GB NP matched Toshiba 2SK1530/2SK201 for F5X

[Horio]

NicMac 8 pairs (2 stereo F5X) (NNNNPPPP x 2)
CanAm Man 4 pairs (1 stereo FX5) (NNNNPPPP)
ramallo 4 pairs (1 stereo FX5) (NNNNPPPP)
oneaclock 4 pairs (1 stereo FX5) (NNNNPPPP)
andrewt 4 pairs (1 stereo FX5) (NN NN PP PP)triple point + possibly 20NN and 20PP single point
Studley 4 pairs (1 stereo FX5) (NNNNPPPP)
ashaw 8 stereo sets? (NNNNPPPP x 8 ??)
triode4 4 pairs (1 stereo F5X) (NNNNPPPP)
heinz1 4 pairs (1 stereo F5X) (NNNNPPPP)
Mravinsky 4 pairs (1 stereo FX5) (NNNNPPPP)
JBdV 8 pairs for 2 F5X (NNNNPPPP x 2)
smyslow 4 pairs (1 stereo F5X) (NNNNPPPP)
APK 12 pairs (3 stereo F5X) (NNNNPPPP)
Horio 2 pairs (2 stereo F5X) (NNNNPPPP x 2)
Westley 4 pairs (1 stereo F5X) (NNNNPPPP)
alazira 4 pairs (1 stereo F5X) (NNNNPPPP)
pmchoong 4 pairs (1 stereo F5X) (NNNNPPPP)
CeeVee 4 pairs (1 stereo F5X) (NNNNPPPP)
lhquam 4 pairs (1 stereo F5X) (NNNNPPPP)
flg 4 Pairs (1 stereo FX5) (NNNNPPPP)
ichiban 4 pairs (1 stereo FX5) (NNNNPPPP)
daanve 8 pairs for 2 F5X (NNNNPPPP x 2)
johnwmclean 4 pairs (1 stereo F5X) (NNNNPPPP)
buzzforb 4 Pairs (1 stereo FX5) (NNNNPPPP)
bkdog 4 Pairs (1 stereo FX5) (NNNNPPPP)
vitalica 8 pairs for 2 F5X (NNNNPPPP x 2)

 

[zhoufang]

So ideally you should lobby Zhou to match at 2A at least.
Keeping the temperature of the MOSFET under control is a bit more tricky than matching at 500mA and Vds = Vgs.

In the end, it is the amount of work required, and as a result how much you are prepared to pay.
Plus that Zhou has the FETs, but probably not the time (and perhaps also interest) to do large scale, complicated matching.


Patrick

I see there is quite some interest for matching at 2A.

I would not mind doing it at 2A instead of 500mA.
The problem is, as I'm currently matching at 27degC (which is fast and highly repeatable), 2A is very hot and it will reduce the accuracy/repeatability of the matching.
So instead of repeatable to 5mv, it will be repeatable to 15 or 20mV.

Testing at 2A 60deg? If there is enough buyer to buy 200 pairs and pay extra $5/pair, then I may grab the hot plate from my work and do the bake slowly. Otherwise, No.



Another thing. I have received my last purchase of 1530/201, and have did some sampling test.
Only 1-2% qualify as PN match. There is just so little overlapping between the polaritys. It used to be much better.

 

[EUVL]

For our own use, XEN Audio matches at 15.5V 0.5~4A (curve traced) with the device under test mounted to on a 60°C thermally stable metal block.

There are some interest within the first Case GB group to repeat that.
But I shall leave them to announce what they intend to do themselves.

I have not tested any 2SK1530/2SJ201 recently.
But I agree with you that it used to be much much better than 1% N-P match.


Patrick

 

[AndrewT]

Zhou,
your ~500mA matched pairs/quads @ 0Vdg, were not at all well matched.
The results when retested by various methods showed that your claimed pairs/quads were not pairs/quads at all and yet you charged a premium price for them.

Now you are asking an even higher "premium+" price !

 

[NicMac]

Dear all,

As you may understand from Patric’s comments some of us with F5X cases from the first GB have been discussing how to get the 1530/201 output devices to finish up our builds the best possible way.

A few weeks ago I took action by purchasing 500+500 devices in Japan with the pivotal help of Nikon1975. I did this fairly costly investment knowing that heinz1 would be able to help me with the matching, ashaw with data analysis and Patrick with special equipment and advice.

The purpose of this effort is to offer quality matched devises to F5X builders with priority to those from the first case GB.

