F6 Amplifier

I'm using the Cree C3M0065090D in my F6 also slightly higher voltage and bias. Plays every day and sounds fantastic. The main reason for changing to the Cree was the lower input capacitance and I wanted to get the high frequency response higher and because this is DIY. We do it because we can and Nelson showed us how.
 
Hi All

Pre-xmas lunch question, I have jfets J74B (10.8) & K170B (9.0) (purchased from the store at different times) but are they close enough as a pair for my F6 build?? I know jim said dont sweat over matching (10%) is close enough, these are just outside that. ?? I'm reluctant to shell out another $75 + by the time there landed in the UK.

TIA, have a good day ya'll

Kind regards from the UK
 
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I built the F6 with all diy store parts except the fets which I bought from Calvin. I also used the store's psu with an antek 4218 trafo. The amp sounds better than great, and seems very strong, beyond it's wattage ratings. This is my first build of anything, and my first experience with class a amps. I'm building a BA3 pre with Salas ultraBiB shunt psu and iselect, with a motorised tkd pot from HiFi collective, with a remote system from Bent audio.



Sooo, soon I need to think about speakers. No more bookshelves, prefferably floor standing, with good bass, versatility, and a wide sweet spot. I listen to rock, jazz, vocal, and classical (the big black page symphonic stuff). I do like to get loud sometimes, but not ear splitting (not a kid anymore). Unfortunately, the speakers will have to be close to the wall, but not cornered. I have been looking at Troels Graveson's page, there are a few interesting candidates; the Fusion (woofers may not be readily available here), the Satori SBA 941, and now the the new Faital 3way.
DIY-Loudspeakers
Faital-3WC
Also the SB12.3 from Zaph audio, which are more affordable, and probably easier placement.

Zaph|Audio - SB12.3 3-Way Tower
Zaph|Audio SB12.3 ~ SB Acoustics 12", Dual Midrange, 3-Way
I've also looked at Speaker Design Works Speaker Design Works
The Anthologys and MiniSatements, and the Halcyons. Speaker Design Works designs seem unconcerned with efficiency.





With the F6, how concerned should I be with efficiency ratings, would the F6 drive any, some or all of speakers well? Any opinions on any of these? The room isn't huge, 20x15 ft, on the wide wall, and the room opens up to a short hall on one side to another 13 x 23 room, an another doorway to a small office on the other. No, it's not a great room, but it's the one I've got.
 
Official Court Jester
Joined 2003
Paid Member
Hi All

Pre-xmas lunch question, I have jfets J74B (10.8) & K170B (9.0) (purchased from the store at different times) but are they close enough as a pair for my F6 build?? I know jim said dont sweat over matching (10%) is close enough, these are just outside that. ?? I'm reluctant to shell out another $75 + by the time there landed in the UK.

TIA, have a good day ya'll

Kind regards from the UK

just introduce source resistors to equalize currents an bring dissipatio down
 
angrypat,

The Faital 3WC looks nice, and I am a big fan of well designed high efficiency drivers from BMS, B&C, Faital Pro, etc...they have quality control and engineering down to a science. The amount of testing they do is astonishing since they have to answer to a MUCH bigger and critical audience, the Pro guys particularly studios and stadiums. Designing for hifi honestly, is chump change.

Best of luck!

Anand.
 
just introduce source resistors to equalize currents an bring dissipatio down

Kind of starts to ruin the output impedance of the jet buffet which is important for driving the Jensen transformer.
I guess it depends how much money the guy has to devote to this hobby.
I think that if he plans to live with this amplifier for more than a year, it’s worthwhile just purchasing more suitable jet pairs.
 
Thankyou for the replies 6L6 and poseidonsvoice. I was hoping that the sb12.3 from zaph would be good fit power wise, as it is sealed, where most other designs are rear vented which makes placement more finicky (these look like the winners so far). Those faitals do look good though. I'm still left with the question of speaker sensitivity for pairing with the F6, is it the big power supply that makes the most difference?
 

6L6

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Joined 2010
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Angrypat - acquisition cost is the cheap part of private aviation...


Re: power supply, there is essentially no difference in over sizing it vs. making it as shown on the original schematic. You want more power, make a bigger amp. You’ll be surprised, however, just how much 25A of real Class-A actually is. :)
 
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6L6 - I suppose aviation and boats share that trait.



I am surprised at how strong it is, the F6 is a beast. I have a Rotel receiver rated at 100w, and the F6 goes louder and keeps it's composure. I also have a Emotiva Mini x a100, rated 50w @8r, it can't even stand next to F6 power wise (or sound wise of course). I have an old Nakamichi TA-2, it also seems stronger than it's numbers would suggest, (bought it new when I was 17, still have the working remote too!) no competition for the F6.
 
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