Live Lab Hangout #1.1 Posted

[cwtim01]

I can see a full box of brand new 182ES beside the heat sink :🙂

Could you share the source, I am still looking for 2SK180s, but unable to find them even in the second hand market of China.

 

[Soundhappy]

@ Cwtim01

2SK180/ 182ES are from Eyelabo so big chance is not good ones
Probably all was radiated by Fukushima accident
and transformed on Frankenvfets....
Kind regards 🙂

 

[cwtim01]

He's an honorable guy, last time I got full refund from him promptly, without any issue.

If your batch turn out to be good, maybe I'll get a very large batch from him, keep the good ones and return the rest .... daydreaming 🙄

 

[Bones13]

I had no troubles with my refund from eyelabo. I suspect he is as disappointed as we are about these transistors.

 

[Michael Rothacher]

I can't recall if I mentioned it here already, but I got my refund very promptly as well. Eyelabo was extremely fair and friendly about the whole thing. I hope he gets a buddy with a curve tracer to help him sort through some of his stock.

 

[R-K Rønningstad]

Michael, you are anyway a marvel of a wiz kid!

 

[hifibluedevil]

I can't recall if I mentioned it here already, but I got my refund very promptly as well. Eyelabo was extremely fair and friendly about the whole thing. I hope he gets a buddy with a curve tracer to help him sort through some of his stock.

may be he can built your curve tracer and test them before selling. I also have a pair from him in untested condition and I don't know If I will have time to built the CT, among daily job and other audio projects.

 

[Soundhappy]

@ Diyers
Seller respond he are not professional in electronic or diyer hobby .
Must of his transistors was used for reparations in old machines
( example : for dental cabinets ) not for hi-fi audio....

But from other peoples i see folks rebuilds B1 Yamaha with Tokin 2SK180 grade D

B-1�@SIT ‚Q‚r‚j‚P‚W‚O

Please scroll down page to see all informations. Cheers

 

[vt4c]

Bought a couple of 2SK182ES from Eyelabo too. Is there any other way to test the device if it's faulty without a curve tracer? The serial number on the devices are 1Z2631, 1Z2632, 1Z2633 & 1Z2634

 

[Soundhappy]

Is there any other way to test the device if it's faulty without a curve tracer ?

Yes diy quick L'Amp prototype adapted to 2SK182ES and make sound

 

[cwtim01]

Another failure mode for 182ES

Was helping a friend to purchase quite a batch of second hand THF-51S and 182ES from China, and some of the 182ES have curves like attached, and need to be replaced.

Probably another failure mode for these SITs 😕.

 

[generg]

May be a problem of Lockys tracer

the voltage for the biasing of the gate is subtracted from the available source drain voltage….

so the ones needing greater Vgs starve on Vds…

But I am not really good in calculations like this ….

only a hint….. Locky himself told us that measuring SITs with the tracer is not really effective.

to be sure I would build Mikes Frankenstein machine……..

 

[cwtim01]

Hi generg,

Thanks for your remark and I'll try some other means to double check. Locky's tracer can give all sort of funny behaviors, especially when the DUT oscillates with it, but I'm not quite sure on this case, as the tracer board was able to trace correctly 10+ 182ES and 20+ THF-51S (an example attached), but I'll check again.

I also plan to build Mikes' Frankenstein machine, but the biggest headache is to get the 300W/120V bulb, I find it harder to get than the SITs (Amazon refuses to ship 120V bulbs to where I live, where the mains is 220V 😱).

 

[generg]

I asked a Canadian diyaudio friend, dantwomey for the bulbs and he was so kind to send me six some time ago….

Maybe you find a guy here as well….. 🙂

 

[generg]

look at my bundle of 2SK180, there is a similar difference in curves.

All these SITs seem to vary very much in transconductance and in Vgs threshold.

So I admit the ones you have on the right side, are really a bit crazy…..

 

[cwtim01]

I think we're showing different curves - the curves I showed are Id vs Vds @ varying level of Vgs bias, of a single SIT.

I guess the curves you showed are Id vs Vgs @ constant Vds, but for many different SITs.

 

[generg]

exactly… I supposed this, but I was not sure!

 

[Michael Rothacher]

A 25 Ohm, 100W or higher resistor will do a decent job in place of the light bulb, though the curves will be slightly more truncated at higher voltage and it's not as fun to look at 🙂

 

[cwtim01]

Thanks Michael, a power resistor will be my last resort, I like the cool looking feel of the glowing filament 😛.

 

[Michael Rothacher]

That's the spirit 🙂