I overlooked that. Sorry. Noticed it after the link was copied into my reply. DOH! But if you already had the table???
Awesome. I thought that's what you meant, but I wasn't sure. I equate Vpp to swing (and I may be dead wrong). So in my mind ... 28Vrms => ~+/- 40V => ~80Vpp => ~80V of "swing". Not everyone uses the same definition of swing, but Vpp and Vrms are clear.
From a practical standpoint, when looking at specs for potential pre-amps... I'd say...
~28Vrms, ~31.5dBu,
A bit more couldn't hurt.
Enjoy!
Could also shoot for some more efficient speakers. These Halcyons are decent but another 3 or 6dB more would be sweetness.
Just threw the Gladiator soundtrack at the system. Never got congested. Hearing detail I haven't heard before. Wish I could turn it up a bit more which means good things. Need to work on speaker setup and room treatments next to dial in the soundstage and imaging. Investigating the feasibility of an Aikido balanced gain stage for a little more oomph.
Just threw the Gladiator soundtrack at the system. Never got congested. Hearing detail I haven't heard before. Wish I could turn it up a bit more which means good things. Need to work on speaker setup and room treatments next to dial in the soundstage and imaging. Investigating the feasibility of an Aikido balanced gain stage for a little more oomph.
Room treatment can make a big difference if it's done well. I think it's best to absorb the damaging bass energy and diffuse the mids and highs. My own room layout doesn't really allow me to use diffusion properly, so I treat the sidewall and ceiling 1st reflection points with absorption, and have as much bass trapping in the corners as I can manage (still has to function as a living room..). We definitely don't want to make the room too dead. It's certainly worth trying some things to see what works.
D
Deleted member 544066
That was the ticket! Guess i didnt have the bias turned down enough. F4 complete and sounding superb!
Interesting... How does it sound?
What is that wooden box?
I'm planning on testing my B1K into the F4 this weekend.
The B1K, with a gain of ~14db, given a 2Vrms input it should put out about 10Vrms, which into my 6 ohm speakers plays into ~16.67 wpc. At 90db/w it ought to be reasonably loud, I think.
My "normal" preamp is a SE tube job that does about 20Vrms so it drives the F4 to a full rated ~33 wpc into 6 ohms. The sound is simply sublime. Likely the best sound I've had in all of my 50 years of being an audiophile.
I've just ordered a set of transformers... Edcor PC600/15K. We'll see how that one works. Cheap enough to play with. It might bring the B1K up to par.. for a single F4 that is.
Longer term a second F4 and balanced preamp are on the works...
What is that wooden box?
I'm planning on testing my B1K into the F4 this weekend.
The B1K, with a gain of ~14db, given a 2Vrms input it should put out about 10Vrms, which into my 6 ohm speakers plays into ~16.67 wpc. At 90db/w it ought to be reasonably loud, I think.
My "normal" preamp is a SE tube job that does about 20Vrms so it drives the F4 to a full rated ~33 wpc into 6 ohms. The sound is simply sublime. Likely the best sound I've had in all of my 50 years of being an audiophile.
I've just ordered a set of transformers... Edcor PC600/15K. We'll see how that one works. Cheap enough to play with. It might bring the B1K up to par.. for a single F4 that is.
Longer term a second F4 and balanced preamp are on the works...
D
Deleted member 544066
It sounds fantastic, noticeably better than the dual mono ACAs I was using previously, and better than the vintage receivers previous to that. My dac, a Holo Spring 3, outputs 2.9v for the single ended, maybe thats just enough to be useable with the B1K. If i plug my phone into the B1k, it is definitely not loud enough, but digital sources are ok. I'll probably build a BA3 pre to replace the B1k, sometime.
My headphones are actually harder to drive than my speakers, and with some quieter tracks, I have to turn the B1k up to almost full volume.
The wooden box is a speaker/headphone switch. I can toggle between speaker outputs and headphone outputs, and the multiple xlr jacks are for different attenuation, so I can plug easier to drive headphones in as well.
My headphones are actually harder to drive than my speakers, and with some quieter tracks, I have to turn the B1k up to almost full volume.
The wooden box is a speaker/headphone switch. I can toggle between speaker outputs and headphone outputs, and the multiple xlr jacks are for different attenuation, so I can plug easier to drive headphones in as well.
