How do you prevent the battery from discharging too low? I want to try this out, but since LiPos can be damaged if discharged to low, I'd want a way for it to shutdown if that voltage threashold is nearing. At the very least, I'd want to be able to see the voltage during regular use, but an auto shutoff, or some form of alarm would be best.
Mr Nelson, thanks for this design. I want to try it but have some questions as i have some 2sk209gr on hand . Is it ok to use say 2x pcs 209gr (for a total of 300mw dissipation) per branch instead of 4 j113? Or 4x 209gr? I think this will also add lower noise into the equation.
Instead of irfp048 may i use a nice SiC's as sjep120r100? If yes, please tell what are the modifications needed for this to work? I am one of those greedy boyz and just wanting to explore more... 😎
Thnaks in advance!
Many battery packs come with a battery management system (BMS) integrated into the pack that limits the charging voltage and the discharge voltage. If you plan to cobble together your own pack from individual cells, then you might want to build one with a BMS, or to hook up a dedicated cheap voltmeter and stop discharging when you get close to 12V (3V per cell). There isn't much stored energy left below 3V anyways for most cells, just as there isn't much point in charging beyond 4.2V per Li-Ion cell ('knees' at both ends of the state-of-charge curve).
Now, regarding the perceived 'sound stage' area (width and depth) and bass improvement: real effects I could imagine are noise reduction, and possibly higher instantaneous current capability, compared to a switching power supply. Are there measurable differences in the noise floor at any frequency? Can this amp use more instantaneous current than the power supply and built-in caps can supply? Or is this more likely a case of 'audio-perceptional exuberance'?
Most LiPo batteries don't have a "battery management system".
That would be great if they did though.
I like the idea of using batteries, but it seems important to note that Lithium Polymer battery packs have a limit on the lower voltage that if one goes below can cause permanent damage.
That would be great if they did though.
I like the idea of using batteries, but it seems important to note that Lithium Polymer battery packs have a limit on the lower voltage that if one goes below can cause permanent damage.
Perhaps it is differing terms and/or I don't have the stats re: "most".
Either way, what matters to me is that every single "pack" vs. single cells that I've purchased had PCM and/or BMS, and they're readily available for what I'd consider reasonable prices.
IMO, reputable sellers to consumers will advise as to whether the PCM / BMS is part of their product. Those same sellers may also sell "bare cells" to be used to build packs (hopefully by those with an understanding) and/or as replacements for cells in a bank / pack / or product that has an existing PCM / BMS (if required).
tl;dr - IMO, Reputable sellers should clearly note PCM / BMS and type. If they don't, then they should be able to respond clearly when asked if you want a product with it built in.
No LiPo packs that I'm aware of contain a BMS. If you discharge below the 3.2V/cell, then you risk damage. A link to a LiPo with BMS would help. I'd be all in to buy that product.
Perhaps I'm totally wrong. Worst case, you have a LiPo fire.
Perhaps I'm totally wrong. Worst case, you have a LiPo fire.
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Many battery packs do have, over-discharge and over-current protection (but definitely not all - always check the datasheed), it is important not to confuse that with a battery management system (BMS). The over-discharge protection threshold is not necessarily at a "safe" level in terms of reliabillity but only in terms of starting a fire, likewise for the over-current protection.
Some cells also have an NTC and a vent valve, but it is not something you should expect without verifying.
Some cells also have an NTC and a vent valve, but it is not something you should expect without verifying.
@birdbox - Again, I don't know if what you want is a PCM (most likely) or a full on "BMS".
They're all over the place. One quick search...
https://www.amazon.com/EEMB-Battery-Rechargeable-Connector-Certified/dp/B08ZCQXFX4/ref=sr_1_7?
If they don't specifically note it on the page then I ignore or contact them to ask. We may get things in entirely different categories though. I know every one that I found for a head-amp project contained proper protection circuitry. I know that all the ones I've looked for (again that were "packs" and not single cells) had PCM or BMS.
These folks have tons and they specifically note - "All lithium polymer batteries from LiPol Battery Co., Ltd come equipped with a PCM to ensure the highest standards of safety and reliability."
https://www.lithium-polymer-battery.net/lithium-polymer-batterys-pcm-and-bms/
They're all over the place. One quick search...
https://www.amazon.com/EEMB-Battery-Rechargeable-Connector-Certified/dp/B08ZCQXFX4/ref=sr_1_7?
