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-   -   Trends Audio TA-10 - right channel crackles. It's rare, but annoying. (http://www.diyaudio.com/forums/class-d/108587-trends-audio-ta-10-right-channel-crackles-its-rare-but-annoying.html)

rbclark 16th September 2007 02:26 PM

Trends Audio TA-10 - right channel crackles. It's rare, but annoying.
 
I'm having a problem with my Trends Audio TA-10.1. There's an occasional crackle in the right channel. It happens repeatably on certain tracks. At 1st I thought it must be a problem with my DIY speakers or cables/connectors - 1st project for me - just finished the speakers a few weeks ago.

After swapping cables around, I've isolated the problem to something in the amp on the right channel.
Both of the right terminal posts were somewhat loose in that if you turn the terminal clockwise to tighten, the whole post rotates. I use banana plugs so I there hasn't been much of this tightening going on. So I opened up the amp and tightened the terminals. After testing some of those repeatable tracks, I thought I had it fixed. A couple days later and the problem is back.

I really like this TA-10 and would like to have it in proper working order, but I've been through a lot with it. By the way, this is my 4th unit. The 1st unit would totally cut out on occasion, the 2nd had no LED, and the 3rd was DOA. I've not seen that others have had a lot of quality problems with these units. Am I the only one?

I'd appreciate any suggestions as to what to look for to solve this problem. I really don't want to send another one back. Even though I feel like it's a quality problem, I feel like the distributor has been though enough given the small amount of money he must make on these.

Thanks!
Bob

Tripath07 16th September 2007 05:59 PM

"I'm having a problem with my Trends Audio TA-10.1. There's an occasional crackle in the right channel. It happens repeatably on certain tracks. At 1st I thought it must be a problem with my DIY speakers or cables/connectors - 1st project for me - just finished the speakers a few weeks ago. "

hi rbclark, from your post above, if it happens (repeats) on the same tracks it might be the cd's.

good luck!

rbclark 16th September 2007 07:37 PM

Quote:

Originally posted by Tripath07
"I'm having a problem with my Trends Audio TA-10.1. There's an occasional crackle in the right channel. It happens repeatably on certain tracks. At 1st I thought it must be a problem with my DIY speakers or cables/connectors - 1st project for me - just finished the speakers a few weeks ago. "

hi rbclark, from your post above, if it happens (repeats) on the same tracks it might be the cd's.

good luck!

It hadn't occurred to me that it could be a bad CD - interesting idea. I investigated this a little more. Actually, my source for this is a SqueezeBox, but I went & got the CD and did a test with it too. Still had the crackle with the CD. Also re-ripped to FLAC and confirmed with AccurateRip. A little more testing and the problem went away. Never touched anything! I think, but it's hard to say for sure, that just walking from 10 feet away to be right in front of the amp/speakers and the problem disappeared. I tried to move back & forth the get something reproducible - but the problem did not return.

I guess I thought it was repeatable - but it's not... exactly. I know for a fact thought that I've heard this "crackle" on some other tracks in the same place more than once. I was guessing it had something to do with a certain frequency or combination?

My definition of "Crackle" - kind of like the sound of static electricity when pulling sheets out of the dryer. It's heard superimposed on the music - maybe not quite as loud as the music. Very disturbing though.

Some other ideas I'd appreciate any thoughts on:
1 - what's a dry solder? Could this be caused by that?
2 - is it possible that the speaker terminal post rotating could have rotated to a the point of some kind of damage?
3 - the tabs (inside the box) that the wires going from speaker terminal to circuit board are connected to - they're not all at 12 o'clock like I notice in a picture of someone's mod'd TA-10. Do they need to be at 12 o'clock?
4 - Is there any evidence that a bad batch of these TA-10s came out with numerous problems?

Thanks for the help!
Bob

Pano 16th September 2007 10:54 PM

Well, as nice as the Trends is, and as good as it sounds, they do have soldering problems.

Having hard my hands in many dozens of these, I can tell you that board flexing/bad solder joins is the major problem.

Very often the amps will go out in perfect working condition, only to get shipped right back with problems, as you well know - Mr. Clark! You seem to be particularly unlucky. :(

Most of the solder problems seem to be around the chip. Trends Audio is aware of the problem and are trying to fix it.

Bottom line seems to be, if you get a good one, it's fine. But many of them suffer in transit or after being handled for upgrades.

Something you might try is to press gently on the chip while the amp is playing and listen for cut outs or noise. I've found that flexing the board at the chip tends really points up the problems. Be careful, the chip can get hot!

rbclark 17th September 2007 12:07 AM

Quote:

Originally posted by panomaniac

Most of the solder problems seem to be around the chip. Trends Audio is aware of the problem and are trying to fix it.

Bottom line seems to be, if you get a good one, it's fine. But many of them suffer in transit or after being handled for upgrades.


