I do not know if technically and audibly it makes much difference but in my set up R13 and R14 are 100 ohms as i did not have any 47's at the time.
The sound is entirely smooth and refined no edginess or sharpness whatsoever. CF the gainclone -IMO the F5's tonality is spot-on-real. There is this wonderful decay to all notes, which is hard to describe, but the slightly longer lingering of each note seems to add a lot of tonal shadings which simply gives vocals and instruments a fuller tone, air and body more akin to what we hear in real life. I am mightily impressed by this 'tubiness'. The gainclone does capture some of this but the preamp is vital IMO here. A valve amp seems to suit it best. With an LDR it can sound sharper and more tonally threadbare,although dynamically it has far more drive with my speakers than the F5.
The sound is entirely smooth and refined no edginess or sharpness whatsoever. CF the gainclone -IMO the F5's tonality is spot-on-real. There is this wonderful decay to all notes, which is hard to describe, but the slightly longer lingering of each note seems to add a lot of tonal shadings which simply gives vocals and instruments a fuller tone, air and body more akin to what we hear in real life. I am mightily impressed by this 'tubiness'. The gainclone does capture some of this but the preamp is vital IMO here. A valve amp seems to suit it best. With an LDR it can sound sharper and more tonally threadbare,although dynamically it has far more drive with my speakers than the F5.
audiojoy's mod on r13&r14
looks like you are dropping signal voltage going into the mosfets-
making the driver transistors work harder for a given volume-
someone who understands this circuit better than I wish to weigh in?
I got a bit of a more "rounded" tone with NP's suggestion of doubling the feedback resistance see post above
rob
looks like you are dropping signal voltage going into the mosfets-
making the driver transistors work harder for a given volume-
someone who understands this circuit better than I wish to weigh in?
I got a bit of a more "rounded" tone with NP's suggestion of doubling the feedback resistance see post above
rob
ccschua said:
See this post for some info: http://www.diyaudio.com/forums/showthread.php?postid=331061#post331061
Lesson Learnt
When I moved the f5 to the larger system the Gainclone shined via the valve preamp and the F5 sounded awful and flat. Teach me a lesson to mess around with such a carefully designed circuit. I replaced the 100 ohm R13 and 14 to 44 ohms, and it came back to full life! Was unnoticeable initially on the tiny monitor speakers!!
When I moved the f5 to the larger system the Gainclone shined via the valve preamp and the F5 sounded awful and flat. Teach me a lesson to mess around with such a carefully designed circuit. I replaced the 100 ohm R13 and 14 to 44 ohms, and it came back to full life! Was unnoticeable initially on the tiny monitor speakers!!
Where are you folks sourcing parts for the F5's, it seems half of the parts are on back order or obsolete, anyone have any suggestions? Mouser and Digikey have most of the parts combined but it seems the issue is these parts...
2SJ74-BL - Obsolete
MUR3060WT - Obsolete
2SK170BLF - B/O
FQA12P20 - B/O
FQA19N20C -B/O
and a few others. Naturally I'd like to get these boards stuffed with good quality parts and have them ready for PS and Chassis by early to mid summer. But as time restraints hold most of us back I'd like the parts here when the time becomes available. Anyone in the Toronto area looking for F5 parts also? I'd be willing to buy local if anyone has the BOM for two stereo amps including PS caps if you have them. PM or mail me if you have it available.... Take care.
2SJ74-BL - Obsolete
MUR3060WT - Obsolete
2SK170BLF - B/O
FQA12P20 - B/O
FQA19N20C -B/O
and a few others. Naturally I'd like to get these boards stuffed with good quality parts and have them ready for PS and Chassis by early to mid summer. But as time restraints hold most of us back I'd like the parts here when the time becomes available. Anyone in the Toronto area looking for F5 parts also? I'd be willing to buy local if anyone has the BOM for two stereo amps including PS caps if you have them. PM or mail me if you have it available.... Take care.
LOL.....
speakrsrfun said:
I actually run out of F5 amp boards, and since there is still demand for those I will order PS boards as well.
Will also get just the rectifier section and those will be available free of charge: http://www.diyaudio.com/forums/attachment.php?s=&postid=1843189&stamp=1243872132
Peter - Yehaw thats the best news I've heard today, order them up Peter, I'm in for a pair for two stereo F5's. Let me know when they arrive and I'll swing by to pick them up.
Woodturner-fan - I'll give him a PM, and see what the price turns out like, thanks for the heads up...
Peace Y'all.
Woodturner-fan - I'll give him a PM, and see what the price turns out like, thanks for the heads up...
Peace Y'all.
I finally figured out the way to deal with 2 types of PS boards and make the rectifiers boards available for free, including shipping (subject only to forum donation)
Here's the All In One Power Supply board and I will try to stock them permanently.
The tiny rectifier boards on the right brake off and can be used as spares by anybody who does not want the complete PS board. That would include me, as I always prefer to wire caps p2p
If someone needs PS for F4 or F5 amps, I will break off the top section, which creates symmetrical PS (+/-V).
For those who want PS for F1, F2 or F3 amps, I will break off the bottom section which makes it a dual positive supply (2x +V).
The whole board is approx 5.5 x 5.2", which is still very reasonable size.
Of course it is also suitable for use with all 3pin regulators, in line stages.
Here's the All In One Power Supply board and I will try to stock them permanently.
The tiny rectifier boards on the right brake off and can be used as spares by anybody who does not want the complete PS board. That would include me, as I always prefer to wire caps p2p
If someone needs PS for F4 or F5 amps, I will break off the top section, which creates symmetrical PS (+/-V).
For those who want PS for F1, F2 or F3 amps, I will break off the bottom section which makes it a dual positive supply (2x +V).
The whole board is approx 5.5 x 5.2", which is still very reasonable size.
Of course it is also suitable for use with all 3pin regulators, in line stages.
Attachments
Good news Peter, and looks great but doesn't this design limit you to large can type caps unless you want to wire caps off board? I may be a relative layman compared to you but most of the F series and FW amps PS’s have the ability to use multiple caps to achieve a higher capacitance rating on board. Other than the obvious of working off board and just running jumpers from the caps to the relative places on the PS board what is the benefit to using a board of your style? Just curious Peter is all? I’m just worried that I’m going to have a hard time finding Caps with high enough rating cheap enough for me to use as F5 supply caps. Unless you have some laying around your willing to sell…. Anyhow I look forward to the final deign and the prospect of getting my F5’s up and running, Peace and take care.
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