60k (two: 30k in series, or 120k in parallel), 120k and 240k. It would be much easier to use an R-2R ladder instead.
https://en.wikipedia.org/wiki/Resistor_ladder

[David Hess]

The thing is i like to make a 6-bit DAC :
5K
10K
20K
40K
80k
160k
320k

I usually end up using some values in series and parallel to reduce the number of separate value needed.  Or use a R-R2 DAC configuration instead which only requires two values:

https://en.wikipedia.org/wiki/Resistor_ladder#R%E2%80%932R_resistor_ladder_network_(digital_to_analog_conversion)

[Bassman59]

Seriously, how hard is this?

(Attachment Link)

I don't know about the OP, but for the typical OCD-addled audiophile type that would trigger a meltdown that would require months of therapy.

You say that like it's a bad thing!

[ogden]

I only wanted to know why 100 resistors cost more then 50 euro without tax.

Proper question shall be - why sane engineer would use such resistors in 6-bit ADC?

[tooki]

I'd have to stockpile them if I thought I would need more.

Stockpiling obsolete parts is a serious thing in this hobby, and you can make good money also if you buy enough.

With parts that have no substitutes, sure. But ordinary resistors? No way. A high-volume manufacturer that needs an unusual value will just order them (or even custom values), since they need lots anyway. And for small volume projects and repairs, you just use combinations of common values.

[Vovk_Z]

For SMD people its easy to advice something like that.

I usually use TH parts (resistors) only when prototyping. Almost totally moved to SMD. There are few places where we really have to use TH parts.

[retiredfeline]

Should be half enough for everybody. 

[TimFox]

I'd have to stockpile them if I thought I would need more.

Stockpiling obsolete parts is a serious thing in this hobby, and you can make good money also if you buy enough.

With parts that have no substitutes, sure. But ordinary resistors? No way. A high-volume manufacturer that needs an unusual value will just order them (or even custom values), since they need lots anyway. And for small volume projects and repairs, you just use combinations of common values.

DigiKey shows several pages of 320 k TH resistors, but none of them is stocked.  If you have need of a sufficient minimum order quantity, they will supply you.  If it were me, I would use two resistors in series.

[Jan Audio]

Thanks all.

Why i use such a DAC ?, it works, i am just happy with stuff that works.

[Jan Audio]

This DAC reacts instantly, while a SPI DAC is slower.
It uses a few parts, the other DAC has more resistors.

[MK14]

Requirements apparently met:

• Through Hole
• 1% Tolerance
• In Stock - Almost 700,000
• Less than $0.05 each. These are around $0.035, for x1000, less for bigger quantities
• 320K
• 0.5 Watts
• Metal Film
• By Vishay  CMF55320K00FHBF

https://www.component-en.com/products/CMF55320K00FHBF/13919735

Disclaimer:
I have no idea on the quality of that supplier, so check them out yourself, please.

[tooki]

I'd have to stockpile them if I thought I would need more.

Stockpiling obsolete parts is a serious thing in this hobby, and you can make good money also if you buy enough.

With parts that have no substitutes, sure. But ordinary resistors? No way. A high-volume manufacturer that needs an unusual value will just order them (or even custom values), since they need lots anyway. And for small volume projects and repairs, you just use combinations of common values.

DigiKey shows several pages of 320 k TH resistors, but none of them is stocked.  If you have need of a sufficient minimum order quantity, they will supply you.  If it were me, I would use two resistors in series.

I know that. You simply rephrased my reply, which was in response to OP’s claim of there being lots of money to be made in stockpiling “obsolete” resistors. I was explaining why that’s silly, since volume customers can get them if they need them (and wouldn’t buy them from some random guy anyway), and small customers would just design around the problem by using combinations. There’s no significant clientele for old stockpiled resistors.

[Jan Audio]

For SMD people its easy to advice something like that.

Seriously, how hard is this?

It seems very hard to make a 320K resistor like this.