Hi,
I have a few questions for anyone with F4 mono-block amp experience before taking this trip myself.
Anyone build F4 mono-blocks and able to comment on their sound versus a single chassis stereo F4?
Was it worth going to mono-blocks vs a single chassis?
Do you think the mono-blocks can drive most speakers reasonably well?
Did you use unbalanced or balanced connection for 50w or 100w? If you tried both, what did you think of the different setups?
Which preamp do you use?
Do you know if any balanced preamp has the needed gain to drive an F4?
How much power supply capacitance did you use per channel?
Thanks!
Vince
I have a few questions for anyone with F4 mono-block amp experience before taking this trip myself.
Anyone build F4 mono-blocks and able to comment on their sound versus a single chassis stereo F4?
Was it worth going to mono-blocks vs a single chassis?
Do you think the mono-blocks can drive most speakers reasonably well?
Did you use unbalanced or balanced connection for 50w or 100w? If you tried both, what did you think of the different setups?
Which preamp do you use?
Do you know if any balanced preamp has the needed gain to drive an F4?
How much power supply capacitance did you use per channel?
Thanks!
Vince
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I'm using every day in my workshop Papa's Koan amp , which is sorta monoblocks ........ 800VA Donut with 4x18 secondaries , so each channel is having (almost) independent power supply
Anuwau , in lieu with meaning of your question - once I had another F4 in my workshop , made by some other guy , which I had to dismantle and change to Babelfish J ; prior to dismantle , I tried these two with Pumpkin , so having 100W/8R A class per side.
Sound was (what else than) good ........
Only problem is - my workshop speakers are easily driven even with decent cans amp, so you must simply believe me when I say that bridged F4 is pretty capable amp - not exactly made for steady 1R load , but it will drive pretty much anything you burden it with
Is it worth ......- if you have tough speakers , needing Cojones and 100W per side , I would advise changing speakers .... but - that's me .....
I'm regularly using 33mF-0R1-33mF per rail , per channel , for regular stereo amp
Anuwau , in lieu with meaning of your question - once I had another F4 in my workshop , made by some other guy , which I had to dismantle and change to Babelfish J ; prior to dismantle , I tried these two with Pumpkin , so having 100W/8R A class per side.
Sound was (what else than) good ........
Only problem is - my workshop speakers are easily driven even with decent cans amp, so you must simply believe me when I say that bridged F4 is pretty capable amp - not exactly made for steady 1R load , but it will drive pretty much anything you burden it with
Is it worth ......- if you have tough speakers , needing Cojones and 100W per side , I would advise changing speakers .... but - that's me .....
I'm regularly using 33mF-0R1-33mF per rail , per channel , for regular stereo amp
https://www.diyaudio.com/forums/pass-labs/201281-burning-amp-ba-3b-balanced-57.html#post4794952
I have the BA3-b monoblocks with F4s in the OS. currently driving Elsinores speakers. great top to bottom control, tight bass
.
I have the BA3-b monoblocks with F4s in the OS. currently driving Elsinores speakers. great top to bottom control, tight bass
.
Thanks Russell, ZM and Koja.
I've considered the BBA3 preamp, but was also considering buying a balanced preamp to save time.
I have (2 different sets same brand) of 86 db speakers at around 6 ohms nominal, which I don't think will be a problem.
I don' t have any truly sensitive speakers, like 95db or above. I'd like to build my own, but would like it to be ultra simple. Always liked the concept of the A25/A26 Seas.
Even though about buying some Klipsch lower end models. Been getting good reviews by Steve Guttenberg.
Two guys I know from here have Elsinores. Really nice speaker! Like the way they used same driver cone for different freq ranges.
I intend on building (one day) a hybrid ribbon speaker with a DIY ribbon for mid and hi and dynamic driver for lows. I have this book- Ribbon Loudspeakers: Justus V. Verhagen Ph.D.: 9781882580446: Amazon.com: Books
This speaker will most likely be less sensitive and perhaps around 4 ohms. I don't listen at high volume, but I do like a nice dynamic range.
I'm fascinated with power buffers right now. Already have power supply boards, two 600VA 18+18v Antek toroids. I'm half way there!
I've considered the BBA3 preamp, but was also considering buying a balanced preamp to save time.
I have (2 different sets same brand) of 86 db speakers at around 6 ohms nominal, which I don't think will be a problem.
I don' t have any truly sensitive speakers, like 95db or above. I'd like to build my own, but would like it to be ultra simple. Always liked the concept of the A25/A26 Seas.
Even though about buying some Klipsch lower end models. Been getting good reviews by Steve Guttenberg.
Two guys I know from here have Elsinores. Really nice speaker! Like the way they used same driver cone for different freq ranges.
