6 Channel TPA3116 + DSP

Hi Guys!
All is up and running, crossover, volume, DAC etc. The problem is with the DAC output though. It has intermitant clicks/pops when the volume of the DSP board is turned up.

When the DAC is connected to the sub channels do you get the clicks/pops when you change either the master volume or the sub volume? Do the clicks/pops stop after the volume change stabilizes?

Maybe you've already tried this, but I'd create a project that only has the sub volume part and try that. My 3e DSP is currently out of service (need to order a replacement crystal) and I'm in the middle of building two pairs of speakers.
 
Hey Ed.

So I doubled checked this and made a fresh project with 3 way crossover going straight to the 6 outputs and the same thing happened without any volume control leading me to (maybe primitively) think it is some sort of either a: data corruption or b: data miscommunication.

Thanks for your input!

Alas, there is always using the second3E board for the two channels of sub but it makes global volume control a fiddle with a two-gang pot to control both boards, a slightly more complex internal audio wiring situation and global EQ will also be a fiddle.

Luckily my friend will now be using an Amazon Dot with has rudimentarty bass/treble so I can just have a sub level and measure the room then set and forget some light room correction.

However, it would be jolly nice to get this going as it is a super neat solution! :)

Someone sent me this that starts on post 29 about using a similar board (which I have 2 of) and I could follow his directions for his settings/board combo. He uses the naff sure board tho!

Tutorial: LowBudget 4Kanal SureDSP mit DIY-Anteil fürs Autoradio, Projekte der Nutzer - HIFI-FORUM
 
Hey Ed.
However, it would be jolly nice to get this going as it is a super neat solution! :)

So you're always getting clicks/pops on the DAC (try a super simple project that goes straight from inputs to the external DAC)? I've had clicks/pops on the DAC when I have had grounding issues. Not sure if you're getting the DAC's +5V from the 3e DSP or from a separate 5V source. Could you post a diagram showing your power supply/supplies and the power/ground connections?
 
Thanks Ed! Yep, tried all that. I tried powering with a USB phone charger via DC-DC isolator. Still the same. (interested in your speaker builds btw...)

BUT! I did have some progress, two steps forward one step back.

So, I tried the same arrangement with the other little DAC board and it worked fine, for a bit. Then I strted to get the same click/popping. It was also cutting in and out but after a lot of fiddling I tried it with a single ended input to the amp and it worked fine. I thought I was going to be on the recieving end of a nasty ground loop but I think all my other protection in this respect has helped and it is dead quiet.

The step back is that I have now lost 6db of gain without the balanced input. I may look at taking the gain on the TPA3116 up 6db but I'm worried about noise and the on/off thump from the DAC as this an unattenuated line straight to the amp.

If I can squeeze one in I might put a little relay/DC protection board in but it's cramped in there as it is.



So, why was it failing? It seemed to not liked the parralelled differential output to the 2 amp channels. This is beyond my knowledge level but the previous DAC didn't work in SE so maybe it got knackered over time?

Onwards!
 

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Hi,



I'm sorry to just jump in on this thread, but I'm building a project tomorrow and grahamgraham's dead amplifier has me worried.


I had planned to feed all inputs on this amp, but for now the Sub and centre won't be connected. Is this going to kill the amp? What actually causes this? Does it just need a load to stop voltage from floating up, ie can I use a high value resistor?




Thanks.
 
Hi all!

So, it's completely finished and given to my friend, Sally! This system is replacing a Sonos boombox style thing so is a big upgrade for her. It's primary use is for every day music and podcasts and music for entertaining (with ample headroom for parties!).


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I have a confession to make, I managed to knacker the other TPA3116 board that Ed very kindly sent me and I had to make a decision so I transplanted part of a 2-way system into this and added a third amp board as I needed to get it done.

I also had some issues with the added DAC board to the single 3E DSP board which I spent a long time trying to remedy but couldn't get to the bottom of it so I went for the less elegant fix of using two DSP boards. (the problem was that the DAC board kept dropping out and nothing I did would stop it. I think it may have something to do with the flat I am in and the dirty mains power sending white goods dirty power into the earth/ground - I could be wrong).

