Jazzy,
Both Lai and I are using the same SMPS as yours with our main T-amps now (we heard how good it is during our first t/t session). It sure is excellent stuff with 4.2A on tap and its DC voltage could be increased to 14V max. Even at 12V setting now, it sounded so much better than my other SMPS – less flat-sounding and less tiring over long period of listening with ample of reserves when demanded upon. I only took 1 shot with my mobile phone - no close ups.


Monkey King,
I’ve just commented positively on the Meanwell S-50-12 SMPS. Perhaps you may like to consider getting it although it’s slightly more expensive over others.


March,
Both Lai and I thought the Vishay MKT1813 2.2uF caps are fabulous sounding (although we have not experiment with many), the sound quality of these caps surpassing that of the highly raved Vishay MKT1822 2.2uF (green square caps) in our 2nd T-amps. You heard them (in Lai’s T-amp) during our first t/t. The lack of power was due to type of SMPS used then.

Name of shop = Online Components S/B

CYL, Thanks, I tested my unit with a test pen and found no current leakage on the cage. However, we do need to be careful with the screw-on connectors behind. For extra precaution, we could consider housing them in plastic casings.

Go for Meanwell SMPS model S-50-12 and you would not go wrong.

Thanks for sharing, Najmods.

I had mentioned that my T-amp with use of Meanwell S-50-12 SMPS sounded substantially better than with computer-notebook-style SMPS. In what manner? The sound becomes fuller, more 3 dimensional (less flat-sounding) and the amplifier behaves like a real 50 watter instead of a mere 20 watter.



This post has been edited by Y.C.: Nov 18 2008, 12:54 PM

Thanks, bsl

The wiki of diyAudio.com (http://www.diyaudio.com/wiki/index.php?page=Class+D+Amplification) states that 3A – 5A regulated supply is typically aplenty as the T-amps only draw about 300mA with a musical signal, with many speakers. Even when a battery is to be used, its recommended amperage-hour is 7Ah. Why do you feel a need for such high current of 60Ah for the T-amps?

I’m sure bsl meant well. He has always been stressing the importance of having adequate power supplies for phono preamps and now the T-amp.

I’d fully agree that the TA2024 chip does not only draw 300mA constantly with musical signal all the time as very loud and complex music passages with lots of bass will definitely draw more current. And with difficult load loudspeakers (their impedances dipping very low), the T-amp will require even more current. Question is, is 4.2A of Meanwell SMPS really insufficient? Jazzy seems to think otherwise and Xtorm quoted a measurement by Ongbs before.

My take is, with the T-amp driving medium sensitivity loudspeakers of benign loads and music not being played to headbanging levels, 4.2A should be sufficient. I could be wrong though. Powering the T-amp with a car battery may be a costly affair and it (the battery) needs regular charging too.

What input capacitors and value you’re having in your T-amp? I believe these are culprits to the 'thump' sound you’re hearing.

In my case, I leave my T-amps permanently on, hardly switching them off. When they’re newly soldered including my well run-in 1st T-amp board (fixing it into an aluminium casing with new wires and speaker binding posts) which I reported no 'thud' sound earlier, I heard it but it disappears the moment the sound becomes run-in again.

March,
I'm not going for battery power although I've read and convinced of its benefits. It's the convenience I'm after instead of absolute sound quality; my T-amp is not part of my main system at home. On leaving my equipment permanently on, I was made to understand that the capacitors of these equipment would last longer than the constant switching on/off.

On the switching-on thump sound, the wiki of diyAudio.com (URL provided in earlier posting) has this to say on "Which input cap is best? What size cap do I need?" - No one has yet to establish a "best" cap. Any good metalized film or film/foil cap will make you happy. Some users have reported preferring electrolytic cap, such as Blackgate, for more bass impact. A value of 2uF or 2.2uF is as large as you need. Voltage can be as low as 5V. Bigger sizes, say 4 to 10uf, will definitely give a big switch-on thump.

Some of us ask questions and once the questions are answered, they would then gleefully disappear without any sort of acknowledgement.

