I'm on a slow pace, multi year hobby project to make a combination of 3-way speakers without analog crossovers, and class D amps with DSP to power them and do the crossovers / filtering.
I started out ordering a 3x200W T-amp board:
Sure Electronics AA-AB35281 3x200W Class D Audio Amplifier Board - T-Amp
And a lowcost DSP:
Dayton Audio DSPB-K DSP Kernel Board and DSPB-KE Kernel DSP Expansion 2-In 3-Out
For what it's worth, I'm powering them with relatively expensive SMPS board:
SMPS600RS | Connex Electronic
But I found out this amp board is pretty noisy, and when connecting the DSP board the noise is increased significantly...
IMHO, these parts *might* be usable for a boombox, but not for a home hifi setup.
To be fair, I've been warned on this forum about using these parts, so I'll add this to my "learning experience" list 🙂
So now I'm looking into getting better quality parts, and I keep reading good stuff about 3E Audio boards (on diyaudio.com for example).
Has anybody here ever put together an amp using 3E's DSP and amp boards?
I started out ordering a 3x200W T-amp board:
Sure Electronics AA-AB35281 3x200W Class D Audio Amplifier Board - T-Amp
And a lowcost DSP:
Dayton Audio DSPB-K DSP Kernel Board and DSPB-KE Kernel DSP Expansion 2-In 3-Out
For what it's worth, I'm powering them with relatively expensive SMPS board:
SMPS600RS | Connex Electronic
But I found out this amp board is pretty noisy, and when connecting the DSP board the noise is increased significantly...
IMHO, these parts *might* be usable for a boombox, but not for a home hifi setup.
To be fair, I've been warned on this forum about using these parts, so I'll add this to my "learning experience" list 🙂
So now I'm looking into getting better quality parts, and I keep reading good stuff about 3E Audio boards (on diyaudio.com for example).
Has anybody here ever put together an amp using 3E's DSP and amp boards?
it is very important lesson and applies to most things, cheap and good are two different products 😉 Sometimes selfmade would be the best, and cheapest, if one doesn't count the spent hours. If hours are counted, selfmade makes sence only when one needs a special thing that is not available anywhere. Or as a hobby where time and cost don't really matter 🙂
Anyway, saddest thing is that there is plenty of useless cheap junk sold online, then shipped around the world and after first try ends up in the trash... my advice to anyone is: save up and buy a quality product, skip the cheap, save yourself from misery, save the planet 😉
Anyway, saddest thing is that there is plenty of useless cheap junk sold online, then shipped around the world and after first try ends up in the trash... my advice to anyone is: save up and buy a quality product, skip the cheap, save yourself from misery, save the planet 😉
Good advice and hopefully I will remember it the next time I'm ordering something because I've had plenty of purchases follow that same exact path. I have totes full of 'inexpensive' amp boards and dacs that is just a stopping point before they go in the trash. Amps that hum, amps that pop loudly on power up etc. I've also run into plenty of cables, connectors and parts of all sorts that look good in the pictures and are junk when I get them.
It is easy to think some of this will perform well with all the hype about low cost components out there but the old 'you get what you pay for' still generally applies. Be it in performance or longevity.
It is good to remember that often the cheapest purchase is the one that lasts you the longest. A $300 component that lasts a decade is super cheap compared to a $100 one that lasts a year and a half.
Last edited:
There's a been a discussion over on ASR, which the 3eaudio guys chiming in on (a little). They also released the Sigma Studio files so one of the early purchasers did some DSP based EQ on his amp. There are issues with the bluetooth unit, but 3e says they have a firmware fix.
3e Audio SY-DAPx002 TPA3250/TPA3255 DSP Amplifier | Audio Science Review (ASR) Forum
3e Audio SY-DAPx002 TPA3250/TPA3255 DSP Amplifier | Audio Science Review (ASR) Forum
Yeah, I don't know nothing about 3e quality so my intent was not to bash them. I've looked their offerings many times but still haven't made a purchase. It is very tempting to buy the less expensive product when there isn't too much money to spare.
