Amb only sell to builders of their amp. I had to do the matching myself and was pretty lucky. Followed : http://www.diamondst...ching_jfet.html

guess it depends on the circuit but in gilmore's amps I match for Vgs at the current used in the circuit, rather than Idss. i found this makes more sense.

Edited October 11, 201213 yr by justin

Bah, I'll just buy some from you guys at inflated prices sometime next year when I'll be ready to tackle a stat amp.

I'm in for 50 2sa1486

I'd take 50 2sa1486

It really sucks how so many of these transistors get discontinued.

I just went in for 50 pairs of matched sk170/sj74 as well. Didn't realize they were getting so rare. Hopefully I can get some decently matched quads in there

Edited October 11, 201213 yr by cobra_kai

^/

Edited November 12, 201510 yr by JoaMat

Also in for 50 x 2sa1486. thanks

I'm in for 50 2SA1486's as well.

I'm in for 100 2sa1486 if it's possible

-- o --

Rodrigo

I'm in on this bus, I'll take 100 of 2SA1486 if available.

I now have my HV running 8.88 mA.

I now have my HV running 8.88 mA.

Congrats! What exactly did you change? Did you have to get a beefier transformer? IIRC your PSU was confirgured for 450V right?

Thanks!

The transformer is a beefier 150VA model, it uses a screen and the 420 V windings are now capable of continuous current @ 250mA.

The psu is standard 450V, for the amp boards I changed R8 and 9 from 180ohm to 113ohm, simply by parallelling 300ohm over the existing 180ohm resistors which saved lifting the amp boards of the heat sinks. I was going to dabble with the third stage, but chose to leave it, I was concerned about not being able to get the boards to balance. As it is I can get both boards under 1 V, but cannot get down to the ~ 0 V where I was before, not that is matters, just worth mentioning. As for heat, there’s not much difference, runs slightly warmer overall.

Listening I found higher frequencies have opened up, sounded really good to my ears and definitely worth the effort.

Justin, I'd like to change my request to 100 pieces of 2sa1486 if possible. Thanks.

John: that sounds pretty interesting. Would love to compare it with the standard resistors.

Congrats John. Any pictures of your mod to show us?

Thanks Victor,

There’s not really much to see, however here is what I did. Either side of the LED in R8 and R9 positions the default 180ohm resistor is still in place I simply paralleled a 300ohm resistor over the top. This changes the value to 112.5ohm.

The calculation mA is derived;

1.7v - vbe junction (.7) /112.5 ohms == 8.8mA

(see Kevin’s post #1893 for detail)

Thanks Kevin and Birgir for all your help with this.

Edited October 13, 201213 yr by johnwmclean

That's smart. Ganna steal that trick for later.

Nice and clean work. What transformer did you change it to? SumR as well?

Edited October 13, 201213 yr by Victor Chew

Nice and clean work. What transformer did you change it to? SumR as well?

Yes SumR.

Better highs wold be good for the 007 and Sigmas; would it make the 009 brighter though?

Edited October 14, 201213 yr by eggil

Justin, I'd like to change my request to 100 pieces of 2sa1486 if possible. Thanks.

John: that sounds pretty interesting. Would love to compare it with the standard resistors.

i'm going to order them but the lead time is 12-14 weeks

If you'd like to reach some price break then just let me know...

Justin, please put me down for 100. I may never use them, but they'll probably be a good investment in that case.

If you'd like to reach some price break then just let me know...

they're only dropping it by 1 or 2 cents a piece, and ive already had up to 4000pcs quoted

For latest version of kgsshv PSU, what value is the current limit set to?

Justin please count me in for 50 2sa1486.

Thanks