If they don't specifically note it on the page then I ignore or contact them to ask. We may get things in entirely different categories though. I know every one that I found for a head-amp project contained proper protection circuitry. I know that all the ones I've looked for (again that were "packs" and not single cells) had PCM or BMS.
These folks have tons and they specifically note - "All lithium polymer batteries from LiPol Battery Co., Ltd come equipped with a PCM to ensure the highest standards of safety and reliability."
https://www.lithium-polymer-battery.net/lithium-polymer-batterys-pcm-and-bms/
Hi all
Any news regarding the availability of the kit?
Chassis and power supply are delivered and now it would be nice to build this amplifier.....
Cheers // Mats
Any news regarding the availability of the kit?
Chassis and power supply are delivered and now it would be nice to build this amplifier.....
Cheers // Mats
As is typically, I'm wrong again. I think I'm getting used to being wrong most of the time. 😆
Thanks for the link!
I just chose cheap voltage monitors that attach to the balance plug. Nice loud alarm goes off at the set voltage of 3.7.
I received a PM regarding my mini review of this ZD2 and how the other SS amps compared. I also didn't mention that I compared this amp against my KT88 P-P and my SE EL-84 with Type 80 rectifier.
By a very slight margin I prefer all of my tube amps to all of the SS amps that I own with the exception of the XA25. My tube amps simply place musical elements into the room while expanding the soundstage, these elements then decay like embers. Let's take this fabulous Cannonball Adderley with Milt Jackson album in the first track Blues Oriental
The XA-25 delivers this track's opening xylophone at the width of the loudspeaker, with each mallet strike full of texture that is both believable, palpable and rich. You can hear the elements decay reward into the background. Not at the same slow speed of a tube amp however, still delivers that experience. The XA25 delivers Adderley's breath in the instrument with depth and width in a very different way than a tube amp. It stretches out his exhales into the room. Additionally, the amp draws you into the presentation, it's like VR: you're inside of the music and are looking around at the elements. The problem with the XA25 is that once you hear it you can't unhear it. It's truly different than other SS amps and unfortunately out of the reach of many avid listeners and builders. IMHO, it's Papa's modern magnum opus (as he's had many).
The Nilai has a lot of similarities with really good class A. It's the warmest of all the high efficiency designs I've heard yet delivers massive amounts of detail without any of that harshness that some of us hear with these types of designs. It has that wonderful listen all day hot running class A sound and does so effortlessly. I bought the mono kits not expecting them to sound as good as they do and I think that Hypex has made me a believer that they can create something that rivals in some ways all of these amazing amps I have to listen to and runs cool, which is great during the summer. I turn them on in the morning and just enjoy them without heating up the room. On top of all that, with the Adderley album the Nilai allows you to simply enjoy the way the music flows and the artist improvising. You don't hear the amp at all, it's really a spectacular experience bringing you very close to the music the way any good amplifier should. Clearly, its PSRR is very, very good.
ACAMini on battery power (or CLC or AmyAlice) is awfully close to what anyone would need as a forever amp. It's excellent and has many of the traits that you want: low distortion, wide soundstage and wonderfully engaging, class A sound. I think on the included brick it sounds cold. On battery it just takes on a warmer, deeper and wider experience. It's truly wonderful and a keeper.
Zenductor 2 is a really nice balance between tubes and SS. It does not sound like a tube amp (nor does my DIY AJ) and at the same time has those qualities that we love in tubes : decay, realism and scale. It gives you the illusion and has some of the jump factor you get when listening where the element bursts into the room and startles you. It does that thing that makes tubes fun.
The reason why I've powered these simple single rail designs with lipos is that I have lots of them and because it's a hobby I tried it. Once you hear it I think you'll understand what a massive affect the PSU has on these designs.
I am fortunate enough to have the time to listen all day, every day and the differences between all of these designs, however, small, are significant to me. Remember, we all don't hear the same things and many will read these words and roll the eyes. That's okay. Quoting Nelson "it's entertainment, not dialyses."
By a very slight margin I prefer all of my tube amps to all of the SS amps that I own with the exception of the XA25. My tube amps simply place musical elements into the room while expanding the soundstage, these elements then decay like embers. Let's take this fabulous Cannonball Adderley with Milt Jackson album in the first track Blues Oriental
The XA-25 delivers this track's opening xylophone at the width of the loudspeaker, with each mallet strike full of texture that is both believable, palpable and rich. You can hear the elements decay reward into the background. Not at the same slow speed of a tube amp however, still delivers that experience. The XA25 delivers Adderley's breath in the instrument with depth and width in a very different way than a tube amp. It stretches out his exhales into the room. Additionally, the amp draws you into the presentation, it's like VR: you're inside of the music and are looking around at the elements. The problem with the XA25 is that once you hear it you can't unhear it. It's truly different than other SS amps and unfortunately out of the reach of many avid listeners and builders. IMHO, it's Papa's modern magnum opus (as he's had many).
