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Amplifier Modules and PCBs For Sale

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Deleted member 148505

454Casull said:
The TPA3255EVM has two 4700 uF capacitors from PVDD to GND. Does yours have anything equivalent, or just the caps on the amp outputs? If the latter, then there's essentially no bulk capacitance on the board itself, right?
Click to expand...

The 4 big caps in my module are for PVDD rail. There are no output caps since the module is configured for BTL. On EVM, there is an electro cap for each output for DC blocking, because each SE output voltage is at the midpoint of PVDD (virtual ground).

I'm currently creating an 'ultra' version, with the new tricks that I've learned :D while I'm optimizing my ASR module.

I will also add a jumper for M2 pin to enable (post inductor) PBTL.

Happy new year to everyone!
 
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Deleted member 148505

I am liking the PFFB + all Elna Silmic II caps + OPA1656.
This will be the default config of my module.

JLesterP said:
I tried comparing opamp + input caps.
---------------------------------------
PFFB
Pre-Opamp cap = Nichicon Muse UES BP 22uF
Pre-TPA3255 cap = Elna Silmic II 10uF
Opamp = OPA1656
- Smooth and slightly veiled sound, the treble is like -3dB on the equalizer, handles complex sound really well (like fluid and dynamic). Less treble than LME49860.
---------------------------------------
Click to expand...
 
4

454Casull

Member
Joined 2004
JLesterP said:
I modified the interface, I placed additional feedback cap on opamps to reduce bandwidth, and changed some resistors, the opamp has less heat now. I will optimize it further. Next month I will use low noise post switching LDO.


Here's the result of my ASR build with the interface running for 10mins (0.0011%).

Noise is slightly higher, it will be improved once I use ultra low noise LDO.

Best is 0.0008% THD, I have to optimize the interface further to get consistency.
Click to expand...
Remind me again if this is a TPA3255 or TPA3251 build?
 
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Deleted member 148505

Soundcard Interface

I will be upgrading the soundcard interface to INA1651, TPS7A49/30 for low noise power supply :D
 

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D

Deleted member 148505

TICore200

I will be releasing the TICore200 soon (ETA 5 weeks), it has a split supply for the opamps so that the frontend caps can be removed.

1pc TPS7A49 ultra low noise supply for TPA3255.

1pc TPS7A49 for positive rail of buffer opamps.
1pc TPS7A30 for negative rail of buffer opamps.

Price is 20USD higher than TICore260BTL
 

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454Casull

Member
Joined 2004
JLesterP said:
I will be releasing the TICore200 soon (ETA 5 weeks), it has a split supply for the opamps so that the frontend caps can be removed.

1pc TPS7A49 ultra low noise supply for TPA3255.

1pc TPS7A49 for positive rail of buffer opamps.
1pc TPS7A30 for negative rail of buffer opamps.

Price is 20USD higher than TICore260BTL
Click to expand...
The split power supply is onboard or discrete?
 
4

454Casull

Member
Joined 2004
JLesterP said:
I am liking the PFFB + all Elna Silmic II caps + OPA1656.
This will be the default config of my module.
Click to expand...
The Silmic II caps aren't bipolar, right?

Bateman's cap distortion tests show that bipolar electrolytics are measurably superior to polar ones for DC blocking (AC coupling) applications. Especially if they are paired up in series.

https://www.dadaelectronics.eu/uplo...ctronics-papers/Capacitor-Sound-C-Bateman.pdf (page 85 of 88)

Fig 13) Series pair of 220mF 63 volt Nitai Bi-polar electrolytics, measured with 18 volt DC bias at0.3 volt, second harmonic distortion has reduced dramatically. It is now seven times smaller than measured on the best polar capacitor tested.
Click to expand...

Mirror: Cyril Bateman's Capacitor Sound articles | Linear Audio NL
 
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D

Deleted member 148505

454Casull said:
The Silmic II caps aren't bipolar, right?

Bateman's cap distortion tests show that bipolar electrolytics are measurably superior to polar ones for DC blocking (AC coupling) applications. Especially if they are paired up in series.
Click to expand...

I will use Nichicon UES muse BP for THD measurements. Neurochrome tested its THD performance already Nichicon Muse ES bipolar caps measured: <-120dB THD, <-140dB IMD.

454Casull said:
The split power supply is onboard or discrete?
Click to expand...

Split supply is onboard, I added buck converter in inverting configuration to generate negative rail. The supply section covers around 60% of front PCB.

bobo le chat said:
Hello
Great, I hope there will be an A or B version.
I currently listen to a "crazy" version with k75-10 capacitors, the sound is very good, but the best capacitor is no capacitor. So long live the new JLester version.
Happy New Year everyone.
Roger
Click to expand...

I will retain the TICore260BTL but will upgrade it to version 2.
 
4

454Casull

Member
Joined 2004
How do you think the TICore260BTL would fare with just 2x1000 uF (or 4x470 uF) onboard bulk capacitance, for full-range use? What about for mid/high use only?

Have a regulated SMPS (SMPS800RS), would like to power 4 amps from it (2x TPA3255EVM and 2x TICore260BTL) but the total capacitance is too high right now.
 
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D

Deleted member 148505

454Casull said:
How do you think the TICore260BTL would fare with just 2x1000 uF (or 4x470 uF) onboard bulk capacitance, for full-range use? What about for mid/high use only?

Have a regulated SMPS (SMPS800RS), would like to power 4 amps from it (2x TPA3255EVM and 2x TICore260BTL) but the total capacitance is too high right now.
Click to expand...

454Casull said:
I posted elsewhere: TI TPA3255EVM

Thoughts?
Click to expand...

Hi, It will depend on the SMPS that you'll use. Some will tolerate large caps. I think 4x470uF will be better if you plan to reduce the capacitance.

Regards,
Lester
 
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stef1777

Member
Joined 2004
github.com/stefaweb/Q17-Amplifier
Hi!

The photo is misleading. There is 3 cm of distance on the width and more than 4cm of distance on the height between the 230v cables and the others. Same for the enclosure power connector. The 100K pot is not used (reused box)

I hear nothing at all when I glue my ears to the speakers (94dB).

I plan to add a speaker protection board to remove the small pop at on/off.

This one: rx 2 fever sound power amplifier special dual channel anti impact DC protection horn protection finished board|Instrument Parts & Accessories| - AliExpress

Cheers,
 
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