I feel your pain... but... the JFETs are all available and have been for a long while now... here in the Store. A year... year and 1/2 ago, it was a different story, but lately, just go and grab a few.
They are indeed special... and one of the main reasons why FW clones can be built with only 2 gain stages.
I think modern devices (transistors) would imply the inclusion of a 3rd gain stage - and no one wants that... that's not progress, right?? 🙂
No, not an interesting question at all. This is a question of a forum member wandering in the Pass labs section for the first time.
There is also very evident lack of understanding that this forum section is more relaxed and comments should always be treated like that. I have to quote myself:
And, here is one for Jean Paul (no hard feelings please, it’s just a little humor):
Yeah herd-like behaviour is a little fun. Maybe it is not known but I sell parts of which many are obsolete (in the past including 2SK170/2SJ74). Todays high chances for fake/relabelled parts make it difficult for the average person to find original parts as well. When sources finally dry up and fellow DIYers stock is now depleted the real hyenas come to play. One should look for available parts before that point. Yes that is an opinion, one that apparently gets the worst out of zealots.
With that knowledge I think it is design poverty to keep using 2SK170 and 2SJ74 in new DIY designs as published here with a world wide audience thereby creating more demand (and bizarre prices plus high chance on fake parts) amongst DIYers than in the parts heydays. Call it deliberate scarcity. It is different from tubes as those are easily available and not the same type is used over and over again in every new design. Sorry.
With that knowledge I think it is design poverty to keep using 2SK170 and 2SJ74 in new DIY designs as published here with a world wide audience thereby creating more demand (and bizarre prices plus high chance on fake parts) amongst DIYers than in the parts heydays. Call it deliberate scarcity. It is different from tubes as those are easily available and not the same type is used over and over again in every new design. Sorry.
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Because this forum is full of aging, miserable men not interested in trying much of anything new or different. Post-Covid, it’s gotten a lot worse as have most forums.
On average, you will find that this forum was a far friendlier, brighter place 10+ years ago. I enjoy those old threads. I do not enjoy reading most of what gets posted nowadays because people typically refuse to answer questions and start interrogating the original poster, then each other. They just want to argue because they’re unhappy.
I have found many search results from this forum of threads that are pointless and never answer the question of the poster with well known designers embarrassing themselves because they get sucked into the vortex of being rude to the poster and arguing with one another. Since they are who they are, the threads ends up completely derailed every single time. And for what? So when they die people can look back at their posts and see how dead they already were? Doesn’t sound so good to me.
OTOH, grumpy behavior is no fun at all. 🙂
Genuine matched 2SK170/2SJ74 pairs are available from diyaudio store. Have you noticed how many times Nelson provided for free, hard to obtain parts, SJEP120R100 being a recent example.
Not grumpy at all and explained in detail. It just seems not to be all roses and daisies to those that may want to build a device with such hard to find parts. That is except those that are lucky and have large stocks of them and often happen to be designing with them.
BTW it can be done, I have a 2SK170/2SJ74 free setup 😉
BTW it can be done, I have a 2SK170/2SJ74 free setup 😉
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Uhhh, that is not the case.... I think you are now overreacting.... Please see my post # 41. I tried to explain why those JFETs are so special. NOTE: they are available in Store.
And, I do agree with tombo56... Nelson has shared his designs, invested his time and helped many DIY-er achieve fantastic sound...
I actually believe that, especially in recent years, the forums here in general, have become much friendlier than before.... Nelson himself jumps in to explain and help... but he always leaves bits and pieces unanswered, so that we learn something as well. And that's the true value of this forum.
Did you miss post #27?
Is there anything wrong with DIY 2022 Front End that does not contain any Toshiba parts?
In the bigger picture it's tough for solid state designers. The devices that go on and on forever aren't the best ones - those were the Semisouth devices, the Sony SIT devices and others that are already extinct. A bit like small signal valves - the guitar amp tubes like 12A*7 go on and on and the DHTs die out, though they're still obtainable.
So today we have some nice Exicon devices to design with. But will Exicon be there tomorrow? Who knows. No wonder Class D amps are liked by manufacturers.
At least op-amps have a fairly safe future in the short term. Good choice for constructors.
So today we have some nice Exicon devices to design with. But will Exicon be there tomorrow? Who knows. No wonder Class D amps are liked by manufacturers.
At least op-amps have a fairly safe future in the short term. Good choice for constructors.
@tombo56:
Does it change the point? And how likely is the chance that people will build pre 2000 designs with maybe also obsolete parts? Many will think the newer designs to be superior to the old ones isn’t it?
Andyjevans seems to nail it. The discrete parts will be scarce and for many through hole parts mean a lot for their hobby and SMD is a harsh end to their DIY projects. I know that feeling. Covid also was a final stroke to many parts. End of an era feeling.
