New TK2050 board

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Further reading into the spec:


"To drive loads having very low impedance obtaining higher output power it is possible to furtherly
connect together on the same load two STA50x IC's (each one already configured as
single-paralleled bridge) doubling the current capability.
The correct connection is putting together the inductor (L1 with L3 and L2 with L4) terminals
on the load side. This to avoid uncontrolled shootrough current spikes, due to time mismatch
between the two IC's, which could be possible if the outputs are directly paralleled on the same
inductor.
The L and C values of the output filter have to be calculated tacking in account the load impedance:
to be noted that the inductance is now provided by two self-inductors in parallel (L1/
/L3 and L2//L4), so each one must have double value.
The inputs must be driven in parallel."

I guess some modification in the output filter is required... But certainly a mono configuration with two sta505 in parallel is possible (idea for next version)

We also have to take care of feedback circuit then.
 
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Chassis orientation

What are some ideas for putting all this into a handmade chassis?
I'm certainly open to suggestions for orientation.

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


The IEC socket on the smps is at the end opposite the visible cord.
I'm currently thinking that I'd put it all in a an aluminum box such that the amp would be above the smps, with a copper plate between the two for shielding.

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


Too crazy?

Or is this more reasonable?

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


Would this create too long a distance to route the input cables?

I'd prefer to have the IEC socket at the "rear," while the pot shaft would be at the "front."

Thanks!
 
The length of the input cable is of some concern, however, the length of the cable *after* the pot is of much more concern, as the signal is very weak there. On this board the pot to chip length is almost zero, as the pot is onboard. The traces on the pcb have a length though.
 
Single chip version sample

I received this sample from hifimediy today.
It the single chip version. This one uses sta508, and should produce 2*80W at 8 ohm. Hifimediy says it can drive 4ohm speakers, but output will be lower around 40W, and in that case, it's best to also use lower voltage for higher current, below 20V.
I have tested it for a couple of hours, and it sounds pretty good. It's hard to say yet how it compares to the other board, they are not night and day. It certainly sounds good also! The tc2000 chip is still the same, so they should sound quite similar.
Also, its just DC input.

Hifimediy says he will make two versions of this, one with the alps pot, which will cost around 7-8 usd more than the other, and one with the same ctr pot as the other board. I want to ask here what people think about different options. I think it might be a good idea to offer one version with alps pot, and the other version without any pot. There should't be too many versions I think.


We are still testing these, so there will be some weeks before they will be offered for sale.



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


An externally hosted image should be here but it was not working when we last tested it.
 
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How tight are the windings on those inductors? They don't look particularly tight wound...

A few weeks ago I handled a TK2350 amplifier with one inductor that got terribly hot after a while. Turned out this was caused by loose windings. After I fixed the windings it ran stone cold again...
 
I received this sample from hifimediy today.
It the single chip version. This one uses sta508, and should produce 2*80W at 8 ohm. Hifimediy says it can drive 4ohm speakers, but output will be lower around 40W, and in that case, it's best to also use lower voltage for higher current, below 20V.
I have tested it for a couple of hours, and it sounds pretty good. It's hard to say yet how it compares to the other board, they are not night and day. It certainly sounds good also! The tc2000 chip is still the same, so they should sound quite similar.
Also, its just DC input.

...

Apologize in advance if I'm boring everyone with my mono requirements, but this unit seems to lend itself to be used as single BLT (figure 7 of http://www.st.com/stonline/products/literature/an/10606.pdf) with very few modifications. I would be interested in a mono version also or instructions in converting it from double blt (figure 6 I suppose) to single paralleled blt (figure 7). The power dissipation will remain the same in the chip but more current will be delivered to the speaker... Thanks for the good work.
 
One channel

Apologize in advance if I'm boring everyone with my mono requirements, but this unit seems to lend itself to be used as single BLT (figure 7 of http://www.st.com/stonline/products/literature/an/10606.pdf) with very few modifications. I would be interested in a mono version also or instructions in converting it from double blt (figure 6 I suppose) to single paralleled blt (figure 7). The power dissipation will remain the same in the chip but more current will be delivered to the speaker... Thanks for the good work.

So if you do that you basically have one channel of the other amp module.
 
more photoes

space.php

space.php
 
cable with rca available

I have made some of these cables that i will include for an additional fee for people who wants to get sound out of the board quick, no need to solder! Of course, if you later want to put the board in a case and install the plugs into the case, you will ned to desolder them.
 

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(Psss: I'm asking for jumpers in the board :))

There is no jumpers on the board as you want. And I don't recommend changing the connection like that, for Class-T amplifiers always request good layout(changing connection mode means modify layout). I still recommend using high current power stage chips to fulfill your demand.
I'm thinking about new version that can use STA508 in parallel, and 160W+160W @4ohm will come out.:D
 
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If you create an amplifier using two STA517B chips to their maximum, and incorporate a good cooling method, and still manage to do this for less than 100 euros, you will have me as a customer :D
Bear in mind that the coils might need to go for bigger/better ones, as there will be much more current flowing through them.
 
BTW, for TA3020, we always use T106-2.
a TA3020 Version will also be contributed ...?

Second question: I received this week my V2.0 board. Thanks to Steinar by this way.

What does that red LED closed to the big cap mean ? It went ON in my case together with the green LED (power on ?). Is there something wrong with my board because usually a red LED light means "problem" in function. I connected the speakers after I powered the board. The amp is working an I can listen to music but I felt it a bit weak powered. Just my feeling. This can also be depended on the red LED light ON that still makes me busy in mind.
Supply power is solid 25 Volts. Sadly no + / - DC input polarity is described on the board. I took the last terminal on the edge of the board (as described in a short manual site from steinar) for DC + input. Hope this helps.

Not all DIY here are pure electrotechnicians.
Thanks in advance
 
a TA3020 Version will also be contributed ...?

Second question: I received this week my V2.0 board. Thanks to Steinar by this way.

What does that red LED closed to the big cap mean ? It went ON in my case together with the green LED (power on ?). Is there something wrong with my board because usually a red LED light means "problem" in function. I connected the speakers after I powered the board. The amp is working an I can listen to music but I felt it a bit weak powered. Just my feeling. This can also be depended on the red LED light ON that still makes me busy in mind.
Supply power is solid 25 Volts. Sadly no + / - DC input polarity is described on the board. I took the last terminal on the edge of the board (as described in a short manual site from steinar) for DC + input. Hope this helps.

Not all DIY here are pure electrotechnicians.
Thanks in advance

the red light just mean there is power input. the green light means the relays are turn on.

the + - for dc is the same which one you use, because of the bridge.
what kind of speakers do you have? it shouldnt feel weak powered, what input are you running into it?
 
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