Which TPA3255 amp do you recommend?

[Lorenzo74]

How do you think you even program the DSP? I don't see any way too and the knob is already doing a lot.

It uses quality components but to me it’s better to use a 3255 than 3250. For dsp better go with minidsp HD , you have more capability and proven platform.
Check 3E audio website, they already provide dsp.
this is an attempt to have an all in one finished product.

 

[somebodyelse]

How do you think you even program the DSP? I don't see any way too and the knob is already doing a lot.

Probably bluetooth, but perhaps via the box header?

 

[chips666]

The product I'm most interested in right now is All in One Amplifire from 3e audio.
Although it has not been released yet, this amp is a very promising one due to the good work of 3e audio products so far.
Unfortunately, the only chips used are the TPA3250 and TPA3255.

https://www.3e-audio.com/finished-amp/tpa32xx-all-in-one-amplifier/

https://www.aliexpress.com/item/100...&terminal_id=5b0226e59b0c48629677e45388a84e8b

Enjoy...

 

[Toku]

How do you think you even program the DSP? I don't see any way too and the knob is already doing a lot.

I cannot comment because the product details have not been announced.
But for me, I would like to see a simple structure of amplifier + power supply + volume pot. There is nothing to expect from a DSP.

 

[jagercola]

Ordered the 3e finished amp. It will be a while before i can give any impressions given the shipping delay. I was going to wait on the 3255, but using a SPL calcuator, the extra power wouldn't make much difference for me.

The 3e amp has a USBI connector to program the DSP, not sure how to actually connect that to the SigmaStudio dsp software. Maybe it requires a dongle like this? Dongle

Edit: English isn't 3e's first language, but based on my response, the bluetooth module on the finished amp doesn't impact audio quality when using RCA inputs.

 

[Bushellj]

Ordered the 3e finished amp. It will be a while before i can give any impressions given the shipping delay. I was going to wait on the 3255, but using a SPL calcuator, the extra power wouldn't make much difference for me.

The 3e amp has a USBI connector to program the DSP, not sure how to actually connect that to the SigmaStudio dsp software. Maybe it requires a dongle like this? Dongle

Edit: English isn't 3e's first language, but based on my response, the bluetooth module on the finished amp doesn't impact audio quality when using RCA inputs.

Hi Jagercola.

Have you had some communications directly with 3e-Audio with regard to this product ? I am also very interested in purchasing and had also been considering waiting for the TPA3255 or TPA3251 if they plan to offer one.

So just studying what you can see from the PCB traces and components on the board.

The RCA input appears to go to the Aux Input on the Bluetooth Board. Bluetooth if present is given priority. I would prefer to be able to switch between the two inputs to stop the Bluetooth from taking priority !! So the RCA input analog signal does appear to be routed through the Bluetooth module !! Let's hope it is quiet and doesn't introduce noise as these Bluetooth modules appear to do on many other "Bluetooth Amplifiers".

The Audio then passes to the two inputs on the DSP Chip. The DSP Chip does the Volume processing and appears to provide four outputs that then drive the balanced inputs of the TPA3250 via the two dual Op-Amps.

Clearly the DSP has a lot more capability that is unused in this amplifier. The only changes that you might want to make would be to modify the EQ settings to better match Speakers.

There is also an ARM based Processor on the Board that controls the Front Panel and the Bluetooth Board.

It appears the board does provide a USBi interface so there is a possibility that the Arm Processor and the DSP Chip can be reprogrammed.

Let's hope they put some more information in the public domain. They must realise that many of their customer are DIY enthusiasts and need to know this stuff !!

 

[jagercola]

Have you had some communications directly with 3e-Audio with regard to this product ? I am also very interested in purchasing and had also been considering waiting for the TPA3255 or TPA3251 if they plan to offer one.

I was asking them if the sound quality suffered because of the bluetooth module. Specifically, if their sound quality suffered like many of the TPA3255 amps with bluetooth modules. That gave a short response saying no it wouldn't. They also said the amp had pop protection unlike a lot of the TPA3255 amps without bluetooth modules.

I'm not savy enough to trace the PCB but your insights are great. I would have preferred no Bluetooth, but if anyone is going to do it right, I'm trusting 3e's reputation for quality.

None of the product documentation tells me exactly how to utlize and connect to the DSP chip to program it. They told me the amp was flat and it sounded like it was totally optional. I'm trying to learn REW, so it would be neat to be able to do some filters to help room response.

 

[Bushellj]

I was asking them if the sound quality suffered because of the bluetooth module. Specifically, if their sound quality suffered like many of the TPA3255 amps with bluetooth modules. That gave a short response saying no it wouldn't. They also said the amp had pop protection unlike a lot of the TPA3255 amps without bluetooth modules.