It now consists of:

2 x TPA3118 boards (one set to 20db for tweeter and the other 26db for mid)
1 x TPA3116 Sanwu board set to 26db for the sub.
2 x 3E DSP boards
1 x Echo Dot


There is a dual gang pot controlling master volume on both boards and then a second pot controlling a second volume subwoofer board giving the sub and vol control on the front.

The subwoofer is a dual-opposing design so it makes no vibrations on the cabinet it will be in at my friends house. I used two Tang Band W6-1138SMF and it really bumps.

SB Acoustics SB19 Tweeter
Peerless HDS 4" Midwoofer
Tang Band W6-1138SMF x2 in a sealed cab.


I ended up making some bad layout choices in the amp which I had to patch up as I went along. The main one was that I stacked two TPA3118 boards and they go very hot from their proximity, especially the top one as heat goes up. On top of the rear exhaust fan I added a 4cm fan to blow air in between these boards and that keeps them very cool. I used two DC regulators to control the speeds of these fans.

Both DSP boards and the fan power circuit have DC isolators on them (not sure if I needed the DC-DC isolator for the fans but I had the space so I thought why not?)

As much as I love them I wanted a more elegant solution than the Wago connectors for power but they are well within rating and they get used in installation. They are epoxied on to the chassis.

Initially, because of the wooden chassis for the amp it stopped my wifi working when close to the router. I did some research and found the general consensus is that cheaper boards oscillate and the speaker cables are antennas and a ferrite bead helps this. I put on a bead and it worked! I have to admit I was skeptical but I can't argue with a result.

All the internal cables were crimped by me which was my first time doing it! It look ages! I give a big recommendation for the Preciva Knipex clone crimper. It made it super easy and was dirt cheap although one day I'll buy the real-deal.

I'm very happy as is my friend!

Thanks for everyone's input and help that makes this such an enjoyable pursuit! :)
 

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The system is a true bookshelf style speaker. It wasn't made for critical listening and I wasn't concerned with the lump on-axis baffle issues as once you are off-axis they mooth right out.


Here are measurements of just the satellite speakers before high-passing:


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Thanks! And no, unfortunately I don't know but I chalk it up to me and my tinkering. Others in this thread have used the board to great effect and had I had the time to re-order from china I would have. I did struggle desoldering caps from Eds board, maybe I heated something up too much?
 
Looks like the system turned out great! And don't worry about frying the amp I sent you, at least it died in the service of DIY. :D. For your next SigmaStudio project try out using the AutoEQ control. It can import your .frd files and will automatically generate the biquads to flatten the drivers response so you can apply standard crossovers. It's not without some warts and problems that you have to work around though. Here's an update of the AutoEQ Wiki where I added comments and work-arounds to most of the problems.
 

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Old thread, I know, but I have the same amplifier and I don't understand one of the input pins

My version of the amplifier (3 screws to the heatsink) has 2 connectors on the front, one labelled IN!, IN2, IN3, IN4, CE, SW, AGND, and that's pretty self explanatory.

The other is a 3 pin connector labelled STB, GND, +PREVCC. The first 2 are pretty self explanatory, Standby and another GND. But I cannot find anything on the +PREVCC

I have not yet removed the heatsink and tried to follow the path. I can see that +PREVCC goes directly under the heatsink
 
Old thread, I know, but I have the same amplifier and I don't understand one of the input pins

My version of the amplifier (3 screws to the heatsink) has 2 connectors on the front, one labelled IN!, IN2, IN3, IN4, CE, SW, AGND, and that's pretty self explanatory.

The other is a 3 pin connector labelled STB, GND, +PREVCC. The first 2 are pretty self explanatory, Standby and another GND. But I cannot find anything on the +PREVCC

I have not yet removed the heatsink and tried to follow the path. I can see that +PREVCC goes directly under the heatsink
Answering my own question after removing the heatsink: +PREVCC is simply connected to the + power supply connector. So it's the power connection for the pre-amplifier, if needed.
 
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