TI TPA3255EVM

[matt_garman]

BTL for the sub and Se for the mid/tweeter. One channel not used.

Plug in filters. HP for the mid/tweeter, BP for the sub.

Had to use TPA3255 because of 40V supply.

My own board though...a little off topic, sorry.

Are you going to do a group buy for that board (like you did with tpa311x)?

Is anyone aware of big name commercial AV equipment manufacturers who are using TI's Class D technologies? I have to believe they sell a lot of their Class D ICs to notable, high volume manufacturers to keep investing in this market.

I saw on another forum (AudioCircle IIRC) that there is an ICEPower module using a tpa325x chip.

 

[DrewT]

Actually, I tried it by accident. As usual, I had extension cords running all over the place during an initial audition. Each orange extension cord had a black plug inserted. I meant to unplug a soldering iron and accidentally unplugged the Mean Well. The music immediately stopped. I just as quickly plugged the Mean Well back in and the music immediately returned with no drama or long-term effects.

I get a moderately loud pop a few seconds after I switch off the A.C. power to the Mean Well. I don't think it's speaker damaging loud, but it's "it would be nice if it didn't do that" loud. It doesn't happen until the green LED on the Mean Well starts to dim. A red LED on the EVM flashes simultaneously with the pop.

Turning on the power produces a barely audible tick.

 

[DUG]

Originally Posted by DUG View Post

Plug in filters. HP for the mid/tweeter, BP for the sub.

Can you elaborate on this?

The three pcb's plugged in to the main board are a 4 pole high pass filter for the mid/tweeter set (passive crossover built in to the Sony tower) and a band pass ( high pass and low pass) filter for the woofer.

 

[Sma1033]

You may need an aux control signal to mute the TPA3255EVM board or use an relay with little control circuit to disconnect speaker when the rail voltage is still in transient state during power supply switch on/of period.

 

[C37]

Where do the guys in Europe get their Mean Well LRS350-48 for a reasonable price? Mouser cannot sell them here. Reichelt does not have them. There was a website in Germany 48,80 Eur but now "nicht mehr verfügbar", audiophonics can get them on order 44,90 eur but two weeks lead time min. anywhere else in the Benelux or France or Germany?

 

[Kjeldsen]

I cant find that model exactly but meanwell have ither 48 volt supplies

ERPF-400-48 MEAN WELL - Pwr sup.unit: switched-mode | TME - Electronic components

RSP-320-48 MEAN WELL - Pwr sup.unit: switched-mode | TME - Electronic components

SP-320-48 MEAN WELL - Pwr sup.unit: switched-mode | TME - Electronic components

 

[C37]

Thanks, but stuff coming from USA ( or asia) are heavely hit by customs here- i've had to pay 25 eur taxes on a 50 USD order for parts for my scooter. Unbelievably the EVM board was taxed... Nothing!

EDIT- Just seen they're in Poland!

 

[Kjeldsen]

Tme.eu is poland = EU

 

[mboxler]

Oh - I thought you meant tweaking the board.

I've been reading up on class d amps, and it seems that the output filter is very important????

The TPA3255EVM has a 10uf inductor/1uf output filter. This seems good for a 4 ohm load, but seems to cause quite an underdamped/peaking problem with an 8 ohm load.

Playing with TI's LC filter designer, it would appear that a 15uf/.47uf filter would work much better with an 8 ohm load, albeit the corner frequency ends up at 60khz vs the normal 40khz. However, the new filter is 3db down at 60khz vs being 2db up with the old filter.

After all that rambling, is it worth it to swap out the inductor/capacitor if your are using 8 ohm speakers?

This is an evaluation module 😉

Mike

 

[emedia4u]

After all that rambling, is it worth it to swap out the inductor/capacitor if your are using 8 ohm speakers?

http://www.ti.com/lit/an/slaa701a/slaa701a.pdf

Check this out and you will find your answer.

 

[goatherder]

My TPA3255EVM just arrived and I'm looking at PSUs. It looks like a 48V Mean Well supply is a good choice, but is there any reason that the 45V or 50V version of this wouldn't work? I like the idea of using the auxilliary 12V 0.5A and 15V 1A supplies to power something else. Potentially a DAC or preamp?

