according to FIRST WATT PRODUCTS
25W/8R means 14.14Vrms
14db gain ........ means 5V/V
so , divide 14.14/5
25W/8R means 14.14Vrms
14db gain ........ means 5V/V
so , divide 14.14/5
UK F6 up and running.
Hi,
My F6 has come together quite conveniently. I used unconventional heatsinks to save money. At first the heatsinks I used were not adequate (ouchy hot) and I experienced a fair amount of fluctuation in bias/offset. I spread the heatsink fins out and now they run quite cool and the amp is stable (on UK mains). The F6 is driving a pair of Fostex 206EN. Only one silly mistake that I have noticed so far, I put an LED in the wrong way around. So far I am very happy with the sound! My last amp was the ACA.
I've put some photos and info of my build process in an imgur album. I'm not entirely finished yet, so I won't make a submission to the pass amp pictures thread 🙂
Thanks again for the help and fantastic diy community.
Hi,
My F6 has come together quite conveniently. I used unconventional heatsinks to save money. At first the heatsinks I used were not adequate (ouchy hot) and I experienced a fair amount of fluctuation in bias/offset. I spread the heatsink fins out and now they run quite cool and the amp is stable (on UK mains). The F6 is driving a pair of Fostex 206EN. Only one silly mistake that I have noticed so far, I put an LED in the wrong way around. So far I am very happy with the sound! My last amp was the ACA.
I've put some photos and info of my build process in an imgur album. I'm not entirely finished yet, so I won't make a submission to the pass amp pictures thread 🙂
Thanks again for the help and fantastic diy community.
Attachments
Hi guys, I'm considering into build this amp as soon as the kits will be available again; does the IRFP 240 should be matched? Will the 4U contenitor be enough for this amp to get bias and offset stability? Last question: does this amp has more 3D soundstage compared to F5? Thanks in advance for your kind reply
Matched Mosfet is helpful, but not strictly necessary.
4U is more than enough.
Much, much, much more 3D than F5.
4U is more than enough.
Much, much, much more 3D than F5.
F-6 kits in store!
Kits are back in the store and I snagged one this time...🙂 Didnt see a message from store, even though I had signed up for one. Just looked in the store and they were in stock.
Russellc
Kits are back in the store and I snagged one this time...🙂 Didnt see a message from store, even though I had signed up for one. Just looked in the store and they were in stock.
Russellc
Last edited:
Yes, I can confirm that the F6 kits did show up again at the store about 2hr ago.
And that 25% of those have already sold. Once those go, it will be late next week at the very earliest for restock.
There will also be a limited amount (as always) of the matched Jfet sets showing up early next week.
And that 25% of those have already sold. Once those go, it will be late next week at the very earliest for restock.
There will also be a limited amount (as always) of the matched Jfet sets showing up early next week.
Fortunately, a bought several sets back when I built my F-5. I'll try to get some of these so I always have at least a few sets!😎
Russellc
Russellc
Is there anyone on this forum offering matched IRFP240s?
The .56 ohm 3W resistors don't seem to be an easy find.
Will these work?
RS02BR5600FB12 Vishay / Dale | Mouser
Is the blue LED, used along with a 10K ohm limiting resistor, a 3mm or 5mm LED?
Jim, can you or someone please provide a link to the appropriate LED from Mouser?
Thanks...
The .56 ohm 3W resistors don't seem to be an easy find.
Will these work?
RS02BR5600FB12 Vishay / Dale | Mouser
Is the blue LED, used along with a 10K ohm limiting resistor, a 3mm or 5mm LED?
Jim, can you or someone please provide a link to the appropriate LED from Mouser?
Thanks...
Hello Ammell,
Why dont you try the 5 watt mills at partsconnexion in Canada. I use thjem all the time when i need high wattage resistors. If i ever build a Nelson Pass amp i would certainly go for these. They are 20ppm maybe that is of no importance but they sound very good.
Just did replace some 3 watt metal oxide resistors in my Curcio Dac by these and they are way better.
Also remember using them in a Daniel preamp some decades ago.
They are a bit more expensive than the ones usually applied but you should try them asnd some other people should replace the ones thjey are using by these ones too.
Greetings, Eduard
Why dont you try the 5 watt mills at partsconnexion in Canada. I use thjem all the time when i need high wattage resistors. If i ever build a Nelson Pass amp i would certainly go for these. They are 20ppm maybe that is of no importance but they sound very good.
Just did replace some 3 watt metal oxide resistors in my Curcio Dac by these and they are way better.
Also remember using them in a Daniel preamp some decades ago.
They are a bit more expensive than the ones usually applied but you should try them asnd some other people should replace the ones thjey are using by these ones too.
Greetings, Eduard
C1, C2 size
Hi,
I'm wondering what is the diameter of the outline of C1 and C2 on the pcb.
Would 18mm diameter caps fit? (If so I'll order some Elna 🙂 )
Thanks,
Dennis
Hi,
I'm wondering what is the diameter of the outline of C1 and C2 on the pcb.
Would 18mm diameter caps fit? (If so I'll order some Elna 🙂 )
Thanks,
Dennis
There is an excess of room around those caps, you will have little difficulty fitting whatever you like.
I used Nichicon FG or KW - one of their audio grade caps.
I used Nichicon FG or KW - one of their audio grade caps.