bakpaosiomay said:
In my setup that I am using F5 for mid-high and another F5 for low end, the F5's offer very good low end control, offer a very 'controlled' in space soundstage, and a warm but clean presentation.
The F4 seems to be maybe a wee-bit warmer, with a little less control. It may appear to be a little more relaxed, with a little less high end sparkle. A 'darker' amp some say. (and too tizzy is bad).
I have yet, to get a proper gain preamp (pumpkin) deployed and with F4 in balanced mode for a comparison.
If I had to offer a starter, build an F5, can always swap out F4 modules with the power supply later. It's only minutely harder to adjust than the F4.
Re: diferent Mosfets
Hi Guys, I'm thinking of trying one of these pairs (or something like them) in an F4, because the real things are v. much more expensive here in Brazil. Did you change anything else in the circuit to use them? Same rail voltages of +/- 23V, or lower?
Cheers
Nigel
tab30 said:
carpenter said:
I'm using the IRF630/9630. They sound great!Very affordable.
Hi Guys, I'm thinking of trying one of these pairs (or something like them) in an F4, because the real things are v. much more expensive here in Brazil. Did you change anything else in the circuit to use them? Same rail voltages of +/- 23V, or lower?
Cheers
Nigel
ch177 said:I use 1 on the MOSFET level of F4 as a buffer before and after using the F5-level results are satisfactory, much like the F4 and F5 combination.
I am considering doing this with an extra pair of F4 boards. Run just one pair. I think we lose some dampening factor. I am not sure this is critical for full range. I plan on running somewhere in the 750 mv range to get equal current output to original F4.
Also considering ZM F4 headphone variation on this as well. I am still wondering if anyone has built it, and if there is a way to squeeze some gain in here.
You would really like to have at least 20Vpk (40Vp-p) of clean signal drive capability. Whatever it is, 5V more probably would not hurt. Anything less may not be necessary, but, dynamic, transient, headroom, and overall "HiEnd" system sound and efficiency may suffer.
Naturally it depends on other factors in your system also but, personally, If I did not have a good clean 10Vpk, with 20V max out, I would be looking for another Pre. Then I would start worring about what sounds the best for me. Just my thoughts
Naturally it depends on other factors in your system also but, personally, If I did not have a good clean 10Vpk, with 20V max out, I would be looking for another Pre. Then I would start worring about what sounds the best for me. Just my thoughts
I had upped the gain on my XBOZ and thought it sounded pretty good. Then I put my Pumpkin on the F4s and was shocked how much more upper end resolution and wider the sound stage was. Just for grins and giggles I am building an Impasse, I will end up letting one of them go eventually.
Bill
Bill
where can i find impasse preamp schematic?
I tried at: http://www.audioxpress.com/ but without any success.
The best way, I think, is to ask Mr. jackinnj personally.
See Post #219 at http://www.diyaudio.com/forums/showthread.php?threadid=136835&perpage=25&pagenumber=9
Best Regards,
a.
I tried at: http://www.audioxpress.com/ but without any success.
The best way, I think, is to ask Mr. jackinnj personally.
See Post #219 at http://www.diyaudio.com/forums/showthread.php?threadid=136835&perpage=25&pagenumber=9
Best Regards,
a.
Attachments
F4 Qs
Ok
Now starting to build my F4
Does anyone have the circuit that Peter Daniels used as ref. for F4 signal PCBs ?
I've been looking at the parts list and find several differences between the parts list and the circuit Nelson provides in the F4_Om.pdf
Why are P1 and P2 different now ( 5k and 500R ) ? - they were both 5k originally .
R24 and R25 ?
Nelson was unable to provide any answers .
Links to 'alternative' circuit do not work if you look back in this thread or F4 PCB thread .
I'll build according to Nelson's circuit as default .
Thanks to anyone who can help .
MJ
Ok
Now starting to build my F4
Does anyone have the circuit that Peter Daniels used as ref. for F4 signal PCBs ?
I've been looking at the parts list and find several differences between the parts list and the circuit Nelson provides in the F4_Om.pdf
Why are P1 and P2 different now ( 5k and 500R ) ? - they were both 5k originally .
R24 and R25 ?
Nelson was unable to provide any answers .
Links to 'alternative' circuit do not work if you look back in this thread or F4 PCB thread .
I'll build according to Nelson's circuit as default .
Thanks to anyone who can help .
MJ