Audientid14
Did you adjust the Allo CM trimmer to suit Aiyima voltage requirement ?
Default from factory is - 0,5 V , meaning the 24 volt that comes in gets 23,5 volt out.
I have , with the trim pot, adjusted the drop out to -1 Volt. The 24 volt that goes in to the Allo card becomes 23 volt out to the amplifier. The card can take 30 volt in though, and that would be optimal I think.
I have , with the trim pot, adjusted the drop out to -1 Volt. The 24 volt that goes in to the Allo card becomes 23 volt out to the amplifier. The card can take 30 volt in though, and that would be optimal I think.
Hi,
I own a Tilear TPA3251 version, it states(from the seller site) it can handle up to 32Vdc, I tired and there didn't seem to be any problem. I notice some of you use 24Vdc. My question:
a. Why you use 24Vdc instead of 32Vdc?
b. 32Vdc would give greater output power?
c. anyone tried the sound reproduction between using 24Vdc and 32Vdc?
Thanks.
I own a Tilear TPA3251 version, it states(from the seller site) it can handle up to 32Vdc, I tired and there didn't seem to be any problem. I notice some of you use 24Vdc. My question:
a. Why you use 24Vdc instead of 32Vdc?
b. 32Vdc would give greater output power?
c. anyone tried the sound reproduction between using 24Vdc and 32Vdc?
Thanks.
Iam driving my Tpa 3251 Tilear 2.1 with a 35v / 7a PSU without any Issues. No overheat as well
A good reason for 32V would be if you have 8Ohm speakers and want some "reserve" for power peaks or similar.
24V/8Ohms according to datasheet is roughly only 35W (THD 0.1%),
32V/8Ohms according to datasheet is ~ 62.5W (THD 0.1%).
similarly: 24V/4Ohms~65W; 32V/4Ohms~115W.
I´m using 32V and all is fine.
24V-PSU´s are more common and usually cheaper so that´s what people get.
But don´t forget all the 36V-PSU´s that can be adjusted down to 32V.
All that said the limitation in this amp towards higher power than 2x50W is most probably the tiny heatsink. (assuming all thermal connections are done 100%, otherwise you would experience a thermal shutdown long before;
the A04´s are OK but rely on thermal paste between chip and a little block of metal, more thermal paste and then the final little heatsink).
Most A04´s as far as I know have 35V caps so I wouldn´t recommend a 35V-PSU unless you change the caps before (yes, you are probably aware of that bro ;-))
Theres now been two comparisons between a Rotel ra1592 amplifier, a HYPEX nc400 and an Aiyima a04 in two high end setups.
The Aiyima with opa2604 was found sounding slightly better than Rotel. No difference between an original Aiyima and HYPEX nc400.
Better bass and a clearer sound compared to Rotel ra1592.
faktiskt.io • Visa trad - Ljudmassig utvardering av tpa3251 Aiyima A04 - klass D
The Aiyima with opa2604 was found sounding slightly better than Rotel. No difference between an original Aiyima and HYPEX nc400.
Better bass and a clearer sound compared to Rotel ra1592.
faktiskt.io • Visa trad - Ljudmassig utvardering av tpa3251 Aiyima A04 - klass D
Last edited:
Will check interesting.
I also own a double Mono NC500MP and 250MP and the Aiyima A04 Tilear 2.1 and many other class D amps... From a subjective opinion, I have absolutely no doubt that a good TPA325X compares with the Hypex Ncore and probably other amps that are worth more than ten times its price
It seems that this amplifier is really good, even compared to really expensive equipment.
Some suggestions of good afordable power supplies to both Aiyima a04 and Aiyima a07 ( tpa 3255) is in the link below.
Read more here :
faktiskt.io • Visa trad - Tpa3251 Aiyima A04 vs Hypex nc400 och Rotel ra1592
Some suggestions of good afordable power supplies to both Aiyima a04 and Aiyima a07 ( tpa 3255) is in the link below.
Read more here :
faktiskt.io • Visa trad - Tpa3251 Aiyima A04 vs Hypex nc400 och Rotel ra1592
Last edited:
We have tried to change the chip to OPA2134PA and LM4562NA on A04 and A07, the sound improved a lot, especially when LM4562NA is used.
