Believe it or not, I can't get the incandescent light bulb shipped to California.
Like before, I had to get halogens shipped to Washington State.
The Dim Bulb Politicians in Sacramentograd I guess figure we'll use LED bulbs..
Anyhow, neat that you built it.... I got some of the parts to build one.... one of these days. I've only built the small ones. What was the hardest part of the build... other than drilling the back panel...?
Like before, I had to get halogens shipped to Washington State.
The Dim Bulb Politicians in Sacramentograd I guess figure we'll use LED bulbs..
Anyhow, neat that you built it.... I got some of the parts to build one.... one of these days. I've only built the small ones. What was the hardest part of the build... other than drilling the back panel...?
the best way I can describe the sound is it sounds real. The sound is very transparent and organic sounding and the high frequency extension is about the best I have ever heard. When I first was able to power it up and listen to it It hit exactly the spot i was missing in upper extension and sparkle with my Schiit Ragnarok 2 powering the speakers(serves as preamp duty for now until I build an ACP+) while also providing more satisfying hefty bass. Clarity and Separation is amazing every instrument and vocal has its own place in the space of the recording. Can’t speak about soundstage as my room is probably not set up the best for the best soundstage(pretty small listening room with no treatment) and that is probably more speaker dependent, but I think if your looking for an amp that has sparkle, clarity, bass heft without mush and you aren’t looking for an super warm sound than this is it for sure.
Hmm... I just plugged in a Nitsch Pietus Maximus into the system. Strictly as DAC. It's an outgrowth of a Schiit DAC and it could work as a preamp. As a DAC it sounds really good.... I got it with the multibit USB board.
You might want to try that with your F5m for a very minimal system? It has one analog input too, so it could run as a two input preamp/DAC/headphone amp...
https://nitschsound.com/products/pietus-maximus
You might want to try that with your F5m for a very minimal system? It has one analog input too, so it could run as a two input preamp/DAC/headphone amp...
https://nitschsound.com/products/pietus-maximus
Honestly I would say it’s actually not hard if you just follow the build guide. I had a lot of difficulty with the Aleph JZM boards I started with(work in progress)and replaced with F5M, but all of that was due to not following the guide correctly. If you follow the build guide step by step you should find success!
That looks pretty cool. I am kind of set on doing it DIY with the ACP+ but if I wasn’t that would be perfect for me
I saw someone ask about using a 100VA transformer for this amp and a reply stated it could be used.
I have an Antek as-1218 I would love to get rid of it and a chassis from an old Ross Mega 800.
Any harm in using the transformer at the full bias?
https://www.antekinc.com/as-1218-100va-18v-transformer/
I have an Antek as-1218 I would love to get rid of it and a chassis from an old Ross Mega 800.
Any harm in using the transformer at the full bias?
https://www.antekinc.com/as-1218-100va-18v-transformer/
^ Two channels at 1A4 Iq? Not something I'd try. I wouldn't even do it for one channel at that Iq.
You know the general rule... 2X to 3X the constant draw. 300VA would be my min with an Antek. I used a 200VA for a "low Iq" build for the guide at 1A1, and it's on my 'edge'.
YMMV.
You know the general rule... 2X to 3X the constant draw. 300VA would be my min with an Antek. I used a 200VA for a "low Iq" build for the guide at 1A1, and it's on my 'edge'.
YMMV.
I second It’sAllInMyHead’s view that a 300VA transformer would be a minimum for a stereo build.
An alternative, if you have space and money, would be to go for a dual mono PS. You could use your existing transformer for one channel, and buy second 200VA for the other channel. Need two PS boards though and space to mount second transformer and second PS boards. PS board could be stacked, though, to save space.
An alternative, if you have space and money, would be to go for a dual mono PS. You could use your existing transformer for one channel, and buy second 200VA for the other channel. Need two PS boards though and space to mount second transformer and second PS boards. PS board could be stacked, though, to save space.
^ Not disagreeing with the overall goals re: above. I like the idea of using kit on hand.
