[Mortsnets]

How about the RS-35M.

Also would these make a difference with the TPA3110?

[randytsuch]

How about the RS-35M.

Also would these make a difference with the TPA3110?

It would work, but it must be a monster, weighs 27 lbs.  My 12A is supposed to weigh 13, but it feels heavier than that.

Same for the 20, although that guy is not as heavy as the 12, but if you get a good deal.

One thing, I wonder if the meter has any effect on sound quality?  The current meter specifically.  I would guess they measure current by passing the output through a very small value, high wattage resistor, but that is just a guess.

Randy

[Wind Chaser]

...the 20, although that guy is not as heavy as the 12...

  From what I've read, the RS-20 weighs 18 lbs.

One thing, I wonder if the meter has any effect on sound quality?  The current meter specifically.

That's a good question, but I'm sure it will sound better than the SMPS.

In any case, I believe the SMPS in my 3116 is 24 volts. How much power output can one expect to lose by using a 12 volt regulated power supply?

[randytsuch]

From what I've read, the RS-20 weighs 18 lbs.


That's a good question, but I'm sure it will sound better than the SMPS.

In any case, I believe the SMPS in my 3116 is 24 volts. How much power output can one expect to lose by using a 12 volt regulated power supply?

From the TPA3116 datasheet,
At 1% THD (they have curves at 1 and 10%)
8 ohm load
24V = 33w
13.8=11w

4 ohm load
24v = 60w
13.8=20w

I used 13.8V because that's what the Astron puts out, unless you open it up and adjust it.  I think it can go up to 15VDC, but you won't gain much power.

So you'll be about 1/3 of the power you are at now.  I doubt you'll miss it, but that is just my opinion.

Randy

[Wind Chaser]

Thanks, Randy. That's very helpful.

[lacro]

Absolutely!

[Poultrygeist]

I am writing to confirm that linear power supply makes a big difference in my TPA3116 sound. I bought a cheap Astron RS-12A just to try and I am quite surprised by the results. $30 well spent!

Of all the mods you've made is this the best?

[moomilk]

Hi everyone, just by the looks of the components can anyone guess which one of these supposed to sound better?
This one I found on eBay:
http://www.ebay.com/itm/Latest-HIFI-2-0-Stereo-Output-Digital-Power-Amplifier-TPA3116-50Wx2-by-WLX-New-/351171255592

or
SMSL SA-36A Pro


I like the inductors and minimum use of SMDs about the first unit, but maybe there is something I don't understand about SMSL SA-36A Pro chip implemention? ,))
Going to use with 24v power supply,
Thanks!

[rhing]

Hi everyone, just by the looks of the components can anyone guess which one of these supposed to sound better?
This one I found on eBay:
http://www.ebay.com/itm/Latest-HIFI-2-0-Stereo-Output-Digital-Power-Amplifier-TPA3116-50Wx2-by-WLX-New-/351171255592

or
SMSL SA-36A Pro

I like the inductors and minimum use of SMDs about the first unit, but maybe there is something I don't understand about SMSL SA-36A Pro chip implemention? ,))
Going to use with 24v power supply,
Thanks!

The film caps at the signal inputs of the WLX amp are only 0.1uF Wima MKP10 caps. I'm not sure if you'll get much bass response. Most TPA31xx amps have at least 1.0uF caps. The SMSL SA-36A Pro has 3.3uF caps.

If the gain of the amp is set to 26dB, the Z (input) = 30kohms. Using the formula for cut-off frequency, 0.1uF for C (input) yields a cut-off frequency of 53Hz.

If the amp's gain is set to 20dB, the Z (input) = 60kohms. 0.1uF for C (input) yields a cut-off frequency of 26.5Hz.

Per the Texas Instruments TPA31xx technical data sheet:

"If a flat bass response is required down to 20 Hz the recommended cut-off frequency is a tenth of that, 2 Hz."

 

Whether the caps are genuine Wima MKP10 film caps or not, this amp might be bass-challenged.

Someone on diyAudio.com mentioned that these Wima caps are bypassing electrolytic caps on the inputs. If that is the case, then what I calculated above will not apply. You may want to contact the WLX seller and confirm whether this is the case or not.

[Trikster]

I was looking at the TI Eval board and noticed that is has speaker protection built in.  My guess is that it is similar to the Audiobah green board.

http://www.ti.com/product/TPA3116D2

[Markvdv]

I was looking at the TI Eval board and noticed that is has speaker protection built in.  My guess is that it is similar to the Audiobah green board.

http://www.ti.com/product/TPA3116D2

I don't think TI EVM uses mute on start-up. It is switch controlled.

Layout of TI EVM gives an indication how critical things mentioned in datasheet could be achieved. Decoupling 2+2 ceramics are under heatsink TI EVM, next to bootstraps for AC1308 (audiobah). TI EVM also has a snubber filter next to bootstraps, AC1308 omits this snubber (but has PBTL-vias under bootstraps that could be used to connect 330pF/10ohm in a neat fashion). DC power traces TI EVM cross outputsignal, AC1308 DC power traces cross inputsignal. Etc

BTW heatsinksize AC1308 is same as TI EVM looking from top.

[Folsom]

The eval board is also like $160 or something ridiculous.

[Trikster]

The eval board is also like $160 or something ridiculous.

Yeah, it isn't cheap at $149.  The regular boards are out there though and pricing seems quite nice.  On Monday I am going to try and order one of the actual TI boards (from what I understand, they are just like the eval boards, we'll see).

[Markvdv]

Yeah, it isn't cheap at $149.  The regular boards are out there though and pricing seems quite nice.  On Monday I am going to try and order one of the actual TI boards (from what I understand, they are just like the eval boards, we'll see).

Well then you can rapidly switch between 400khz-1200khz and between other options. Specs could be close to datasheet, but not better. Nice reference point if you like modding other boards

[Folsom]

I would love to know how the higher switching sounds.

[Folsom]

Maybe I'll do some tracing modifications for science... 

Has anyone tried this? My board I think has all three AM legs connected to ground. I haven't seen in the documentation whether to change it, you simply disconnect them or provide PVCC source.

Nevermind, the EVM board schematic makes it clear, you connect it to PVCC. I think I can just jumper 12 & 13 

[Folsom]

Never mind, 13-15 are one pad on my board. Damn.

[Trikster]

What does the switching speed do for the sound?

[Folsom]

No idea, yet.

[Markvdv]

What does the switching speed do for the sound?

I mentioned "but not better" befor. TI's Paul Chen designer of TI EVM puts it like this:

EVM is a good starting point. Select inductors that does not saturate at peak current. Any loss of inductance of more than 3% up to the peak load current can increase THD. Use at least X7R or better capacitors (MKP/MKT).

You may also use AM0, AM1, and AM2 to select higher PWM freq which can provide slightly better THD+N at the expense of higher idle current.

reg,

Paul Chen