Early this year, I built an Aleph J. Some of you may remember helping me with that. Thanks!
A month ago, I built a Korg/B1 and use it as my pre.
This week, I completed an F6.
My speakers, for the moment are Klipsch RP600M's. They're rated at 8 ohms, but their impedance drops at lower frequencies.
The months I listened to the Aleph J, my appreciation for how it presented texture in the mids grew to a large degree. It's difficult to tell if it was me adjusting to it, but I think it benefitted from break-in. The low end was, as expected with these speakers, weak.
This is my first week with the F6. The bottom presents dynamics I'd not heard with the Aleph J, making some selections sound much more alive. I feel as if the mids don't have quite the same magic as the Aleph J, but can't tell if it's potentially my imagination or a lack of a break-in.
I don't have the room for large speakers (bummer), nor do I have the budget for anything exotic.
Is my experience with the F6 typical when compared to an Aleph J?
If the F6 is going to break in, I might be in great shape. I really think it's quite good. If not, would an F4 provide the best of both?
Does the Korg/B1 have enough gain to drive an F4? On paper, it looks like it does. If not, I can drive it with a 300B SET I built a few years ago.
Thanks in advance!
A month ago, I built a Korg/B1 and use it as my pre.
This week, I completed an F6.
My speakers, for the moment are Klipsch RP600M's. They're rated at 8 ohms, but their impedance drops at lower frequencies.
The months I listened to the Aleph J, my appreciation for how it presented texture in the mids grew to a large degree. It's difficult to tell if it was me adjusting to it, but I think it benefitted from break-in. The low end was, as expected with these speakers, weak.
This is my first week with the F6. The bottom presents dynamics I'd not heard with the Aleph J, making some selections sound much more alive. I feel as if the mids don't have quite the same magic as the Aleph J, but can't tell if it's potentially my imagination or a lack of a break-in.
I don't have the room for large speakers (bummer), nor do I have the budget for anything exotic.
Is my experience with the F6 typical when compared to an Aleph J?
If the F6 is going to break in, I might be in great shape. I really think it's quite good. If not, would an F4 provide the best of both?
Does the Korg/B1 have enough gain to drive an F4? On paper, it looks like it does. If not, I can drive it with a 300B SET I built a few years ago.
Thanks in advance!
tweak your F6 to alter its THD Spectra to your liking - buzz 2Picodumb about that, he is greatest F6 champion around (logically, he's too dumb to see that M2 is greatest of them all)
B1K is not capable enough for F4, maybe only with extra efficient spks in moderate SPL conditions
considering what you have now of amplification ( I mean, enough for now), think of bigger speakers ; in most cases - standalone speakers are effectively not occupying more floor space than bookshelf ones, positioned on pedestals
ok, Klipsch-es are efficient, but even with Klipsch-es old saying is true - better having Bigger Klipsch than Small Klipsch 🙂
B1K is not capable enough for F4, maybe only with extra efficient spks in moderate SPL conditions
considering what you have now of amplification ( I mean, enough for now), think of bigger speakers ; in most cases - standalone speakers are effectively not occupying more floor space than bookshelf ones, positioned on pedestals
ok, Klipsch-es are efficient, but even with Klipsch-es old saying is true - better having Bigger Klipsch than Small Klipsch 🙂
I recommend leaving the Aleph J as-is and tweaking the F6. There are several things that can make the F6 sound like a (somewhat) different amplifier. Think about swapping the simple JFet front end for a diamond buffer. Then try different output Mosfets and biasing current.
No need to build a whole new chassis and power supply, that is unless you really want to. 😉
No need to build a whole new chassis and power supply, that is unless you really want to. 😉
Yeah F6 is awesome.
I can help tweak it to sound more like an Aleph J while still having all of the benefits of being more dynamic than Aleph J etc.
M2 would probably be a very good match with the Korg though. If I had the korg I would probably build the M2.
If you didn't have the korg as preamp then I would definitely go with F6.
For example if you had a Whammy as pre (and not the korg) or a B1 R2 then definitely I would go with a tweaked F6.
Since you have the Korg I'd probably go with M2.
I can help tweak it to sound more like an Aleph J while still having all of the benefits of being more dynamic than Aleph J etc.
M2 would probably be a very good match with the Korg though. If I had the korg I would probably build the M2.
If you didn't have the korg as preamp then I would definitely go with F6.
