Are people more interested in this manufacturer or in getting the original toshiba part? I've been working on sourcing hard to find parts for a DIY amp/speaker supply company and am interested in peoples opinions on what I should be looking for. I'm good at sourcing "obsolete" components and have the ability to buy large bulk amounts so that I can offer attractive prices. Is the BL code the favorite out of the different color codes??? (I've seen that specified in a few schem.) I might be able to facilitate some group buys in the future; If there's sufficient interest in something I can probably source more quantity while keeping the price low for DIYer's, and having leftovers available for those who weren't in on the original buy. I'm working on the lovoltech JFET's right now and that's looking positive. I've seen the original toshiba's available too, but if everyone wants the LSK's... maybe I should be looking at those??? Thanks for the input,
Dave
ps... now that I've typed all that, maybe I should have started a thread asking for peoples opinions favorite hard to get parts.
Dave
ps... now that I've typed all that, maybe I should have started a thread asking for peoples opinions favorite hard to get parts.
Hi Dave
I would be very wary of any so called original Toshiba JFets you find these days. There are many fake parts around and if I was you, I would be getting your suppliers to commit to the following.
1. Supply samples for testing by someone who knows how to properly test them.
2. Supply written documentation on their authenticity.
3. Supply a guarantee that if they supply fake parts, then they will reund in full plus extra postage charges on getting fake parts back in a GB. See the GB for 2SJ109 and 2SK389 by A'af in Indonesia for all the troubles that caused.
4. I do believe there are still stocks of the genuine parts available, but at what cost. I think you will find the average Audio DIYer will baulk at the cost and authenticity these days.
Good luck to you if you do manage to find some at a decent price. BL code seems to be the fave for these devices.
That is my 2c worth. I am lucky as I got quite a few of the genuine Toshiba original parts a few years ago before the rush. I have sold a few to peopls here, but I am keeping the rest.
Regards
Gary..
I would be very wary of any so called original Toshiba JFets you find these days. There are many fake parts around and if I was you, I would be getting your suppliers to commit to the following.
1. Supply samples for testing by someone who knows how to properly test them.
2. Supply written documentation on their authenticity.
3. Supply a guarantee that if they supply fake parts, then they will reund in full plus extra postage charges on getting fake parts back in a GB. See the GB for 2SJ109 and 2SK389 by A'af in Indonesia for all the troubles that caused.
4. I do believe there are still stocks of the genuine parts available, but at what cost. I think you will find the average Audio DIYer will baulk at the cost and authenticity these days.
Good luck to you if you do manage to find some at a decent price. BL code seems to be the fave for these devices.
That is my 2c worth. I am lucky as I got quite a few of the genuine Toshiba original parts a few years ago before the rush. I have sold a few to peopls here, but I am keeping the rest.
Regards
Gary..
I am interested in 10 pcs of the 389, prefer C grade, but B grade OK.
I wonder however if I am getting something wrong here, or if everybody else is? According to the datasheets (for both 389 and 170) the C grade is the highest IDSS grade, corresponding to Toshibas V grade. Yet, the C grade is surprisingly the cheapest for both types? Is there any good reason not to go fot the C grade that I am missing?
I wonder however if I am getting something wrong here, or if everybody else is? According to the datasheets (for both 389 and 170) the C grade is the highest IDSS grade, corresponding to Toshibas V grade. Yet, the C grade is surprisingly the cheapest for both types? Is there any good reason not to go fot the C grade that I am missing?
Power dissipation. The parts are usually run with 10V Drain-Source or more which give a power dissipation larger 100mW. This half of the max power dissipation value is usually the agreed limit for reliability.
All the best, Hannes
EDIT: I'm refering to the Toshiba part, I do not know the power dissipation for the metal can LSK.
EDIT2: the LSK389 has 400mW, so an improvement over the original part. I guess then the only reason is commodity, since all schematics are for the Toshiba part and not specifically tuned for the LSK. However the difference in transconductance is not that big.
h_a said:
Good point. I didn't think of that, actually. John Curl always tells people to buy the V grade of Toshiba, and he seems to like to run them on high voltage.
Checking the datasheet, it seems the 389 has a max Pd of 400 mW, just like the 170, so that effectively halves the Pd per device for the 389 compared to the 170. Hm, think you convinced me to go for the B grade instead.
jackinnj said:
This will not help much unless there is a thermal pad under the package. An interesting problem is coupling vs just sinking, i.e. a big heat sink across both would tend to keep the temperatures down but maybe not very effective at keeping the die at the same temperature. OTOH heavy heat sinking might keep them closer than a strap simply coupling them. I can't imagine actually running a SOT23 at 400mW.
gary s said:Hi Dave
I would be very wary of any so called original Toshiba JFets you find these days. There are many fake parts around and if I was you, I would be getting your suppliers to commit to the following.
1. Supply samples for testing by someone who knows how to properly test them.
2. Supply written documentation on their authenticity.
3. Supply a guarantee that if they supply fake parts, then they will reund in full plus extra postage charges on getting fake parts back in a GB. See the GB for 2SJ109 and 2SK389 by A'af in Indonesia for all the troubles that caused.
4. I do believe there are still stocks of the genuine parts available, but at what cost. I think you will find the average Audio DIYer will baulk at the cost and authenticity these days.
Good luck to you if you do manage to find some at a decent price. BL code seems to be the fave for these devices.
That is my 2c worth. I am lucky as I got quite a few of the genuine Toshiba original parts a few years ago before the rush. I have sold a few to peopls here, but I am keeping the rest.
Regards
Gary..
Thanks for the advice Gary, I appreciate it... however my situation is a little different, we are a direct importer already and retain our own independent agent in Hong Kong. I wouldn't structure anything as a group buy per se, or require payment in advance of purchase (we ship same day); once I have them in hand and have verified them myself, matched, sorted and priced them, they would be made available on our website and I would post an announcement in the Vendor's Bazarre (I just haven't set up a thread yet, I'm still in research phase). I noticed on A'af's thread the mention of the Violet color code being the most flexible type, though you mentioned the most commonly used is the Blue. As far as surplus goes I'll look for both.
We also strive to maintain an excellent business reputation, you can google us (deepsurplus, no space) and get 50,000 returns, or check our Ebay feedback, we are a well known networking/structured wiring/electronics business expanding into a new area. We also have the honor of being an INC. 500 member (370th fastest growing privately held co. in the USA, 9th fastest computer & electronics co.) I'm mainly asking these questions because I'm thinking of calling Linear and buying about 10,000 pieces or more and making them available on our site without the need for a group buy (although we do offer quantity discounts, and at lower break points than a manufacturer... we're very price competitive, just look at our patch cable prices). I'll give them a call and see what I can set up.
Thanks, Dave
