[Cyrix_2k]

I recently moved and found myself staring at an old Kevin Gilmore Dan Gardner Dynalo PCB I've had sitting on my bookcase, oh, for the past 7 years. I want to assemble the Dynalo and am finding it hard to source some components. The situation is so bad that some of the common substitutions for EOL'd parts are NLA.
 
So far, I'm having trouble finding a replacement (or original parts) for the 2SK389 N Channel JFET (use pairs of LSK170s?) & the 2SA1015  PNP transistors. I think I have a source lined up for original 2SJ109s (at an obscene cost). AMB supposedly has the 2SA1015s, but I don't know if they'll sell to me. Any help is greatly appreciated.

 

[00940]

You can find lsj74 and lsk170 to replace the input jfets on the diyaudio store. Fetaudio is also a reliable source for matched pairs of those jfets.

 

[stixx]

Do you know this thread --> http://www.head-fi.org/t/116635/dynalo-rev-c-construction-thread/165 ?
It has a schematic drawn by Avro Arrow that is showing the replacements for the input Jfets.
 
Ti from Amb Labs is a very kind person... when you tell him your plans he will probably sell the transistors
to you. At least he sold some other rare items to me (building a Dynahi).

 

[Bizzel]

I'm in a very similar boat to you, having picked up my Dynamid (balanced Dynalo) build after a couple of years on the shelf. My boards are complete so I have a few spare transistors laying around - mainly the output stage transistors (2SA1015 and 2SC1815). There may also be some SK170s and SJ74s hanging around but I'm less sure about that. Once I've tested the boards (a few weeks) then these will be going spare.
 
Check with Ti Kan from AMB first of all since that's where I got my transistors from a few years back. They're not listed on the store page anymore but perhaps he has some left over. If you still have no luck then drop me a PM and we can work something out.
 
- Paul

 

[Cyrix_2k]

Thanks for all the help. Are there any opinions on using the 2SJ109s vs pairs of LSJ74s? It looks like the cost is about equal. 

 

[00940]

The 2SJ109 will track better, thermally speaking. Iirc, the curves of the new LSK170/LSJ74 aren't exactly similar to the old fets. You might want to check on diyaudio where curves were published. So I would try to locate matched 2SK170 to complement the 2SJ109.
 
Another point to consider is that, at those prices, you really don't want to get fakes, which became all too common. All the sources above are known to be reliable, I just assume the same goes for your 2SJ109's source.
 
PS: I'm carefully hoarding 4 quads of matched 2SJ74/2SK170, this thread reminds me why.