TPA3116 for sub?

[surfstu]

I have a YJ version 2 (Danzz design) as found here: TPA3116D2 Boards - diyAudio

I also have a sealed sub driver from my car (either 10" or 12" - won't know until I dig it out of my garage in a few weeks) and it was half decent when I bought it. It has not been in my car for years and I want to finally catch up and put some bass in my home.

I've slowly moved from Gale 401's to Celestion ditton 66 and then tannoy gold lz's and now I'm at kef reference bookshelf speakers - don't think I can get any smaller now. Anyway, i miss the bass!

I'm only dipping my toes in at the moment and am wandering how i can power the car sub that I have. Are the TPA3116 chips powerful enough with a 19V laptop supply rated at 4A or am i dreaming?

I understand that these amps are already in some kind of bridged mode? But it is a stereo amp, can the two channels be combined into one to double the power? Can anyone tell me how to do this or point me to a better solution?

cheers

Stu

 

[xrk971]

You can modify the amp to PBTL mode and that doubles the power to 100watts but only for 2ohm load. You may want a 26 volt supply or a 12v to 24v step up converter. A decent 95dB sensitive 2ohm DVC driver with a 100w can get pretty loud in a car.

Check out the massive 3116 thread for tips and also the Wiki for tips on how to mod the amp.

 

[sk971]

I have a blue board with large 2200uf Panasonic FM caps which was running a sub at 16v out of one channel (ie it wasn't PTBL) it didn't shake the walls but the low end was impressive.
The larger FM caps seem out of favour because they are not so smooth in the treble region but for bass only applications they may be ideal.

 

[xrk971]

I power a 99dB/@2.83v sensitive bass horn (35Hz to 300Hz) with mine and it DOES shake the walls when turned up past 12 o'clock and still sounds clean. I am using the tiny Panasonic 330uF 25V SEPF OSCON's. Still in stereo mode but both channels driving multiple voice coils.

 

[surfstu]

Thanks, I have two of these boards and all the mods suggested in the wiki that I ordered months ago and have not had time to do, think I've got the panasonic oscon 330uf for the DC power caps.

Also have the bootstrap snubber mod but unsure how effective this will be on the amp that i will use for sub duty.

Also I don't understand what PBTL mode is and what it means regarding 2ohm drivers. I will report back when i check if i have 2ohm drivers or 4ohm drivers.

Also have to work out how i will get mono from my stereo 12b4 preamp, can I send the 3116 a stereo signal from the pre and then just implement a summing circuit between the 3116 and the sub?

 

[xrk971]

PBTL is parallel bridge tied load and uses both left and right circuits as one (only 2 inductors) in mono. There are some switches and a few solder bridges that have to be implemented.

A summing junction pre amp is one way to get mono. It can also be done passively with a split transformer.

 

[DUG]

To see the difference between an IC connected as a BTL and the same IC used in a PBTL circuit look at Fig 37 on page 26 of this data sheet:

http://www.ti.com/lit/ds/symlink/tpa3116d2.pdf

The top part is BTL (stereo) and the bottom is PBTL (mono).

Some IC's come as stereo single ended and can be configured as BTL mono by driving the second channel with an inverted (180 deg) signal of the first channel.

 

[surfstu]

Great, how would other people suggest I approach getting the signal from a valve preamp into a 3116 amp and onto one sub. At some point summing needs to occur to have both left and right channel s presented to a single sub,

Cheers stu

 

[DUG]

Great, how would other people suggest I approach getting the signal from a valve preamp into a 3116 amp and onto one sub. At some point summing needs to occur to have both left and right channel s presented to a single sub,

Cheers stu

Here is what I did.

 

[surfstu]

Thank you! This is what I'm looking for, although I still don't quite understand the circuitry. Still relatively new to electronics. Also, I do not want to run a Hpass filter for the main outs, the pre feeds a homemade valve power amp that I made and then onto some bookshelf speakers, I only want to add a sub but not provide any less bass to the bookshelfs.

From what I can tell, the diagram from Dug the +right channel and the +left channel to the 3116 in PBTL mode, I've probably got it wrong but don't we need a common ground also?

cheers Stu

 

[surfstu]

Thank you! This is what I'm looking for, although I still don't quite understand the circuitry. Still relatively new to electronics. Also, I do not want to run a Hpass filter for the main outs, the pre feeds a homemade valve power amp that I made and then onto some bookshelf speakers, I only want to add a sub but not provide any less bass to the bookshelfs.

