On a totally different subject, I took out all the stuffing, fluffed the hell out of it (took hours) and put back a tiny fraction of what I took out. Sounds better. I must have had a couple pounds in each cabinet. I kept putting more and more in. Each time it "seemed" to sound better, but I'm not sure now. The amount I took out almost filled a whole black 55gal industrial trash bag (fluffed). Now I have a tiny fraction of the old stuffing, but it's well-fluffed, and the bass seems to be cleaner, if perhaps a little less deep. But not boomy.
Got an F4 amp working and in the system as a stereo amp. Very happy with the pairing. Seems to be highly resolving but very musical. The Halcyons are disappearing.
The Benchmark DAC3 doesn't have enough voltage on the SE outputs to drive the F4 to concert levels but it is loud enough to enjoy. Planning to get the other F6 converted tomorrow. Then for some quality listening with the balanced configuration. Already switched the internal attenuator jumpers from -20dB to 0dB in prep. Should be enough gain buy-back to drive me out of the room.
The Benchmark DAC3 doesn't have enough voltage on the SE outputs to drive the F4 to concert levels but it is loud enough to enjoy. Planning to get the other F6 converted tomorrow. Then for some quality listening with the balanced configuration. Already switched the internal attenuator jumpers from -20dB to 0dB in prep. Should be enough gain buy-back to drive me out of the room.
Very much digging the F4 over the F6. There seems to be much more detail but it is very musical, not fatiguing at all. Authority: seems to have a good grip on the bass; not under pronounced, not over pronounced, just right. For frequency response and detail/resolution, it is like listening via headphones except I got a stereo image and room-filling sound. I think Nelson Pass said it is the closest to the whole straight wire with gain (minus the gain) and I agree. The amp is quite transparent and playing very well with the Halcyons.
The only downside so far is I kept wanting to turn up the volume a bit more. It'll be a marathon session tomorrow but crossing my fingers I can get the other F6 converted and balanced operation keeps on giving.
The only downside so far is I kept wanting to turn up the volume a bit more. It'll be a marathon session tomorrow but crossing my fingers I can get the other F6 converted and balanced operation keeps on giving.
Very cool. The way you described your experience before listening to the halcyons, It sounded like effortless was not a word if you would have used.
The f6 is a great amp. Like you, I noticed that with other amps with more capable output stages, My speakers had a more effortless sound. I currently use my SDW speakers with a 70ish watt class A. It has a hefty dual mono power supply and I had noticed that the bass has a lot of control.
Looking forward to your next update! You have any pictures?
The f6 is a great amp. Like you, I noticed that with other amps with more capable output stages, My speakers had a more effortless sound. I currently use my SDW speakers with a 70ish watt class A. It has a hefty dual mono power supply and I had noticed that the bass has a lot of control.
Looking forward to your next update! You have any pictures?
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Hmm... being lazy... what is the power of the F4 in balanced mode? There is a cable connector that allows an SE output to drive the F4 balanced?
I assume a maximum of 20V from the preamp ( source ).. more typical, I think 14.4V is about the current than the F4 can provide ( 6 ohm load in my case ). about ~33 wpc.
I got one clone F4 right now, driven by a Pearl 2 / CJ PV9 and that has enough swing to drive the F4. Good enough that I splurged and bought a pair of used Audio Note AN-K speakers (90db/w) (*) but even so, I can hear the F4 running out of oomph sometimes.. the vocals get a little strained... when it starts to clip... and the speakers can handle much more power so I'm really thinking of going for more F4 power! I wonder if I could get 65 wpc, that would give me a nice 3db gain which would make the Audio Notes SING!
The F4 is indeed a jewel. I have an F5 sitting on top of it... unused.
(*) These replaced a pair of Elac Unifi-2 B52 speakers which are a steal... but at ~85db/w played not loud enough, BUT played sublime as well. I ought to note that the Audio Notes (3rd hand, only 5 years old ) have explosive dynamics with the F4.
I assume a maximum of 20V from the preamp ( source ).. more typical, I think 14.4V is about the current than the F4 can provide ( 6 ohm load in my case ). about ~33 wpc.
I got one clone F4 right now, driven by a Pearl 2 / CJ PV9 and that has enough swing to drive the F4. Good enough that I splurged and bought a pair of used Audio Note AN-K speakers (90db/w) (*) but even so, I can hear the F4 running out of oomph sometimes.. the vocals get a little strained... when it starts to clip... and the speakers can handle much more power so I'm really thinking of going for more F4 power! I wonder if I could get 65 wpc, that would give me a nice 3db gain which would make the Audio Notes SING!
The F4 is indeed a jewel. I have an F5 sitting on top of it... unused.
(*) These replaced a pair of Elac Unifi-2 B52 speakers which are a steal... but at ~85db/w played not loud enough, BUT played sublime as well. I ought to note that the Audio Notes (3rd hand, only 5 years old ) have explosive dynamics with the F4.
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FirstWatt documentation says 100W into 8R. When 6L6 tested my F5 monsterblocks in balanced mode, they put out about 70W before distortion was noticeable. No idea on the actuality of the F4s.
