Brian,
Worldway Electronics from Hong Kong have a bunch of KSA1381ESTU. Approx. 19,470 parts
https://www.worldwayelec.com/pro/onsemi/ksa1381estu/120797?from=octopart
https://www.microchipusa.com/parts/...topart&utm_medium=PartSearch&utm_campaign=ADJ
Microchipusa has around 2660 parts
MM
Worldway Electronics from Hong Kong have a bunch of KSA1381ESTU. Approx. 19,470 parts
https://www.worldwayelec.com/pro/onsemi/ksa1381estu/120797?from=octopart
https://www.microchipusa.com/parts/...topart&utm_medium=PartSearch&utm_campaign=ADJ
Microchipusa has around 2660 parts
MM
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Rochester has 37,427 On-Semi 2SA3503E at the time of this post.
https://www.rocelec.com/part/01t4w00000NZ6gXAAT-2SC3503E
They have the metal collector heatsink tab, so must use an insulator.
I just took delivery of 1000 pieces today, and they are genuine!
https://www.rocelec.com/part/01t4w00000NZ6gXAAT-2SC3503E
They have the metal collector heatsink tab, so must use an insulator.
I just took delivery of 1000 pieces today, and they are genuine!
That is the source of those 2SC3503E for this group buy.
The issue currently is acquiring the complimentary 2SA1381E (or KSA1381ESTU) that seem to be unobtainable now.
If someone can facilitate a large purchase from the links provided in post #164 above, that would be spectacular. If all of us request a quote at once for those the price is gonna skyrocket, so we need just one person to step up and look into it.
The issue currently is acquiring the complimentary 2SA1381E (or KSA1381ESTU) that seem to be unobtainable now.
If someone can facilitate a large purchase from the links provided in post #164 above, that would be spectacular. If all of us request a quote at once for those the price is gonna skyrocket, so we need just one person to step up and look into it.
ksa1381 is available for puchase from US companies, but....
"we're only set to sell the OEMCM so can you give us a message but I will drop you an email give us a message and will let you know if we can service you"
Flip electronics and other ones are selling to companies only.
"we're only set to sell the OEMCM so can you give us a message but I will drop you an email give us a message and will let you know if we can service you"
Flip electronics and other ones are selling to companies only.
Well Zed Audio, Corp. has a business license and we would be able to make bulk purchases for members. I have never done this thing before and would need some guidance on the process.
I guess each member places an "order" and sends money. How to send money I do not know as we only use Paypal (Urrrggg), credit cards, T/Ts (expensive) and cheques.
We placed a request from
https://www.worldwayelec.com/pro/onsemi/ksa1381estu/120797?from=octopart
yesterday but have not yet received a reply.
I also put feelers out to Microchip and they replied but of course it is the weekend and will have to wait for Monday.
The Rochester version is a SIP3 package which I have never heard of. All our PCBs are designed for TO216/TO220 parts.
We are running out of our stock of 3503/1381s and need to replenish them and would prefer to purchase both N and P types from the same company, which Worldwaylec seem to have.
All thoughts and suggestions are welcome.
We also use lots of KEC KTD600K and KTB631K in TO126 packages and when used in a cascoded VAS, give very similar measurements to 3503/1381 pair BUT must have minimal Vceo across them and as stated we have only 2.2v Vceo.
Stephen Mantz
Zed Audio
Feel free to call me at 805 499 5559 PST
I guess each member places an "order" and sends money. How to send money I do not know as we only use Paypal (Urrrggg), credit cards, T/Ts (expensive) and cheques.
We placed a request from
https://www.worldwayelec.com/pro/onsemi/ksa1381estu/120797?from=octopart
yesterday but have not yet received a reply.
I also put feelers out to Microchip and they replied but of course it is the weekend and will have to wait for Monday.
The Rochester version is a SIP3 package which I have never heard of. All our PCBs are designed for TO216/TO220 parts.
We are running out of our stock of 3503/1381s and need to replenish them and would prefer to purchase both N and P types from the same company, which Worldwaylec seem to have.
All thoughts and suggestions are welcome.
We also use lots of KEC KTD600K and KTB631K in TO126 packages and when used in a cascoded VAS, give very similar measurements to 3503/1381 pair BUT must have minimal Vceo across them and as stated we have only 2.2v Vceo.
Stephen Mantz
Zed Audio
Feel free to call me at 805 499 5559 PST
Central coast CA area code. I went to Cal Poly for school. I'd be happy to chat with you about accommodation of getting extra 2000qty for this group buy. I can be a single purchaser to help you out and then collect funds from individuals in this group buy and distribute to simplify your workload. I bet Brian would also be willing to do that since he already has most folks funds for the SA1381E in hand and just needs the parts to distribute.
Your offer is greatly appreciated!!!!!
Your offer is greatly appreciated!!!!!
@MOER , @birdbox
I agree that Brian has to be involved with a transfer of money, and Brian also knows what people have paid or not paid, and what people ordered. I have not seen a response from Brian since Thursday.
Stephen, I am in for whomever you choose to order from, whatever suits your company.
Note: Stephen I assume you meant TO126/TO220 from Rochester, not TO216/TO220.