Anyway, I've bought some Sure (wondom jab) products since they felt a bit better chinese product than the sub 5$ TPA3116 stuff in ebay or aliexpress and was available from european resellers. Surely they must be a good product, right?! Bluetooth stopped working in few days, otherwise they've been working hundreds of hours. Except the noise is bad due to bad design. Bought the rechargeable battery extension, but really cannot use it since for charging one must swap some wires.. Good on paper but really bad implementation. i believe those jab boards I have have had many revisions, hopefully the newer ones are better. Anyway, already few hundred euros 2.1 amp project and it is barely worth it despite all the cool features.
I've felt into the trap many times and still do, buying products that make me feel bad and /or sad. Gotta avoid bad purchases. Gotta remember that any commodity we buy will endup in a landfill someday, every single one (altought some of them get recycled, in Africa!) There are a lot of products available that have no meaning to anyone when they are made, consumed and recycled/reused. Some of them really arent even consumed (I've recycled clothes I never wore!). What a waste.
And then there are products that are made by love, handled with love and eventually handed to the next generation who might still appreciate the value for years. We all can make a difference buy choosing what to buy, what to support.
Sorry about the rant but eventually this is the most important thing, be happy and have fun! 🙂
Anyway, I've bought some Sure (wondom jab) products since they felt a bit better chinese product than the sub 5$ TPA3116 stuff in ebay or aliexpress and was available from european resellers. Surely they must be a good product, right?! Bluetooth stopped working in few days, otherwise they've been working hundreds of hours. Except the noise is bad due to bad design. Bought the rechargeable battery extension, but really cannot use it since for charging one must swap some wires.. Good on paper but really bad implementation. i believe those jab boards I have have had many revisions, hopefully the newer ones are better. Anyway, already few hundred euros 2.1 amp project and it is barely worth it despite all the cool features.
I've felt into the trap many times and still do, buying products that make me feel bad and /or sad. Gotta avoid bad purchases. Gotta remember that any commodity we buy will endup in a landfill someday, every single one (altought some of them get recycled, in Africa!) There are a lot of products available that have no meaning to anyone when they are made, consumed and recycled/reused. Some of them really arent even consumed (I've recycled clothes I never wore!). What a waste.
And then there are products that are made by love, handled with love and eventually handed to the next generation who might still appreciate the value for years. We all can make a difference buy choosing what to buy, what to support.
Sorry about the rant but eventually this is the most important thing, be happy and have fun! 🙂
Last edited:
Sorry for posting of topic previously. I'm also in search for Class D amps and DSP for a threeway speaker project 🙂
Yes I have used the 3E DSP board and an additional I2S DAC along with 3 of their amp boards to make a battery powered 6 channel amp box:
Additional Input and Outpus on 3e Audio ADAU1701 DSP and Aliexpress
I'm overall quite satisfied with the quality of the amps and DSP, with 100dB/1w speakers noise is acceptable. If I where to say there was a weak point It would be that the DAC/ADC built into the DSP IC have poor specifications compared to stand alone DAC/ADC ics and so (especialy in a scenario where volume control is done via digital scaling) would prefer a DSP with dedicated ADC/DAC chips.
Additional Input and Outpus on 3e Audio ADAU1701 DSP and Aliexpress
I'm overall quite satisfied with the quality of the amps and DSP, with 100dB/1w speakers noise is acceptable. If I where to say there was a weak point It would be that the DAC/ADC built into the DSP IC have poor specifications compared to stand alone DAC/ADC ics and so (especialy in a scenario where volume control is done via digital scaling) would prefer a DSP with dedicated ADC/DAC chips.
....as I said, it's a slow pace project.. ;-)
A lot has happened since, I hope y'all are all in good health without having being attacked by wild coronas.
So anyways, I ordered my 3E Audio parts - amps and DSP - last year..
..and then I got back from holiday to find a note saying "tried to deliver, you weren't home - pick up at our local place".
Got to the local post office, got told "yeah your stuff has been here for a week, nobody picked it up, so it got sent back"... :-/
So here we are, 8 months later... I ordered 2 amps and a DSP unit from 3E Audio again yesterday.
Hopefully they will arrive in a few weeks.
And hopefully I'll be home. 🙂
..to be continued 🙂
A lot has happened since, I hope y'all are all in good health without having being attacked by wild coronas.
So anyways, I ordered my 3E Audio parts - amps and DSP - last year..
..and then I got back from holiday to find a note saying "tried to deliver, you weren't home - pick up at our local place".
Got to the local post office, got told "yeah your stuff has been here for a week, nobody picked it up, so it got sent back"... :-/
So here we are, 8 months later... I ordered 2 amps and a DSP unit from 3E Audio again yesterday.
