Very nice. I bet that sounds really good.
Try 0R47 as well. it does effect the sound in a interesting way.
Try 0R47 as well. it does effect the sound in a interesting way.
Well, I do really like the sound of my F5m as-is ... not really wanting to change anything ... 🙂
I still need to do the distortion measurements (REW and Focusrite).
Problem is, now the sailing season has started ... my sons and I are racing sailing dinghies (the storied Laser / ILCAs). That takes up a lot of time, with traveling to the races on the weekends and all ... have to make the most of it, as long as I still can do it age-wise. And for me, it's at least as much fun as building amps 😀
Regards, Claas
I still need to do the distortion measurements (REW and Focusrite).
Problem is, now the sailing season has started ... my sons and I are racing sailing dinghies (the storied Laser / ILCAs). That takes up a lot of time, with traveling to the races on the weekends and all ... have to make the most of it, as long as I still can do it age-wise. And for me, it's at least as much fun as building amps 😀
Regards, Claas
Claas.
Thank you for posting the waveforms.Did you follow the original circuit? Didn't you put a low-pass filter on the input?
You bought the kit from Diyaudio store ? or Did you use your own parts? and jfets ? Matched at Idss ?
Thank you for posting the waveforms.Did you follow the original circuit? Didn't you put a low-pass filter on the input?
You bought the kit from Diyaudio store ? or Did you use your own parts? and jfets ? Matched at Idss ?
@Nikos I had just bought my first O-scope last spring and ran a square wave through the first 2 home brew f5m channels I built. I didn't save an image but apparently everything looked good enough that I followed up with multiple channels without any changes. The jfets were matched, as were the resistors but The mosfets were straight out of the tube. I need to re-bias and test a pair of channels in the near future and will capture a square wave image when I do.
@seventenths
I don't want to be boring .....I'm just starting out haha... remember how many in ma idss are the matched yours jfets?
I don't want to be boring .....I'm just starting out haha... remember how many in ma idss are the matched yours jfets?
@Nikos I'm pretty sure they were 7.9x mA and came from the diyaudio store.
I usually try to match to within 0.1mA but I've used pairs that were 0.2- 0.3 out without any noticeable problems. I've also used pairs as low as 5mA and as high as 10mA on other Pass amps. For piece of mind, and per Nelson's suggestion, I do add a small press-on heat sink to units above 8mA
I usually try to match to within 0.1mA but I've used pairs that were 0.2- 0.3 out without any noticeable problems. I've also used pairs as low as 5mA and as high as 10mA on other Pass amps. For piece of mind, and per Nelson's suggestion, I do add a small press-on heat sink to units above 8mA
Yeah.... I was actually thinking of two external bricks... but that will do as well... thanks.
Time to search Mark's AmyAlice boards.
I was actually thinking of doing it in two boxes... put the power supply external so I can play in the future. A 2U 300 chassis for the audio signal ( enough heat sinks ? ) would be very nice and easy to stash in the rack.
It's an extremely tightly fit for the 2U/300. Making a separate PSU chassis would help. I was able to bias at 1.1A and had 55°C heat sinks in a warm room, however the build has two tiny 24V Noctua fans inside blowing air out from the Meanwell supplies. It got a little warmer without the fans.
It's really sounds amazing!
It's really sounds amazing!
Yes, they do have SMD and they work fantastic. You probably can get away with two AmyAlice filters, but I went with 4 to just be sure I had lots of margin. The AmyAlice are limited to 3A max per board. It should be fine with two FETs on each AmyAlice (just two filters vs four) if biased at 1.1A = 2.2A per filter. With 4 separate filters, that's 1.1A per filter before music plays.
FZ: There's a motel in Seattle, Washington, called the Edgewater Inn . . . The Edgewater Inn is built out on a pier . . . so that means that when you look out your window you don't see any dirt, it's . . . got a bay or something out in your backyard
FZ: And to make it even more interesting, in the lobby of the aforementioned motel there's a DIY shop where the residents can go down and, whenever they want to, rent a soldering pole and some lead free solder and schlep back up to their rooms, open the window, warm up their little iron outside and within a few minutes actually burn the house down so that they can put Smoke On The Water and do whatever they want with it, you know what I mean?
I think you miss the point... the idea is to make this as simple as possible. Short of buying a Bose...
BTW. are those 3 D printed stands in your amp?
FZ: And to make it even more interesting, in the lobby of the aforementioned motel there's a DIY shop where the residents can go down and, whenever they want to, rent a soldering pole and some lead free solder and schlep back up to their rooms, open the window, warm up their little iron outside and within a few minutes actually burn the house down so that they can put Smoke On The Water and do whatever they want with it, you know what I mean?
I think you miss the point... the idea is to make this as simple as possible. Short of buying a Bose...
BTW. are those 3 D printed stands in your amp?
If you're referring to the "AmyAlice Quad Rack", yes I made that design specifically to hold the 4 filters in that tiny 2U/300 chassis. Works really well and also allows for the star ground approach. Happy to print one for anyone interested who doesn't have access to a 3D printer via a Makerspace or buddy. I can be the "buddy" with a 3D printer 😉
Here's the star ground scheme with 4 filters inspired by @lhquam .
Here's the star ground scheme with 4 filters inspired by @lhquam .
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