Alexis,
I understand that you understand.
But others might get impatient and think that they should not miss the boat.
Only that the boat has not seen water yet, right out of the dock.
So not too many people on the trial run.
Patrick
I understand that you understand.
But others might get impatient and think that they should not miss the boat.
Only that the boat has not seen water yet, right out of the dock.
So not too many people on the trial run.
Patrick
I would like to get 2 sets once Euvl and Ashaw have worked out the final number, hoping it will be 10 (else of course I will wait for the next and bigger GB.)
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.
"400",
Please kindly confirm if you are home so that we can dispatch your GB MOSFETs.
Thx,
Patrick
Please kindly confirm if you are home so that we can dispatch your GB MOSFETs.
Thx,
Patrick
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
wasn't someting like 7,2 mA IDSS and 8,1 mA the ideal pair for this amp?
I am not sure any more in what thread this can be found, may need to dig deeper tonight in my private time ...
I am not sure any more in what thread this can be found, may need to dig deeper tonight in my private time ...
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 was asking as I had also asked him for some transistors, and was wondering what level of match you were wanting. I asked for 0.05mA match, I was wondering what level of match you asked for.
will be interested in what he says . out of the 400 j74'2 and 400 k170's that i bought , i couldn't come up with even one set of those values . these were toshiba packaged 200/bag bl grade fets .
good to see another source to continue the good times 🙂
cheers Woody
good to see another source to continue the good times 🙂
cheers Woody
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)
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)
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Since he has a large pool to match from, you should make use of the opportunity and ask him to match for transconductance as well as bias current.
I am sure he knows how. If not he can PM me.
Patrick
I am sure he knows how. If not he can PM me.
Patrick