I have two wired up for stereo on the workbench now using one power supply. The sound is good. I just share the power with them both from an on/off switch. The input grounds are shared as well. Easy and sounds good. What I would like is what simple and inexpensive upgrade is recommended to get better than muddy. Or what is the mods suggested to improve sound, possibly in order of most improvement. It is hard for a novice(me) to study thru this thread and decipher what is best, what has actually been done and proven, and what is just proclaiming a "what-if" mod or configuration. And then exactly how to implement.
Fit input transformers, if you're not feeding the amps with a balanced signal the transformers will help reduce ground noise (muddiness).
Second, and this depends on the amount of output power you need, fit output transformers.
Those two changes worked the best in raising the SQ from my TDA8932 amps.
Of course transformer mods can either be simple (buying) or inexpensive (making) but never both 😛
Second, and this depends on the amount of output power you need, fit output transformers.
Those two changes worked the best in raising the SQ from my TDA8932 amps.
Of course transformer mods can either be simple (buying) or inexpensive (making) but never both 😛
Power output is not the end all for me. I just want to take a sip of some fine wine that I could never afford to buy. Been playing and enjoying these amps, 3116, 3118, 8932, 2497. All are nice in stock form. Each do there own thing and are cheap to implement in stock form. Have built about a dozen systems or so. Started with hivib3n computer system and L2020A+, and each new amp is a walk down a different path. I just want to try MORE, MORe! Thanks Abraxalito, but I am too stupid to take "input transformers,output transformers" and figure out what to purchase and how to utilize them to improve the sound of these board. Something like buy these caps and connect them together like this and attach them to the + input to the board would really help. I mostly give to people to see them happy, not selling any. Also have in every room in the house! Thanks for reply, I have to try to take to next level for the wow factor, and hopefully end this addiction!!!!!
I'm the same way. While I respect the science of how they work I could care less. They are cheap and fun to play with. It would be nice to have a guide for newbs like me so we aren't asking repeated questions.
Not exactly newb, but not EE either. I fully respect the innovation, engineering that smarter than I people put into this diy audio world. Just that sometimes I feel that it's a ******* contest between designers to see if they can lay out the most technical electronic speak possible. It does have a learning curve for sure but plainer language/layout is for us humble wannabes!n thanks for all the work that this community provides. It is like I can see it, smell it, even salivate over it all but have a fence in front of the dining table that leaves me hungry! I see that Daniel has another thread for dual stereo boards and some simple? Mods but it jumps around so much I don't get which mod and how. The amp boards are even about half price now from when first written. Just need simple cuz I'm stupid!?
If you're asking the simple question I think you are, just do this:
Run a wire from your power supply's V+ to the first board's V+. Run another wire for the power supply's GND to the first board's GND.
Then simply run a wire from board one's V+ to board two's V+. Then another wire from board one's GND to board two's GND.
Alternatively, you could run two wires out of each of V+ and GND from your power supply. One pair of wires (V+, GND) goes to board one, and the other pair goes to board two.
Both accomplish the same thing, just choose which ever is easier and/or cleaner.
Some class D amplifier chips (e.g. Texas Instruments tpa3116) have master and slave modes. In that case, you still power the two boards as I mentioned above, but would additionally configure one board as master and the second as slave, and run an extra signal wire between the boards. But even then, you don't have to do that---I never have (just did it the quick and dirty way described above). At least with the tpa311x amps, I've only read of one person who actually had to use the master/slave mode functionality.
But I'm not sure if this tda8932 chip has the master/save settings or not. But even if it does, it doesn't look like these cheap boards have solder pads/holes for them. If that functionality does exist, you'd have to solder directly to the chip pins.
Point is, I wouldn't worry about it. Just wire the power in parallel as described above and see how it goes. Before I killed my tda8932 boards, that's exactly how I had them wired up, and they were fine.
Yes, that's it! Is splitting the input about the same? I just want to verify since it takes so long to get these. I'd hate to fry one.
As long as you get the voltage polarity right (positive to positive, negative to negative) you are very unlikely to fry the board using either method.
I'd favor giving each board its own run back to the PSU, rather than chaining them, because I'm lazy, and that's simpler than working through wether it's actually likely to make any difference.
I'd favor giving each board its own run back to the PSU, rather than chaining them, because I'm lazy, and that's simpler than working through wether it's actually likely to make any difference.
You shouldn't need to worry about splitting the input. I think all the boards I've seen in this thread are mono. So left channel goes to one board, and right channel goes to the other board.
If your source has three pin output (L, R, GND), then you would need to split the ground, so you can do L+GND to one board and R+GND to the other.
I thought he was referring to the power input.
Either way, he should have the answers he needs.
Either way, he should have the answers he needs.
We did test these as durable. During the tests, they were not used smartly. Come to think of it, I couldn't say if these chips do anything expected of Class D products.
After I managed to break the two red boards, I thought I'd pass on these amps. But I kept coming back to this thread, and couldn't help myself. I bought a couple of the "Sanwu" boards, and got the "BT" chips. I didn't do any mods this time, just hooked them up to a cheap SMPS. I have to say I really like the sound coming out of these. I can't put my finger on what I like. I have more tpa311x amps than I care to admit, and while the TI chips might be a bit more detailed and have slightly "blacker blacks", there's some charm on these tda8932 chips that makes me smile...
