Which TPA3255 amp do you recommend?

[somebodyelse]

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 !!

I'd rather they spend the difference on components that make a measurable change to performance, such as output inductors. Take a look at the TI application notes for some indication of the difference they make to distortion - it's not small!

 

[Bushellj]

I'd rather they spend the difference on components that make a measurable change to performance, such as output inductors. Take a look at the TI application notes for some indication of the difference they make to distortion - it's not small!

I think the general opinion is that the Output Filter is probably the best opportunity for improvement with any of these TPA325x based amplifiers but also the most difficult for the DIY enthusiast !!

Certainly for the popular Aiyima A04 and A09 Amplifiers, the biggest issue is the lack of space for any larger components. You can purchase the inductors (Coilcraft) that are used on the TI EVM Module and some people have tried to install these. I think they are slightly higher and don't fit in the case and the wires are heavier gauge so are difficult to insert in the existing holes in the PCB.

For the 3e-Audio amplifier they already used a dual Coilcraft Inductor and TDK MKP Capacitors. Again there is very little space for any alternative Inductors. I think you would need to make some serious PCB design changes to go down any other route and that would clearly add to the cost of the amplifier.

Be good to see how it measures against the other products in this area.

 

[3eaudio]

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.

Input source selection:
sorry my poor description not explain good for you to understand, for auto source selection you don't need disconnect BT,it will auto switch to BT input when BT audio signal it active(let's say threshold set at -90dBV).
OP-AMP
this is based on what we used more common part on other product,not depand on diy case totally,also it related to cost,let's say NE5532 cents vs 1602 dollar,OPA1656 is cheaper than 1602,but someone or some circuit is more listentable when using FET OP-AMP i guess?
DSP
it is just a ADC+DAC when you ignore DSP function.

 

[3eaudio]

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)

correct,this is very clear to us,make a highly integrated BOX amp(refer as BT amp + external power adapter) achieve best performance based on corresponding price and adding a DSP feature for extend another way for audio system tuning.

 

[3eaudio]

I think the general opinion is that the Output Filter is probably the best opportunity for improvement with any of these TPA325x based amplifiers but also the most difficult for the DIY enthusiast !!

Certainly for the popular Aiyima A04 and A09 Amplifiers, the biggest issue is the lack of space for any larger components. You can purchase the inductors (Coilcraft) that are used on the TI EVM Module and some people have tried to install these. I think they are slightly higher and don't fit in the case and the wires are heavier gauge so are difficult to insert in the existing holes in the PCB.

For the 3e-Audio amplifier they already used a dual Coilcraft Inductor and TDK MKP Capacitors. Again there is very little space for any alternative Inductors. I think you would need to make some serious PCB design changes to go down any other route and that would clearly add to the cost of the amplifier.

Be good to see how it measures against the other products in this area.

we don't recommend doing that on a finished product,you can move to our Pure Amplifier Board which given more flexible for trying OP-AMP,inductor,Caps on coupling and filter,and etc.

 

[Bushellj]

we don't recommend doing that on a finished product,you can move to our Pure Amplifier Board which given more flexible for trying OP-AMP,inductor,Caps on coupling and filter,and etc.

Thank you for your replies. I totally agree with you on this finished product. This is one to use as supplied. There are plenty of other amplifiers more suited for the DIY community to play with.

 

[Bushellj]

Input source selection:
sorry my poor description not explain good for you to understand, for auto source selection you don't need disconnect BT,it will auto switch to BT input when BT audio signal it active(let's say threshold set at -90dBV).
OP-AMP
this is based on what we used more common part on other product,not depand on diy case totally,also it related to cost,let's say NE5532 cents vs 1602 dollar,OPA1656 is cheaper than 1602,but someone or some circuit is more listentable when using FET OP-AMP i guess?
DSP
it is just a ADC+DAC when you ignore DSP function.

Input source : I am so pleased to hear that I don’t have to disconnect the Bluetooth device in order to use the RCA input. Almost all the other Bluetooth amplifiers require you to disconnect before you can use another input.

Op-Amp : There is a whole discussion on the benefits of Fet vs Bipolar but I am no expert and there are plenty of people on this forum who have much better knowledge. My comments were only based on the Op-Amp discussions across various forums and a little personal experience of Op-Amp rolling on some of the entry level TPA325x products.

DSP : I am looking forward to see what can be done with the DSP functionality and whether this is really something that the amateur can play with.

Thank you for bringing this interesting product to market. When can we expect the TPA3255 version ? Will this operate at a higher voltage or use the same power supply ?

James

 

[3eaudio]

Input source : I am so pleased to hear that I don’t have to disconnect the Bluetooth device in order to use the RCA input. Almost all the other Bluetooth amplifiers require you to disconnect before you can use another input.

Op-Amp : There is a whole discussion on the benefits of Fet vs Bipolar but I am no expert and there are plenty of people on this forum who have much better knowledge. My comments were only based on the Op-Amp discussions across various forums and a little personal experience of Op-Amp rolling on some of the entry level TPA325x products.

DSP : I am looking forward to see what can be done with the DSP functionality and whether this is really something that the amateur can play with.

Thank you for bringing this interesting product to market. When can we expect the TPA3255 version ? Will this operate at a higher voltage or use the same power supply ?

