Me too...was shipped to me already or so they said some time ago, now saying post returned the boards to them and offering the Danzz blue YJ board instead...
I just implemented a FAST with Fostex FF105wk in BR and a Polk PSW111 sub that's driven by a Dayton APA-150 amplifier with variable crossover from 50-150hz. The Fostex boxes are tuned to 72hz and I cross the sub around 100hz. But here's my question. The Fostex are running full without any high pass filter, since they are powered by a separate 2.0 channel amp. I think it sounds good, but the SPL is pretty low. I am now tempted to make a high pass filter for them. What would people recommend for the easiest and cheapest solution? I am intrigued by the 200hz cutoff, though my sub is the weak link. Perhaps 125hz would be a happy medium?
I believe TI datasheet has formula for high pass by changing 4 input caps, believe 4x0.5 uF is around 100hz??? I intend to change those, dont know if somebody did already???
This is the reply to my question what is wrong with the boards:
Because our board design errors, the boot is likely to cause a short circuit.
So we have stopped selling this product.
Too bad, it looked like a nice version...
Also a nice board but no anti-thump. I still wonder what the function of the extra transistors on the other board was 😉
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The transistor might be related to a "soft start" anti-pop feature?
We all have KJA 2013 to thank for that nice aid - I like to include it occasionally as it is on a post several pages back now (post #1667).
You should look at making a line-level second order XO for the FAST. First order will still let quite a bit of energy leak through to throw your excursion. I would frankly add stuffing to your BR box and seal the vent. Make the XO at 200 Hz and you will get much cleaner impulse response from your full range because there is no need for a vented box if you don't go below 200 Hz. The SPL handling will go way up since the cone doesn't move much anymore, however you will still have to deal with thermal dissipation from the voice coil so don't go crazy with the power.
Here is a link to a handy spreadsheet calculator. You may have the caps and resistors already. TLS.org | Passive Line-Level Crossover
You need to know the input impedance of the amp, if you are running a standard red YJ 2.0 board, I believe the input gain is 26dB and the impedance is 30kohms.
Doing it this way you use tiny cheap caps instead of huge expensive ones to get 200 Hz high pass at speaker level.
New (?) one:
Åú·¢²É¹ºÒôÏì²úÆ·-TPA3116 ¹¦·Å°å 100W-Êý×Ö¹¦·Å°å TPA3118¹¦...
And another one designed in Italy
http://www.aresaudio.com/nanoamp.html
Åú·¢²É¹ºÒôÏì²úÆ·-TPA3116 ¹¦·Å°å 100W-Êý×Ö¹¦·Å°å TPA3118¹¦...
And another one designed in Italy
http://www.aresaudio.com/nanoamp.html
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That is small! Looks like a PBTL monoblock but where is the main power rail capacitor? The soldering looks pretty sloppy and like a hand-made proto?
minimum quantity 600-699, so could be proto, I like size and them being mono too, need to scroll back to see if we saw design here before🙂
Wow, that Italian amp is not very neat inside. Looks like some high school kids made it while practicing their soldering skills.
Regarding the ChengZhi 2.0 board, I got the same message from my Aliexpress seller, "Beauty really.
What sellers did others use?
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Thanks for the tips! I will start experimenting. Just out of curiosity, does anyone use or make inline filters like these:
FMOD Crossover Pair 200 Hz High Pass | 266-278
Could it be that 1 Aliexpress-seller could not get Chengzhi boards anymore for whatever reason so could not deliver orders he already had, and made a story about it??? The boards are still offered on Ali and on Taobao and probably many other places too....
Regarding XO, formula TI is identical to first order from xrk971 link except TI likes you to double them for tpa31xx input stage being fully differential. For the external fmod's I don't know...probably single too??
Regarding XO, formula TI is identical to first order from xrk971 link except TI likes you to double them for tpa31xx input stage being fully differential. For the external fmod's I don't know...probably single too??
A person who had been posting on another forum thread regarding the TPA3110/TPA3116 amps sent one to me for free to try out. Frankly, I couldn't figure out what all that extra circuitry up front was all about, so it' stayed in its ESD packaging in my garage workshop. Should I try to power it up and see if it works, or leave it alone?
In the meantime, I've been listening to my Yuan Jing 2.0 TPA3116D2 blue board amp. I noticed the two larger blue box input caps were oriented differently. I had mentioned that the right channel input (on the side labeled on the board as left channel) seemed to have a faint buzz/hum. So. I decided to orient that cap in the same direction as the left channel input cap. I noted when I desoldered the right channel input cap, one of the solder joints was a cold joint and the solder had not flowed onto the thru-hole eyelet. After desoldering he cap in the reoriented direction, I connected the amp to my main system. The amp is so quiet now, I wasn't even sure it was on until I played music. The sound is now better balanced between left and right channels and the amp sounds better with no noise.
Just ordered one from Aliexpress to try out with my Altec MX 5021 setup
My Chinese friend translated the 4 pot descriptions from an image at taobao, left to right:
1. Sub XO frequency
2. Sub volume
3. Treble
4. Master Volume
I guessed correctly 🙂 Those are exactly the adjustments one needs. I might get this too then.
Thanks for the translation.