Time to try out exciting new stuff 😀
Does it change the point? And how likely is the chance that people will build pre 2000 designs with maybe also obsolete parts? Many will think the newer designs to be superior to the old ones isn’t it?
Andyjevans seems to nail it. The discrete parts will be scarce and for many through hole parts mean a lot for their hobby and SMD is a harsh end to their DIY projects. I know that feeling. Covid also was a final stroke to many parts. End of an era feeling.
Time to try out exciting new stuff 😀
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Yes, it does.
Would you stop ignoring the fact how many great designs with easily available parts are present in this forum section.
There is no point to criticize usage of Toshiba parts. They are not mandatory.
👍 I'm doing just that for some time.
If anyone's interested in building a clone of Nelson Pass's "Threshold NS-10" preamp from 1978, I've got a stash of the kick asszs Motorola MPS-6571 bipolar transistors which made it possible. I bought them N.O.S. from Quest, back when their minimum order was 100 pieces. Also bought the complement (PNP) device called MPS6523, which, a little surprisingly, Nelson chose not to use in the NS-10.
Just send me a photograph of your actually-fabricated NS-10 PCBs, front and rear, to show you're a NS-10 builder and not a drylabber & parts hoarder. We can negotiate a barter.
BTW I personally think the NS-10 schematics they have on radiomuseum.org , are likely to be the best (greatest accuracy) available from any/all sources. In my opinion anyway.
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Just send me a photograph of your actually-fabricated NS-10 PCBs, front and rear, to show you're a NS-10 builder and not a drylabber & parts hoarder. We can negotiate a barter.
BTW I personally think the NS-10 schematics they have on radiomuseum.org , are likely to be the best (greatest accuracy) available from any/all sources. In my opinion anyway.
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Attachments
The NS-10 basic circuit is still alive today, and you can actually buy it from the diyAudio Store. It's a VFET/Theseus Front End card called BULWARK, which is the NS-10 circuit "flipped upside down". NPNs and PNPs have swapped places, then the MPS6571 & PN4250 have been replaced by current components.
I know Andy from the other forum and he is a big experimenter, combining different tubes, PS topologies etc etc, so I find it interesting that he is wandering through the SS world as well. Maybe there is a better chance for an answer in the Solid State forum though?
I think we are quite relaxed 🙂
Thanks Erik - yes, I build with tubes and specifically DHTs. I can't design solid state so I'm dependent on existing designs. Coming from the world of single ended low power tube amps with triodes and no feedback, I'm used to independent stages with no feedback where you can endlessly change each stage. Hence the "big experimenter", since it's easy to put together all kinds of combinations of stages.
I'm very much in sympathy with Nelson Pass for his Class A designs and care for the DIY builders of his designs. Who doesn't love Nelson Pass!
But I'm also in sympathy with Jean-Paul here when he says that solid state has become tough on constructors with SMD replacing through hole parts and a number of really good designs that depend on discontinued components. I think the point isn't that the DIY Store has matched parts - that's a great resource. Though it must always be remembered that constructors are spread around the world and have to pay import duty, handling and shipping charges on top of the basic price for anything USA-centric. The point is more about choice. Constructors like to have choices, and it's nice to buy locally to save money wherever you live.
Going from tubes to solid state the challenge for me is the fact that almost all designs incorporate feedback loops, which also mean a dependency on the input stages in the designs. So I always have an eye for single ended designs with no feedback. And Nelson has created those as well amongst his vast portfolio of designs. I'm a novice to his work, but it's endlessly fascinating.
I'm very much in sympathy with Nelson Pass for his Class A designs and care for the DIY builders of his designs. Who doesn't love Nelson Pass!
But I'm also in sympathy with Jean-Paul here when he says that solid state has become tough on constructors with SMD replacing through hole parts and a number of really good designs that depend on discontinued components. I think the point isn't that the DIY Store has matched parts - that's a great resource. Though it must always be remembered that constructors are spread around the world and have to pay import duty, handling and shipping charges on top of the basic price for anything USA-centric. The point is more about choice. Constructors like to have choices, and it's nice to buy locally to save money wherever you live.
Going from tubes to solid state the challenge for me is the fact that almost all designs incorporate feedback loops, which also mean a dependency on the input stages in the designs. So I always have an eye for single ended designs with no feedback. And Nelson has created those as well amongst his vast portfolio of designs. I'm a novice to his work, but it's endlessly fascinating.
I had to find new bipolar transistors for 75% of the ones in my 23-year-old amplifier design. The new ones are electrically superior but the output transistors no longer come in nice TO-3 packages. 😉
Ed
Ed