Ok, I'll give that a try. My soldering skills are pretty amateur. If I find that the amp responds to pressing on the chip, would you say that I can repair this by desoldering/resoldering the chip?

Or maybe I do need to send this little guy back for replacement one more time. From the outside, it's kind of hard to explain why you would rely on something with such a run of bad quality/luck.

Maybe if I could get my money back (I hate to do that to the distributor, it's not his fault), I could go for one of the modded TA-10s already checked out and tweaked to boot?

Another thought I had was to spend a little more and go for a KingRex. But I do like this TA-10... when it's working - it works great!


Thanks!
Bob

Pano 18th September 2007 01:15 AM

Quote:

Originally posted by rbclark
If I find that the amp responds to pressing on the chip, would you say that I can repair this by desoldering/resoldering the chip?
Probably not, if you're not great at solder skills. I have had luck running a fine tip iron over the legs of the chip to resolder. Some times it helps, sometimes not. No extra solder, just reheat.

Quote:

From the outside, it's kind of hard to explain why you would rely on something with such a run of bad quality/luck.

A good point, but maybe it's "the devil you know instead of the one you don't." There are many more good Trends than bad, it's the bad ones that call attention to themselves. You seem to have had really bad luck. :xeye:

None of the T-Amps I've seen have been 100%, except maybe those I've only seen one example of. ;) I don't think it's a chip problem, more a problem with board manufacture. It is frustrating, though.

rbclark 23rd September 2007 01:54 PM

As far as soldering skills, I'm using DIY speakers with amateur soldering for the internal wiring to driver and binding posts. Could this cause the intermittent crackle problem?

I'm listening to these speakers right now with a home theater receiver to see if the crackle still ocurrs. If it does, it may not be coming from the TA-10.

Pano 24th September 2007 10:10 AM

Could be from the speakers.
Pressing on the board of the Trends is a good test..

rbclark 30th September 2007 08:40 PM

It's not the TA-10!
 
Quote:

Originally posted by panomaniac
Could be from the speakers.
Pressing on the board of the Trends is a good test..

I tried pressing on the board and the chip inside the TA-10 while it was playing - nothing. Rock solid. But I did isolate the problem to my Pioneer VSX-816 receiver.

Please read on, because I still need some help though.

1st, I'll describe my standard layout:
Squeezebox -> digital coax -> receiver -> receiver preamp outputs -> TA-10.

I pulled the left channel speaker cables off of the TA-10 and plugged them into the amplified right channel output from the receiver. This left speaker would be fed only by the receiver - not the TA-10. After several hours of listening, both speakers started the crackle at the same time - they were both being fed the right channel - but one from the TA10 and one from the receiver. Also, since I wasn't listening to one good channel and one bad channel at the same time, I realized how much audio I was losing when this condition occurred. It was terrible! Sometimes there was no sound at all!

The next test, was to bypass the receiver and feed my squeezebox directly to the TA-10. In several hours, I haven't heard any crackle. I think the problem must be with the receiver. Whew!

As I've been reading the DIY forums, I've come to trust/appreciate the minimalist approach. I love my full range (Fostex 167e) speakers and the TA-10. But since I wanted to listen to my cable box and DVD player through the TA-10, I needed something to switch sources. I've been a little worried that I wouldn't get the best sound going through this Best Buy quality receiver as a pre-amp - but you know what? It sounds great in this combination! Does that make sense? I figured I'd keep reading/learning and ultimately figure out how to get the job done with a better quality (low cost!) pre-amp.

What I'd like some help with us understanding why the receiver-pre-amp helps so much. With it in the loop, the sound has much more depth. I'm going to get my wife to help me with some blind AB switching. It wasn't until I did this troubleshooting that I realized how much of a difference it makes. This receiver has microphone that you can plug in and let it send test signals at it through the speakers. Doing this, it figures out what speakers you have (left,right, surround, center, sub) and how far they are from the microphone. I guess it does some things that help make up for the room acoustics. Could this be why I like the sound through the pre-amp/receiver so much more? Or does it have something to do with just using a pre-amp? I think not, because when I put the receiver in "direct" mode, the sound flattens out again. By the way, I'm just listening to the 2 front channel speakers for music.

So my whole problem is, based on what I read here, that all this receiver magic stuff (acoustic EQ, etc) is supposed to color the sound, taint the sound, etc. That I shouldn't like the sound as well. Am I crazy? I haven't even received my junior audiophile wings yet.

Thanks for any thoughts on this.

Bob

rbclark 1st October 2007 09:09 AM

Re: It's not the TA-10!
 
Quote:

Originally posted by rbclark


I'm going to get my wife to help me with some blind AB switching.

Scratch this part. I got this post and another I'm thinking about mixed up (hearing the difference between 3 different DACs and the best one is 9 years old!).

No AB testing is required to hear the difference between "direct" and "stereo" modes thru the receiver. The "direct" mode is flat.


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