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Interest for genuine Semisouth SJEP120R100 curve tracer matched pairs & quads

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We are pleased to inform you that we are about half way through our measurements.
After that they shall need to be paired and sorted / packed by hand.
And then we shall be informing you here soon for details of yield, costs, payments, etc.

Also I assume most here are planning to build the FW J2.
FIRST WATT

We shall be offering about 30 sets of 2SJ74BL matched quads for that in a separate GB.
Those first on the quad list here will be given priority.


So stay tuned,
Patrick
 
This is good news, thanks for the update.
We are pleased to inform you that we are about half way through our measurements.
After that they shall need to be paired and sorted / packed by hand.
And then we shall be informing you here soon for details of yield, costs, payments, etc.

Also I assume most here are planning to build the FW J2.
FIRST WATT

We shall be offering about 30 sets of 2SJ74BL matched quads for that in a separate GB.
Those first on the quad list here will be given priority.


So stay tuned,
Patrick
 
Matching Data

Here is the matching results of about 2/3 of our stock.
So still 1/3 to go, probably till early September.

The plot shows transconductance (Yfs) vs Vgs at 1.25A and 55°C case temperature. Vds 24V.
As you can see, the production consistency is poor and the data spread is all over the place.
If we have the same number of Toshiba FETs, we would have had quite well-matched quads for both Vgs and Yfs.
But not Semisouth's.

We shall have no choice but to give priority to Vgs match (probably ~10mV), with say 10% Yfs match.
And there will be very few quads and probably mostly 2 pairs (mainly due to Yfs mismatch).
And reject rates will be much higher than we expected.


Patrick

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Attachments

  • Semisouth Match.png
    Semisouth Match.png
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So sticking to 10mV Vgs and 10% Yfs as matching criteria (in most cases well below), we have a yield of :

49% for quads
31% for pairs
20% for singles

Using the same percentage to apply to the entire batch, we shall probably get :
50 quads
33 2-pairs

We should be able to supply everyone, worst case with 2 pairs.
And those first on the list are given priorities for quads.


Patrick
 
Patrick, I admire the dedication and work you've put into this project.

Those members who end up receiving these parts will owe you a debt of gratitude that can never be fully repaid. The sound of the FirstWatt J2 is exceptional, proven by the fact that it is still in production after 10 years.

I now wish I hadn't freaked out and removed myself from the list when I was laid off in January. :D
 
Matching Allocation to come soon

As planned, matching work was finished on 31 August.
Sorting has taken quite some time, as it has to be done manually.
First indication is that there will be 50+ quads, and 60+ pairs, according to the matching criteria (10mV Vgs and 10% Yfs).

In the next day or two, we shall post a priority allocation list for both quads and pairs.
You can then re-confirm your allocation according to the list.
We shall allow 3 weeks for that, so that the allocations will be final by the end of September.
Payment can then follow, and we expect to ship around mid-October.

No extra reminder will be sent by PM.
Just too many to send, as the forum limit 5 addressee at a time.
So please keep an eye here for any updates.


Cheers,
Patrick
 
Priority for Allocation

As mentioned, we have to offer 50 quads and 60 pairs.
Since we promised 70 quads, we shall allocate 40 of the pairs as "Twin-Pair" for the last 20 quad subscribers.

i.e.
The first 50 subscribers on the "Quad" list will be given priority to quads.
The remaining 20 will get Twin-pairs with closest possible Vgs between pairs.
If anyone opts out of the quad list, the Twin-pair list moves up automatically.
If anyone opts out of the Twin-Pair list, the "Twin-Pair" waiting list will move up.

That leaves 20 pairs for the "Pair" subscribers.
There will be waiting lists also for "Pair".

So these are the "rules". :)
The lists will follow.

There might be additional quads and pairs slightly out of matching specs.
We'll offer them later after the first round (need more sorting).
So you don't necessarily have to be disappointed.


Patrick
 
The Priority Lists

Here are the lists.

We worked out the prices as follows, in order to cover all our costs.

Quads -- HKD 2600 including Paypal fees and insured post with tracking world wide (4x FETs)
Twin-Pairs -- HKD 2150 including Paypal fees and insured post with tracking world wide (4x FETs)
Pairs -- HKD 1200 including Paypal fees and insured post with tracking world wide (2x FETs)

If you still want them, please copy the entire list, and add "confirmed" behind your name.
If you do not want them any more, please also kindly copy the entire list but delete your name.
Upward movements of the waiting lists will only be done at the end of the 3-week period to avoid chaos.




