About one year ago, I built a F6 amp. I used the PCB from diyaudio with a little modify, unfortunately my heatsinks are too short so I must cut the PCBs and wiring interstage transformer🙁
Some images to show and hope all of you like it!
About me, I always love these images because I built this amp at my old home that I was live for 31 years🙄














Some images to show and hope all of you like it!

About me, I always love these images because I built this amp at my old home that I was live for 31 years🙄














Nagini, your work is really inspiring.
BTW, how hot does you F6 get? I'm wondering if it actually needs that fan.
Thanks,
Dennis
BTW, how hot does you F6 get? I'm wondering if it actually needs that fan.
Thanks,
Dennis
Nicely assembled . nice workmanship
Immediate impression is the Helluvalot of additional Complexity tho.
Imo it seemingly goes against the KISS basis of the design.
As pointless digression;
there are 'other' solutions to a too short Heatsink, beyond sawing off bits of the PCB...
remembering that Only the irfp240's needs be on the sink 😉
Immediate impression is the Helluvalot of additional Complexity tho.
Imo it seemingly goes against the KISS basis of the design.
As pointless digression;
there are 'other' solutions to a too short Heatsink, beyond sawing off bits of the PCB...
remembering that Only the irfp240's needs be on the sink 😉
Imo it seemingly goes against the KISS basis of the design.
I think he has speaker protection and soft start in there. Maybe he has speakers he wants to protect?
@nagini262 if you change mosfet's blue pads with good ones, you will take better stability performance and cooling. I had too bad experience about blue silicon pads. 😉
I must fix the chassic with the heatsink so my chassic size is not good and of course the mica insulator is better blue insulator😛
The amp running very hot so the fan is necessary😡
The amp running very hot so the fan is necessary😡
I must fix the chassic with the heatsink so my chassic size is not good and of course the mica insulator is better blue insulator😛
The amp running very hot so the fan is necessary😡
Beautiful chassis work, but also very densely populated internally. Ample vents on the bottom to draw in cool air under the toasty bits?
BK
Yes, you right! The bottom is so close, I can not drill some holes for air flow😡Beautiful chassis work, but also very densely populated internally. Ample vents on the bottom to draw in cool air under the toasty bits?
BK
F6 different transformers
Hello Passlab's people 😛
I am thinking of making a new poweramp. reusing my old chassis, capable of dissipating around 200w (AlephJ/F5 etc...)
So i swapped some drivers with some transformers, which i would have been using for the shade enabled poweramp.
I can see, that those transformers are much like the original Jensen F6 transformers, and my quistion is, if i can use them for the F6 ?
I hope somebody a little more experianced into transformers than me, would take a look at the attached two .pdf?'
Jesper.
Hello Passlab's people 😛
I am thinking of making a new poweramp. reusing my old chassis, capable of dissipating around 200w (AlephJ/F5 etc...)
So i swapped some drivers with some transformers, which i would have been using for the shade enabled poweramp.
I can see, that those transformers are much like the original Jensen F6 transformers, and my quistion is, if i can use them for the F6 ?
I hope somebody a little more experianced into transformers than me, would take a look at the attached two .pdf?'
Jesper.
Attachments
I'am lucky enough? 😀
Directly from Linear Systems.
LSJ74A x 24 and LSK170A x 24
That's for replacement in my F6 amplifer.
Question: do i need to match them or i can use grade A with grade B, or better A with A without doubt?
Directly from Linear Systems.
LSJ74A x 24 and LSK170A x 24
That's for replacement in my F6 amplifer.
Question: do i need to match them or i can use grade A with grade B, or better A with A without doubt?

Last edited:
I'am lucky enough? 😀
Directly from Linear Systems.
LSJ74A x 24 and LSK170A x 24
That's for replacement in my F6 amplifer.
Question: do i need to match them or i can use grade A with grade B, or better A with A without doubt?
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This is from build thread
Q2 2SK170BL or LSK170B
Q3 2SJ74BL or LSJ74B
(This circuit will benefit from the input Jfets having a similar Idss, but don’t obsess about getting matches down to 3 decimal points — within 10% is more than good enough.)
If they need to be within 2,5 - 6,5mA range (LSK170A) or more i dont know through?
Jesper.
lykkedk
As i understand transistors have A,B,C,D grades with different idss in each grade and where A is lowest noise with idss 2,5 - 6,5 mA, so as i understand (i can be wrong maybe) you need to get one grade and match them to difference of each other not more than 10%. that 2,5 * 0,10 = 0,25 mA. I'am right?
As i understand transistors have A,B,C,D grades with different idss in each grade and where A is lowest noise with idss 2,5 - 6,5 mA, so as i understand (i can be wrong maybe) you need to get one grade and match them to difference of each other not more than 10%. that 2,5 * 0,10 = 0,25 mA. I'am right?
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