I'm not savy enough to trace the PCB but your insights are great. I would have preferred no Bluetooth, but if anyone is going to do it right, I'm trusting 3e's reputation for quality.

None of the product documentation tells me exactly how to utlize and connect to the DSP chip to program it. They told me the amp was flat and it sounded like it was totally optional. I'm trying to learn REW, so it would be neat to be able to do some filters to help room response.

Do you actually have some documentation from 3e-Audio about this product ?? Please share what you have with the group.

With regard your comments about the Anti Pop Protection circuitry - are you talking about the Aiyima A04 (TPA3251) and A07 (TPA3255) finished/cased models or just Chinese TPA3255 boards in general ?? The A07 PCB is available with or without Bluetooth.

The Aiyima A04 or Tilear model has the Anti Pop present on all releases of PCB. The Aiyima A07 did not have AntI Pop on the first release of PCB but it now appears to be included on the later PCB based boards. The trouble being that most sellers are still selling the old stock so you don’t know what PCB release you are going to get until it arrives and you can’t tell from the outside !!

There is also another version being sold under the Aiyima and other names that has a completely different PCB in both Bluetooth and non-Bluetooth versions which appears to be a much cheaper build and I would avoid if at all possible !! You can see the difference clearly in the photos as the Output Inductor coils are in a different place and there is only one Power Supply Capacitor mounted to one side.

Of course there are other products available but I only have experience of the ones above. If you don’t use the switch on the front panel to turn on and off - just turn the power supply one and off at the wall then you avoid the Pop Problem. I have one of the early A07 models so it either just stays powered up or I control it from the Power Supply switch.

With regards to REW and programming the DSP. 3e-Audio also provide a DSP based preamplifier that is based on the same DSP chip and this is specifically designed to be programmed for different applications by the user using the SigmaStudio software development kit. See https://www.analog.com/en/products/adau1701.html#product-overview. There was a Bluetooth option for this board but it has now been discontinued.

I don’t know what documentation or files 3e-Audio provide but I guess there must be some stuff available or the product wouldn’t be very useful !! This whole area is probably quite complex and I have not looked at it.


The Audio from the RCA sockets on this integrated amplfier appears to go through several others modules (including ADC and DAC conversions) before it gets to the TPA325x amplfier chip which probably all adds additional noise and distortion to the final output. That said it should be minimal and maybe not audible. The Aiyima models discussed above only have a Volume Control and an Op-Amp between the inputs and amplifier chip so likely to be a cleaner signal and they certainly sound very good.

But this is exactly why we all sit in these groups to play with the various technologies available and find practical solutions to getting the best sound !

 

[jagercola]

https://www.3e-audio.com/finished-amp/tpa32xx-all-in-one-amplifier/

This had some more info on it. No manual though but you can also go to there DSP board for that info.

 

[somebodyelse]

The web site seems to be getting updates with little bits of extra information, so worth keeping an eye on. A template for SigmaStudio is mentioned but doesn't seem to be available yet. When it appears it should answer a lot of questions.

 

[Bushellj]

https://www.3e-audio.com/finished-amp/tpa32xx-all-in-one-amplifier/

This had some more info on it. No manual though but you can also go to there DSP board for that info.

I was nearly right - Just connected the RCA at the wrong point ! Given the RCA and Bluetooth are connected to the DSP it should be possible to update the software so the Bluetooth input doesn't always take priority. A switch on the front panel would be nice to select input.

Interesting that the DSP is producing the two out of phase signals to drive the Balanced input on the TPA325x.

Be really interesting to hear what this sounds like in comparison to the Aiyima A04 TPA3251 based amplifier.

 

[3eaudio]

I was nearly right - Just connected the RCA at the wrong point ! Given the RCA and Bluetooth are connected to the DSP it should be possible to update the software so the Bluetooth input doesn't always take priority. A switch on the front panel would be nice to select input.

Interesting that the DSP is producing the two out of phase signals to drive the Balanced input on the TPA325x.

Be really interesting to hear what this sounds like in comparison to the Aiyima A04 TPA3251 based amplifier.

we implement a design by DSP that the 2 source from RCA(anglog) and Bluetooth(Digital) can be AUTO switch.
when no audio or no play from Bluetooth,it will auto switch to RCA source,so it can reduce a switch on front panel which is not good in appearance design.

*I was lucky found some people discuss our AMP release few days ago on this forum and we would like to share and open discuss more topic here.

 

[Bushellj]

we implement a design by DSP that the 2 source from RCA(anglog) and Bluetooth(Digital) can be AUTO switch.
when no audio or no play from Bluetooth,it will auto switch to RCA source,so it can reduce a switch on front panel which is not good in appearance design.