I intend on building (one day) a hybrid ribbon speaker with a DIY ribbon for mid and hi and dynamic driver for lows. I have this book- Ribbon Loudspeakers: Justus V. Verhagen Ph.D.: 9781882580446: Amazon.com: Books
This speaker will most likely be less sensitive and perhaps around 4 ohms. I don't listen at high volume, but I do like a nice dynamic range.
I'm fascinated with power buffers right now. Already have power supply boards, two 600VA 18+18v Antek toroids. I'm half way there!
btw: if you can put up with the size (85L) and if you are up for a drive to Detroit-Windsor I can sell you my Elsinores at the cost of material (US$1,500) which is dirt cheap compared to any commercial offerings. cherry veneered with mahogany inserts on front. One has a veneer crack on the back. These are an easy amplifier load (four 8ohm drivers in series-parallel config) and you can hear them with BA3b monos. And as a sidekick I can demo for you my OBs as well. I just have too many speakers and need to free up space.
here a pic before they were finished (open back and cherry veneer not varnished)
https://www.diyaudio.com/forums/multi-way/97043-elsinore-project-thread-161.html#post3618366
here a pic before they were finished (open back and cherry veneer not varnished)
https://www.diyaudio.com/forums/multi-way/97043-elsinore-project-thread-161.html#post3618366
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I was offered the Elsinore's a ridiculously low price and declined it. Finished cabs and parts included.
The cabs were CNC machined by a cabinet maker. Was a sweet deal, but I'm kind of a knuckle head when it comes to speakers.
I always think I can do better. If I spent enough time on one project, I probably could.
I bounce around too much. It's a curse.
Beautiful speakers though...
Thanks anyway.
The cabs were CNC machined by a cabinet maker. Was a sweet deal, but I'm kind of a knuckle head when it comes to speakers.
I always think I can do better. If I spent enough time on one project, I probably could.
I bounce around too much. It's a curse.
Beautiful speakers though...
Thanks anyway.
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Understood. I am all too well familiar with "the curse" of diy audio. I myself though do not spend time on box designs as IMHO it is not worth it. too many well engineered designs around. If a guy like Joe R. spent a ton of time beating it to death, and then a group of users drove some refinements to it, I am not likely to add anything to it. So between those it is only a matter of choosing for the right application (room, type of music, amps available etc.).
I do invest my time though in OB designs and I also use Siegfried L designs here as a sort of benchmark for myself. I try for an OB which I can drive with FW clones. Good luck.
I do invest my time though in OB designs and I also use Siegfried L designs here as a sort of benchmark for myself. I try for an OB which I can drive with FW clones. Good luck.
When you say mono block, you mean a stereo one running balanced bridged, yes?
Remember that a standard F4 (RCA in) needs about 40v Pk-Pk from the preamp to make full power (15v RMS)
The same F4, wired into a bridged monoblock (via the XLR) will now need double the voltage to make full power, about 80v Pk-Pk (28v RMS)
I know of exactly one commercially available preamp that can do that...
I have two mono-blocks of F4, four channels in total
When using a balanced pre-amp (Impasse) I use them as monoblocks, with unbalanced pre I don’t even bother firing the second box, one channel per side is more (much more) than adequate with my 90bB speakers
My favourite now is driving F4(s) with a DHT pre amp, best of both worlds
Having four channels in two boxes can come handy if you decide to go active crossover route later
When using a balanced pre-amp (Impasse) I use them as monoblocks, with unbalanced pre I don’t even bother firing the second box, one channel per side is more (much more) than adequate with my 90bB speakers
My favourite now is driving F4(s) with a DHT pre amp, best of both worlds
Having four channels in two boxes can come handy if you decide to go active crossover route later
Similar story here: a pair of DIY F4s which I really like. The flexibility of configuring as bridged, parallel, or bi-amp is nice.
Let me add the Aikido tube preamp as a being a good fit (unbalanced output) providing enough voltage swing and gain. I need all the gain I can get for the low output moving coil cartridge. This is less of an issue for digital sources.
Let me add the Aikido tube preamp as a being a good fit (unbalanced output) providing enough voltage swing and gain. I need all the gain I can get for the low output moving coil cartridge. This is less of an issue for digital sources.
You can tailor gain building the Aikido with various tubes. I built a low gain (10-12db) Aikido using 4 X 6CG7.
Today I received an email from a local DIY friend and member here.
He has an Aikido preamp I can try out and also has spare PC boards.
Been wanting to build a tube amp or tube preamp for a long time, so this could be a route. Perhaps it has enough gain to drive MoFo to get an idea of what the Aikido can do.
Still, the real target is a set of F4s stereo amps. Everything else is DIY audio icing on the cake!
Thanks!
Vince
He has an Aikido preamp I can try out and also has spare PC boards.
Been wanting to build a tube amp or tube preamp for a long time, so this could be a route. Perhaps it has enough gain to drive MoFo to get an idea of what the Aikido can do.
Still, the real target is a set of F4s stereo amps. Everything else is DIY audio icing on the cake!
Thanks!
Vince
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