With that said, with the 100VA on one channel, I'd still strongly recommend an overall lower Iq of ~1A to 1A1 at the upper end. I've not specifically looked at the regulation of the 100VA or the sag under load, or temps, so I could not be sure. Plus, I like my channels to match (as closely as practical) operating conditions, so I would not operate one channel (with the 200VA) at 1A4 and the other at 1A1 (estimate examples).
It's just one more thought.
With that said, with the 100VA on one channel, I'd still strongly recommend an overall lower Iq of ~1A to 1A1 at the upper end. I've not specifically looked at the regulation of the 100VA or the sag under load, or temps, so I could not be sure. Plus, I like my channels to match (as closely as practical) operating conditions, so I would not operate one channel (with the 200VA) at 1A4 and the other at 1A1 (estimate examples).
It's just one more thought.
I would limit both channels to the same, lower bias, for sure! Forgot to mention that!
Looks like modushop chassis? Next order,have them punch out a rear panel like the "Deluxe" chassis version. It won't sound any better, and maybe the scars from a labor of love or whatever. Plus it's on the back!
Love the DBT power cord. No need for box, or receptacle for power cord plug.
Russellc
Love the DBT power cord. No need for box, or receptacle for power cord plug.
Russellc
The original F5 (my first First Watt clone) as well as new F5m are the simplest amps ever. F5m has even fewer parts. Many with original stripped them down just like this. Originals had no P3 either, like F5m
The rest of the amp is just like any other First Watt, chassis, power supply and so forth, but board build is super brief. No caps, hardly any weight, both my F5 and F5m boards are hanging dead bug style, off the mosfet legs.
If you want some real entertainment, go Way back in original F5 thread (it is gigantic) you can see me stumbling around trying to fire that thing up. I couldn't believe it worked! If I did it, most anyone stubborn enough can.
Russellc
I've had to order the last few from Italy, modushop ya know. They are super easy to work with. For F5m, I used 3U, had them punch rear panel "deluxe" style. I didn't use the perforated inner tray, but I did get the 400mm deep. Version. Chassis is plenty stiff for dual transformers.
Gives a really nice low and deep look. Cats love it as it is same area on top as 5U
Russellc
Gives a really nice low and deep look. Cats love it as it is same area on top as 5U
Russellc
Another one up and running.
Modushop 3U / 300 mm cabinet.
Bias at ca. 0.438 V / 0.93 amps.
After a couple of hours i got 46 deg on the fins and 60 deg on the transistors.
There is a tiny-tiny "thump" on power up, nothing on power down.
Used on my Lowther PM6 + flh JMLC 200 and Fostex T90A combination.
Replacing a pair of ACA's in bridge / balanced mode.
Modushop 3U / 300 mm cabinet.
Bias at ca. 0.438 V / 0.93 amps.
After a couple of hours i got 46 deg on the fins and 60 deg on the transistors.
There is a tiny-tiny "thump" on power up, nothing on power down.
Used on my Lowther PM6 + flh JMLC 200 and Fostex T90A combination.
Replacing a pair of ACA's in bridge / balanced mode.
So for a stereo F5m for double power supplies you recommend the deluxe, 3U, 400mm?
I've always gone for the aluminum case and handles front and back.
How about full dual mono blocks?
I've always gone for the aluminum case and handles front and back.
How about full dual mono blocks?
A dual mono F5m should fit nicely in a 3U 400.
What do you mean by "dual monoblocks"? Bridged / Balanced? If so, check out Mike's F5mX.
What do you mean by "dual monoblocks"? Bridged / Balanced? If so, check out Mike's F5mX.
It does. I posted insides of mine here somewhere. It's the same "floor area" as a 5U deluxe. It's just shorter. As I believe it was 6L6 who pointed out the 3U 400 has more heatsink area than the 4U deluxe chassis, which I have used for F6, M2, and Aleph J. All 3 worked just fine, but floor space is limited, I used a single 500VA Antek in all of those three. Dual mono was plenty of room for the dual supplies.