Matched JFETs
- Description
Idss Choices
One of the most common questions is what Idss sub-group to choose. All JFETs are grade B/BL (6-12mA). You can now choose from an Idss sub-range. If you are building any of the First Watt products, Nelson has provided a summary. Learn more about how to choose the right Idss for your project.
Project use reference
Below is a list of JFETs required for some of the most common projects.
- P Channel Quad: AlephJ BA1 Gain Stage ACP+
- N Channel Quad: Mezmerize
- NP Quad: F4 F5 F5T V1/2/3 F6 BA3 Gain Stage F5T V3 Balanced (Qty 2)
Offerings
- N Channel Quad (NNNN)
- Linear Systems LSK170 Quad Idss 6-8mA
- Linear Systems LSK170 Quad Idss 8-11mA
- P Channel Quad (PPPP)
- Toshiba 2SJ74 Quad Idss 6-8mA
- Toshiba 2SJ74 Quad Idss 8-11mA
- NP Quad (NNPP)
- Toshiba 2SK170/2SJ74 Quad Idss 6-8mA
- Toshiba 2SK170/2SJ74 Quad Idss 8-11mA
- NP Octet (NNNNPPPP)
- Toshiba 2SK170/2SJ74 Octet Idss 6-8mA
- Toshiba 2SK170/2SJ74 Octet Idss 8-11mA
Specifications
- All parts are guaranteed to be new and authentic (Linear Systems are new, Toshiba are new-old-stock)
- Guaranteed matched to within ±0.2mA. Tested at 10V / 22'C. For more information visit the JFET matching information page.
- Manufacturer specifications: LSK170 | LSJ74 | 2SK170 | 2SJ74
- Note that any letters or numbers printed on Linear Systems JFETs do not refer to grade, they are batch identification. All grades have identical physical housing. You cannot tell the grade by looking at the JFET itself. The only way to know the grade is by testing for Idss.
Quantity Limits
- N Quads: Limit of 8 units per customer per month
- P Quads/NP Quads: Limit of 2 units per customer per month
- NP Octets: Limit of 1 units per customer per month
These JFETs are provided as a service to the do-it-yourself audio hobbyist community, and it's important that we can always keep these parts in stock for small orders from hobbyists. Please only buy what you need.
If you need more than the above quantity for a particular build, please email contact@diyaudiostore.com.
Customer Reviews
I bought "Toshiba 2SK170/2SJ74 Octet IDSS 6-8mA" and used them to building up my latest Dead Bug Power Amplifier, 80 ~ 100(W) continuous rated power. (Dead Bug means Flying Wired without PCB artworks)
The FETs are so exactly matched that there is no struggle to adjust DC bias. At next chance, I will also use these FETs. Here after I attached several photos of my last project.
I'm very happy with my purchase . I have used them in my new Hiraga Les Monstre and the overall sound is amazing
I've just built B1 around those. Haven't auditioned it yet, but the oscilloscope says it's basically perfect 10Hz-500kHz. I'm very happy so far, I'll probably come back for more.
Cheers!
I have ordered these original Toshiba 2SK170/2SJ74 - JFets (BL-range) a few weeks ago.
Today I measured them with great results - they are matched very, very well!
Delivery was fast. They have been packed extremely well! Thanks a lot to the diyAudio-store!
On the pics some measurements - you know with different temperatures and test-equipment
you can get different values - very good matching job!
Cheers
Dirk
Many thanks to Elena and diyaudio for sorting out customs issue. Excellent service.
Where would I be without these jfets?
Currently underway with BA1/2 pre with 610/9610 headphone buffer nailed on, 27V rails, 2.4R degeneration, 450/550 regulation from Waynes Pearl 1 circuit. Balanced xlr input only from my balanced DAC, 4 gang tkd pot. Nearly done, just got to connect boards, psu, pot etc. I can alter source resistors, load resistance and may try extending feedback loop to buffer output.
Also F5 in a galaxy box (!), 500VA, 4 x 47000 caps, 37V rails, cascoded jfets, 240/9140 mosfets just to be different, soft start, yet to fit heatsinks and audio boards, should probably renew my eyebrow insurance before I switch this one on.
Pearl 1 MC phono stage using three LSK170 quads.
BA3 pre, mje 15034/5 cascoded jfets, 35v rails, 510/9510 mosfets, biassed to over 300mA, multiple source and load resistors for adjustment, TL431 psu regulation for easy adjustment of supply voltages.
But can you tell which one is which?
Genuine 2SK74 jfets are getting harder to find, let alone having enough of them to match properly with the 2SK170 complement. DIY Audio Store to the rescue! The 8 I bought are superbly well matched to each other and complement the 2SK170s I already have very well. Finally, the low distortion complementary jfet MC headamp is a reality.