*I was lucky found some people discuss our AMP release few days ago on this forum and we would like to share and open discuss more topic here.

3e-Audio - We welcome you to our forum and really appreciate that you are happy to discuss your products with us.

3e-Audio have created a good reputation for your range of TPA325x boards and we are really pleased you have now expanded your range of products to include a finished product in a case. I think quite a few of us are waiting to see the release of the TPA3255 and possibly a TPA3251 based finished product.

I am always concerned by Bluetooth products that automatically take priority over the RCA inputs as often it is a real pain to disconnect the Bluetooth source from the Bluetooth receiver when you no longer want to use this as the source.

Are you saying that if there is no sound coming from the Bluetooth source it will switch back to the RCA inputs or do I have to do a full Bluetooth disconnect ?

As we all tend to be audio enthusiasts that exchange messages on these sites we are also the ones that generate interest and potential sales of your products. I am very concerned that you are saying that only the first batch of products will be using the OPA1602 Op-Amps and then you will be moving to a cheaper Op-Amp such as the NE5532 !! WHY ???? Would you not consider using the OPA1656 Op-Amp which seems to be getting very good reviews from a lot of people. Surely you want to maintain the best quality for your customers ??

I would order one today but why are the postal costs so high for this product compared to the other products you sell ?

Not all users have the technical capability to reprogram the DSP for correcting the EQ so we would like the best Sound Quality “out of the box”. Please don’t start cutting corners on the component quality just to save a few cents in production costs. We want the best !!

Many thanks and we look forward to hearing lots more from you in the future.

James.

 

[Lorenzo74]

we implement a design by DSP that the 2 source from RCA(anglog) and Bluetooth(Digital) can be AUTO switch.
when no audio or no play from Bluetooth,it will auto switch to RCA source,so it can reduce a switch on front panel which is not good in appearance design.

*I was lucky found some people discuss our AMP release few days ago on this forum and we would like to share and open discuss more topic here.

hi 3eaudio, nice to see you here.
I share above comments from Bushellj.
if you want to challenge smsl (I guess you can) you need to keep the balance between cost and performance but not give up few € where it matters.
here people are very “peaky“ and knowledgeable so you have the right place to test your product and expand your market. this is the Michelin guide...

could you pls let us know when you will release the 3255 version? I’m on it, ready to try it.
my Best
L.

 

[Bushellj]

we implement a design by DSP that the 2 source from RCA(anglog) and Bluetooth(Digital) can be AUTO switch.
when no audio or no play from Bluetooth,it will auto switch to RCA source,so it can reduce a switch on front panel which is not good in appearance design.

*I was lucky found some people discuss our AMP release few days ago on this forum and we would like to share and open discuss more topic here.

I just wanted to add to my previous comments.

Given that you have a Microprocessor and a DSP controlling the Volume and a Bluetooth wireless interface what is the possibility of providing a remote control for the Volume (minimum requirements) and possibly selecting the input ? Either a dedicated remote or an App on a mobile phone ??

I use my amplifier as part of an AV System and having remote control is really mandatory.

Thank you.
James.

 

[nodigital]

I've got to congratulate 3e Audio on what I see as a major step - Low cost, high quality digital amplification with DSP audio correction. Get the quality right and with useable software and it takes a big step to dramatic audio improvements from a single box solution. Will be interesting to see how it compares to others in a listening test with a speaker correction profile applied to the DSP (Presuming possible from screen shot on their site)

 

[somebodyelse]

As we all tend to be audio enthusiasts that exchange messages on these sites we are also the ones that generate interest and potential sales of your products. I am very concerned that you are saying that only the first batch of products will be using the OPA1602 Op-Amps and then you will be moving to a cheaper Op-Amp such as the NE5532 !! WHY ???? Would you not consider using the OPA1656 Op-Amp which seems to be getting very good reviews from a lot of people. Surely you want to maintain the best quality for your customers ??

We tend to be audio enthusiasts who care about evidence of performance, and good engineering. Given the other parts in the signal chain there's every chance the performance is unchanged by switching to the 5532. If that's the case then there's no technical reason to waste money on a more expensive opamp. If 3e were to send in one of each for testing, and they measure the same, would that be good enough?

 

[Bushellj]

We tend to be audio enthusiasts who care about evidence of performance, and good engineering. Given the other parts in the signal chain there's every chance the performance is unchanged by switching to the 5532. If that's the case then there's no technical reason to waste money on a more expensive opamp. If 3e were to send in one of each for testing, and they measure the same, would that be good enough?

Hi Somebodyelse.

There have been loads of discussions about "Op-Amp Rolling" on the various TPA325x based boards and I have both Aiyima A04 TPA3251 and Aiyima A07 TPA3255 based Amplifiers as well as a lot of previous generation TPA3116 boards.