500W amplifier switching power supply board dual-voltage PSU +/-55V | eBay

In the meantime, I'll be using a 24V 5A laptop brick.

 

[mboxler]

My TPA3255EVM just arrived and I'm looking at PSUs. It looks like a 48V Mean Well supply is a good choice, but is there any reason that the 45V or 50V version of this wouldn't work? I like the idea of using the auxilliary 12V 0.5A and 15V 1A supplies to power something else. Potentially a DAC or preamp?

500W amplifier switching power supply board dual-voltage PSU +/-55V | eBay

In the meantime, I'll be using a 24V 5A laptop brick.

You would only be using one side of the supply, and I wonder if that would cut the available current in half??? If you could get a +/- 25 volt supply, I think you would then be able to connect to the - and + to get 50 volts, but that doesn't seem to be a choice.

 

[goatherder]

You would only be using one side of the supply, and I wonder if that would cut the available current in half??? If you could get a +/- 25 volt supply, I think you would then be able to connect to the - and + to get 50 volts, but that doesn't seem to be a choice.

Ah, yes. The available current probably would be cut in half. Thanks for the reply.

 

[DreadPirate]

The Mean Well LSR-350-48 for $30 - $40 is pretty hard to beat in terms of performance per dollar. In fact, impossible.

 

[goatherder]

The Mean Well LSR-350-48 for $30 - $40 is pretty hard to beat in terms of performance per dollar. In fact, impossible.

Thanks for the tip -- I ordered a Mean Well LSR-350-48.

I now have the TPA3255EVM running from a 24V 6A laptop brick and have to say that I like what I'm hearing. It seems to drive the 4-ohm Elac Uni-Fi UB5's effortlessly. Looking forward to hearing it with some more power behind it.

 

[DizRotus]

Who else is running theirs in DIFF(balanced) mode?

 

[DizRotus]

Reminds of the little girl who asked for a pony,;but was handed a box of manure with the instruction, “Dig, a pony must be in there somewhere.”

 

[globalplayer]

MW RSP-320-48: Schaltnetzteil, geschlossen, 320 W, 48 V, 6,7 A bei reichelt elektronik
MEAN WELL original NES-350-48 48V 7.3A meanwell NES-350: Amazon.de: Computer & Zubehor
DIY Schaltnetzteil 5V/12V/24V/48V Netzteil Trafo LED Strip Power Supply Free DHL | eBay
Power Supply 48V 36V 24V Schaltnetzteil Netzteil fur Stepper/Servo Motor Driver | eBay
480WATT 48V / 10A Netzteil / AC/DC-Bauteile Ausgangsspannung Ca, 40-52V DC | eBay
https://www.reichelt.de/Schaltnetzt...dex.html?ACTION=3&GROUPID=7266&ARTICLE=108280
https://www.reichelt.de/Schaltnetzt...GROUPID=7266&artnr=SNT+HRPG+600+48&SEARCH=%2A
https://teask.com/600w-meanwell-se-...MIvoyDg4_41wIV1TLTCh0SYwzYEAQYAiABEgKXm_D_BwE
https://www.elpro.org/de/320-watt-ip65-einstellbar/36032-hlg-320h-48a.html
https://www.proconnecting.de/Netzteile/LED-Schaltnetzteile/HLG-320H-48A::978.html


^
That`s all I got after ordering the last 2 from hobbyhifiladen.

 

[Kay Pirinha]

As said some times before, I'd prefer this one:

SNT RSP-750-48: Switching power supply, slim, 753.6 W, PFC, 48 V - 15.7 A at reichelt elektronik

at least, if you intend to extract continuous maximum power from your TPA3255. It's not that cheap, though...

Best regards!

 

[goatherder]

Nice. I’d like to try the balanced inputs, but don’t have a Pono or similar player. Is there a good inexpensive DAC with balanced outputs? A Google search isn’t bringing up much of anything that I would consider inexpensive (~US200$).