It is recommended to use LM4562, which has a wide operating voltage range and ultra-low distortion.
LM4562 is a high-fidelity dual op amp introduced by National Semiconductor Corporation in recent years. Its distortion is very small, with only 0.00003% total harmonic distortion and noise (THD+N). In other words, the distortion of this op amp is almost negligible.
The LM4562 chip has the advantages of extremely low distortion rate, low noise, high conversion rate, wide operating voltage range and larger output current, and its performance is unprecedented. Because this operational amplifier has these advantages, it is suitable for professional and high-end audio systems, such as audio-visual system receivers, pre-amplifiers, audio decoders and high-fidelity power amplifiers, as well as various medical imaging systems and industrial equipment.
The design of the LM4562 chip is very unique, not only a built-in high-speed 6MHz unity gain bandwidth operational amplifier, but also a proprietary stereo audio driver amplifier. Under standard working conditions, the input noise density of this operational amplifier is as low as 2.7nV/√Hz, the noise corner of the intermediate frequency is up to 60Hz, the output current is up to 26mA, and it can drive a load of 600Ω. The conversion rate of the LM4562 chip is up to 20V/μs, and the gain bandwidth product is up to 55MHz.
The LM4562 chip can maintain stable operation within a supply voltage range of ±2.5V to ±17V, with a maximum output current of up to 45mA. When the chip is operated within the above-mentioned supply voltage range, the common mode rejection ratio (CMRR) and power supply rejection ratio (PSRR) of the input circuit are both as high as 108dB or more, and the input bias current is as low as 10μA (typical value).
It is recommended to use LM4562, which has a wide operating voltage range and ultra-low distortion.
LM4562 is a high-fidelity dual op amp introduced by National Semiconductor Corporation in recent years. Its distortion is very small, with only 0.00003% total harmonic distortion and noise (THD+N). In other words, the distortion of this op amp is almost negligible.
The LM4562 chip has the advantages of extremely low distortion rate, low noise, high conversion rate, wide operating voltage range and larger output current, and its performance is unprecedented. Because this operational amplifier has these advantages, it is suitable for professional and high-end audio systems, such as audio-visual system receivers, pre-amplifiers, audio decoders and high-fidelity power amplifiers, as well as various medical imaging systems and industrial equipment.
The design of the LM4562 chip is very unique, not only a built-in high-speed 6MHz unity gain bandwidth operational amplifier, but also a proprietary stereo audio driver amplifier. Under standard working conditions, the input noise density of this operational amplifier is as low as 2.7nV/√Hz, the noise corner of the intermediate frequency is up to 60Hz, the output current is up to 26mA, and it can drive a load of 600Ω. The conversion rate of the LM4562 chip is up to 20V/μs, and the gain bandwidth product is up to 55MHz.
The LM4562 chip can maintain stable operation within a supply voltage range of ±2.5V to ±17V, with a maximum output current of up to 45mA. When the chip is operated within the above-mentioned supply voltage range, the common mode rejection ratio (CMRR) and power supply rejection ratio (PSRR) of the input circuit are both as high as 108dB or more, and the input bias current is as low as 10μA (typical value).
Once more, I am asking you the same question I already asked you in ASR forum and I would expect a real response for all members :
What caps are you using in the XZD-1752PRO (TPA3255 amplifier).
AS PER REMINDER : Aiyima distributes its amplifiers under the Tilear brand and Aiyima
this one :
Last edited:
Since I posted this on October 14th TPA3251d2 - Page 187 - diyAudio I have gone through an Extensive amount of A/B listening tests between the OPA1656 and LM4562, keeping all factors exactly the same.
All equipment and Op Amps have well past 250 hours of operating time.
Simply stated; The OPA1656 sounds better at everything when compared to the LM4562.
If anyone is going to do one simple mod to this amp, give it an OPA1656 Op Amp.
Rob43
Main caps + buffer caps please. Want to make sure that this version of the TPA3255 (XZD-1752PRO) is sold with quality caps.