New TK2050 board

[Nick122147]

You can measure the current consumption with a multi meter set to amps. It is a series measurement so you will have to connect the + wire from the batteries to the ground input of the meter. Connect the amps connector of the meter to the + input of the amp. Battery - still goes straight to the amp -. Measure amps on the larger scale. I would guess that it will be around 150ma at idle and 250ma - 300ma when playing music with 25v in.
.
Playing with the batteries in series shouldn't be any problem with uneven discharge unless there is a mismatch or one is going bad already. Chargers will be better in parallel which is why you often see an XLR connector used for the external battery connection.
.
If the amp draws 300ma then two, 3 amp hour batteries in series will play for 8-10 hours on a charge. If you forget to turn it off and leave it on for 20 hours (or a number of days), the battery level will go below the recommended discharge voltage of 11v each. Permanent sulfation will occur and you will ruin the batteries on the first try. This is what happens to many people using these amps with batteries.

Thanks Scott!
I also dont see any problems with using two batteries in series. Mine two measure exactly the same voltage at all times.
I'll measure the current draw today.

 

[ArjenShenzhen]

Ive tested the fresh boards from the PCB factory, and to my surprise the result is even better than the board i had hand soldered ! THD is even 10X lower! ( probably due to the fact that i didn't use 1% resistors in my test board )

The measurement result is:

30V, over 1.77A of power use, Load is an 8 Ohms 100W resistor.

30X1.77= 53.1Watt 53/100X90= 47.79 Watts to the speaker terminals.

Distortion is 0.0025%! i wonder what rating the other boards have, this is really very low for a class-D amplifier.


30V supply 1KHZ input signal assuming 90% efficiency ( at high power this is surly the case )

I'm supplying 1.77A over 30 volts, and i read a distortion of 0.0025%! this can be measured as my distortion meter at the finest setting detects a full scale of 0.1%. the Distortion meter used is a Japanese Meguro MAK-6571W the signal source is a Japanese Leader LAG-120B audio generator.

photo's will show the results. this test is repeatable by anyone that has a THD meter and a signal source and its a guaranteed value.

the photo's:

http://www.data.helderhifi.com/0boardDUT.JPG
http://www.data.helderhifi.com/0thd0.0025.JPG
http://www.data.helderhifi.com/0psu.JPG

if there are any questions, ill gladly answer them


Greetings,

Arjen Helder

 

[ArjenShenzhen]

just tested for 4 Ohms also, gives 105 Watts at 0.3% distortion, also more than i had expected.

up to 90 watt at 0.0025%.

 

[teamacc]

Why are there 2 relays? Putting in one would save space/assembly time and would not affect anything in a bad manner.

Also, as v-bro noted that loose winded output coils can cause some heat generation, is this the case?


And why are you supplying an aux 5v line to the board? Is the onboard lm317 that bad?

 

[ArjenShenzhen]

Hi there Teamacc,

There are 2 relays, not really needed, but why save on them, it completely disconnects the speaker.

the coils are from micrometals and stay cold, even at maximal load, logically so there made with thick copper wire!

Im not supplying anything to the board by 30V and the input signal. the black clamp is connected to the jumper wire that connects the 2 ground planes together.

 

[jean-paul]

Hi Arjen, although your amp looks and measures nice it has no use advertising it in this thread of one of the many competitors in the field of class D/T amps.

Therefore I asked the mods to move your posts to a separate thread. It is very confusing as at first it seemed you are connected with the designs of hifimediy in one way or another. After asking I discovered this is not the case and I am probably not the only one that got confused.

If you have nice products to sell please open an own thread next time.

BTW maybe this thread should be moved to the vendor forum as well.

 

[hifimediy]

Hi Arjen, although your amp looks and measures nice it has no use advertising it in this thread of one of the many competitors in the field of class D/T amps.

Therefore I asked the mods to move your posts to a separate thread. It is very confusing as at first it seemed you are connected with the designs of hifimediy in one way or another. After asking I discovered this is not the case and I am probably not the only one that got confused.

If you have nice products to sell please open an own thread next time.

BTW maybe this thread should be moved to the vendor forum as well.

Hi, I think you got the point. I hope we can talk about technology only here, and share our opinion, I will be very happy and thankful.

 

[SoldierAnt76]

Hi Arjen, although your amp looks and measures nice it has no use advertising it in this thread of one of the many competitors in the field of class D/T amps.

Therefore I asked the mods to move your posts to a separate thread. It is very confusing as at first it seemed you are connected with the designs of hifimediy in one way or another. After asking I discovered this is not the case and I am probably not the only one that got confused.

If you have nice products to sell please open an own thread next time.

BTW maybe this thread should be moved to the vendor forum as well.

