chip amps: Almost everything you ever wanted to know

[DizRotus]

Chris -

Thanks for posting the photos. They're useful.

I just ordered another Lepai. I'll definitely tinker with them, starting with the power supplies.

We'll need to compare notes. I'll buy you lunch at The French Laundry.

[Escher]

Cool - Glad to be of help!

I didnt realize you were local!

[rhing]

I considered the Lepai TA-2020 T-amp for modding, but found another TA-2020 T-amp sold on eBay for $55 including shipping. The S.M.S.L. SA-S1 TA-2020 follows the original Tripath recommended circuit design, uses higher quality components like film caps on the inputs, comes with a 13.8V/4A switching power supply and is housed in a far better looking Aluminum case. I bought mine from eBay seller smsl-china. There are other vendors, but smsl-china is the manufacturer based in Shenzhen, China. Straight out of the box in stock form, this T-amp rivals the best TA-2020 amps including the Trends TA-10.1 T-amp, the DIY Paradise Charlize and Sonic Impact Super T-amp. I use an Audio Research LS7 line stage and Dynaco Stereo 35 6BQ5/EL84 power amp as my main amps with my upgraded Klipsch Forte II's, but the S.M.S.L. SA-S1 T-amp is in no way embarassed by the tube amps. In fact, I've even hooked up my Audio Research PH5 phono stage directly to S.M.S.L. amp and really enjoyed vinyl playback.

I told my buddy in Alabama who also owns a pair of Forte II's about this T-amp, and he bought one too. He is very pleased with the purchase. For $55, this is one of the great bargains in 2-channel audio. I am a DIYer, and I thought I would have to roll new input caps or different inductors, but this amp sounds great as-is. I did touch up some of the solder joints, because they weren't the best-looking solder joints, but that's it.

[DizRotus]

Rich-

Based upon your recommendation, I just bought an S.M.S.L. SA-S1 TA-2020 with a 13.8V/4A switching power supply off eBay for $55 including shipping. I'll compare it to the Lepai and report back.

dale_S suggested (in an email) that modding the small Lepai might not make sense. My reply was that I need a physically small amp to fit with the boombox shown above and that part of the fun of this hobby is making a silk purse from a sow's ear.

At a minimum, I'll try a better power supply (the 13.8V/4A just ordered) with the Lepai and probably a larger capacitor in the amp's internal power supply. Then I might as well bypass the volume, tone, power switch and . . . . wheeeeee . . . . headed down a slippery slope now, but aint it fun.?

[rhing]

At a minimum, I'll try a better power supply (the 13.8V/4A just ordered) with the Lepai and probably a larger capacitor in the amp's internal power supply. Then I might as well bypass the volume, tone, power switch and . . . . Wheeeeee . . . . headed down a slippery slope now, but aint it fun.?

When the Sure TA-2024 T-amp boards were all the rage with DIYers performing mods, I invested in new caps at the inputs and output filter, and even replaced the output inductors. At the end of the day, it sounded good, but nothing like my tube amps in terms of soundstage size, imaging, wamth and smoothness.

I also did something a bit similar with Helder HiFi's TA-2020 MkIII T-amp module, and I was able to eek out a bit better performance, but nothing spectacular. It's different with the S.M.S.L. SA-S1. I suspect the air core inductors and other good components contribute to this amp's performance. I honestly have no desire to change anything in this T-amp. It's not the last word in high end audio, but I use this amp more than my tube amps, just becaus I it is very musical and I can keep it on all the time.

[Mallette]

For $55, this is one of the great bargains in 2-channel audio.

Now THERE is understatement if I ever saw it! I haven't heard this amp, but I always take the word of Klipsch Klan and from what you say this is not simply a "great bargain" but more of a miracle.

It hasn't been that long since anything less than 500.00 new was in the "barely listenable" range and "real" hifi started at a grand.

Rejoice!

Dave

PS - Bet we won't see a review in $tereophile. [6]

[DizRotus]

I edited the subject to broaden the discussion to all chip amps and the hot rodding of same.

As I type this, I'm enjoying the variety of Pandora's shuffle feature--from Roy Orbison to Beethoven to Brubeck to Alvin Lee, etc.--outside, on a gorgeous Michigan afternoon, from my new boombox powered by a totally stock Lepai TA2020, which sounds darn good to these old ears.

Nonetheless, I'm eager to compare it to the S.M.S.L. SA-S1 which is on its way from China (thanks to rhing) and to tinker (thanks to Escher) with this Lepai and the one on the way.

I know, there's a 12 step meeting I should go to if I'm to be cured of this addiction.

[Mallette]

I know, there's a 12 step meeting I should go to if I'm to be cured of this addiction.

Yezzir. Step one is to ship ALL that stuff that is eating away at your life to me.

Dave

[CECAA850]

Here's a good article comparing some of the little amps. I have one of the Indeed amps and really like it, however it's idle at the moment. I think mine is a 2021.

http://techtalk.parts-express.com/showthread.php?228702-Budget-T-Amp-Shootout-Lepai-vs-Indeed-TA2020

[rhing]

Here's a good article comparing some of the little amps. I have one of the Indeed amps and really like it, however it's idle at the moment. I think mine is a 2021.

http://techtalk.parts-express.com/showthread.php?228702-Budget-T-Amp-Shootout-Lepai-vs-Indeed-TA2020

I can't remember if it was in Audiokarma or diyAudio.com, but someone had discovered that S.M.S.L. and Indeed T-amps are manufactured by S.M.S.L. Anyway, here is a good review of a KingRex TA-2020 T-amp by David Kan of Six Moons.

http://www.6moons.com/audioreviews/kingrex/t20.html''>http://www.6moons.com/audioreviews/kingrex/t20.html'>http://www.6moons.com/audioreviews/kingrex/t20.html

Through auditioning T-amps, David Kan discovered the synergy between Klipsch speakers and T-amps. He actually uses Klipsch Synergy F2 speakers as part of one of his reference systems. Who would have thought that SF2's would be used by a professional reviewer, but he claims it gives him many of the qualities he loves about LaScala's.