Populated F4 and BA3 PCBs now ready.
Using 4U 400mm deep modushop chassis capable of 375w dissipation (187w per heatsink).
Standard F4 @ 3A needs to dispose of 75w of heat per side - which is sensible.
Worth considering upping DC voltage, or better to bias as much as practically possible and stick with the standard first watt power supply?
Thanks
Using 4U 400mm deep modushop chassis capable of 375w dissipation (187w per heatsink).
Standard F4 @ 3A needs to dispose of 75w of heat per side - which is sensible.
Worth considering upping DC voltage, or better to bias as much as practically possible and stick with the standard first watt power supply?
Thanks
Yes, fair play, aim for 100w per side.
Just wondered how you’d use the available 100w heat budget - current vs volts…
Just wondered how you’d use the available 100w heat budget - current vs volts…
set F4 as prescribed, if you're building it with regular PSU
means 18Vac secondaries
you'll not gain much with increased bias
means 18Vac secondaries
you'll not gain much with increased bias
BA3 in the same chassis as the F4. Shall I:
1. Just power it off the amplifiers power supply
2. Give it it's own secondaries and dedicated power supply (unregulated)
3. Own secondaries + regulated bipolar power supply (e.g. Jan Dickinson super regulator)
?
1. Just power it off the amplifiers power supply
2. Give it it's own secondaries and dedicated power supply (unregulated)
3. Own secondaries + regulated bipolar power supply (e.g. Jan Dickinson super regulator)
?
#3.
Imagine if you had built the F4 in its own enclosure solo and the BA3 also solo in its own enclosure. What would you do then?
The BA3 is a pretty beefy linestage, I would give it all the respect it needs since F4’s sonic qualities will be dependent on it.
Looking forward to your build!
Best,
Anand.
Imagine if you had built the F4 in its own enclosure solo and the BA3 also solo in its own enclosure. What would you do then?
The BA3 is a pretty beefy linestage, I would give it all the respect it needs since F4’s sonic qualities will be dependent on it.
Looking forward to your build!
Best,
Anand.
Another advantage in this case of running the front end with a different power supply is that you can run it at a higher voltage, which is documented to give better objective performance.
Anyway, have fun with your build.
Anyway, have fun with your build.
- Jan Dickinson superegulator needs 5v drop
- XRK971's Smooth like Buttah power supply I'm using also has a 5-6v drop.
F4 default power supply is 18vac giving typically +/-24vdc. Perhaps I'd be better off running 26vac secondaries, then both the SLB and super regulator (with it's own rectifier and cap bank) would give some 28vdc into both the F4 and BA3?
How's that sound? Probably a gain of about 20dB from BA3?
- XRK971's Smooth like Buttah power supply I'm using also has a 5-6v drop.
F4 default power supply is 18vac giving typically +/-24vdc. Perhaps I'd be better off running 26vac secondaries, then both the SLB and super regulator (with it's own rectifier and cap bank) would give some 28vdc into both the F4 and BA3?
How's that sound? Probably a gain of about 20dB from BA3?
I know many have done it... but with LS parts... some might say 28VDC is a bit much. Some would say Toshiba parts in Q1 / Q2 for the BA-3 would give more margin, and perhaps better performance.
Also, maybe ask around in practice what folks are getting as their DC from 26VAC secondary transformers from various manufacturers at various loads with the mains voltage where you are and with those two PSU designs.
I know if I ran 26VAC with the typical size transformers I used, with my amp loads, and with my mains voltages, with those configurations (SLB and super reg), I'd be closer to 30VDC most likely.... and even though some very wise people have said 30VDC is just fine... I am too much of a fraidy cat to run that without cascoding. One guy... one opinion... <
Also, maybe ask around in practice what folks are getting as their DC from 26VAC secondary transformers from various manufacturers at various loads with the mains voltage where you are and with those two PSU designs.
I know if I ran 26VAC with the typical size transformers I used, with my amp loads, and with my mains voltages, with those configurations (SLB and super reg), I'd be closer to 30VDC most likely.... and even though some very wise people have said 30VDC is just fine... I am too much of a fraidy cat to run that without cascoding. One guy... one opinion... <