I can understand why the moderators don't want thinly-disguised ads and other spam in a forum devoted to technical discussions. But the difference between "discussing" and "selling" an item is ambiguous. For what it's worth, I probably wouldn't have found out about this board if this thread were in the vendor section, and I suspect the discussion wouldn't be quite as interesting.

 

[teamacc]

To arjen:
What do you estimate to be the price of your tk2050 mono board?
thx

 

[TheDealer]

I tried direct comparison between the two amps and could not tell much difference, it's hard to do when switching speaker cables back and forth. I think that this board has a slightly smoother sound quality and does not have as much hash coming through the tweeter and mid range as the Sure. There is a slight hiss with my ear to the speaker but it can't be heard when the music is playing. The noise from the Sure is louder

that´s also my impression. This board is much more quiet while you hear a present buzzing with the sure board. I call the the sure-sound a bit "toxic", more present and naughty compared to the smoother one from hifimedy. It´s a point of taste and the rest of the chain I think what the better board makes.

When you regard the built in potentiometer and the speaker relay of hifimedy´s board for the same price - it is the better deal

 

[sendler]

No Buzzing

that´s also my impression. This board is much more quiet while you hear a present buzzing with the sure board. I call the the sure-sound a bit "toxic", more present and naughty compared to the smoother one from hifimedy. It´s a point of taste and the rest of the chain I think what the better board makes.

When you regard the built in potentiometer and the speaker relay of hifimedy´s board for the same price - it is the better deal

No buzzing in my Sure boards but this is the better deal.

 

[soldersmoker]

No buzzing in my Sure boards but this is the better deal.

Better deal as far as better value for the buck or just plain better sound in general? I'm looking forward to getting mine any day . . .

For what it's worth, I think the Sure boards sound great, especially with Meanwell power supplies, but I got tired of damaging them when trying to mod those boards. My eyesight can't handle SMD, and I'm just a bit clumsy, not much of a craftsman.

 

[ArjenShenzhen]

Teamacc,

For price info i suggest you find the retail channels, I've been slapped over my fingers already by placing this post, but any technical Questions i'll gladly answer.

maybe it could be fun to open a thread that compares measurements of all boards?

there are many boards out there for the TA2020/2024 now several for the TK2050, listing tests depend on speakers more than amps, and the rest, but measuring power/THD/ bandwidth will tell you the most important things of any amplifier.

 

[dw1narso]

hi Hifimediy,

thanks for your effort making this very good sounding amp and affordable amp (stereo TK2350 board amp)

I check my amp, the right channel DC offset is only 25mV, but the left channel is 80mVDC. Is there a way to adjust the DC offset on this amp?

what are the two multiturn-pots near the volume pot for?

Regards,
---
David

 

[hifimediy]

hi Hifimediy,

thanks for your effort making this very good sounding amp and affordable amp (stereo TK2350 board amp)

I check my amp, the right channel DC offset is only 25mV, but the left channel is 80mVDC. Is there a way to adjust the DC offset on this amp?

what are the two multiturn-pots near the volume pot for?

Regards,
---
David

Hi, the blue pots near the volume pot are used for DC offset adjustment.

 

[hifimediy]

Teamacc,

For price info i suggest you find the retail channels, I've been slapped over my fingers already by placing this post, but any technical Questions i'll gladly answer.

maybe it could be fun to open a thread that compares measurements of all boards?

there are many boards out there for the TA2020/2024 now several for the TK2050, listing tests depend on speakers more than amps, and the rest, but measuring power/THD/ bandwidth will tell you the most important things of any amplifier.

And for you, I'm giving my best respect for now. but you're not welcome here.
You can leave my thread with your ads.

 

[dw1narso]

Hi, the blue pots near the volume pot are used for DC offset adjustment.

I see... thanks...

 

[SOSx]

Dear hifimedy,

A quick question? As I have stated I am using your boards for a mobile audio system.
I am looking at batteries for the system.

We would very much like to employ a 24v lifepo4 battery pack due to size and weight.

Most seem to have nominal full charge of 28v-30v which I know from your posts is fine (if not near optimium) but the problem i can see is that the voltage cut off levels are generally between 16&19v.

Also as DC offset is varied according to input voltage, so surely as the batteries voltage lowers with discharge the dc offset will increase?

Will the board still operate safely at 16-19v?

Your thoughts (or anyone else for that matter)

Kind regards

 

[Don Jerry]

Another question for hifimediy:
using the same type of capacitors, what I should expect using 2.2uF caps intead of 3.3uF? I read the Tripath datasheet but honestly I didn't understand in which manner the uF value affects the audio signal.
Thanks, bye!!

 

[SOSx]

Another quick question. Does this board require a separate 5v dc power line also?