The Nilai has a lot of similarities with really good class A. It's the warmest of all the high efficiency designs I've heard yet delivers massive amounts of detail without any of that harshness that some of us hear with these types of designs. It has that wonderful listen all day hot running class A sound and does so effortlessly. I bought the mono kits not expecting them to sound as good as they do and I think that Hypex has made me a believer that they can create something that rivals in some ways all of these amazing amps I have to listen to and runs cool, which is great during the summer. I turn them on in the morning and just enjoy them without heating up the room. On top of all that, with the Adderley album the Nilai allows you to simply enjoy the way the music flows and the artist improvising. You don't hear the amp at all, it's really a spectacular experience bringing you very close to the music the way any good amplifier should. Clearly, its PSRR is very, very good.
ACAMini on battery power (or CLC or AmyAlice) is awfully close to what anyone would need as a forever amp. It's excellent and has many of the traits that you want: low distortion, wide soundstage and wonderfully engaging, class A sound. I think on the included brick it sounds cold. On battery it just takes on a warmer, deeper and wider experience. It's truly wonderful and a keeper.
Zenductor 2 is a really nice balance between tubes and SS. It does not sound like a tube amp (nor does my DIY AJ) and at the same time has those qualities that we love in tubes : decay, realism and scale. It gives you the illusion and has some of the jump factor you get when listening where the element bursts into the room and startles you. It does that thing that makes tubes fun.
The reason why I've powered these simple single rail designs with lipos is that I have lots of them and because it's a hobby I tried it. Once you hear it I think you'll understand what a massive affect the PSU has on these designs.
I am fortunate enough to have the time to listen all day, every day and the differences between all of these designs, however, small, are significant to me. Remember, we all don't hear the same things and many will read these words and roll the eyes. That's okay. Quoting Nelson "it's entertainment, not dialyses."
Thanks! That was great. We need more of that on diyaudio. It doesn’t mean we don’t look at measurements, instead, it helps build a picture of what things should sound like. You did a great job describing the sound and I could follow what you were saying.
OK, but what is the preamp and speakers? Single ended or balanced? The sound changes so much! The soundstaging, speed, treble, etc... is that crash hat in the room? Is the singer right behind the plane of the front wall? Etc... amps are affected by the source and load.
Yesterday I compared the bridged F4/ BA3 with the XA252. The difference were not subtle. On Maggie 1.7.
I've tried low powered amps ( ACA ACA Mini, Zenductor, (Zon Of) Zenductor II, on the Maggies... pfft... the only one that did something it had no reason to was the Sissy SIT. Even so, it lacked dynamic range. It just didn't have any bass slam, it was all in the midrange...
I do need to explore the battery option... Ideally, I'd like a power supply option for all of those amps that is common, just a switch to select the operating voltage. As it is, I got a drawer full of power supply bricks for these amps...
I've been planning to post the amp comparison.... but I don't know which forum. I might start a thread on bridged F4 vs 252?
I think the bridged F4 with BA3 is a hidden jewel.
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Yes, it is. My entire F4 bridged chain is balanced... from P3, to Iron Pre Bal, BA3 Bal and F4s. You've never heard Maggie Bass Slam until you've heard this chain.... The 252 was also driven the same way.
I will observe that the bass came into is own once I plugged the Iron Pre Bal to the BA3 Bal with a balanced cable. With a SE connection, the sound was very good, but once I hooked up that balanced wire, the magic kicked in. I didn't hear this magic when I had the Iron Pre Bal to the 252 with THE SAME CABLE...
So maybe, all of our amps should have no FE and just a direct connection to the OP? Use the BA3 Bal for all?
I'm afraid this is not the forum for this discussion.... 😛
I will observe that the bass came into is own once I plugged the Iron Pre Bal to the BA3 Bal with a balanced cable. With a SE connection, the sound was very good, but once I hooked up that balanced wire, the magic kicked in. I didn't hear this magic when I had the Iron Pre Bal to the 252 with THE SAME CABLE...
So maybe, all of our amps should have no FE and just a direct connection to the OP? Use the BA3 Bal for all?
I'm afraid this is not the forum for this discussion.... 😛
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I moved my observations on the BA3/F4 vs 252 here...