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DizRotus

chip amps: Almost everything you ever wanted to know

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I installed one of the SURE digital volume controls in my DIY boombox.

 

Without it, the signal was delivered via Bluetooth or a TRS cable.  In either case, the volume was controlled by the iPod, iPhone, iPad, Pono player (not Bluetooth), etc.  In addition to the volume control, I added RCA inputs.  A TRS to RCA plugs cord connects my Pono from line-out to the RCA inputs.  The small rocker switch sends power to the Bluetooth in one position, the SURE digital volume in the other position and is OFF in the center position for when the TRS input is being used.  The metal plate for the handle is now quite crowded.

 

I'm very pleased with the SURE digital volume control.  Using line-out from the Pono player, the volume is more subtly adjustable, plus there is a push to mute function.  The maximum volume is now louder than when using the headphone output directly into the TRS connector.

 

IMG_0053 (Medium).JPG

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On 6/25/2017 at 8:30 PM, DizRotus said:

 I suppose I could get a second SURE unit to keep the two balanced outputs

 

Turns out I bought two more.  One is in the boom box.  The other two will go in the case with my Wiener TPA3118.  That way I can preserve the balanced output from my Pono player.  The question is whether to combine both channels of each to control a single channel of balanced output, or use just one channel of each stereo digital volume control?

 

Any thoughts @rhing or anyone else?

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Today I finally got around to trying the Texas Instrument TPAS3255EVM received about a week ago, due to the corruption by Rich, @rhing.  The 3255 is fed 48v from a Mean Well PSU also recommended by Rich.  The improvement over the excellent TPA3118 is startling.  I can't recall how much power it puts out in 2-channel BTL mode when fed 48 volts.  Perhaps Rich will chime in with the informed details.

 

For info regarding the speakers in the photo of my cluttered basement, go to the thread below.

 

 

IMG_0317 (Medium).JPG

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Hi Neil,

 

Welcome to the TI TPA3255EVM club. At 48VDC from the power supply and assuming a nominal 8 ohm load, your amp is capable of about 140 watts power. I highly doubt you are pushing 1 watt with your efficient speakers. This amp combined with my Audio Research LS7 tube linestage preamp is great for listening for hours. 

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I wanted to take a moment and close the loop on something from waaaaaaayback in the beginning of this thread regarding the Ta2020 Lepai amps.

 

I had to take mine out of service after a few months (years ago now)... as I found that the output inductors were getting super hot and the ceramic was actually darkened (read:cooked!).  Not sure what happened there... but I can't in good conscience say the output mod I did is safe.   I know its ancient history - but if any of you folks run these and have done my mods - PLEASE check your output inductors for signs of overheating!!!

 

Again - sorry for not responding sooner - I had completely forgotten about this project until I was going through some old threads and remembered why I stopped using them..

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Today I finally got my Texas Instruments TPA3225EVM working in a case.  The pressure of the 8/10/19 gathering of Southeast Michigan forum members forced me to complete the project.  Lack of time and the excellent sounding Wiener TPA3118 made it easy to ignore the 3225.  The first photo is the exposed Wiener.

 

Without even hooking the four Anarchy Exodus TH subs back up, the sound improvement over the Wiener is remarkable, that’s why I’m remarking about it.  The Wiener will be the power for my outdoor HIPs.

 

A DIYer’s dream come true.  At first power up, glorious sound and no smoke.

 

5a24aba45df20_20171203_201315(Medium).thumb.jpg.61fa89ad32fad1e82cf4aa32e3e67e9a.jpgTPA3225EVM.thumb.jpg.f97482699864649f59c534ceac680069.jpg

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5 minutes ago, DizRotus said:

Today I finally got my Texas Instruments TPA3225EVM working in a case.  The pressure of the 8/10/19 gathering of Southeast Michigan forum members forced me to complete the project.  Lack of time and the excellent sounding Wiener TPA3118 made it easy to ignore the 3225.  

 

Without even hooking the four Anarchy Exodus TH subs back up, the sound improvement over the Wiener is remarkable, that’s why I’m remarking about it.  The Wiener will be the power for my outdoor HIPs.

 

A DIYer’s dream come true.  At first power up, glorious sound and no smoke.

 

5a24aba45df20_20171203_201315(Medium).thumb.jpg.61fa89ad32fad1e82cf4aa32e3e67e9a.jpgTPA3225EVM.thumb.jpg.f97482699864649f59c534ceac680069.jpg

No smoke on the first try? How boring. The hard part is getting the smoke back into the wires.

Admit it, you pushed the ON button REAL slow didn't ya?

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6 minutes ago, MookieStl said:

No smoke on the first try? How boring. The hard part is getting the smoke back into the wires.

Admit it, you pushed the ON button REAL slow didn't ya?

 

No, but I was wearing eye protection.

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On 7/21/2019 at 7:55 PM, DizRotus said:

Truth be told, one output was out of phase.

 

Now that I think of it, both outputs were out of phase.  One output was wired with reversed polarity.

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Some immediately tweet everything in their heads that passes for a thought. Others are more deliberative.  Still others are just slow. I confess to the latter.

 

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