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You can get Connexelectronics SMPS in the US from HiFiMe.
SMPS300RS 48V 110V SMPS Switch Mode Power Supply | Hifime Audio
SMPS300RS 48V 110V SMPS Switch Mode Power Supply | Hifime Audio
Thanks, that's handy.
It's funny SMPS datasheets often mention the proper mains ground be used (Green wire in USA). Unfortunately many old houses in the USA only have two wire wall outlets (Black-hot & White-neutral), no green ground connection. Hopefully the SMPS that are sold in the USA had proper transformer Insulation, Creepage and Clearance distances in the transformer & interconnects.
I only have 3-wire outlets in the Bathrooms and Kitchen, which have been remodeled & completely rewired with permits. It is one of the realities of living in an old house (in the USA, there are many people living in these old houses).
One of the benefits of using a cheap UL certified wallwort is the proper certification for safety & insulation. This insures proper insulation including proper Creepage and Clearances distances in the transformer & interconnects.
How to Use AC Isolation Transformers in Medical Equipment to Prevent Shock
There are many agencies that certify the safety. Most of the standards documents require one to pay a fee to order the standards.
Agency Certificates
UL Standards: UL 5085-1, UL 5085-2, UL 60601-1, UL 60950-1, UL 1097, UL 2097
Meets UL 864, UL 913, UL 916, UL 924, UL 1012, UL 1069, and UL 1238
CSA Standards: 22.2 #66.1, File # 221070
IEC/EN Standards: IEC / EN 60950 (VDE License 1447)
CE Compliance: VDE Declaration of Conformity 73/23/EEC
Cheers James,
I will see how I get on with them and will let you know. I've ordered some from Digikey. Did you add decoupling caps over the op-amp like ClaudeG as in the Aiyima 3251 mods thread?
I'm considering both the Meanwell LRS-150-36 and a SMPS LLC single ended PS from AliExpress. I'm thinking 36V as this board has caps rated to 63V. They are about the same price, but keep reading that LLC topology is better. I have a couple of SMPS that I have used for other projects and tended to add a capacitance multiplier after it if I needed lower ripple. I might give the LLC a try and measure/learn the differences on the scope.
@Audioflux - Don't know how relevant this is to this TPA3255 discussion, but I wanted to build my own amp using "existing building blocks" also, so I built / lego'ed together an amplifier based on the cheap Yuan Jing TPA3116D2 blue board..
Followed the instructions on the thread here (okay it took some time reading over a thousand pages...
) to desolder / replace all the sub-par parts (which ended up being almost all of the parts that were easily desolderable - is that even a word?) with proper parts, which cost me probably around $45 in new parts..?
It ended up being so good that I got rid of my $1300 Onkyo amplifier.
The DIY TPA3116D2 has been going strong for a long time now here, and it's outperformed my expectations.
It's dead quiet - ear-to-tweeter, no noise / hiss. Even with that silly zero gain tube buffer (also replaced all caps with proper ones on that) acting as volume control
I hope you'll be able to get as much fun modifiying your TPA3255 as I still have from my modded TPA3116D2
DIY hybrid tube / class D amplifier (TPA3116D2) - YouTube
It's the middle thing in this photo of my DIY family :
Followed the instructions on the thread here (okay it took some time reading over a thousand pages...
) to desolder / replace all the sub-par parts (which ended up being almost all of the parts that were easily desolderable - is that even a word?) with proper parts, which cost me probably around $45 in new parts..?It ended up being so good that I got rid of my $1300 Onkyo amplifier.
The DIY TPA3116D2 has been going strong for a long time now here, and it's outperformed my expectations.
It's dead quiet - ear-to-tweeter, no noise / hiss. Even with that silly zero gain tube buffer (also replaced all caps with proper ones on that) acting as volume control
I hope you'll be able to get as much fun modifiying your TPA3255 as I still have from my modded TPA3116D2
DIY hybrid tube / class D amplifier (TPA3116D2) - YouTube
It's the middle thing in this photo of my DIY family :
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Cheers daniboun.
I've been reading through a couple of mods that are recommended in a couple of threads (ClaudeG tpa3251 mod) as well this one.
- swap out op-amps
- add decoupling caps?
- swap out the film caps for 8 Ohm speakers
Anything else you would suggest with this particular board?
Will you be controlling the volume externally from the assembled unit?
@Pygmy Thank you and thank you for sharing, I'm looking forward to this journey. That setup looks great, did you also go about building your own speakers? I've got B&W LM1's that I'm planning to use the amp with, but if this journey starts getting out of hand, I might end up trying to build some LXminis 
And yes, I would use the term desolderable. I was wondering about what I should do in regards of volume control.. Is that a brass/copper baseplate you are using inside the case?
