If anyone needs additional FETs please send me a PM and tell me what Idss range you are looking for. There are some additional pairs and quads available, but nothing with Idss >10mA.
Hey, thank you all for your confirmation that you received your JFets. I shipped everything on thursday and i will send tracking numbers to everyone who did not receive their parcels yet.
I have to apologize for the second hand ESD bags i used for shipping your JFets. I was sure that i had about 80 fresh ESD ZIP bags somewhere (from the last group buy) - but they must have gone missing. I could not find them.
I wish everyone successfull projects with the jFets. If anyone faces any problems please contact me.
Regards, Andreas
I have to apologize for the second hand ESD bags i used for shipping your JFets. I was sure that i had about 80 fresh ESD ZIP bags somewhere (from the last group buy) - but they must have gone missing. I could not find them.
I wish everyone successfull projects with the jFets. If anyone faces any problems please contact me.
Regards, Andreas
Hi Alchamist,
those differences are in the range of measurement error on my non-professional matching jig. So maybe the matching is even better, or even worse.. Build that simple Jig you can find in Post #1 of this thread and you can experiment yourself. You will see how measurements differ with surrounding temperature. We match at 20°C, but we use them in amps with 30°C, 40°C, 50°C Temperature inside.
Of course it is impossible to get 20 octets with 101% perfect matches when using a pool of "only" 400 or 600 devices.
As you can see each octet consists of 2 tighter matched quads with very equally Idss and Vds and you can pick your devices like you need them. Each quad consits of 2 tight matched pairs with almost 100% same Idss and Vds. As we can see on your pictures each device is marked clearly and if you cut the stripe after every two devices you will have 4 perfectly matched pairs.
If you degnerate matched JFETs of both left and right channels of a preamp with a source resistor of 5 ohms to 100 ohms then they will "match better" and their curves will be almost identical. This would be the case for some JFET RIAA preamps ("le Pacific", Pearl, BHL deluxe, 'Salas FSP' second gain stage).
In PM you asked me about the use for SEN IV. I am not into this project, but a quick search using the words "SEN IV idss match" gave me the answer:
Every application is different. So you might answer your upcoming questions by searching for "name-of-project Idss match" or something like this.
those differences are in the range of measurement error on my non-professional matching jig. So maybe the matching is even better, or even worse.. Build that simple Jig you can find in Post #1 of this thread and you can experiment yourself. You will see how measurements differ with surrounding temperature. We match at 20°C, but we use them in amps with 30°C, 40°C, 50°C Temperature inside.
Of course it is impossible to get 20 octets with 101% perfect matches when using a pool of "only" 400 or 600 devices.
As you can see each octet consists of 2 tighter matched quads with very equally Idss and Vds and you can pick your devices like you need them. Each quad consits of 2 tight matched pairs with almost 100% same Idss and Vds. As we can see on your pictures each device is marked clearly and if you cut the stripe after every two devices you will have 4 perfectly matched pairs.
If you degnerate matched JFETs of both left and right channels of a preamp with a source resistor of 5 ohms to 100 ohms then they will "match better" and their curves will be almost identical. This would be the case for some JFET RIAA preamps ("le Pacific", Pearl, BHL deluxe, 'Salas FSP' second gain stage).
In PM you asked me about the use for SEN IV. I am not into this project, but a quick search using the words "SEN IV idss match" gave me the answer:
Every application is different. So you might answer your upcoming questions by searching for "name-of-project Idss match" or something like this.
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