For balanced operation, you'll need a balanced source or a phase splitter. A transformer can accomplish the latter passively, otherwise, gotta go active.
For balanced operation, you'll need a balanced source or a phase splitter. A transformer can accomplish the latter passively, otherwise, gotta go active.
True, on 2nd thought, I will need a balanced source... yes, the transformer would work as well, maybe I do need that BA3 preamp with balanced outputs... but I may need a transformer to run the SE preamps.
Interesting... I've compared my F5 and F4 and the latter sounds MUCH better. The F5 has a "fatter" bottom end but the F4 just sounds more realistic. I've been curious about going to an F5 turbo V3 as well, but with the SiTs coming and perhaps an XA252... and then now looking into a second F4... plus the preamp... I'm honestly running out of room and, being in SoCal, I can't afford a bigger house... and my wife won't let me build over the garage... So I finally have reached the point where I have to make some choices..
F4 over F5.
( I reserved the right to change my mind... after all, if my wife can have all of those shoes and handbags, why can'I have more amp? I did draw the line -so far- at getting an ARC VT200-II amp... I finally saw on in the flesh -metal. It's simply TOO BIG... however, a pair of VTM-200.... hmmm.... hmmm... )
More boxes, more cables, more lights ( blue of course ), more switches, knobs... I gotta say that's up my alley. ;-)
Thanks
Interesting... I've compared my F5 and F4 and the latter sounds MUCH better. The F5 has a "fatter" bottom end but the F4 just sounds more realistic. I've been curious about going to an F5 turbo V3 as well, but with the SiTs coming and perhaps an XA252... and then now looking into a second F4... plus the preamp... I'm honestly running out of room and, being in SoCal, I can't afford a bigger house... and my wife won't let me build over the garage... So I finally have reached the point where I have to make some choices..
F4 over F5.
( I reserved the right to change my mind... after all, if my wife can have all of those shoes and handbags, why can'I have more amp? I did draw the line -so far- at getting an ARC VT200-II amp... I finally saw on in the flesh -metal. It's simply TOO BIG... however, a pair of VTM-200.... hmmm.... hmmm... )
More boxes, more cables, more lights ( blue of course ), more switches, knobs... I gotta say that's up my alley. ;-)
Thanks
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This is puzzling to me. Did you ever solve the level mismatch? I have usually had more then enough voltage swing from my DAC3 HGC to drive any amp I have tried. I have noticed a big difference in listening to complex music at higher levels (Digital levels not analog) from my DAC3 HGC. It is much cleaner in that case than anything else I have. This is due to the intersample peak clipping which Benchmark has eliminated. I didn't think I would notice, but on some recordings it is obvious. I have not incorporated this feature into any of my own designs but I definitely will in the future.
It is time for me to change my drive to the Halcyons to the DAC3/AHB2 amp combination now that I have gotten used to them on my 6-year-old streaming amp design. Hoping I will hear an improvement.
-david BTW
The F4 has no gain. According to the F4 product manual, it needs a balanced source providing +/-14 volts to get decently loud. The DAC3's single-ended outputs are a measly 3.7Vrms. Hooking the sole working monsterblock in balanced mode gives me plenty o' loudness. Using the single-ended outputs, it gets it to an enjoyable level but not anywhere near to driving me out of the room.
I'm still troubleshooting this other F4 monsterblock as it has some distortion problems. Once it is operating as designed, I'm sure the DAC3 will be up to the job using the balanced outputs. Using just the one working monsterblock by itself definitely gets loud.
Using a single F4 amp in stereo, the shoutiness has disappeared but as I'm not able to get to full volume, can't reproduce the conditions to root cause. Would be interested in your impressions with the AHB2 hooked up. I think it'd be a data point towards differentiating whether I have a speaker/room interaction problem or a amp/speaker interaction problem.
I'm still troubleshooting this other F4 monsterblock as it has some distortion problems. Once it is operating as designed, I'm sure the DAC3 will be up to the job using the balanced outputs. Using just the one working monsterblock by itself definitely gets loud.
Using a single F4 amp in stereo, the shoutiness has disappeared but as I'm not able to get to full volume, can't reproduce the conditions to root cause. Would be interested in your impressions with the AHB2 hooked up. I think it'd be a data point towards differentiating whether I have a speaker/room interaction problem or a amp/speaker interaction problem.
The distortion on the sort-of working F4 monsterblock, listening. Very, very audible. ZM and Dennis Hui gave me some help over in the F4 build thread on the MOSFET matching. Next step is to move a couple. If that doesn't work, time to figure out how to use an o-scope. It'll be awhile before I get to it. Too little time.
Latest update. Finally got the second F4 monsterblock functioning. Went the route of buying 1% source resistors from Mouser and getting a matched set of MOSFETs off of ThatcherDIYAudio @ Etsy. Cranked the bias voltage up to 300mV and got very good matching current across the triplets, ~2%. Have the monsterblocks in the system and just threw the Gladiator soundtrack at 'em. No sweat. No congestion. Hearing things down in the details that I've never heard before. Next step is to work on speaker placement and room treatments.
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