matching transistors - DIY

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elektrouwe
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Re: Anything to this idea?

Post by elektrouwe » Wed Dec 04, 2019 1:36 pm

jakobprogsch wrote:
consumer wrote: I read through this post, but never saw anyone respond to this idea: Is there any merit to multiplying the gain in order to exaggerate the offset?

Or would that just introduce more uncertainty?
I'd say no merit since at least the garden variety opamps that aren't specifically marketed as low offset probably have input offset specs in the mV range themselves.

I have to admit all this talk about the DMM digits in this thread has me confused anyway. Isn't the whole point of these "differential" circuits that you don't have to measure absolute voltage but only relative one? How many digits the DMM has is pretty irrelevant as long as it has a mV range setting.
true, matching is a relative measurement. That's why such a simple thing like YATMA can match to 50uV if you need it without precision DVM.
viewtopic.php?t=153845

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cygmu
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Re: Anything to this idea?

Post by cygmu » Thu Dec 05, 2019 2:07 am

elektrouwe wrote: true, matching is a relative measurement. That's why such a simple thing like YATMA can match to 50uV if you need it without precision DVM.
viewtopic.php?t=153845
I may have said this further up the thread, but: I love my YATMA! It is a very useful device and makes transistor matching actually enjoyable :) Thank you elektrouwe.

As a practical point, I have found the YATMA much easier and faster to use than my build of the Fritz circuit. Obviously it took a few more hours to put together but the time saved since and the reliable matches found are worth it, to me at least.

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jet
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Re: matching transistors - DIY

Post by jet » Fri Feb 07, 2020 1:17 pm

Is there a parts list/BOM for Ian Fritz's board available on OSHPark? I just order a batch of 3 and will probably have two to pass on.

I found this switch https://www.mouser.com/ProductDetail/Mo ... xlwcUaE%3D in an earlier post, maybe I can scrounge all the other parts at a hackerspace?
industrial designer, interaction designer, cello student, hacker

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KittenVillage
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Re: matching transistors - DIY

Post by KittenVillage » Sat Feb 08, 2020 5:10 pm

jet wrote:
Fri Feb 07, 2020 1:17 pm
Is there a parts list/BOM for Ian Fritz's board available on OSHPark? I just order a batch of 3 and will probably have two to pass on.

I found this switch https://www.mouser.com/ProductDetail/Mo ... xlwcUaE%3D in an earlier post, maybe I can scrounge all the other parts at a hackerspace?
I think I've got a couple of those switches I could pass on to you for one of your boards. I'll pm you.


Eurorack is an exercise in delayed desire.

tenma
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Re: matching transistors - DIY

Post by tenma » Wed Feb 19, 2020 1:54 am

Hi, I bought an Ian Fritz transistor matching kit. I assembled the pcb but I'm wondering how I power it. It comes with a small ribbon cable, but what should I connect the ribbon cable to? Can I rig it to power of a 9V battery?

Thanks
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jorg
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Re: matching transistors - DIY

Post by jorg » Wed Feb 19, 2020 12:16 pm

tenma wrote:
Wed Feb 19, 2020 1:54 am
Hi, I bought an Ian Fritz transistor matching kit. I assembled the pcb but I'm wondering how I power it. It comes with a small ribbon cable, but what should I connect the ribbon cable to?
That looks like a Eurorack power connector.

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jet
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Re: matching transistors - DIY

Post by jet » Sun Mar 08, 2020 11:17 am

I think this is the switch, ordered a few and will report back:

https://octopart.com/search?q=1MD1T6B11 ... SD&specs=0
industrial designer, interaction designer, cello student, hacker

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