Just from my own listening experience with both these amplifiers I have come to prefer the OPA1656 Op-Amps over various other options. Tried so far NE5532, OPA1622 and OPA1656. I also have some OPA627AU to try based on other peoples experience but not yet had time to test them. Maybe the OPA1656 Op-Amps sound better because I personally had to solder the chips onto the adapters !

3e-Audio clearly use various Op-Amps in their designs - The current TPA325x boards seem to use JRC4580 Op-Amps. These are a pretty old design now and one would hope that manufacturers are getting better at designing these chips. There is quite a story behind the design of the OPA1656.

I am absolutely with you about caring about measured performance and especially good engineering (I am an engineer at heart) and I would love to see some comparative testing with different Op-Amps.

Like so many things in the Audio space, it comes down to what it sounds like in the end. Do you use Silver wire or tinned copper for example ? Some would claim that digital interconnects affect the sound. As long as the 1's and 0's get to the other end in the right order what does it matter ? Why do people pay $100's Dollars for an HDMI cable or Optical Cable ?

I agree, with this particular amplifier where everything passes through a DSP Chip with its ADCs and DACs, that other components may be less critical. I just wonder at the manufacturing stage what the difference in cost is between using an NE5532 and an OPA1656. Mouser UK pricing at 1,000 units :- NE5532 £0.21, JRC4580 £0.30, OPA1656 £0.99 and OPA1602 £1.04. I am sure they are much cheaper in China !!

But we are all here to play and without these discussions where would the fun be ? Be interesting to put the original NE5532 Op-Amps back in my amplifiers and see if I can still hear the difference now these units are well burnt in !! Oh, and I need some better speakers !!

 

[Xulonn]

about "Op-Amp Rolling"

Since this - ASR - is a science-based forum that you decided to to participate in, I assume that you know that the only way to accurately and reliably compare opamps or any other electronics variables is to have two identical devices, then set up precisely level-matched signal chains, and switch between them quickly following established double-blind or ABx protocols - correct?

And I also assume that you are aware that, based on decades of repeated and confirmed research by psychoacoustics professionals, that sighted comparison of supposed audible differences are utterly and totally unreliable for well-engineered audio electronics that have very low levels of distortion and noise, especially when the period between that blind listening to the compared sources is more than a few seconds

Therefore, since there is only one "transparent" and "accurate" signal down the chain from source to to amplifier output, if their are differences, those differences are caused by distortion - including differences in frequency response, which is by definition also a form of signal "distortion".

You are essentially telling us that you are perceiving different types and levels of distortion - and that you prefer some types and levels of distortion over others. Is that correct?

 

[Bushellj]

Since this - ASR - is a science-based forum that you decided to to participate in, I assume that you know that the only way to accurately and reliably compare opamps or any other electronics variables is to have two identical devices, then set up precisely level-matched signal chains, and switch between them quickly following established double-blind or ABx protocols - correct?

And I also assume that you are aware that, based on decades of repeated and confirmed research by psychoacoustics professionals, that sighted comparison of supposed audible differences are utterly and totally unreliable for well-engineered audio electronics that have very low levels of distortion and noise, especially when the period between that blind listening to the compared sources is more than a few seconds

Therefore, since there is only one "transparent" and "accurate" signal down the chain from source to to amplifier output, if their are differences, those differences are caused by distortion - including differences in frequency response, which is by definition also a form of signal "distortion".

You are essentially telling us that you are perceiving different types and levels of distortion - and that you prefer some types and levels of distortion over others. Is that correct?

I thought that was exactly the point I was making in my post ?!

If all Op-Amps were perfect and added no distortion or frequency dependant artefacts to the signal passing through them we wouldn’t be having this discussion. Precisely the same point I made about digital interconnects. If the 1s and 0s still come out the other end why do we have such a range of cables ? Measurement is the only way of establishing the differences.

So without measurement we don’t know if the perceived changes are down to more accurate signal transfer through the chain or just a pleasant sounding ”distortion”. Manufacturers continue to produce new designs for the ultimate Op-Amp so more recent designs you would expect to produce better measurements.

This post is headed up as “Which TPA3255 amp do you recommend”. So how can you answer this question without a discussion on all aspects and component choices. Some of us may be looking for the ultimate “money no object“ solution. Others may be looking for the best solution under $50 dollars. The little Aiyima amplifiers measure well out of the box and sound good - doesn’t stop people wanting to modify them and see if we can get them to sound even better - usually by swapping out components that introduce distortion.

The current discussion was about the the new 3e-Audio boxed amplifier and whether including the DSP is good or bad for the audio performance, whether having Bluetooth on board affects the quality of the signal !!

Let’s see some measurements then from those members that have the necessary equipment.