The whole thing is not going to happen in a few weeks, as I will first get the devises mid July. As a moderately optimistic estimate I would say that distribution could be done the first half of September.

Although the final matching procedure has not been decided yet, it will be done at operating temperature/current using a curve tracer. Different methods are being tested and we will continue this testing until the fets arrive. I will of course post the exact method and I hope that AndrewT will check a set of devices to validate the quality claims we will come with

I find it useless to discuss what kind of pairing to do until we have a good idea of what we have in hand.

As for pairing, pricing cannot bee decided until we know the device spread. I hope the cost will be similar to the price offered by zhoufang. I’m not doing this to earn money (fortunately I already have a good day job), but considering the work and the risk I’m taking I think making a loss would also not be fair.

I’m not asking you for any upfront payment, but simply to have a bit of patience and stay tuned. If you are in a rush to listen to your F5X, which I very well understand, I guess you can use what you already have at hand or get devices from zhoufang - entirely your choice.

Nevertheless, as the investment has already been made I hope for your continued support.

Cheers,

Nic

 

[AndrewT]

.........................A few weeks ago I took action by purchasing 500+500 devices in Japan with the pivotal help of Nikon1975. I did this fairly costly investment knowing that heinz1 would be able to help me with the matching, ashaw with data analysis and Patrick with special equipment and advice.

The purpose of this effort is to offer quality matched devises to F5X builders with priority to those from the first case GB..................... ............................I find it useless to discuss what kind of pairing to do until we have a good idea of what we have in hand.

As for pairing, pricing cannot bee decided until we know the device spread..................................considering the work and the risk I’m taking I think making a loss would also not be fair..........................as the investment has already been made I hope for your continued support.

I fully support you.

I fully understand the advice to not pre-empt the matching results, with promises that are out of our control. It depends on what Toshiba supplies. FETs from experience and datasheets are very variable. We take what can be achieved with the devices, even if they are not ideal, eg. no N to P channel matching.

I would expect all those who have shown interest to stay with you.
I would expect all the Group Buyers to stay with you.

These Group Buys are only organised for the benefit of the Members. I would think of any Member who abandons you with your stock of mosFETs to be a traitor to the Group Buy cause.

 

[ichiban]

I would expect all those who have shown interest to stay with you.
I would expect all the Group Buyers to stay with you.

Amen!

 

[mravinsky]

I fully agree with Andrew.

 

[EUVL]

Firstly I admire the courage of the three gentlemen who take this task on.
It demands a huge effort.



And I have no doubt they will have no problems "getting rid" of these devices.
I am sure most GB scubscribers will support their action.
Perhaps I would not have gone as far as using the word "traitor".


Patrick

 

[Horio]

Nic, what a generous offer by you, ashaw, heniz1 and nikon! This is definitely no small undertaking and all of your efforts are greatly appreciated. As much as I would love to get my F5X running a couple months sooner, I am more than happy to wait a bit longer for FETs specifically matched for this amp. Let me know if I can help with the US distribution, if that makes things a bit easier for you.

 

[vitalica]

I fully support you!
Are waiting for your transistors.

 

[Nikon1975]

Pictures are worth more than 1000 words. One thing I like of this forum/hobby is the trust we have among each other, it makes me have some hope about human kind. Nicmac bought 1000 of these expensive devices and asked for shipment to my place.

I really hope we will have good success in this matching campaign, and I am happy I could give a little help. There is a lot of work ahead of us.

Davide

 

[Luke]

beautiful

 

[ramallo]

Pictures are worth more than 1000 words. One thing I like of this forum/hobby is the trust we have among each other, it makes me have some hope about human kind. Nicmac bought 1000 of these expensive devices and asked for shipment to my place.

I really hope we will have good success in this matching campaign, and I am happy I could give a little help. There is a lot of work ahead of us.

Davide

Wow!! I'm impressed, thanks for your efforts

 

[otherside]

This is a great effort.

Just a bit confused, do we add on the spreadsheet of copy-edit here?

