LSJ74 matched pair for sale?
I'm building an Aleph J and seem to have buggered one of the LSJ74s, and a ZTX450. Both were purchased in the diyAudio store, but as parts of larger sets.
I see the LSJ74s are sold as matched quads only, and the ZTX450 was part of the Aleph J set. Does anyone know if the store also offers the LSJ74s as matched pairs? The ZTX450s as singles? If not, perhaps someone could suggest another source.
Many thanks!
I'm building an Aleph J and seem to have buggered one of the LSJ74s, and a ZTX450. Both were purchased in the diyAudio store, but as parts of larger sets.
I see the LSJ74s are sold as matched quads only, and the ZTX450 was part of the Aleph J set. Does anyone know if the store also offers the LSJ74s as matched pairs? The ZTX450s as singles? If not, perhaps someone could suggest another source.
Many thanks!
I though I’d damaged an LSJ74 during my build but it seemed to fix itself by desoldering and resoldering. A bad joint that looked visually perfect to me.. Worth a try. You might get lucky. Contact the Store and see if they might be getting pairs together soon.
The ZTX450 isn’t special so you can buy them from any of the component suppliers.
The ZTX450 isn’t special so you can buy them from any of the component suppliers.
Thanks for the replys, BigE and Roo2. I did contact the store about getting a pair rather than a quad, but this being a holiday week I don't expect to hear from them for a while. Also, I did order a couple of ZTX450s from Digikey. I'll replace the suspect one then retest. Good suggestion to resolder the existing jfet. If nothing else it will keep me engaged until I can find replacements.
The only products the store sells are the ones listed in the store currently. We did used to offer pairs but the demand was low and we're keeping things simple by offering quads which is where the demand seems to be. The products are matched by qualified audio gurus and shipped to us as complete products (quads), so we can't split them, sorry.
I've been in touch with Mr Paul Norton from LIS regarding the LSJ74 / LSK170 parts in the 1-3mA IDSS range = equivalent to Toshiba's 2SJ74Y / 2SK170Y as used in Jean Hiraga's Le Monstre amplifier (yes, the more recent Toshiba data sheets don't even list the "Y" grade, but google for their 1983 Small Signal Transistor data book or check the Japanese FET Manuals from the '70s, and it's there alright).
Paul said they may have suitable wafers that would just need to be "built" into actual parts, but the couple thousand dollars I would be able / willing to invest into this is not nearly enough to finance the project.
I realize this is a silly question, but wouldn't the diyAudio Store be able to strike a deal with LIS to offer the "Y" grade JFETs for sale for Le Monstre builders?
Alternatively, Paul mentioned they should be able to supply - at a cost - the stock "A" grade parts pre-selected for IDSS in the 2-3mA range - that could also be a welcome addition to the Store...
Thanks!
Paul said they may have suitable wafers that would just need to be "built" into actual parts, but the couple thousand dollars I would be able / willing to invest into this is not nearly enough to finance the project.
I realize this is a silly question, but wouldn't the diyAudio Store be able to strike a deal with LIS to offer the "Y" grade JFETs for sale for Le Monstre builders?
Alternatively, Paul mentioned they should be able to supply - at a cost - the stock "A" grade parts pre-selected for IDSS in the 2-3mA range - that could also be a welcome addition to the Store...
Thanks!
Thank you for letting us know about your need.
Right now what we are offering in the store in terms of JFETs is the result of previous product demand and sales, which is primarily in the B grades. As the store grows, we're very happy to consider stocking more options, and stocking matched A grade JFETs is on the cards for the future. Eventually stocking specific IDSS ranges would be great. But then balancing stock levels, lead times, matching, match-yields, prices, all becomes quite involved.
This is not meant to be a slight at all, just that we're presently very busy with a lot of stuff and right now everything is a matter of priorities. Your request is noted and we'll try to do it when we have the resources available.
Right now what we are offering in the store in terms of JFETs is the result of previous product demand and sales, which is primarily in the B grades. As the store grows, we're very happy to consider stocking more options, and stocking matched A grade JFETs is on the cards for the future. Eventually stocking specific IDSS ranges would be great. But then balancing stock levels, lead times, matching, match-yields, prices, all becomes quite involved.
This is not meant to be a slight at all, just that we're presently very busy with a lot of stuff and right now everything is a matter of priorities. Your request is noted and we'll try to do it when we have the resources available.
Wow just got everything to build my Aleph j except that set of matched quads from the diystore now I will have to source and match my own or not finish it for ‘several months’ I could not be more disappointed, since many people cannot source and match there our jfets shouldn’t you warn people that parts crucial to completing there project are currently unavailable?
I feel you! And you make a great suggestion.
This has been a common occurrence over the years. JFETs are hard to source. We go in and out of stock regularly. There have sometimes been JFET "droughts" for many months at a time.
We really want to look after the community so we've done various things to try and protect our builders and stop hoarding:
* Ordered as many as we financially are able, and place standing orders early (unfortunately the lead time is unpredictable and often very long)
* Implemented sales restrictions (maximum units allows per customer per month)
But the situation you find yourself in is one many have found themselves before, so we have recently decided that moving forward the best thing to do will be bundle JFETs directly with PCBs so that "if you have the PCB you have the JFETs". So, that's the new plan to ensure the situation you are in now, won't happen to others.
This is DIY however, and parts in BOMs regularly go out of stock, become obsolete, or become unavailable. Finding solutions to those problems is part of the DIY experience and always will be unless one buys a complete kit with everything included in the one package.
I really like your suggestion that we should have functionality in the store that when one part of a kit (which often will need half a dozen things - PCB, JFETs, MOSFETs, Chassis, components, keratherm) goes out of stock, it would be amazing if that OOS message flushed through to every other product in the store that used it, and then changed it back automatically when it came back in stock. Something for the future.
Regards your situation, please contact the helpdesk at contact@diyaudiostore.com and we'll do out best to try and find a back channel to help you out.
This has been a common occurrence over the years. JFETs are hard to source. We go in and out of stock regularly. There have sometimes been JFET "droughts" for many months at a time.
We really want to look after the community so we've done various things to try and protect our builders and stop hoarding:
* Ordered as many as we financially are able, and place standing orders early (unfortunately the lead time is unpredictable and often very long)
* Implemented sales restrictions (maximum units allows per customer per month)
But the situation you find yourself in is one many have found themselves before, so we have recently decided that moving forward the best thing to do will be bundle JFETs directly with PCBs so that "if you have the PCB you have the JFETs". So, that's the new plan to ensure the situation you are in now, won't happen to others.
This is DIY however, and parts in BOMs regularly go out of stock, become obsolete, or become unavailable. Finding solutions to those problems is part of the DIY experience and always will be unless one buys a complete kit with everything included in the one package.
I really like your suggestion that we should have functionality in the store that when one part of a kit (which often will need half a dozen things - PCB, JFETs, MOSFETs, Chassis, components, keratherm) goes out of stock, it would be amazing if that OOS message flushed through to every other product in the store that used it, and then changed it back automatically when it came back in stock. Something for the future.
Regards your situation, please contact the helpdesk at contact@diyaudiostore.com and we'll do out best to try and find a back channel to help you out.
Thanks for the reply Jason, the jfets were already unavailable when I ordered the rest of the parts, I didn’t think anything of it. The community had an instant answer and I already have jfets on the way. With so many dependencies, I understand the issue I just never realized it could be several months. I appreciate the store and your time Jason.