Manu said:You mean my own 250's ...
I ll first try the J fet front end you posted, on a little daughter board, together with my A5 ...
Manu
Magura said:
I'll sort you out with 250's.
I still have a few that are not spoken for.
Only condition is that they are not just collecting dust.
Magura
it's not even hard or frightening to say ..... I like ya guyzzzzzz
Zen Mod said:
nope ..... that is not new ; just look at last pages of few last active AlephX threads ..... boyz do that again and again ........
ya know - to vec i vrapci znaju ......
o.k. but you are talking about new set of PCB for the some sort of X amp which is diferent than alephX V1.0 PCB ?
yoke said:
nope , really ;
connected to "Burning Amp" topic , I'm working with AR2 on transfering his set of V1.0 pcbs to X with Jfet input ;
who knows ...... - Manu recently shows some excitement for constructing pcbs , and he is "pcblessles" for that project ...........
I am too lazy and too dumb for that sort of things .......
carpenter said:I think I just got lucky:
I was rummaging through my pcb collection and ran across a pair of BrianGT Aleph boards.
I'm comparing schematics (Aleph 3 and Aleph J) and they seem similar except for values, transistors, and transistor footprints.
Looks like I've got some reading to catch up on--unless Nelson's planning a quick turn around on his pcbs. Just in case, I've got a little bitty kitty hidden under the house...
Hummmm.
I agree. The BrianGT boards look like they will work for this. I did an Aleph 2 and used an extra set of the external FET boards for the 2, so I have a spare set for the single FET version. Worth trying with some matched 250's I have and will see how it turns out.
To clarify further, the boards are Aleph X 1.0 so they are X'ed already, but Zenny is gonna help AR2 (and apparently a 100 other guys and their brothers - including me and my brother!) change the inputs to JFETS, the "latest thing" by slightly changing the boards. It shouldn't be a bunch of changes..
As I mentioned elsewhere, Nelson told me that the IRFP250's are just a TO-3 can with 2 IRFP 240 dies inside. Clearly you can use 240's but you need twice as many ( my math skills- amazing! ) Apparently they are pretty pricey these days, as I believe that they are no longer made. If you can't use TO-3 format you don't want IRFP250's
A major factor driving this is that a bunch of us got lovely and huge amp chassis' with heatsinks and power supplies donated by Nelson at the Burning Amp Festival. It is a bit more complicated because the chassis came with 240's and 9240's installed for a pushpull setup. But we also got pocketsful of IRFP250 MOSFETS so why not use them?
As I mentioned elsewhere, Nelson told me that the IRFP250's are just a TO-3 can with 2 IRFP 240 dies inside. Clearly you can use 240's but you need twice as many ( my math skills- amazing! ) Apparently they are pretty pricey these days, as I believe that they are no longer made. If you can't use TO-3 format you don't want IRFP250's
A major factor driving this is that a bunch of us got lovely and huge amp chassis' with heatsinks and power supplies donated by Nelson at the Burning Amp Festival. It is a bit more complicated because the chassis came with 240's and 9240's installed for a pushpull setup. But we also got pocketsful of IRFP250 MOSFETS so why not use them?
Variac said:
There seems to be some confusion about those TO-3 can parts.
The TO-3 can parts are IRF250, the IRFP240 and 250 are of the TO-247 package variety.
It's not all that complicated, as the parts that comes in both flavors, are named IRF-XXX for the TO-3 package, and IRFP-XXX for the TO-247.
Just to make sure you're all on the same page.
Magura