Allocation Priority for matched Quads:

yoaudio 1 quad
alazira1 2 quads
sampsonite 2 quads
tazzz 2 quad
brownaye 2 quads
secanbj 1 quad
qwertyl 1 quad
Itsmee 2 quads
carsten.witt 2 quads
Arthur 2 quads
samoloko 2 quads
aparatusonitus 2 quads
JeffYoung 1 quad
bk856er 1 quad
woofertester 1 quad
Soundslave 2quad
twitchie 1 quad
spades 1 quad
fabian 1 quad
Rodeodave 1 quad
Dennis Hui: 1 quad
Stanney2017: 1 quad
mordikai: 2 quads
Vitalica: 2 quads
Mctavish: 2 quad
JimS: 2 quads
NicMac: 2 quads
joshvi: 1 quad
AVWERK: 1 quad
vvs07: 2 quads
Stones 1 quad
SyncTronX - 2 quads
biju55 1 quad


Allocation Priority for matched Twin-Pairs:
(and reserve list for quads)

obh 1 twin pair
zchopper 1 twin pair
vasillis 2 twin pairs
andreasw. 1 twin pair
meldano 1 twin pair
necplusultra 1 twin pair
kevinheem 1 twin pair
D to the G 1 twin pair
Prakit 1 twin pair
leejh 1 twin pair
nashbap 1 twin pair
lhquam 2 twin pairs
feds27 2 twin pairs
Lazybutt 1 twin pair
gig 1 twin pair
UKToecutter 1 twin pair
tadek 1 twin pair


Matched Twin-pair Waiting List:

tadek 1 quad
dieter12 1 quad
Ouantensprung 2 quads
Boilermaker1618 1 quad
meldano 2 quads
Blackmani 2 quads
Myint67 1quad


Allocation Priority for matched Pairs:

aspringv: 1 pair
Algar_emi: 1 pair
PierreQuiRoule: 1 pair
Cochleus: 1 Pair
Murdoc: 1 pair
Spades : 2 pairs
oreo382: 1 pair
HelmutHolz: 1 pair
maartentje: 1 pair

Matched Pair waiting list

maartentje: 1 pair
olen: 2 pairs
G600: 2 pairs
GnuB: 1 pair
ne5532 : 4 pair
Blackdod: 2 pair
enochRoot: 2 pair
Reima 2 pairs
obh 1 pair
flancfuster 2 pairs


Patrick
 
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Allocation Priority for matched Quads:

yoaudio 1 quad
alazira1 2 quads
sampsonite 2 quads
tazzz 2 quad
brownaye 2 quads
secanbj 1 quad
qwertyl 1 quad
Itsmee 2 quads
carsten.witt 2 quads
Arthur 2 quads
samoloko 2 quads
aparatusonitus 2 quads
JeffYoung 1 quad
bk856er 1 quad
woofertester 1 quad
Soundslave 2quad
twitchie 1 quad
spades 1 quad
fabian 1 quad
Rodeodave 1 quad
Dennis Hui: 1 quad
Stanney2017: 1 quad
mordikai: 2 quads
Vitalica: 2 quads
Mctavish: 2 quad
JimS: 2 quads
NicMac: 2 quads
joshvi: 1 quad
AVWERK: 1 quad
vvs07: 2 quads
Stones 1 quad
SyncTronX - 2 quads
biju55 1 quad


Allocation Priority for matched Twin-Pairs:
(and reserve list for quads)

obh 1 twin pair
zchopper 1 twin pair
vasillis 2 twin pairs
andreasw. 1 twin pair
meldano 1 twin pair
necplusultra 1 twin pair
kevinheem 1 twin pair
D to the G 1 twin pair
Prakit 1 twin pair
leejh 1 twin pair
nashbap 1 twin pair
lhquam 2 twin pairs
feds27 2 twin pairs
Lazybutt 1 twin pair
gig 1 twin pair
UKToecutter 1 twin pair
tadek 1 twin pair


Matched Twin-pair Waiting List:

tadek 1 quad
dieter12 1 quad
Ouantensprung 2 quads
Boilermaker1618 1 quad
meldano 2 quads
Blackmani 2 quads
Myint67 1quad


Allocation Priority for matched Pairs:

aspringv: 1 pair
Algar_emi: 1 pair
PierreQuiRoule: 1 pair
Cochleus: 1 Pair
Murdoc: 1 pair
Spades : 2 pairs
oreo382: 1 pair
HelmutHolz: 1 pair
maartentje: 1 pair

Matched Pair waiting list

maartentje: 1 pair
olen: 2 pairs
G600: 2 pairs CONFIRMED
GnuB: 1 pair
ne5532 : 4 pair
Blackdod: 2 pair
enochRoot: 2 pair
Reima 2 pairs
obh 1 pair
flancfuster 2 pairs
 
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Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.