Jump to content
The Klipsch Audio Community
DizRotus

chip amps: Almost everything you ever wanted to know

Recommended Posts

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

Share this post


Link to post
Share on other sites
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?

Share this post


Link to post
Share on other sites

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

Share this post


Link to post
Share on other sites

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. 

  • Thanks 1

Share this post


Link to post
Share on other sites

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..

  • Thanks 1

Share this post


Link to post
Share on other sites

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

  • Like 1

Share this post


Link to post
Share on other sites
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?

  • Haha 1

Share this post


Link to post
Share on other sites
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.

  • Like 2

Share this post


Link to post
Share on other sites
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.

Share this post


Link to post
Share on other sites

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.

 

  • Like 1
  • Haha 1

Share this post


Link to post
Share on other sites

The Texas Instruments TPA3255EVM and Mean Well 48v power supply are housed in the black case above the pair of iNuke1000dsp amps that each powers a pair of Anarchy Exodus tapped horn subs.  The 2-channel system is now totally powered by class-D chip amps. The ability of the 3255. and the iNukes to accept the balanced outputs of a Pono player results in glorious sound in my small basement space.

 

At present, the main speakers are the “Superized” HIPs in front of pairs of TH subs.  My wife slightly  prefers the HIPs to the DIY Supers inboard of the HIPs and so do I.

 

The efficiency of the HIPs and TH subs prevents the chip amps from ever getting even slightly warm.  One knock on iNukes is their noisy fans.  To address this I immediately removed the fans.  Not once has either INuke been shut down by its thermal protection circuit, even after extended bass heavy selections at relatively high volume.  DSOM rattles objects upstairs but the fan-less iNukes soldier on.

 

At idle, the tweeters are dead silent.  The power consumption at idle is minimal, heck it’s minimal at high volume, so I often leave the whole system powered on for weeks at a time.

 

FYI, the three DIY Fostex 103 bass reflex single drivers in the photo are for TV/HT sound only.  My original plans to share the subs with the HT system never materialized.  It’s not worth the hassle to switch the subs from the balanced chip amps to the unbalanced Onkyo AVR.  In reality, the HT sound provided by the five (2 rear channels not visible) DIY single drivers is more than acceptable.  We would rather have the TH subs provide tight bass for music than explosions for movies.

 

I can’t imagine a return to space heater tube amps.  With class-D chip amps replacing tube gear my music enjoyment has increased and my AC costs have decreased.  YMMV

 

6BC8D6DF-7213-40DA-91E2-E3671034CA87.thumb.jpeg.8fc4687a0a32ce625096328f00833e4f.jpeg

  • Like 1

Share this post


Link to post
Share on other sites
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
Thanks for showing us your exposed Wiener.

Sent from my SM-G950U using Tapatalk

  • Like 1
  • Thanks 1
  • Haha 2

Share this post


Link to post
Share on other sites

It only took six months for that setup to be spiked.

Share this post


Link to post
Share on other sites

Just for the record :

I'm using an actively tri-amped system (if you include the subs)

ever since I tried the mini class D / T amps I was hooked! 

Currently have a 25W SMSL SA50 on the 40-400Hz range driving Peavey FH1 bass horns with K33E inside; above 400Hz is a fully modded Trends TA10.1 tripath amp (8W) driving the mid and tweeters; the clarity, imaging, detail, and impact are out of this world - in active bi-amplification each amp operates within its limits at all times (at least with 104dB speakers in a home-audio context) and my ears give up way before the sounds starts to distort or get harsh; only the active subs have more traditional class AB amps.

 

My preamp and amps stay on 24/7/365 and stay cold and don't consume much electricity; I've stopped worrying about having an amplifier suddenly failing (and destroying a driver while doing so), and the sound is better than I ever had with any "high end" class AB or class A amplifiers I've owned.

 

As active crossover I'm using the K231 from Sublime Acoustic, which I highly recommend if you can live without digital delay and DSP; the sound is fantastic and it's as silent as a tomb. It takes a couple weeks of burn-in (quite harsh and fuzzy fresh out of the box) but after that it's a fantastic crossover at ANY price.

  • Like 2
  • Thanks 1

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


×
×
  • Create New...