James

yes, for TPA3255 it work higher voltage let's say 40~44V,

i think maybe other supplier feed RCA input into Bluetooth that cause hard to make a source switch smartly?
anyhow,audio system is not only an Op-AMP,we treat it as a more complex system that involved both electrical,mechanical and acoustics.if you want to do it good you should try them all in combine.

 

[Toku]

Input source selection:
sorry my poor description not explain good for you to understand, for auto source selection you don't need disconnect BT,it will auto switch to BT input when BT audio signal it active(let's say threshold set at -90dBV).
OP-AMP
this is based on what we used more common part on other product,not depand on diy case totally,also it related to cost,let's say NE5532 cents vs 1602 dollar,OPA1656 is cheaper than 1602,but someone or some circuit is more listentable when using FET OP-AMP i guess?
DSP
it is just a ADC+DAC when you ignore DSP function.

Isn't there any major change in the circuit of the main amplifier from the conventional amplifier board?
I hope that a PFFB circuit (Post Filter Feed Buck) whose patent has recently expired will be adopted.

 

[Lorenzo74]

yes, for TPA3255 it work higher voltage let's say 40~44V,

i think maybe other supplier feed RCA input into Bluetooth that cause hard to make a source switch smartly?
anyhow,audio system is not only an Op-AMP,we treat it as a more complex system that involved both electrical,mechanical and acoustics.if you want to do it good you should try them all in combine.

Hi, just a quick question, why don’t you run it at 48-50V?
I do it so far without any issue even at sustained power.
would be possible?
My best
L.

 

[3eaudio]

Hi, just a quick question, why don’t you run it at 48-50V?
I do it so far without any issue even at sustained power.
would be possible?
My best
L.

it can but thermal will be a big concern,with current aluminum box we evaluated,48~50V won't be suitable in this case.
44V we get 100W at 8ohm and 200W at 4ohm, we did it by this approach.

 

[somebodyelse]

@3eaudio - More measurements please, or better yet send one in for testing. You may have the best performing amp yet tested at this price point, with the bonus of DSP for room correction and speaker EQ.

 

[morpheusX]

@3eaudio, are you considering offering a finished amp WITHOUT Bluetooth and DSP?

 

[3eaudio]

@3eaudio, are you considering offering a finished amp WITHOUT Bluetooth and DSP?

Currently not plan yet,if you want higher power and performance may consider the Individual Amplifies board(module).

 

[jagercola]

Currently not plan yet,if you want higher power and performance may consider the Individual Amplifies board(module).

I would but I don't know what case to get that would fit that is reasonable in cost. If you sold a kit, including power supply, that people could assemble with basic soldering skills and/or a screw driver, I think it would sell very well.

 

[Lorenzo74]

Did you notice that Minidsp choose tpa3255 over Icepower for his latest SHD amplifier?

https://www.minidsp.com/products/streaming-hd-series/shd-power

Any comment? I think we will see more implementation of Tpa3255 in the future.

Actually I have minidsp DDRC24 (dirac) + DIY tpa3255.

90% of SHD POWER but half the price...
My Best
Lorenzo

 

[somebodyelse]

Interesting - the tpa3255 doesn't seem to be mentioned on minidsp's page (at least I couldn't find it) but a couple of the resellers mention it.

 

[maty]

by xrk971

TPA3255 Reference Design Class D Amp GB
https://www.diyaudio.com/forums/group-buys/340880-tpa3255-reference-design-class-amp-gb.html

-> https://www.diyaudio.com/forums/gro...rence-design-class-amp-gb-48.html#post6212677

https://www.diyaudio.com/forums/gro...eference-design-class-amp-gb-post6230584.html

[ Just to clarify, the revised BOM goes with the rev002 (Mar 2020) version of the TPA3255 (green PCB). If you have the rev001 (Oct 2019) a blue PCB, I have already contacted you via Etsy's messaging system to let you know that you can get a replacement to the new rev002 at no charge. The new BOM can also be applied to the rev001 PCBs minus 4 resistors. It will have a lower value 220R input reistors vs 2k2 which will increase the amp gain. The 2k2 was used in conjunction with a 220pF NP0 cap to ground as an input RFI filter - but it was found to operate very quietly with only 220R or even 51R and gave a few dB greater gain to reduce your preamp drive requirements. All of the shipped RTR amps already have the smaller 51R resistors installed.

The rev001 amp works fine and sounds excellent and will have about 21dB of gain vs the rev002 which only has 15dB of gain and 6 to 7 dB less THD than rev001. ]

 

[corletts]

View attachment 47703View attachment 47704

Those are superb capacitors for this system. Hard to find those vintage versions. Have you tried any other 10000uf caps that are currently available and sound just as good. I'm about to set up essentially the same system, but with a SMPS, same one you've shone in other posts.

 

[Lorenzo74]

Interesting - the tpa3255 doesn't seem to be mentioned on minidsp's page (at least I couldn't find it) but a couple of the resellers mention it.

Is there...

• Proprietary custom 2 x 120W amplifier (8Ohms/4Ohms), SNR >110dB (at 1kHz A-weighted, 120W in 8Ω), Embedded PCM1795 DAC chipset + TPA3255 Class D chipset