That could very well be the case, but I won't know unless I try. I'm interested if the amp measurements indicate any changes correlating to any audible improvements. Per the TI white paper, PFFB should produce a measurable difference. I suspect the input transformers will clean up the sound a bit, although a very small amount.
Yes, 6dB or 0.003% to 0.001%. 🙂
Power demand on really high compressed music is 1/5 of rated amplifier output, so 200W would be enough - in practice if the supply is able to handle 600W burst without hiccup.
Power demand on really high compressed music is 1/5 of rated amplifier output, so 200W would be enough - in practice if the supply is able to handle 600W burst without hiccup.
Oops...so sorry. Ha,ha,ha. I murdered your name. The auto selection on my tablet does it again.
I guess, no one has any experience on Antek's power supply.
I guess, no one has any experience on Antek's power supply.
Can't see what's too wrong about it. Might get a little nervous about potential high voltage unloaded/high line voltage, but your boards will take a little.
I just don't see how it's providing any advantage over something like the aforementioned lrs-350-48, which is much cheaper and compact.
Thanks for the input. I may end up with Mean Well.
I plan on using the differential inputs (my first) on the board, to be connected to Emotiva's XDA-2 DAC.
I plan on using the differential inputs (my first) on the board, to be connected to Emotiva's XDA-2 DAC.
If you won't tell why, no-one can go with you and agree or decline..
It has no case, is twice as expensive, also needs a fan for full power. So what's the deal - Pfc?
It has no case, is twice as expensive, also needs a fan for full power. So what's the deal - Pfc?
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LRS-350-48:
MeanWell LRS-350 350W Enclosed Low Profile Single Output Switching Power Supply | eBay
EPP-400-48:
[POWERNEX] MEAN WELL NEW EPP-400-48 48V 8.4A 400W Single Output Power Supply | eBay
Granted, it's 20 USD more , at least including shipping to me. But twice as expensive?
Without active cooling it's rated for ~250W, more than enough for my application, no need to mod/remove fan. Placement in a reasonably well thought out chassis in regards to ventilation should allow for at least 300W, and if making a compact cube with all the parts oriented correctly and a 12cm fan with a mesh filter in the bottom blowing air up over the components you get less fan noise at max load and also a little bit of cooling over the amp modules at the same time. I see it as easier to put together as a "whole package".
So no reason at all, but personal preference. I see it as a better design well worth 20USD more.
Edit:
I allready have the SE-600-48 though, but if I'd known about the EPP series before that's where my money would go.
MeanWell LRS-350 350W Enclosed Low Profile Single Output Switching Power Supply | eBay
EPP-400-48:
[POWERNEX] MEAN WELL NEW EPP-400-48 48V 8.4A 400W Single Output Power Supply | eBay
Granted, it's 20 USD more , at least including shipping to me. But twice as expensive?
Without active cooling it's rated for ~250W, more than enough for my application, no need to mod/remove fan. Placement in a reasonably well thought out chassis in regards to ventilation should allow for at least 300W, and if making a compact cube with all the parts oriented correctly and a 12cm fan with a mesh filter in the bottom blowing air up over the components you get less fan noise at max load and also a little bit of cooling over the amp modules at the same time. I see it as easier to put together as a "whole package".
So no reason at all, but personal preference. I see it as a better design well worth 20USD more.
Edit:
I allready have the SE-600-48 though, but if I'd known about the EPP series before that's where my money would go.
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I should just like to point out the real price of the meanwell's.
This is where I bought my LRS-350-48.
Mean Well LRS-350-48 Ultra thin Switch Power Supply 48V 7.3A 350W | eBay
This is where I bought my LRS-350-48.
Mean Well LRS-350-48 Ultra thin Switch Power Supply 48V 7.3A 350W | eBay
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All of them are Meanwell, the LRS, the EPP and the SE are just different series.
I see the price of the one you listed is 36 USD, for some reason they list "Doesn't post to Norway" which may explain why I have not seen that unit when searching. The lowest price I've seen was 27USD but that was for used units, and not including shipping. Total cost was not far off the just over 50USD for a brand new one.
Still. I might have to refine my searches, as we are having different conversations about the same thing if I see one price, and everyone else sees something completely different. But it's increasingly difficult to get away from ISP geo tagging.
I see the price of the one you listed is 36 USD, for some reason they list "Doesn't post to Norway" which may explain why I have not seen that unit when searching. The lowest price I've seen was 27USD but that was for used units, and not including shipping. Total cost was not far off the just over 50USD for a brand new one.
