Thank you for a comprehensive response.
My hope for an Aleph J is revived, and I will be proceeding down that path.
Ah yes, the "DIY rabbit hole". Took my initital plunge a few years ago with a Lampizator tube buffered DAC from an eBay CS4398 board which sounded quite good, but my interest drifted to other things.
Then I decided to try the ACA.
I was quite surprised at how much improvement entry level Papa Pass amplification brought to my listening pleasure.
I want more.
I'm still intrigued by the F4, perhaps my next project will be an Aikido to enable that experiment if an Aleph J build goes well and I gain some skill and confidence.
1rst things 1rst, and I need to get cracking on a 5U chassis/power supply platform to plug Firstwatt clone amp boards into.
The diyAudio store should be expecting an order shortly.......
F4 pcbs?
Hello all, does anyone know where to get a set of F4 pcbs? The DA store is out of stock and I didn't see anything on the Group Buy or Swap Meet forums.
I may have gone search blind, so please forgive me if I overlooked something obvious. I have not looked on ebay yet, i'd prefer to support this community under the blessing of Nelson Pass.
Hello all, does anyone know where to get a set of F4 pcbs? The DA store is out of stock and I didn't see anything on the Group Buy or Swap Meet forums.
I may have gone search blind, so please forgive me if I overlooked something obvious. I have not looked on ebay yet, i'd prefer to support this community under the blessing of Nelson Pass.
post in few more F4 related threads , in swap meet ..... there must be plenty of unpopulated pcbs around
Hello all, does anyone know where to get a set of F4 pcbs?
Well I have an extra pair made by cviller. But shipping from Finland...
Can someone tell me why the full wave rectifier part of the power supply isn't being used. This is my first venture into solid state and my first reading of schematics in over 35 years. I'm just trying to figure out what I'm missing in understanding the project.
The PSU V3.0 and the F4. Is the PSU only using half the AC wave and smoothing that out? I'm just familiar with reading a power supply schematic that uses something like a rectifier tube. Like I said it's been almost 40 years since I looked at this type of stuff but have a desire to relearn and build some things.
It can swing the voltage but the standard gain of 10 dB is a bit low for the F4.
For example, if your CD has a max output of 2V RMS then 10dB will only get
you a max of around 5W into 8 ohms.
For example, if your CD has a max output of 2V RMS then 10dB will only get
you a max of around 5W into 8 ohms.
In looking at the build photos of peoples' amps, some builders are using the rectifier section of the power supply and it looks like others aren't. Am I just not seeing it or is "optional". If optional, what would be the argument for and against?
Thanks
Thanks
Which post numbers are you seeing this difference?
AC must become DC from rectifier section.
Maybe what you are seeing is a monolithic bridge rectifier is some amp pics and discrete components in others. The discrete rectifiers are sometimes soldered directly on to the rectifier/capacitor boards.
AC must become DC from rectifier section.
Maybe what you are seeing is a monolithic bridge rectifier is some amp pics and discrete components in others. The discrete rectifiers are sometimes soldered directly on to the rectifier/capacitor boards.
Post 497 shows a monolithic bridge
Post 351 shows discrete diodes connected to the chassis to dissipate heat.
Post 351 shows discrete diodes connected to the chassis to dissipate heat.
Thanks for the links. I see now what I was missing.
Any reason to use the bridge diode section of the PSU board vs. a monolithic rectifier?
Any reason to use the bridge diode section of the PSU board vs. a monolithic rectifier?
Short answer is no. Long answer is with discrete diodes you can pick exactly what you want, for example, ultra-fast, soft recovery diodes or some other variation. On the other hand, you can find specialized monolithic bridge rectifiers. I find "special" monolithic diodes to be more expensive.
With monolithic bridges mounting them is simpler. Just 1 or 2 screws to mount it.
Diodes & Rectifiers
HexFred Rectifiers
ultra-fast soft recovery diode Semiconductors | Mouser
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Newbie question: I’m interested in building an F4 and am investigating what parts are needed. Looking at the BOM for both the F4 and the universal power supply I see no mention of a power transformer. It’s clearly discussed in the build guide.
