Sure Electronics New Tripath Board tc2000+tp2050

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#1,721
Not Daisy chained

I had separate + and - wires from each amp to the power supply with a star ground and still observed the noise. Personally, I don't really care about the shared power supply noise phenomenon as I am just as happy to use a dedicated power supply for each amp module anyway and bi-amp with complete separation for right and left back to the AC. The well known benefits of reduced cross talk, better regulation and improved current supply headroom from multiple and bigger power supplies will apply and cost is not an issue at $40. I was just curious to try to explain the noise.
dr suad said:
Scott,

I wrote to Sure Electornics about your situation and got the following reply:

"Thanks a lot for your letter.
According to our past test, there is no phenomenon of mutual interference among the amplifier boards when powered by one power supply. But a certain effect of EMI exists due to the following 650 KHz high frequency amplifying signal; even though amplifying signal was removed by LC Low Pass Filter.
And we doubt that it is the overlarge ripple wave of the power supply itself which lead to the interference. It is suggested that you should connect the two amplifier board respectively to avoid the interference."

I then asked an electrical engineer I knew and he said: "if output impedance of power supply was high, you might get some of the ripple of one mixing with other one , say 651 Khz mixing with 650 to give 1 Khz tone. SInce switch freqs are free running, the difference could be anything.

Use separate plus and minus from each amp to power supply and not daisy chained through each amp."

Perhaps this was the issue?
Click to expand...
 
#1,722
Buffer

Hi guys.
I just want to put something in between ,some kind of tube buffer or something else .Just to take of the sharp edge.
I feel that sound is a bit thin .Then again i don't want to loose that clarity this little amp have🙂.
Im feeding now with Zero DAC at the moment.

best regards
 
#1,723
sled108 said:
Whoooaa...V-Bro....What's that Mill out of?
Click to expand...

Perhaps it was a Zwesda afterall!
zwesda.jpg
 
#1,724
Me too

I have spent quite a long time wading through the 170 pages of posts here but have only read about 10% of the stuff that's been written.

I bought one of these things, hooked up the inputs to my mac headphone output, hooked up a pair of cornwalls, connected a stupid 12VDC .7A wall wart and it sounds very, very fine. No noise, good, solid bass. The wall wart does NOT overheat. The gain settings are on the lowest level.

The worst thing about it, for me at least, is that sometimes I get a short, screaming explosion through my speakers when I do something like switch between iTunes and some embedded video I am watching on the nets. I have not blown the tweeters yet but I am sure that is inevitable in this setup.

I like this amp enough to build it a decent power supply. But I really want to know if anyone has dealt with speaker protection issues when using this board?
 
#1,725
13 gauge inductors

I found some cores at my local surplus store and decided to give it a go winding the inductors with 13 gauge wire I had laying around. I had no clue what values I could get so I used my oscilloscope,a 800Khz sine wave and a decade resistor box to figure out the value. By chance, two complete tight layers around the core yielded a value of 11.5uH +- 2%. A little big though so I had to stagger the height.

I am using 100db full range speakers so I can't really turn up the volume so I guess I am only using less than 10 watts per channel.

Removed the stock input caps and suppressor and put 3.3uF's below the board.

Also found a brand new Meanwell RS-150-24 at allelectronics in LA (local store) for 26 dollars, they sell them on their site. It works quite well. I believe this model has better specs than the S series smps.

It sounds quite good. I have the fan on and with my sensitive speakers you can hear the fan buzz is you put your ear next to the driver, so I can't hear anything from my listening position. I did try it with the fan off, but even at low wattages the heatsink gets hot and the sound starts to degrade.

I have included a couple of pictures.

Alfredo
 

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#1,726
Try this one on for size:

An externally hosted image should be here but it was not working when we last tested it.


V18 Mini!!

Sorry, moving back on topic.

sendler said:
If you want to use balanced cables;
Wire pin 1 to ground, Pin 2 to your input cap, pin 3 can be terminated with a 22k resistor to pin 1 to balance the cable. You may also want to experiment with a fixed attenuator at the amp as the DCX has way too high an output level. I would start with -12db. Once you get this right, you will be able to use the DCX with it's digital input and use digital volume control. Add 4k resistors in series with pins 2 and 3 and then another set of resistors from the output of the 4k resistors to pin 1 to form the pad. Start with 1.3k for the shunt resistors. increase or decrease from there to get the right listening level for your speakers with the digital in and to just keep from peaking the the analog input meters when the system is playing at your loudest listening level. If you have one driver that is much more efficient than the other, you can also use different pads for the tweeters and woofers to get them to a closer match so you don't have to use so much digital attenuation in the crossover of the louder driver.
Click to expand...

These are the input caps, right?

Just making sure I understand you correctly, this is all I need to do?

Is a standard 0.6Watt resistor fine for this?

