The purchase was for 10 sets, 7 of those went to the testing team, the other 3 went to in less than 30 seconds. The people who got the components have got just exactly that, the components to go onto the board. This is jsut so people can get in early. The components are easily available from element14, excluding a bridge rectifier that can be bought from digikey and mouser, and the LED which has several online sources, and if you can handle red/green rather than red/blue can be bought from element 14 too. This was only to do with price.
For those still hunting for 2SJ74BLs :
http://www.diyaudio.com/forums/swap-meet/131284-toshiba-2sk170bl-sales-12.html#post2667790
Patrick
http://www.diyaudio.com/forums/swap-meet/131284-toshiba-2sk170bl-sales-12.html#post2667790
Patrick
Once again the relationship between Idss of 2SK/2SJ with the 5R1 degeneration :
http://www.diyaudio.com/forums/atta...894848-f5x-euvl-approach-f5-frontend-bias.png
Patrick
http://www.diyaudio.com/forums/atta...894848-f5x-euvl-approach-f5-frontend-bias.png
Patrick
You need to get what you can get.
6-7mA Idss are rare for BL grade. Most of them are around 8-10mA.
That is why I give you a table so that you can pick what you can get your hands on.
The only difference is the amount of negative feedback, which is proportional to the drain resistor value.
That is, the smaller the Idss, the larger the Rd, the more NFB you get.
But load impedance also has a direct influence.
So for your purpose, anything from 6-9mA bias is OK.
Patrick
6-7mA Idss are rare for BL grade. Most of them are around 8-10mA.
That is why I give you a table so that you can pick what you can get your hands on.
The only difference is the amount of negative feedback, which is proportional to the drain resistor value.
That is, the smaller the Idss, the larger the Rd, the more NFB you get.
But load impedance also has a direct influence.
So for your purpose, anything from 6-9mA bias is OK.
Patrick
I have asked for perfect pairs (7,0 and 8,18 mA) and higher current versions if not available, of course everybody can contact Spencer, but I think one joined effort may be better for all parties.(my response to him was pretty quick)
I am willing to buy 50 or maybe more of his best pairs (quads, octets), and provide them for cost to all F5X builders (as far as they need them)
I will keep the rest for future ventures.
I am willing to buy 50 or maybe more of his best pairs (quads, octets), and provide them for cost to all F5X builders (as far as they need them)
I will keep the rest for future ventures.
I have asked him to mark all suitable fets with current value with 2 digits after the comma, so picking for best pairs from a bigger quantity will be effective (normally he matches within 0,2 mA)
I have two "dengen" octets left. Matched to better than 3%.
PM for info.
It looks like we are lucky! Spencer will be able to provide pairs of fets in 2 ranges:
K170 will be 6.9 to 7.0 or 7.0 to 7.1 and J74 will be 8.1 to 8.2 or 8.2 to 8.3 mA
There will be enough for all F5X builders if they want.
I will buy the complete lot from Spencer and offer them to all F5X builders for cost.
(The rest I will save for future adventures)
K170 will be 6.9 to 7.0 or 7.0 to 7.1 and J74 will be 8.1 to 8.2 or 8.2 to 8.3 mA
There will be enough for all F5X builders if they want.
I will buy the complete lot from Spencer and offer them to all F5X builders for cost.
(The rest I will save for future adventures)
Last edited:
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