From what I can tell, the diagram from Dug the +right channel and the +left channel to the 3116 in PBTL mode, I've probably got it wrong but don't we need a common ground also?

cheers Stu

 

[xrk971]

Here is what I did.

Dug,
How did you implement these circuits? As a custom PCB of your own design using op amps, or by off the shelf pre-amps? If you made a circuit for this, I think a lot of folks would be interested in it. Maybe another group buy?

 

[DUG]

Dug,
How did you implement these circuits? As a custom PCB of your own design using op amps, or by off the shelf pre-amps? If you made a circuit for this, I think a lot of folks would be interested in it. Maybe another group buy?

I made a three way board but only use it as a two way. The space for caps is OK for what I used (280Hz) but would have to be redone for lower frequency.

Sorry for the off topic but I will throw out this question.

Where should I post my build of a boombox that uses the crossovers mentioned, a DUG-1 and DUG-3 class D amps, a single Goldwood GW-10PC4 (4R), and a pair for each side of Faital 3FE25-4R (sort of FAST)?

 

[xrk971]

I made a three way board but only use it as a two way. The space for caps is OK for what I used (280Hz) but would have to be redone for lower frequency.

Sorry for the off topic but I will throw out this question.

Where should I post my build of a boombox that uses the crossovers mentioned, a DUG-1 and DUG-3 class D amps, a single Goldwood GW-10PC4 (4R), and a pair for each side of Faital 3FE25-4R (sort of FAST)?

I would post that in the Full Range speaker forum as that is where FAST projects reside. Sounds interesting and I know a lot of people would benefit from a good basic XO that you have developed for a FAST implementation.

For those who do not know, FAST stands for Fullrange Assisted Subwoofer Technology or basically a 2-way speaker with a low freq XO circa 100Hz to 400Hz that uses a high passed full range driver for the top where coherence and imaging are important and lets a woofer handle bass where lots of excursion is needed. This really lowers distortion on the fullrange and lets it get more power.

3FE25r4 is a great driver - I use those in a Karlsonator.

 

[surfstu]

Could someone please enlighten me as to Dugs circuit. As I need to sum the left and right channels and provide some form of lpf, it seems dugs circuit does this? Could someone tell me which components I would need to do this? Thanks in advance, stu

 

[xrk971]

Look in full range forum. DUG made a thread there where he will describe the circuit.

 

[Buehgemeiste]

i use a danzz-board for my home-sub, too.
i've modded it to pbtl, 3.3uF input caps, chemi-con KZM 470uF power-caps.
i put a summer, a 3rd order mfb low pass and virtual ground from a voltage divider on perfboard (with cheapo TL07x opamps).
(i've tried with subsonic filters with high Q, 24db filters and so on, but a simple 18db simply fitted best.)
all that went into an unused hdd-housing, with a volume pot at the frontpanel.
i simply looped the signal through a 4x rca-panel, to feed my already existing active stereo with the fullrange signal.
(i'm lucky that i can eq the bass on that stereo to a good fitting value. a high pass was the original plan, but wasn't necessary.)
there's absolutly no magic in doing that and result is more than satisfying.
with my 10" woofer (Mivoc AWM 104) this system is on par with much pricier solutions some of my friends paid into (i see the disbelieve in their eyes when i tell them what i actually paid for that earthquake).

but:
for my outdoor party-machinery i prefer higher power amplifiers.

so:
go with the 3116 for your home sub!
try an analog filter on perboard.

 

[surfstu]

Thanks Buehgemeiste, still trying to get my head round it. is the virtual ground and voltage divider there to give you + and - DC rails for the opamps of your filter?

And the summing still confuses me, my pre will send fullrange to my power amp, no problems with that.

My Pre will also send stereo signal to the 3116, so how did you sum the left andd right channel?

cheers stu

 

[surfstu]

Hi buegermeiste, that is exactly what I want to do. Would be very grateful if you could post the circuit diagram for the summer, 3rd order lowpass that you made and the opamps that you used,

Cheers stu

 

[Buehgemeiste]

Hi surfstu,

i didn't find the diagram which shows the exact circuit.
this week i'll have a bit of spare time and i'll redo that with lt spice.
you might want to have a look at this site:

3rd order Multiple feedback Low-pass Filter Design Tool

i highly recommend balanced outputs on the preamp (that will be in the diagram, no expensive transformer) and balanced input on the 3116 module (i guess that's possible with the board you use).