As for the attenuator.... if I use one, do I still need the 22k resistor (R1 in my drawing)?
Do I want my circuit to look like this:
An externally hosted image should be here but it was not working when we last tested it.

?

Or am I misunderstanding you? Also, once again, are 0.6W resistors fine for this?

Thanks for the information!
 
#1,727
Seems like a great board for my boombox modding project - I think there should still be decent power on these running them on 12V (or 15, still need to get the old boombox & check) - do I still need to run active cooling on this power level or can I slap a passive cooling fan in there?
 
#1,729
Correct

All that you show is correct. If you go for the attenuator, the least wire following the series resistor the better the sound. Any size resistor will do, 1/4 watt, 1/8, 1/10. You can keep the 22k on pin 3 in addition to the attenuator to balance the cable but I doubt if you would hear a difference in sound quality compared to just leaving pin 3 open and, the actual input impedance of the amp may be closer to 11k with the addition of the virtual load of the input gain setting resistor so trying to keep the cables perfectly balanced will be tricky anyway. You can use the terminal block or just solder to the input terminal of the cap. I like the sound of the Susumi surface mount resistors the best and for through hole, I like the Yageo metal film resistors much better than the Vishay/Dales that got so popular. If you are going that far you will really want to replace the input caps with a nice 2-3uf Obbligato and remove the input suppressor. And go passive with the cooling and ... And do the direct out mod to the DCX and...
.
.
klankymen said:
These are the input caps, right?

Just making sure I understand you correctly, this is all I need to do?

Is a standard 0.6Watt resistor fine for this?

As for the attenuator.... if I use one, do I still need the 22k resistor (R1 in my drawing)?
Do I want my circuit to look like this:
An externally hosted image should be here but it was not working when we last tested it.

?

Or am I misunderstanding you? Also, once again, are 0.6W resistors fine for this?

Thanks for the information!
Click to expand...
 
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#1,730
Last edited:
#1,731
sendler said:
All that you show is correct. If you go for the attenuator, the least wire following the series resistor the better the sound. Any size resistor will do, 1/4 watt, 1/8, 1/10. You can keep the 22k on pin 3 in addition to the attenuator to balance the cable but I doubt if you would hear a difference in sound quality compared to just leaving pin 3 open and, the actual input impedance of the amp may be closer to 11k with the addition of the virtual load of the input gain setting resistor so trying to keep the cables perfectly balanced will be tricky anyway. You can use the terminal block or just solder to the input terminal of the cap. I like the sound of the Susumi surface mount resistors the best and for through hole, I like the Yageo metal film resistors much better than the Vishay/Dales that got so popular. If you are going that far you will really want to replace the input caps with a nice 2-3uf Obbligato and remove the input suppressor. And go passive with the cooling and ... And do the direct out mod to the DCX and...
.
.
Click to expand...

Thanks a lot for all your information, just making sure I have it clear. To clarify, this amp won't see any frequencies above 100Hz, so I'm not hugely worried about sound quality (or sound of resistors, although odds are I will be using Yageo due to availability). I'm just trying to eliminate any clearly audible effects such as humming or clipping. Mods to the DCX are planned, but rather low priority, considering I don't even have my DCX yet 😉
 
#1,732
In response to post #1683:

I wouldn't get torqued about someone buying Tripath chips and putting them onto any old board that people want to buy. A chip is a chip, and no flaky ideas about "exclusivity" are going to lead to profits in the world of chips. Unless Tripath sells hudreds of millions of chips, which it looks like they may be on their way to doing, they'll go the way of Pacific Microsonics, who thought they were too cool to sell to anyone.

Unless I can get my hands on a full datasheet, buy parts at Digikey, and get all the firmware for free I'm likely not to buy anything. The fact of the matter is it'll all be garbage in 6 months compared to new parts.
 
#1,739
upgraded new version (AA-AB32181)

Today i got my sure amp (AA-AB013) and now i see , that there is a nuw upgraded version with regulated cooler and a better Snr of 100db instead of 85db.
Does someone know how the noise was improved?

However i found out that there is a diode at the input section.
What is the function of it?
An externally hosted image should be here but it was not working when we last tested it.




greetings sunny
 
#1,740
Im glad somebody mentioned this! You cant tune a zobel by ear. You'll most likely end up with a wildly inaccurate frequency response if you do.
Ouroboros said:
Don't forget that on these amplifiers, where the NFB is taken from before the output filter, that the optimum values of L and C in the filter varies with the load impedance. For example, a simple SPICE simulation of the filter shows that for 4R loads, the best inductor value is around 10uH, whereas for 8R loads, a value of around 16uH is better. (Obviously the capacitance values also need also to change to give the optimal load matching and the flattest response). I'm a little surprised that some people seem to think that you can tune the output filter by ear! A simple frequency spectrum sweep into the desired load is better. (There's plenty of s/w out there to do this if you have a good sound card to use as the audio interface. I use ARTA for the measurement s/w.)
Click to expand...
 
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