And yes, I would use the term desolderable. I was wondering about what I should do in regards of volume control.. Is that a brass/copper baseplate you are using inside the case? 
You can ask 110 / 220V, I've been living in France (220V).
The Connex is a clean PSU as well, see Jlester measurements a few pages back VS Meanwell.
For the Micro Audio, you need to contact Cresnet member :
https://www.diyaudio.com/forums/members/cresnet.html
With the updates, it is a very clean and great module.
I did another listening session yesterday and I am really impressed with the performance / price ratio!
If you are looking for some OPA1656 in DIP8 socket, ask to :
https://www.diyaudio.com/forums/members/bushellj.html
Checkout what Jlester measured :
Meanwell LRS-350-36 vs SMPS300RS (LLC)
Not sure that LLC provides a big difference... Both are reliable but unsuitable for my project.
I wanted to stay consistent with my specifications: a compact and efficient TPA3255, a compact and reliable SMSP LLC power supply. I think that with my modifications I found a good combo that fits my 131*249*55mm case.
Anyway :
the Meanwell has a higher switching noise (65kHz) (192mV-pp).
same ripple for both
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Hi,
in itself (stock version) the module is already good.
I try to move forward in stages and modify what already seems to me to be substantial, this why I did the following :
For TPA3255 module : Remove 2X Nichicon VZ serie 2200UF/63V > Install 2X Nichicon 4700UF KW serie (low ESR Audio grade)
For LLC SMPS PSU : Remove Output Caps 2X Nichicon PM serie 50V/1800UF > Install 2X Nichicon 2200UF KW serie
OP amps : Remove NES5532 Op amps > Install OPA1656 gold pins.
Add a DC/AC filter to avoid any EMI/RFI and get a clean power
Probably next step : I probably intend to update the film caps which have a pitch of 0.5 to 0.75 and install some MKP film caps @0.47uf for 8 ohm (as TI suggests). But the ones already installed seem good and work fine with my 2.5 way 8 ohms / 93DB floor speakers (ribbon tweeter).
Decoupling caps are great in this module > the buffer is already equipped with Nichicon FW Audio grade caps.
I am driving this amp via my DAC with a dematerialized volume controller.
Keep in mind that the main idea is to get the best possible alternative to the excellent Aiyima A04 (I mean the Tilear 2.1 with black PCB and full Elna caps). So I want a small and reliable amplifier with a great performance that fits my 131*249*55mm case.
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Also.... SOIC-8 to DIP Adapter - BrownDog Adapters - 970601
Can be ordered with and without various Op Amps.
Hi audioflux.
I have not tried decoupling caps to date on the OPA1656 but I did follow ClaudeG's thread and plan to modify my Aiyima A04 (and possibly A07).
I need to put in an order at Mouser for various parts as I also have a couple of the XRK Audio, BTSB Buffer modules to build. I think these give a nice flexible input Buffer to drive any of the TPA3255 Modules whether Balanced or SE Inputs. The latest version offers RCA, Jack and XLR inputs (SE and Balanced) with Balanced and SE outputs to drive whatever Amplifier module you want.
With this latest cheap module that only provides an SE input it might be possible to remove the Op-Amps completely and just couple the Balanced output of the BTSB Buffer directly to the inputs of the TPA3255 via the Op-Amp Sockets !!??
James.
Several people have said the MeanWell LRS-200-24 or LRS-150-24 have less noise than the higher current or higher voltage models further up the range. I don't have any suitable equipment to do these measurements but I can confirm that all my Aiyima and 3e-Audio amplifiers are absolutely dead quiet using this supplies - I can hear a very faint hiss but only if I put my ear within 10cm of the speakers !!
The advantage of the MeanWell LRS series is they are cheap and appear to perform rather well. Disadvantage is they are not particularly small so I understand why Danny would not want to use them in a "Compact Chassis". These units are about three times the size of the Amplifier boards !!
Danny - I am still trying to find the PSU models you listed but in Single Output versions - Seem to be only Dual Output versions on AliExpress ????
For this, you need to contact Hisonauto ICP Store in Aliexpress, the guy is really fair. You can ask for single or dual rails LLC PSU, you can custom your PSU and he will do it. (these PSU are well made; also well protected and they are still compact)
The other alternative for a single rail and RTR LLC PSU (the size is OK 142*66*45mm) :
LLC doux commutation amplificateur de puissance carte alimentation 600W simple double sortie tension Positive et negative 36V 50V 60V 70V 80V | AliExpress
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