For example if you had a Whammy as pre (and not the korg) or a B1 R2 then definitely I would go with a tweaked F6.
Since you have the Korg I'd probably go with M2.
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I think you should get in line for one of the DIY Sony VFETs coming up...
Tell us more. 🙂
I think you should get in line for one of the DIY Sony VFETs coming up...
If it is here, I'm 5th in line? 🙂
I think you should get in line for one of the DIY Sony VFETs coming up...
Horshack Ooh Ooh - YouTube
2 picoDumbs, can you please direct me to a post that describes modifying the F6 in the way you suggested? My searches have returned *many*, and some guidance would be appreciated.
The M2 looks like a great project. Currently, the case and power supply for the Aleph J could be made available; and I'm willing to build something else while I wait for the Sony VFET (which, if I read the correct information, seems impossible to get parts for).
I've never bi-amped, but I began wondering if this may be an approach also. My speakers are equipped to. I wonder how it would sound if I built the 6-24 crossover and used it to run the horns off the Aleph J and the woofer off the F6?
I began to think about one more thing: why adjust 2nd harmonic presence in the F6 when one could do so in the B1K?
The M2 looks like a great project. Currently, the case and power supply for the Aleph J could be made available; and I'm willing to build something else while I wait for the Sony VFET (which, if I read the correct information, seems impossible to get parts for).
I've never bi-amped, but I began wondering if this may be an approach also. My speakers are equipped to. I wonder how it would sound if I built the 6-24 crossover and used it to run the horns off the Aleph J and the woofer off the F6?
I began to think about one more thing: why adjust 2nd harmonic presence in the F6 when one could do so in the B1K?
Pico's Magic F6 Trick
With the korg, a good deal of what you're hearing is the korg itself, so that is why I made those caveats earlier.
With the korg, a good deal of what you're hearing is the korg itself, so that is why I made those caveats earlier.
I've spent what free time I had over the weekend going through F6 threads and Googling things I didn't quite understand in the discussions. I also finished my second PS and chassis, so I can run the Aleph J and the F6 at will. This time, I went with the monolithic bridges in the PS; of which I have a question. As a side note, it was great building the second time around - knowing all the ways I can make it tidy.
During my reading, I found the F6 should be biased to 611mV if that post was correct. I had mistakenly thought it should be 500mV (which is apparently for initial power up). This one change made the mid range more mellow and pleasing. While still not the Aleph J, it's absolutely beautiful.
My weekend reading has informed me this increases the range through which the amp will operate in Class A. Is this as important in a PP amp? When bias is increased, what are the sacrifices if any?
Thanks to ZM and 2picoDumbs for your previous explanations - and thanks again to Nelson for recommending I hold out for the Sony VFET. How can I argue with a genius? That's exactly what I'm going to do 🙂 Though, I may play around with bi-amping since I have them both and I'm curious.
Two last questions for the evening:
1: Is this okay for the PS:?
VS-36MB05A Vishay Semiconductors | Mouser
It seems to be working fine, though I understand it's probably overkill.
2: I'm sure people have tried experimenting with fancy capacitors for C1/C2. Has anyone said this is worth the expense?
Thanks in advance 🙂
During my reading, I found the F6 should be biased to 611mV if that post was correct. I had mistakenly thought it should be 500mV (which is apparently for initial power up). This one change made the mid range more mellow and pleasing. While still not the Aleph J, it's absolutely beautiful.
My weekend reading has informed me this increases the range through which the amp will operate in Class A. Is this as important in a PP amp? When bias is increased, what are the sacrifices if any?
Thanks to ZM and 2picoDumbs for your previous explanations - and thanks again to Nelson for recommending I hold out for the Sony VFET. How can I argue with a genius? That's exactly what I'm going to do 🙂 Though, I may play around with bi-amping since I have them both and I'm curious.
Two last questions for the evening:
1: Is this okay for the PS:?
VS-36MB05A Vishay Semiconductors | Mouser
It seems to be working fine, though I understand it's probably overkill.
2: I'm sure people have tried experimenting with fancy capacitors for C1/C2. Has anyone said this is worth the expense?
Thanks in advance 🙂
More bias more good.
Certainly way more critical for a single ended design but the benefits are just as important for push pull.
Bias the F6 for 1.5A
Certainly way more critical for a single ended design but the benefits are just as important for push pull.
Bias the F6 for 1.5A