Nice to see from progress.
MM
I agree that Brian has to be involved with a transfer of money, and Brian also knows what people have paid or not paid, and what people ordered. I have not seen a response from Brian since Thursday.
Stephen, I am in for whomever you choose to order from, whatever suits your company.
Note: Stephen I assume you meant TO126/TO220 from Rochester, not TO216/TO220.
Nice to see from progress.
MM
Hi
i have got my pcs from brain.
i had 1381_E but bought the wrong other hfe group of KSC3503_D.
now i have 2sc3503 E.
my hfe and vbe measurements are now a better fit but not realy close what i expected.
for my amps i tried TTA004B_Q and TTC04B_Q and i got "better" hfe and vbe fit.
these are availabe .
for higher voltage (230V) the TTA06B, TTC011B are available too.
kr
chris
i have got my pcs from brain.
i had 1381_E but bought the wrong other hfe group of KSC3503_D.
now i have 2sc3503 E.
my hfe and vbe measurements are now a better fit but not realy close what i expected.
for my amps i tried TTA004B_Q and TTC04B_Q and i got "better" hfe and vbe fit.
these are availabe .
for higher voltage (230V) the TTA06B, TTC011B are available too.
kr
chris
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Hi Guys,
Regarding WorldWay and other online resources claiming to have stocks of KSA1381E... I have found that most of these are not legitimate or they are B2B only. Resellers often leave stale posts up to get you to contact them. Then they offer you "alternative products". I've gone through this scenario several times with these listings.
I have reached out to Worldway in the past for a 2SA1381E listing they had up as was told they only have C grade. . I'll reach out again for the KSA1381 listing, but I am not optimistic.
If someone has a business license, we can try to engage Flip. However, they seem to be pretty thorough about vetting their customers. I suspect you would have to be clearly in the electronics business with a physical business address to pass their screening... possibly a manufacture too and not simply a reseller. Please reach out to me if you'd like to tackle this together. I can "purchase" the lot from whoever makes the purchase from Flip and handle distribution.
Regarding WorldWay and other online resources claiming to have stocks of KSA1381E... I have found that most of these are not legitimate or they are B2B only. Resellers often leave stale posts up to get you to contact them. Then they offer you "alternative products". I've gone through this scenario several times with these listings.
I have reached out to Worldway in the past for a 2SA1381E listing they had up as was told they only have C grade. . I'll reach out again for the KSA1381 listing, but I am not optimistic.
If someone has a business license, we can try to engage Flip. However, they seem to be pretty thorough about vetting their customers. I suspect you would have to be clearly in the electronics business with a physical business address to pass their screening... possibly a manufacture too and not simply a reseller. Please reach out to me if you'd like to tackle this together. I can "purchase" the lot from whoever makes the purchase from Flip and handle distribution.
Hi Chermann,
The beauty of the SC3503 / SA1381 combo is their very low COB. Nothing else in the TO-126 package comes close. Depending on the topology, the low COB may or may not be important. I agree that TTC004B / TTA004B is the best in-production alternative, but the Cob is higher.
I recently acquired a lot of 2SC3502E / 2SA1380E that I am testing for authenticity. They have a lower 200V Vce, but a 20% higher average gain than 2SC3503E / 2SA1381E. It's a large lot, but not enough to cover this GB unfortunately.
Also purchased a large lot of 2SC3503F, but cannot locate a F grade P-channel compliment. These would be interesting in a N-channel single-ended VAS where the gain of the CCS isn't as important.
The beauty of the SC3503 / SA1381 combo is their very low COB. Nothing else in the TO-126 package comes close. Depending on the topology, the low COB may or may not be important. I agree that TTC004B / TTA004B is the best in-production alternative, but the Cob is higher.
I recently acquired a lot of 2SC3502E / 2SA1380E that I am testing for authenticity. They have a lower 200V Vce, but a 20% higher average gain than 2SC3503E / 2SA1381E. It's a large lot, but not enough to cover this GB unfortunately.
Also purchased a large lot of 2SC3503F, but cannot locate a F grade P-channel compliment. These would be interesting in a N-channel single-ended VAS where the gain of the CCS isn't as important.
Question for those in the GB:
If I do manage to find SA1381E from a secondary source of unknown reliability, what would make you feel comfortable that they are legit?
Other than a visual inspection, sending them out for testing is likely too expensive. So, I am thinking of testing a sample from each bag. Something like this.
The easy testing would be:
Thoughts?
If I do manage to find SA1381E from a secondary source of unknown reliability, what would make you feel comfortable that they are legit?
Other than a visual inspection, sending them out for testing is likely too expensive. So, I am thinking of testing a sample from each bag. Something like this.
The easy testing would be:
- Test for breakdown voltage (using a eBay tester like this)
- Test for Gain on a Mega328
- Curve trace (on something like a Diligent Analog Discovery). SC3503 & SA1381 has a curve with a quasi-saturation region which should be easy to spot.
- Higher current load testing than the Mega328 or curve tracer is not capable of. Maybe a breadboard circuit at 10V - 20V Vce and 10mA or 20mA? Verify that the gain is good at a higher current and they don't fry.
Thoughts?