Still. I might have to refine my searches, as we are having different conversations about the same thing if I see one price, and everyone else sees something completely different. But it's increasingly difficult to get away from ISP geo tagging.
quick question re. 3255 EVM behaviour.
im doing my first testing of the board since receiving it, before butchering it into my project.
connected as per the suggested test setup in the guide.
all works fine, and plays music (badly at the moment, im outputting to two bare subwoofer drivers on a wooden worktop.. not exactly hifi!)
however there is one behaviour that surprised me.
if i disconnect the audio cable from my test source (phone) and touch the jack tip, id expect the typical hum from the speaker, like with every amplifier..ever..
in this case it immediately lights the "fault" led and i have to reset the amp.
is that normal? seems rather fragile behaviour..
im doing my first testing of the board since receiving it, before butchering it into my project.
connected as per the suggested test setup in the guide.
all works fine, and plays music (badly at the moment, im outputting to two bare subwoofer drivers on a wooden worktop.. not exactly hifi!)
however there is one behaviour that surprised me.
if i disconnect the audio cable from my test source (phone) and touch the jack tip, id expect the typical hum from the speaker, like with every amplifier..ever..
in this case it immediately lights the "fault" led and i have to reset the amp.
is that normal? seems rather fragile behaviour..
It can be normal. If you have any static charge, or are otherwise at a different potential than the system ground (which itself may bot be earth ground), you would be attempting to amplify DC causing possible speaker or amplifier damage.
Assuming no other faults, attempt to touch the input while another finger (not the other hand) is resting on system ground. This should not fault the system.
As others have done, I sent a question to the TI support staff since there has been no activity on my order in a month. Despite showing stock when I ordered it, the expected ship date is now 12-29-17. That should give me time to find a suitable power supply. I know that I have a big 48 volt switcher that I removed from a 2.5 KW (pulse) MRI RF amp somewhere. I also have several 24 volt 600 watt switchers from cell tower amps. I think two of these can be wired in series. I haven't seen any of these since moving twice, so it might take a month or two to find them.....then whatever long lost goodies I find during the search may distract my attention off in a new direction.
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Why would you disconnect the source on a high power amplifier without an attentuator in between? The amp goes into protection, otherwise it would kill your speakers easily.
You should not do so at any time when the amp ist running.
You should not do so at any time when the amp ist running.
Is your TPA3255EVM grounded or mounted to a grounded chassis through metal standoffs? I had something similar before I connected the ground connectors onto the Mean Well power supply ground connection. The heat sink heated up quite a bit and the amp would go into "Fault" within seconds. I added the ground connections, and no more problems.
I added the Altec Peerless 15335A transformers, some Neutrik RCA connectors, some Molex connectors for the differential inputs and some Duelund DCA20GA hook-up wire.
The improvements are subtle. The midrange is cleaner, more detailed and more fluid. It sounded a bit grainy before, especially with drum brushes and some cymbals. The soundstage is deeper. I do not have any measurement tools set up, but I swear the noise floor has dropped as well.
I have a couple parts on back-order with Mouser for the PFFB mod. That is next.
Attachments
@Robin the amp just protects your speakers from seeing 50/60Hz full power output. The other effect is statics and floating ends of the decoupling caps.
@rhing, can you describe "fluid" a bit more?
@rhing, can you describe "fluid" a bit more?
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After extensive listening to many familiar tracks, I hear more low level detail, which translates into more sustained notes and just more enjoyable listening. Before the additions to the amp, the upper mids and highs were a bit blurred or "grainy" sounding. Now, everything is clearer and better defined. When I use the word "fluid," the music doesn't sound grainy.
These are subtle improvements, but more pleasing to my ears. On Pink Floyd's Dark Side of the Moon, the multiple clock alarms and chimes at the star "Time" occupy their own space in the soundstage and stand in greater contrast against a blacker or quieter background. With some music tracks, there are no noticeable differences.
Sounds like possibly increased K2 to me. (from the transformers)
PFFB shouldn't/will not touch this.
PFFB shouldn't/will not touch this.
Ok, quick question, i am currently modifying a couple of these boards, removing unneeded components and adapting to fit a case. It was necessary to remove heatsinks during this process. Ideally i would check amps regularly during mods to make sure ive not broken anything, but i cannot refit heatsinks until custom machined blocks arrive that will fit.
Question: can i power up these boards without a heatsink briefly? Maybe with inputs shorted? Advice appreciated.
Question: can i power up these boards without a heatsink briefly? Maybe with inputs shorted? Advice appreciated.