Hopefully they will arrive in a few weeks.
And hopefully I'll be home. 🙂
..to be continued 🙂
Right... so some time has passed... 🙂
I have here in front of me a set of 3E Audio boards :
- TPA3255 480W
- TPA3255 2x260W
- DSP ADAU1701-2In4Out
So I'd like to connect these to power a single active 3-way speaker.
But now I found out that the 3E Audio DSP board is configured for 1.0Vrms input.
And the Google Chromecast Audio that I'd like to connect it to has 2.0Vrms output.
Which, I would assume, would lead to severe clipping.
I checked and the 3E Audio DSP board can be configured to take 2.0Vrms input signal by swapping a resistor; the PDF at ADAU1701-2In4Out | 3e Audio says to swap the "input resistor" to 18.8kohm
...which I'd love to do, but the PDF doesn't specify *which* resistor on the board is the resistor I'm looking for.
The 3E Audio guy, when asked, basically replies "did you RTFM?".
But - yeah I did, I just can't figure out where on the board the f'ing resistor is located that I need to replace!
Any help here would be *greatly* appreciated 🙂
I have here in front of me a set of 3E Audio boards :
- TPA3255 480W
- TPA3255 2x260W
- DSP ADAU1701-2In4Out
So I'd like to connect these to power a single active 3-way speaker.
But now I found out that the 3E Audio DSP board is configured for 1.0Vrms input.
And the Google Chromecast Audio that I'd like to connect it to has 2.0Vrms output.
Which, I would assume, would lead to severe clipping.
I checked and the 3E Audio DSP board can be configured to take 2.0Vrms input signal by swapping a resistor; the PDF at ADAU1701-2In4Out | 3e Audio says to swap the "input resistor" to 18.8kohm
...which I'd love to do, but the PDF doesn't specify *which* resistor on the board is the resistor I'm looking for.
The 3E Audio guy, when asked, basically replies "did you RTFM?".
But - yeah I did, I just can't figure out where on the board the f'ing resistor is located that I need to replace!
Any help here would be *greatly* appreciated 🙂
Last edited:
This attachment should help. You need to change 2 resistors, one for each channel (i.e ADC0 and ADC1). A full explanation is in the ADAU701 datasheet in the "Audio ADCs" section, page 21 I believe.
Thank you SO much!
I haven't been able to figure out where those resistors are located and the Chinese 3E vendor hasn't been very helpful...
This should get my on my way (I hope 🙂) - thanks a lot!
Hello Pygmy , Have you had a chance to listen to the Amplifiers yet?? - I am looking for a good sounding amplifiers , and am on a budget - Thanks!
For my part, I do not have the 3E Audio dsp but only their 3255 stereo amplifier with a 300W 36-38 V power supply from Connex Electronic. I have nothing to say other than good things. Associated with a Topping E30 or a D10s on small bookshelves speakers, no background noise except the ear glued to the loudspeakers, very nice 3D soundstage, nice precision. On the same albums, with the D10s it's a bit excessive, but with the E30 the details are there but it's softer, the listening is more pleasant. I can not really say why since these 2 dacs have quite similar technical characteristics. But of course, if I can hear any difference between them, that says a lot about the transparency of the amp. (And obviously the listening was done blindly - and same dB level - in order to be sure of the veracity of the impressions.)
In short, there are clearly amps with better technical test results, but I wonder how much the difference is audible. For me, this amp is simply excellent value for money and, unless you have very insensitive speakers, you will not be disappointed with this choice of amp.
In short, there are clearly amps with better technical test results, but I wonder how much the difference is audible. For me, this amp is simply excellent value for money and, unless you have very insensitive speakers, you will not be disappointed with this choice of amp.
I have the 3e DSP and their 4 X 100 amp. If you're using their DSP then I would certainly recommend using their amps. The DSP and amps are designed for each other: the DSP has line drivers to boost the 1701's DACs max 0.9V max output. The amps are designed to match the DSP's output and both can use differential signals. In my case all the DSP/Amp interconnecting cables were supplied so it was plug and go.