---

Added on November 16, 2008, 4:35 pmWe thought you're truly a music lover, and that is a compliment.

Take your time, bro.





This post has been edited by Y.C.: Nov 16 2008, 04:35 PM

Gabanyayaya,
I'd not be able to tell whether those Alps Blue A X2 / RK27112 going for sale at eBay for RM56.XX (USD16.XX) are only replicas and not the real thing themselves. The representation made is they are genuine. Yes, I joined hohodiy bulk order and bought one 50K pot for myself, again not 100% sure it is not an imitation although I doubt it is fake.

I am not really a believer of Alps volume pot. Built-wise, it may be better than the Alpha pots from JP but in term of sonics (transparency and musicality), no way near the resistor type. And I am not alone in my thought, see the following comment at Audiomahus:

"You will find a new volume control potentiometer, the Precision Electronic Components (PEC) volume pot. Made in Canada, this all-carbon POT with a solid-carbon wiper is resin sealed and built to military specs. We spent a long time searching for a great pot and we found something very special with the PEC. It is transparent and very musical ?span style="font-size: 10pt;"> more detailed than the Alps Blue, but with the mass and substantive build that the Alps lacks"

March, I agreed with this part of your comment - "a capacitor primarily functions as a on-off energy storage device, i.e. it is constantly charging and discharging while you are using the amp." I'd think during standby mode, the capacitors are not working (charging and discharging) but merely getting ready to work anytime. Although the T-amp's TA2024 chip is not a capacitor, it runs hot when music is playing and when all is idle, it gets cold again although the amp is still being powered up.

I believe in more damages being inflicted to the capacitors during powering up, just like cars during their cold start in the morning, as a result of sudden insurge of current into them. Perhaps I may have been incorrect, but I believe that "...for the best sound quality, our systems should be left on all the time. They give the best performance, the best ultimate sound quality and according to studies carried out, equipment left on all the time has a reduced incidence of breakdown. Switching electronics on puts enormous stress on the internal components and this shock damage is the main reason for component failure." quoting the words of RA.


This post has been edited by Y.C.: Nov 16 2008, 11:48 PM

Gabanyayaya, I already have the RM2.50 Alpha pot from JP in my second T-amp. I am getting the Alps RK27 as it is better built and should make a slightly improvement to the sonics of my T-amp at RM30 thereabout.

Jazzy, since you are already happy with the current sound quality of your pre-amp, you could forget about Alps volume pot although my personal belief is that replacing your existing volume pot with something better would not upset its sonic balance and it could only get better.

Gabanyayaya, I ordered Alps RK27 at NT$225 each or RM27 - RM33.75 (@ 0.12 - 0.15), depending on actual exchange rate and this amount is before shipping & handling charges or custom duties (if applicable).

Wui, Since your T-amp is having 2.2uF input capacitors, it should not have the switching-on 'thump' sound once it is fully run-in. That is my personal experience with 2 T-amps so far and Lai (my colleague) concurred with his units.

March, not at all.

The subject, just like those on use of dedicated powercords and exotic cables, could be debated endlessly without much conclusion, so the adage of "To Each Their Own" shall apply.

I first adopted this practice many years ago following recommendation of equipment manufacturers in the accompanying instruction manual with great unease but as time goes on, I got immune to it and now very much a believer myself. And whenever I come across articles that sang my tune, my ego would be inflated and I will tend to quote them.

BTW, my resident amplifier in main system is another of such equipment and during powering up, there would be quite a loud 'thump' sound of which the distributor pronounced it as 'normal' as the manufacturer has purposely omitted the use of relay in its input stage so as not to compromise its ultimate sound quality.

I would offer "To Each Their Own" as answer.

I am only using the RM0.30 per metre run of AWG-26 multistrands copper wires for internal wiring throughout. Read about my thoughts and rationale behind some of the actions in building my T-amp: Summary of T-amp project, most if not entirely all were expressed in this thread before.

There are several links to some very interesting sites in my said article which is updated from time to time.





This post has been edited by Y.C.: Nov 19 2008, 12:15 PM