New TK2050 board

[Trebla]

Originally Posted by zanlation

Can I just check the order of RCA parts. from external to internal - PLUG -> plastic washer -> chassis -> plastic plug -> ground washer/ring -> nut -> positive wire soldered to end.

Yes, that's right.

[midyim]

I am seeing heatsink temperature of 30C over ambient...with local temps approaching 30C. Need suggestions to extend the heatsink {or do I have a problem with my T2{M}?

Using 24Vac supply giving 35.5Vdc {appears the AC is higher then rated}
No input, no load, DC offset=0V

Thks...eng hoe

[zanlation]

I conducted some experiments to try and isolate my noise problem. I rewired the input RCA plugs, including giving them a common ground, and double checked other wiring.

The 2ch T4 when powered up gives a high pitch sound from the amp itself (and when the speakers are connected too). The red LED comes on, but no sign of the relay green LED lighting up and no clicking sound.

The 1ch T4 (with grounded left channel) doesn't make a sound, the red LED comes on OK, but the relay green LED flashes on and off, with clicking sound, but eventually fails.

I rewired from SMPS800RE to each amp with all three wires (Live, Ground, Neutral). I noticed that these T4 boards have a different layout to my previous one (that also have mundorf caps). The SMPS800RE has been set to output 34V.

Can anyone point me to some potential problems?

[alkasar]

T4 needs single voltage dc power supply or dual voltage transformer.
SMPS800RE is a symetrical voltage power supply (+/- voltage). How exactly have you wired the power supply to the amp ?

34Vdc is probably too low to trigger the relay. Specs says min voltage is 36Vdc.

Also, it sometimes helps to reference smps 0V output to earth. Either through a wire or a 10 to 100ohm resistor. This eliminates noise in some circumstances.

[zanlation]

Originally Posted by alkasar

T4 needs single voltage dc power supply or dual voltage transformer.
SMPS800RE is a symetrical voltage power supply (+/- voltage). How exactly have you wired the power supply to the amp ?

34Vdc is probably too low to trigger the relay. Specs says min voltage is 36Vdc.

Also, it sometimes helps to reference smps 0V output to earth. Either through a wire or a 10 to 100ohm resistor. This eliminates noise in some circumstances.

Hmmm, looks like I made a mistake on the voltage. So, 34-0-34 is AC and I needed 36V+ for DC--- which I have on my other amp in DC mode. So, can I manually change the voltage on the SMPS800RE?

[alkasar]

you can adjust smps800RE output voltage a little, 5% or so. There is a small potentiometer on board to do that, using a screwdriver.

However, the smps output is dc, not ac, and should be wired to T4 as a dc supply, like you did with 500RS (S stands for single) on your other amp.

Althought not recomended, you can try using only the V+ output and leave the V- unconnected. It's a pity as you lose hal of the smps power.

SMPS800RE is not suited for T4.

[zanlation]

Originally Posted by alkasar

you can adjust smps800RE output voltage a little, 5% or so. There is a small potentiometer on board to do that, using a screwdriver.

However, the smps output is dc, not ac, and should be wired to T4 as a dc supply, like you did with 500RS (S stands for single) on your other amp.

Althought not recomended, you can try using only the V+ output and leave the V- unconnected. It's a pity as you lose hal of the smps power.

SMPS800RE is not suited for T4.

Thanks for the help, this project is taking me a lot longer than my previous amp and my knowledge is being stretched again, which is good

Which single SMPS would you recommend to run the two T4s?

[zanlation]

Is the noise issue related to lower than min required voltage?

[alkasar]

Originally Posted by zanlation

Is the noise issue related to lower than min required voltage?

don't think so. reference smps 0V to earth has a better chance to eliminate noise.

To recomend a power supply, need to know how you will use this amp.
why not try with the 500RS of your other T4 stereo amp ?

[TheDealer]

Originally Posted by alkasar

To recomend a power supply, need to know how you will use this amp.
why not try with the 500RS of your other T4 stereo amp ?

maybe a bit offtopic but I hope you can give me answer. As here the RCA issue was discussed lastly I was wondering how channel separation works when R and L share same GND on for example T1 board . Isn't R and L channel connected together in this case ? I measured also a T2 board. Indeed R and L are connected together through the GND Thanks in advance for a tip