Stepped attenuator made for Volt +...10K
Using 1206 SMD with 0.1% thin film. Price will be around 30$
Using 1206 SMD with 0.1% thin film. Price will be around 30$
whatever vol control you use, make sure you buffer it before you drive practically any amp, esp. the chip amps.
I am using PGA chip based preamps and they have a buffer on-chip, but I even buffer after that (for various reasons) and then send that signal to this chip (3118) and have great success.
every time I used a passive pot with no buffer to lower the output-z, the noise was uneven and often very loud. even with the pot very close to the input of the chip-amp.
I am using PGA chip based preamps and they have a buffer on-chip, but I even buffer after that (for various reasons) and then send that signal to this chip (3118) and have great success.
every time I used a passive pot with no buffer to lower the output-z, the noise was uneven and often very loud. even with the pot very close to the input of the chip-amp.
tpa3118 $6 unbranded PBTL in final resting spot. Very fun this bargin basement tinker system.
I had an old Dragonfly 1.0 DAC so using it with lossless files to hybrid pre with tilt tone.
Interesting hifi sound with Minimus7 speakers. Mono both in parallel. Not as effecient as the Kef Uni-q but hey its almost fee.
What really stands out is how I can tell difference from 320kbit MP3 compared to lossless. Not possible before.
cheers
I had an old Dragonfly 1.0 DAC so using it with lossless files to hybrid pre with tilt tone.
Interesting hifi sound with Minimus7 speakers. Mono both in parallel. Not as effecient as the Kef Uni-q but hey its almost fee.
What really stands out is how I can tell difference from 320kbit MP3 compared to lossless. Not possible before.
cheers
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That is insightful question, been listening three months and the answer not simple. As you suspected some music actually sounds better compressed due to mastering or poor originals.
The tubes seem to fix that on the fly.
A percentage guessing right now would be 10-15% compressed sound better than raw.
More current recordings 95% sound better un-compressed.
Hi all.
I'm starting on my second amp using Sanwu mono blocks. This one will be for my daughters room and be powering smaller speakers. I used a 24v power supply for first amp and it was a bit overpowered in my opinion.
I was looking at using a 12 volt power supply for my second one. I was considering this one (AC DC Converter 220v to 12V MAX 8A 100W Regulated Transformer LED Power Supply | eBay) since its the little brother to the ones I used for my first amp.
Does anyone see a downside to using this power supply? Or any suggestions for a different power supply?
I'm starting on my second amp using Sanwu mono blocks. This one will be for my daughters room and be powering smaller speakers. I used a 24v power supply for first amp and it was a bit overpowered in my opinion.
I was looking at using a 12 volt power supply for my second one. I was considering this one (AC DC Converter 220v to 12V MAX 8A 100W Regulated Transformer LED Power Supply | eBay) since its the little brother to the ones I used for my first amp.
Does anyone see a downside to using this power supply? Or any suggestions for a different power supply?
Received two cheap mono boards from ebay. They don't have sanwu logo in the back as I ordered the cheapest I could find.
With original gain (39k/100k) noise was quite loud. With 20 dB there is no noise at all (39k/-). After quick listen they sound quite nice. Bass is OK. For the price they make excellent sound.
The turn on pop was very massive, more like turn on BOOM. I happened to have same kind of relay as Mortenhoe and that fixed the problem. I highly recommend using some kind of relay with these boards.
Chips have painted dot next to pin nr. 1 . Should I assume they are actually remarked TPA3130 chips? Is there any test that would confirm this assumption? Mind you I don't have any special measurement tools.
I'm thinking about getting real sanwu boards since these already sounded very promising.
With original gain (39k/100k) noise was quite loud. With 20 dB there is no noise at all (39k/-). After quick listen they sound quite nice. Bass is OK. For the price they make excellent sound.
The turn on pop was very massive, more like turn on BOOM. I happened to have same kind of relay as Mortenhoe and that fixed the problem. I highly recommend using some kind of relay with these boards.
Chips have painted dot next to pin nr. 1 . Should I assume they are actually remarked TPA3130 chips? Is there any test that would confirm this assumption? Mind you I don't have any special measurement tools.
I'm thinking about getting real sanwu boards since these already sounded very promising.
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What lot-code do they have printed on?
If my "fakes" arrive soon, i'll decap the chip and compare the die to a genuine one.