 

[Nikitas]

NicMac 8 pairs (2 stereo F5X) (NNNNPPPP x 2)
CanAm Man 4 pairs (1 stereo FX5) (NNNNPPPP)
ramallo 4 pairs (1 stereo FX5) (NNNNPPPP)
oneaclock 4 pairs (1 stereo FX5) (NNNNPPPP)
andrewt 4 pairs (1 stereo FX5) (NN NN PP PP)triple point + possibly 20NN and 20PP single point
Studley 4 pairs (1 stereo FX5) (NNNNPPPP)
ashaw 8 stereo sets? (NNNNPPPP x 8 ??)
triode4 4 pairs (1 stereo F5X) (NNNNPPPP)
heinz1 4 pairs (1 stereo F5X) (NNNNPPPP)
Mravinsky 4 pairs (1 stereo FX5) (NNNNPPPP)
JBdV 8 pairs for 2 F5X (NNNNPPPP x 2)
smyslow 4 pairs (1 stereo F5X) (NNNNPPPP)
APK 12 pairs (3 stereo F5X) (NNNNPPPP)
Horio 2 pairs (2 stereo F5X) (NNNNPPPP x 2)
Westley 4 pairs (1 stereo F5X) (NNNNPPPP)
alazira 4 pairs (1 stereo F5X) (NNNNPPPP)
pmchoong 4 pairs (1 stereo F5X) (NNNNPPPP)
CeeVee 4 pairs (1 stereo F5X) (NNNNPPPP)
lhquam 4 pairs (1 stereo F5X) (NNNNPPPP)
flg 4 Pairs (1 stereo FX5) (NNNNPPPP)
ichiban 4 pairs (1 stereo FX5) (NNNNPPPP)
daanve 8 pairs for 2 F5X (NNNNPPPP x 2)
johnwmclean 4 pairs (1 stereo F5X) (NNNNPPPP)
buzzforb 4 Pairs (1 stereo FX5) (NNNNPPPP)
bkdog 4 Pairs (1 stereo FX5) (NNNNPPPP)
vitalica 8 pairs for 2 F5X (NNNNPPPP x 2)
mekanixz 4 Pairs (1 stereo F5X) (NNNNPPPP)

 

[otherside]

NicMac 8 pairs (2 stereo F5X) (NNNNPPPP x 2)
CanAm Man 4 pairs (1 stereo FX5) (NNNNPPPP)
ramallo 4 pairs (1 stereo FX5) (NNNNPPPP)
oneaclock 4 pairs (1 stereo FX5) (NNNNPPPP)
andrewt 4 pairs (1 stereo FX5) (NN NN PP PP)triple point + possibly 20NN and 20PP single point
Studley 4 pairs (1 stereo FX5) (NNNNPPPP)
ashaw 8 stereo sets? (NNNNPPPP x 8 ??)
triode4 4 pairs (1 stereo F5X) (NNNNPPPP)
heinz1 4 pairs (1 stereo F5X) (NNNNPPPP)
Mravinsky 4 pairs (1 stereo FX5) (NNNNPPPP)
JBdV 8 pairs for 2 F5X (NNNNPPPP x 2)
smyslow 4 pairs (1 stereo F5X) (NNNNPPPP)
APK 12 pairs (3 stereo F5X) (NNNNPPPP)
Horio 2 pairs (2 stereo F5X) (NNNNPPPP x 2)
Westley 4 pairs (1 stereo F5X) (NNNNPPPP)
alazira 4 pairs (1 stereo F5X) (NNNNPPPP)
pmchoong 4 pairs (1 stereo F5X) (NNNNPPPP)
CeeVee 4 pairs (1 stereo F5X) (NNNNPPPP)
lhquam 4 pairs (1 stereo F5X) (NNNNPPPP)
flg 4 Pairs (1 stereo FX5) (NNNNPPPP)
ichiban 4 pairs (1 stereo FX5) (NNNNPPPP)
daanve 8 pairs for 2 F5X (NNNNPPPP x 2)
johnwmclean 4 pairs (1 stereo F5X) (NNNNPPPP)
buzzforb 4 Pairs (1 stereo FX5) (NNNNPPPP)
bkdog 4 Pairs (1 stereo FX5) (NNNNPPPP)
vitalica 8 pairs for 2 F5X (NNNNPPPP x 2)
mekanixz 4 Pairs (1 stereo F5X) (NNNNPPPP)
otherside 4 Pairs (1 stereo F5X) (NNNNPPPP)

 

[AndrewT]

I note that everyone except andrewt are asking for NNNNPPPP matched octuplets.
What if that proves to be impossible to supply?

 

[NicMac]

I guess people continue dreaming

Getting a fair number of good PP/NN quads matched at operating conditions should be more achievable and is really what I hope for. I think I will be able to live with a tiny channel imbalance as I can always move my chair a bit...

Cheers,

Nic

 

[Nikitas]

I find nothing wrong with dreaming...
If you take a minute to check the sheet with the preferences you will notice that "desirable" dominates and even for those who WANT octuplets they have checked other options as well.