What other necessary parts are not mentioned in the BOM?
Any suggestion on wire? Colors, gauge?
I’ve only ever built kits...
Thanks.
What other necessary parts are not mentioned in the BOM?
Any suggestion on wire? Colors, gauge?
I’ve only ever built kits...
Thanks.
Hi odamone, perhaps I can help out here as well.
The F4, as you have seen, is more of a diY build than the ACA. However there are a few partial kits that will help a lot. First is the Deluxe 4U Aluminum chassis from the diyAudio store. This has all the holes you will need pre-drilled and tapped, pretty much an essential item for a large amp with lots of transistors and mounting holes like the F4. This also includes the galvanized steel inner baseplate with holes on 10mm spacing. Very convenient for mounting the other bits & pieces that you see in the illustrated build guide. The silver front panel also has a set of threaded M3 holes for mounting items. While you are on the ordering page for the chassis, follow the link to the back panel parts kit and add it as well. That will give you a pretty complete set of mechanical bits and pieces to support the physical build of the amp.
About the power transformer: Recommendations do vary a bit on this one, but for your application where the F4 will be part of a bi- or multi-amp system, a 300VA, 2x18V transformer such as the Antek AS-3218 will be sufficient. Your voltage rails will end up around +/- 23V if you use the recommended bridge rectifiers. I went with the Antek AS-4220, as I wanted to goose more power and current from the amp for an eventual set of dual monoblocks. But I'm just nuts that way.
For the big power caps, I like the Cornell-Dubilier SLPX series with 50V rating. These will last the lifetime of your amp due to their generous ripple current and voltage rating. Up to you whether to go with 15000 uF or 18000 uF. I went big 🙂
The boards you will be using support up to 14 ga. wire soldered directly into the speaker and power connection holes. The Universal Power Supply board also supports Euro screw terminal blocks which are very handy. Here is a photo of my build in progress – setting the initial bias before the RCA inputs or speaker outputs had been wired. If you dress your power wiring as I have done, then simple CAT5E twisted pairs (28 ga. solid core) will be sufficient for the RCA inputs.
The F4, as you have seen, is more of a diY build than the ACA. However there are a few partial kits that will help a lot. First is the Deluxe 4U Aluminum chassis from the diyAudio store. This has all the holes you will need pre-drilled and tapped, pretty much an essential item for a large amp with lots of transistors and mounting holes like the F4. This also includes the galvanized steel inner baseplate with holes on 10mm spacing. Very convenient for mounting the other bits & pieces that you see in the illustrated build guide. The silver front panel also has a set of threaded M3 holes for mounting items. While you are on the ordering page for the chassis, follow the link to the back panel parts kit and add it as well. That will give you a pretty complete set of mechanical bits and pieces to support the physical build of the amp.
About the power transformer: Recommendations do vary a bit on this one, but for your application where the F4 will be part of a bi- or multi-amp system, a 300VA, 2x18V transformer such as the Antek AS-3218 will be sufficient. Your voltage rails will end up around +/- 23V if you use the recommended bridge rectifiers. I went with the Antek AS-4220, as I wanted to goose more power and current from the amp for an eventual set of dual monoblocks. But I'm just nuts that way.
For the big power caps, I like the Cornell-Dubilier SLPX series with 50V rating. These will last the lifetime of your amp due to their generous ripple current and voltage rating. Up to you whether to go with 15000 uF or 18000 uF. I went big 🙂
The boards you will be using support up to 14 ga. wire soldered directly into the speaker and power connection holes. The Universal Power Supply board also supports Euro screw terminal blocks which are very handy. Here is a photo of my build in progress – setting the initial bias before the RCA inputs or speaker outputs had been wired. If you dress your power wiring as I have done, then simple CAT5E twisted pairs (28 ga. solid core) will be sufficient for the RCA inputs.
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do you find that all the different anodized pieces are safely electrically connected to the safety earth without running dedicated wires to them ?