The loud power-on pop might be due to high capacitance input coupling caps. May you measure one? I've seen up to 10uF on another board.
If my "fakes" arrive soon, i'll decap the chip and compare the die to a genuine one.
The loud power-on pop might be due to high capacitance input coupling caps. May you measure one? I've seen up to 10uF on another board.
Lot-code was the same as seen here before: 4AAD6TTG4
I'm wondering how big the production lots usually are. 😀
Input caps were 3,4uF - 4,2uF, when measured in-circuit. Don't know if this has any effect.
LCR meter was DER EE DE-5000 @ 1kHz.
I'm wondering how big the production lots usually are. 😀
Input caps were 3,4uF - 4,2uF, when measured in-circuit. Don't know if this has any effect.
LCR meter was DER EE DE-5000 @ 1kHz.
Thank you for the tip. Turn on/off is no problem with the relay and I have many of them just collecting dust, but now I know where I can finally use them.
Speaking about inputs. I came across some cheap input transformers in ebay.
5Pcs Audio Transformer EE14 Transformateur POS Transformador 1300 : 8 Ohm | eBay
5Pcs Audio Transformers 600:600 Europe 1:1 EI14 Isolation Transformer Ringing | eBay
I understand they are not very hifi, but the price is more in-line with boards compare to transformers made by for example Lundahl. Wondering what impedance ratio would be correct and how it's calculated.
There was also some comments about using buffer instead of simple pot. What chip would be most recommend considering sound/simplicity/price? Ready made buffers in ebay seem to have additional features, but if we just consider volume control.
Speaking about inputs. I came across some cheap input transformers in ebay.
5Pcs Audio Transformer EE14 Transformateur POS Transformador 1300 : 8 Ohm | eBay
5Pcs Audio Transformers 600:600 Europe 1:1 EI14 Isolation Transformer Ringing | eBay
I understand they are not very hifi, but the price is more in-line with boards compare to transformers made by for example Lundahl. Wondering what impedance ratio would be correct and how it's calculated.
There was also some comments about using buffer instead of simple pot. What chip would be most recommend considering sound/simplicity/price? Ready made buffers in ebay seem to have additional features, but if we just consider volume control.
Not a good idea at all. These are simple modem xformers, not suitable for serious audio applications. Even worse, they are not screened, that is they will pick up any magnetic hum and noise emanating from power transformers etc.
I believe I have genuine boards. Turn on pop is an issue. It may be mitigated.
If my USB sound card is up and initialised by LINUX/ALSA, there is no pop.
If I simply turn on a disconnected speaker set, I get a huge thump through the 8" woofer with quite a lot of excursion on the woofer. In normal music playing, I have to tough the cone to detect/know that it's operating.
J.
Like we can buy tpa3110 ampboards and tpa3118 ampboards, tpa3130 ampboards would have real value too.
So I just recieved one of these sanwu tpa3118 to see what all the buzz is about, unmodded and all just freaking wow, the sound quality is clear with tight bass.
I got mine connected to a 24v psu 1.4a max, line in from a bluetooth device with its own power source. As long the bluetooth device is powered on before the amp then there will be no pop sounds.
I will attempt on some mods to make it more practical but I dont think I'm gonna touch the r27 since its so freaking small!
Thanks for this one guys really love it.
I got mine connected to a 24v psu 1.4a max, line in from a bluetooth device with its own power source. As long the bluetooth device is powered on before the amp then there will be no pop sounds.
I will attempt on some mods to make it more practical but I dont think I'm gonna touch the r27 since its so freaking small!
Thanks for this one guys really love it.
Hello together ...
I also ordered two of theses sanwu TPA3118 clones. After first tests I really like their sound. But I somehow have a problem with the "mute-function" of the boards. Actually nothin happens, when I shorten the two pins labeled with mute. As I understand from the TI datasheet, this normally shoud immediately mute the output.
Am I doing something wrong, or does somebody else came across this problem?
Thanks, Lars
I also ordered two of theses sanwu TPA3118 clones. After first tests I really like their sound. But I somehow have a problem with the "mute-function" of the boards. Actually nothin happens, when I shorten the two pins labeled with mute. As I understand from the TI datasheet, this normally shoud immediately mute the output.
Am I doing something wrong, or does somebody else came across this problem?
Thanks, Lars