Preamplifier Dispre 2 - JFET

[mz543578854]

@PMA I would be interested in one PCB.

 

[william2001]

I have a collection of old and new JFETs that I can scrape together to meet the prescribed tolerance for the project.

 

[manniraj]

Interested in Dispre 2 PCB and the ZT15VA if possible.

Thanks

 

[PMA]

Also interested in a board if they become available again. @PMA is there a (current) BoM available somewhere?

There will be a new BOM available (though not very different from the original one) and the link will be posted. Also everyone who will order the PCB will be provided with a link to valid documentation with schematics and project manual. This will happen after I have the new boards produced, which is supposed in the beginning of the next week.

I have also requested the mods to re-open my old thread in "Vendors bazar" dealing with PCB's sale. I can be also contacted through email through my web page.

 

[PMA]

Thanks to the mods, the thread dealing with Dispre 2 - JFET boards sales in the Vendors bazar section was re-opened.

Thread 'Dispre II PCBs available'

2010-04-30 8:20 am

Edited May 12, 2025
I would like to inform those who are interested in Dispre 2 - JFET PCBs, that they are again in production and available.

For technical information on the design please visit

https://pmacura.cz/dispre2-jfet_en.htm
and the project thread
https://www.diyaudio.com/community/threads/preamplifier-dispre-2-jfet.167033/latest

• PMA
• Replies: 38
• Forum: Vendor's Bazaar

Please use it for further communication regarding the project boards, or send me direct email. Thank you all.

 

[RM]

DisPre Key components offer.

As many of you have noticed, I’m currently selling matched octets of original Toshiba 2SJ74BL / 2SK170BL. Which is exactly what this preamp needs.

I’m offering an octet Jfets, four Fischer SK95 heat sinks and matching number output transistors for €100, shipping within EU included.
Please stipulate which IDSS you want.

I had originally planned to offer this via a normal ad, but after contacting PMA he graciously allowed me to post in his own thread. Hats off to that gentleman.

So guys, dig in and order these parts to be ready when the board arrives.

PMs preferred.

Regards
RM

 

[HRDSTL]

Pavel, black is very Cool 😍

 

[PMA]

Please stipulate which IDSS you want.

4 - 9mA is fine, as it can be trimmed by R8/R9 choice of parallel resistors. Original prototype (still in operation) was built around 8.5mA Idss parts.

@HRDSTL - thank you, but please take into account that the images are from the PCB manufacturer's preview only and the silkscreen on the top side is not visible.

 

[PMA]

THD vs. output voltage measurement (1k load):

 

[RM]

Ok, I will choose Idss myself and pass on that information. Several customers have already lined up.
Your preamp is highly admired Pavel.

R

 

[EUVL]

The original design uses 2SK170/2SJ74 JFETs. Those Toshiba parts are unobtainium.... I think we might switch to LSK170/LSJ74 by Linear Systems. Any experience with these parts?

Pavel,

See below :
www.diyaudio.com/community/threads/replacement-for-toshiba-2sk170-2sj74.317563/post-7278090

One can easily get Toshiba's from the DIY store.
No reason not to use them.


Cheers,
Patrick

 

[EUVL]

BTW, if you are still using BD139/140, may I suggest you give TTA/TTB004 a try ?
My standard go-to parts for TO126 BJTs these days.


Patrick