One limiting factor of any 1701 based system when using the analog inputs are the 1701 ADCs: they're spec'd at THD+N of −83 dB. That's a deal breaker for some, but at this price point for DSP capability and 4 channels of amplification it's acceptable to me. I attached a graph of THD tests I ran on the 3e DSP and 4 X 100 amp. I used the analog inputs and a DSP program which just routes the inputs straight to the DACs. I started the tests using 30 VDC, but the amp distortion quickly rises above 65 W. So the tests above 65 W were done at 36 VDC and only driving 2 channels instead of 4 (my Meanwell power supply is rated for 350 W). The one outlier in the graph is the 100W/channel measurement. I used 4 ohm loads for all tests.
One limiting factor of any 1701 based system when using the analog inputs are the 1701 ADCs: they're spec'd at THD+N of −83 dB. That's a deal breaker for some, but at this price point for DSP capability and 4 channels of amplification it's acceptable to me. I attached a graph of THD tests I ran on the 3e DSP and 4 X 100 amp. I used the analog inputs and a DSP program which just routes the inputs straight to the DACs. I started the tests using 30 VDC, but the amp distortion quickly rises above 65 W. So the tests above 65 W were done at 36 VDC and only driving 2 channels instead of 4 (my Meanwell power supply is rated for 350 W). The one outlier in the graph is the 100W/channel measurement. I used 4 ohm loads for all tests.
Last edited:
Sorry for being late to the party but I have built an integrated around the 3e Audio DSP and TPA3255. The build is documented on my blog and you find the first part of it here: https://emumannen.blogspot.com/2021/04/the-ultimate-integrate-part-1.html
It all started with me initially using the DSP as an active XO in my 3-Way Retro Build documented here: https://emumannen.blogspot.com/2020/10/the-3-way-neo-part-5.html
Here is a link to all posts about the integrated (using tags): https://emumannen.blogspot.com/search/label/UmateIgrate
And here is another to all posts about the 3-Way Retro build (also using tags): https://emumannen.blogspot.com/search/label/3WR
Just follow the link to "Older Posts" to get to all of them.
I am super happy with the results even given the limitations of the ADAU1701.
It all started with me initially using the DSP as an active XO in my 3-Way Retro Build documented here: https://emumannen.blogspot.com/2020/10/the-3-way-neo-part-5.html
Here is a link to all posts about the integrated (using tags): https://emumannen.blogspot.com/search/label/UmateIgrate
And here is another to all posts about the 3-Way Retro build (also using tags): https://emumannen.blogspot.com/search/label/3WR
Just follow the link to "Older Posts" to get to all of them.
I am super happy with the results even given the limitations of the ADAU1701.
Last edited:
So last week I found some time again to work on this project.
I have the parts for a single speaker - one TPA3255 480W for the subwoofer driver, and a TPA3255 2x260W for the Mid and Tweeter, and the DSP for, well, the DSP duties.. 🙂
I've wired it all up and then thought - "Right, time to order the same for the other speaker".
And now it looks like 3E Audio is either out of business, or their products are out of production.. :-/
Only the TPA3255 2x260W board is still available on the 3E Audio site / AliExpress page - neither the 1x480W amp nor the DSP are available.
I've emailed 3E Audio days ago but haven't had any reply.
Just in case I bought an extra 2x260W board - if I can't get an additional DSP / 480W amp, at least I'll have one DSP and 2 2x260W boards, leaving me the option to use the single DSP to drive 2 channels for the left and 2 channels for the right speaker (and the amp boards to support that).
I can still go for active 3-way then but I'd have to do the tweeter crossover / filter the analog way then.
I have the parts for a single speaker - one TPA3255 480W for the subwoofer driver, and a TPA3255 2x260W for the Mid and Tweeter, and the DSP for, well, the DSP duties.. 🙂
I've wired it all up and then thought - "Right, time to order the same for the other speaker".
And now it looks like 3E Audio is either out of business, or their products are out of production.. :-/
Only the TPA3255 2x260W board is still available on the 3E Audio site / AliExpress page - neither the 1x480W amp nor the DSP are available.
I've emailed 3E Audio days ago but haven't had any reply.
Just in case I bought an extra 2x260W board - if I can't get an additional DSP / 480W amp, at least I'll have one DSP and 2 2x260W boards, leaving me the option to use the single DSP to drive 2 channels for the left and 2 channels for the right speaker (and the amp boards to support that).
I can still go for active 3-way then but I'd have to do the tweeter crossover / filter the analog way then.