...Or maybe it's just the price. See the pics for my current setup, hacked together quickly for testing. I spent under $8 on the two tda8932 boards, just under $11 for the PSU. I spent another $10 or so for better caps for that SMPS. So for $30 I have what I think is a real keeper. Waiting on a cheap case to put it all in.
...Or maybe it's just the price. See the pics for my current setup, hacked together quickly for testing. I spent under $8 on the two tda8932 boards, just under $11 for the PSU. I spent another $10 or so for better caps for that SMPS. So for $30 I have what I think is a real keeper. Waiting on a cheap case to put it all in.
Attachments
The audible charm is placidity. It does have electronic means for charm built in. What we have here is an "excellent mid-fi" amplifier and the friendly sound is why they exist and why you might need one. The cost is slightly lower resolution, as you have mentioned. It happens to be the cost of decreased listening fatigue (as well as a HUGE list of other practical beneficial features). High gain is also decreased negative feedback, and so that the relevant costs (only one) and benefits (very many) apply directly.
With most amplifiers, the fix would be to trim the gain as low as possible without souring the tone. However, that is not relevant in our case, with a fixed gain amplifier.
The one means provided for adjustable performance (including resolution) is the difference between SE mode vs BTL mode.
This then leaves bi-amp as the only remedy for the resolution cost of using this ear-friendly amp.
Therefore, I have an experiment for you. . .
Try a basic: Get a tweeter (any speaker 2" or smaller) and a 1u cap (it may need to be less or have a series resistor at tweeter's opposite pole). Situate the cap at amplifier power ground and use that cap for tweeter+. Attach tweeter- to ONE of the speaker output terminals (don't use both speaker output contacts for this experiment--we are doing return to ground with series cap for dc block). You'll have to experiment for phase to see which one of the speaker output taps you should use. For this fast-n-dirty experiment, position the tweeter face up, on top of the speaker, to achieve a physical 90 degree separation. This not exactly the best way to bi-amp, but I think it will work well and is very fast to do. Also, I did try it, with just one chip.
So, what do you hear? Do you hear hi-fi?
P.S.
Please also try your TPA311x collection as tweeter-only amplifiers, in a bi-amp scheme with TDA8932 on bass and mids. That collection that you're not using? Those might be really useful as tweeter amplifiers.
I am interested in this phase tweet/bass/mid biamping thing as well. Could u give a pic or sketch of this setup please? I have extra 3118 and 8932 to play with, as well as drivers. Sounds interesting, but for me a bit confusing. The 8932 plays bass real good but something is missing in the entire spectrum. Where the 3118 plays flat and lacks true bass and seams constrained or compressed or something? Would u need separate power suplies for each amp or pair of amps? I am actually researching gain clone/card and or other architecture s to try and get cheap Nirvana. Difficult as I have never heard them to know if they are better than classD and most info if from10yrs ago or more? Thanks, cheap fun!!!
My inbox got so broken. Even so, I was very glad to hear from you. Those wattage levels that you quoted require such a goodly heatsink effort that I can't guarantee it will happen in real usage. Sure do wish that I had something more important to say, but that was it for now.
I just wanted to say that I am really happy with this little amp. It is more than enough for my "second" system (for daiyly listening).
If I want to really rock out, I have my QSC GX5 and my Cerwin Vegas.
But for casual listening, this amp is great with my Grundig Box 5600 speakers and my 18" DIY sub ( turned way down low).
If I want to really rock out, I have my QSC GX5 and my Cerwin Vegas.
But for casual listening, this amp is great with my Grundig Box 5600 speakers and my 18" DIY sub ( turned way down low).
Can do, but try my experiment first:
Get a couple of tweeters (for right and left), if paper then 2" or less or if dome then 3/4th's" or less. And get a pair of capacitors in the range of 0.68u to 1u.
The position for the added tweeter is atop the speaker facing up.
The electronic hookup is that the little cap that I've suggested (for DC blocking) goes series between power ground and tweeter positive; and, then, in that case, the tweeter negative is connected to only One of the speaker terminals (experiment to find which one sounds better).
That experiment is to quickly unscrew the resolution costs of bridging in a most inexpensive way. Although quite likely to work, it couldn't work every time because of broad variety in speakers. Even so, it is a minimal cost way to explore and probably attain the resolution that you wanted to hear from the bridge amplifier that you already own.
If this experiment doesn't work then we need to find out why. . . or, if it does work, since it probably will, then we can go on towards exploring somewhat more elegant (and adaptable) bi-amp approaches (which are of some value with bridge amplifiers; but, only if you don't run the tweeter from bridge mode).
When I've tried this easy cheap experiment, all of the examples worked; albeit, some of them worked just slight more attractively than others. I do think that the odds are high that the matter, along with the audio, could become quite clear at minimal expense.
Thanks Dan, let me see if I got it right? I take the 8932 and connect a cap say1.0u to the amp board as you suggest. Do I use the same amp speaker outs for the woofer? One amp for both tweeter and woofer in a two way or do I use separate amps for each driver one normal and in the way you suggest? And, mount the woofer in conventional way, front of baffle and then mount the tweeter on top pointing up? I have done the other way- woofer pointing up and tweeter forward like O'Riley style. I will do as you suggest for the learning aspect if nothing else? Please let me know if I am on track? Thanks the completed speakers using the 8932 are long gone to 9 year old grandson with passive 6.5 sub, and coax 4 inchers in 8" spherical enclosures. So I have a clean slate to start a new project! Woopwoop