ICIETDIYEUR
Member
It's all about compromise !
What do you think of this change ? ->
What do you think of this change ? ->
That is interesting that the power supply noise will remain pretty much the same. As I repeat - I am not an engineer, so thank you for explaining.View attachment 237717
According to the datasheet, the TPA3255 will also work at 18 V supply voltage.
Another thing is that at 18V and at 50V the output ripples of power supply will be almost the same. So at 18V, the signal-to-noise ratio at the output will be worse than at 50V.
That's all the math...
Actually one other question - what is the signal-to-noise at the output? Are you guys able to replicate Amir's SINAD measure?View attachment 237717
According to the datasheet, the TPA3255 will also work at 18 V supply voltage.
Another thing is that at 18V and at 50V the output ripples of power supply will be almost the same. So at 18V, the signal-to-noise ratio at the output will be worse than at 50V.
That's all the math...
I just noticed that the pics in the OP show the circuit board is V1.1 and the one being sold shows V1.5 (pic below)Hi amigos )
As promised, I am sharing some spec and pictures about the new Breeze Audio TPA3255 amplifier.
This is the only full balanced finished amp that I found for less than $200 )
The amp comes in an black aluminum case of modest size but seems robust however.
In the front plate you will find the RCA / XLR inputs selector with that motorized volume pot and the ON/OFF switch
I am still wondering why spending so much money on a motorized potentiometer since the amp doesn't have a remote...
The speakers banana connectors are OK and seem solid.
The XLR connectors are OK as well with a secure clip. RCA inputs are conventional
I do not observe any play on the volume knob and nothing to complain with.
You can see that the inside speaker cables and PSU to module cables are directly soldered to the PCB. (no JST connector here)
Safety is important: the amplifier is properly grounded ) Nice for a Chinese amp. )
BUT :the neutral and the phase were reversed... I corrected it )
Little mod I made :
- Update OP amps > OPA2210 (crazy op amps, give a try really !)
- Twisted the 220V cables
- Reversed the Neutral / Phase properly
- Insulated the PSU to module 36V cable
- added ferrites on the speaker cables
- added copper film to the transformer core
Listening test still in progress. But after 1 hour I can say; dead silence (even with my ears glued to the speakers) I only tested the XLR inputs with my Gustard A18 DAC.
The OPA2210 definitely worth trying! as good of the OPA1656 in term of Soundstage but with the best of the OPA1692. This super BETA Bipolar OP amps is really fast with a very low DC offset. The amplifier sounds great and very loud with the volume @ 30%. I tried to turn the volume @Max, it remains ultra silent, good point here.
For the rest, I can't say too much more, it's too early....
NB : I ve been testing many OP amps all Genuine from Mouser : OPA1622 / 1656 / 1612 / 1692 / 2210
TPA3255 MODULE :
WIMA MKS Caps (next to the volume pot) = 2U2J63 2.2uf / 63V
Electrolytic SMD Caps next to the OP amps = 220uf / 16V
Panasonic FC caps between inductors : 50V / 220uf
Switching Voltage Regulator = TI LM2575S-12
Electrolytic SMD Caps next to the Voltage regulator = 220uf / 16V
Power caps next to XLR inputs : 470uf / 50V
Polypropylene Film Capacitors : MKP10 / 0.1-250
Hongfa Relay = HFD4 / 5-S
Sagami Inductors
Volume pot : Alps Motorized Quadrirotor RK168 100K 100KAX4
PSU :
SMPS PSU 36V / 9.5A @342W
Epsilon 400uf / 400V x2
United Chemicon 1000uf / 50V x 4
Stable @ multimeter !
Yes but:
36 Volts x 9,5 Ampères = 342 VA (~ Watts)
So = 350W
There is a mistake on the table -> it's only written 4,2A !
In addition, concerning the amplifier: I can tell you that the available power is really present
Don't worry
Regards
Yes but:
36 Volts x 9,5 Ampères = 342 VA (~ Watts)
So = 350W
There is a mistake on the table -> it's only written 4,2A !
In addition, concerning the amplifier: I can tell you that the available power is really present
Don't worry
Regards
Then a push-pull of EL84 will be enough
Unfortunately, I don't have hardware+software like amirm (APx500) that creates such great measurement graphs.Actually one other question - what is the signal-to-noise at the output? Are you guys able to replicate Amir's SINAD measure?
The Allo Volt D I have is 84db. The Aiyima A07 is 83db. Yours would be after your modifications possibly but Icediyeur has an unmodified'ish one.
Not being greedy or anything ;-)
Reading about FET input OP's - many say they can be slightly valve like.TPA3255 3251 3221 or 3116? which sounds more like an EL84?
Calculating the SINAD would be seriously interesting - not sure if we can get a before and after. Great thread.Unfortunately, I don't have hardware+software like amirm (APx500) that creates such great measurement graphs.
But in the near future I will try to make several measurements of my 3255XLR instance and calculate SINAD using the formula.
View attachment 237822
And you are right about the main thing: everyone decides for himself what parameters of his equipment he wants to achieve and how much money to spend on these modifications.
Let's not be too greedy...
My choice would be to get this amp connected to a oscilloscope and view the power supply output to determine if 10,000+ micro Farad is required. Otherwise have fun and put them where you can. If you drastically increase the power supply smoothing capacitance with a switching power supply like you have here you may experience issues with the power supply operation. The only way to know is to try it.Hi everyone
@v1adpetrov2:
What do you think about replacing the 220μF polymer with an electrochemical 470μF ? ->
View attachment 237902
I also redid suggestions for more readable capacitor bank locations:
-MOD 1
View attachment 237904
Total = 10 000 µF
-MOD 2
View attachment 237906
Total = 10 000 µF
-MOD 3 (20 'HP' for 18 inches speakers )
View attachment 237908
Total = 20 000 µF
What do you think ?
What would be your choice ?
Regards
1. The dataset LM2575HV recommends using a 330μF capacitor. Therefore, you can easily change to 470μF without hesitation...1. What do you think about replacing the 220μF polymer with an electrochemical 470μF ? ->
2. I also redid suggestions for more readable capacitor bank locations:
-MOD 1 Total = 10 000 µF
-MOD 2 Total = 10 000 µF
-MOD 3 Total = 20 000 µF
What do you think ?
What would be your choice ?
Erm, no, not really... The only thing they have in common is a super high input impedance.Reading about FET input OP's - many say they can be slightly valve like.
Why? What benefit would it bring?What do you think about replacing the 220μF polymer with an electrochemical 470μF ? ->
Exactly. This isn't a linear supply where "more capacitance equals more better".My choice would be to get this amp connected to a oscilloscope and view the power supply output to determine if 10,000+ micro Farad is required. Otherwise have fun and put them where you can. If you drastically increase the power supply smoothing capacitance with a switching power supply like you have here you may experience issues with the power supply operation. The only way to know is to try it.
Erm ... people do say this ... I was saying something different ...Erm, no, not really... The only thing they have in common is a super high input impedance.
Why? What benefit would it bring?