[DizRotus]

The second Lepai TA2020 arrived today. The good news is it seems to sound even better than the first one using the Lepai supplied 12v 2A power supply (PS). The bad news is I had to open it up to repair one of the spring-loaded speaker terminals right out of the box.

At the suggestion of Chris, aka Escher, I ordered a 12v 6A PS from Amazon. I also found a Motorola 12v 3A PS in my trunk full of junk too valuable to throw away.

Even the 3A PS is a noticeable improvement over the 2A PS. The most obvious improvements are improved bass and more headroom. Those same areas are further improved by switching to the 6A unit.

The photo shows left to right:

LCD Monitor AC Adapter 12v 6A (measured @ 12.50v) purchased from Amazon for $9.79 with free shipping.

Logitech Bluetooth adapter attached to the 15v 3A PS for Klipsch iGroove not yet used with the Lepai

Motorola 12v 3A (measured @ 12,22v) found in a junk box

12v 2A (measured @ 12.17v) supplied with Lepai amp at ~ $5 extra charge.

Based upon my limited experience, were I to order another Lepai, I'd skip the PS supplied and put the savings toward another LCD 12v 6A PS

[DizRotus]

On the recommendation of Rich, aka rhing, I also purchased a SMSL SA-S1 off eBay (see pdf attached). That amp will have a 14v 3.8A PS. It will be interesting to see how the Lepai reacts to that, and, conversely, how the SMSL likes the other PSs.

According to the tracking info, that unit has now made it from Hong Kong into the hands of USPS in Chicago. It should be here any day.

[DizRotus]

The S.M.S.L. SA-S1 arrived today. Everything looked fine. Unfortunately, Christmas in August produced a lump of coal.

The lights came on, but nobody was home. Although I knew the problem wasn't the source, as I'd just been using it to power Lepai #2, I re-checked all connections; nothing. Next I substituted a CD player for the Bluetooth adapter as the source; nothing. Then I tried another power supply; nothing. Finally, I removed the S.M.S.L. from the system and returned Lepai #2, using the S.M.S.L. 14v 3.8A PS; sound poured from Lepai #2.

The S.M.S.L. PS works, but the S.M.S.L. amp does not. BTW, Lepai #2 sounds better than ever on a diet of 14v 3.8A.

Next I'll be able to report on the S.M.S.L. customer service. Fingers crossed.

[Marvel]

The S.M.S.L. PS works, but the S.M.S.L. amp does not. BTW, Lepai #2 sounds better than ever on a diet of 14v 3.8A.

My daughter and family were over today, and brought someelectric train stuff they had bought. One of the power supplies was a Tyco, with 18VDC at 6A. That would probably work pretty well too. Although the DC may not be too smooth.

Sorry to hear the amp was DOA. []

Bruce

[DizRotus]

So far, I'm impressed with the response of SMSL to this DOA amp. I sent a message today (Saturday) about 6:00 PM EDT. Within a few hours I received the following through eBay"

"Hello Neil

We will re-shipping today.

But this is a very strange phenomenon.

Prior to shipment, we have carried out specialized tests. Hard to imagine that this thing will happen.

Anyway, today we will be re-shipping.

best regards

- smsl-china"

Since then we've exchanged a few emails about the symptoms and diagnostic possibilities. They would like the defective unit returned. Their concern and desire to identify the problem seem genuine. At one point they said:

"Hello Neil

We have just been discussing the problems that may arise.

Because we have not encountered this problem. OK, you can open it.

And then sent back to us. When you receive a new one.

best regards

- smsl-china"

While I selfishly wish they would send a working unit and let me keep this one, I understand and admire their desire to identify the problem. Therefore, I will reluctantly not open it so they can see it's condition without wondering if I changed anything.

I asked them to let me know what they find.

They're sending a replacement by air mail.

[djk]

"18VDC at 6A."

The magic smoke escapes at 16V, I had to order another TA2020 chip for a friend at work who got his supplies mixed up.

[rhing]

Neil,

That's unfortunate that you received a defective unit. As much as I like my SMSL SA-S1 amp, I had to touch up some of the solder joints between the amp PCB and the speaker binding posts and the RCA connectors. The right channel would sometimes cut out, and I suspected the solder joints might not be the most solid connections, so I applied a bit more solder to reflow the joints. Since then, the amp has actually sounded better. It looks like SMSL used some lead-free solder that might be brittle.

I hope that SMSL can send you a good working unit and you can evaluate it along with the Lepai TA2020 T-amp.

[DizRotus]

After exchanging several emails, it was unclear whether they wanted me to open the unit. I explained that I would stifle my curiosity so that they would see it exactly as I received it. I received the following at 11:24 pm EDT:

"Hello

I would prefer to satisfy your curiosity, hohoho.

and, when you get re-shipping one, please turn off CASE. Thank you

- smsl-china"

I replied that I'd open it in the morning and send photos and a report. They wished me "good night."

All in all, it's been a pleasant and interesting experience and international dialogue.

"Please turn off CASE" refers to the open eBay resolution case, not the amp's case.

[DizRotus]

After the international arm twisting by SMSL-China, I opened the amp. Unfortunately, there was no obvious explanation of the failure. Some photos are attached to this and subsequent posts.

On cursory observation, the soldering looked good. Some basic continuity testing with a DVM found no fault.

In this photo the seal is still intact.

[DizRotus]

The hood is open.