Help required on Logitech Z-2300 toroidal transformer

[RishiGuru]

Hi, i am a newbie in this forum, and require help on my Logitech Z-2300 2.1 multimedia speaker system. My Z-2300 toroidal transformer have died and i need a replacement. But i do not know the VA rating of this transformer.

I opened my Z-2300 subwoofer and clicked some pictures, which i am posting below:

Toroidal Transformer


Z-2300 slow blow fuse rating


Input voltage from the wall


I was also able to gather the following information from the net:

Transformer Details
Manufacturer: Ten Pao International Ltd.
Model No: TOG433028F0
Input: AC 230V/50Hz
Output: AC 20.1V x 2
Diameter: 9.5 cm;
Height: 4.5 cm.
Amperage: Unknown

Also i want to change my capacitors from CapXon which are know for bulging & exploding. Which company capacitor should i use? Will a even higher farad value give an even better result?

Capacitors

[John Audio]

A quite accurate way to work out the VA rating of a toroidal transformer is to weigh it and compare it with the specification of a manufacturers range.

Based on the size - I would guess that this one is about 120VA.

Does it weigh about 1.3kg?

[RishiGuru]

Thanks John, i will try to dismantle the toroid & weigh it. I cannot find any details of their toroids in Ten Pao website. I am providing the specification of Z-2300 below. I don't know but in some forums i found out that the output power of a system can provide some insight about the VA of its toroid used.

Z-2300 Specifications

Total Continuous Power(RMS): 200W
System THD: Better than 0.05% before clipping
Total Peak Power(RMS): 400W
Power distribution: 120 W (Subwoofer) + 2 X 40 W (Satellites)
Subwoofer: 120 W @ 8 ohms @ 10% THD @ 100Hz
Subwoofer Size (inch): 8
Subwoofer Type: Long Throw with 6th order bass reflex
Satellites: 80 W (2 X 40 W) @ 8 ohms @ 10% THD @ 1kHz
Satellite Size (inch): 2.5
Satellite Type: Polished aluminum phase plug drivers
Frequency response: 35 Hz - 20 kHz
Signal to noise ratio(SNR): @ 1kHz > 100dB
Sound Pressure Level (SPL): 117db
Total weight : Near 18 Kg

[RishiGuru]

I have sent a request to the manufacturer Ten Pao in their en-query section asking for the VA rating, till now no answer.

However here is another picture of the toroid.



Can anybody refer to a company that makes similar toroid, that i can fit into my Logitech Z-2300. Thanks in advance.

[quadtech]

There are many companies in India such as Delta, Miracle etc
which can supply you a 2x20V toroid. There are also a number
of smaller winding shops who do not have a web presence.
In a pinch, you could use a regular EI type transformer too.

-: MIRACLE :-

[RishiGuru]

Originally Posted by quadtech

There are many companies in India such as Delta, Miracle etc
which can supply you a 2x20V toroid. There are also a number
of smaller winding shops who do not have a web presence.
In a pinch, you could use a regular EI type transformer too.

-: MIRACLE :-

quadtech, though i know the toroid has 20.1V x 2 output, I do not know the amperage of the toroid. Do you think, considering the size that it is a 120VA?

[Minion]

I had a Logitech 5.1 system that had 6 TDA7293 chips and the torriod in it was a 2x24v 520Va ...... a simular 2.1 system with 4 chips would probably need about 300Va .....


Cheers

[RishiGuru]

Originally Posted by Minion

I had a Logitech 5.1 system that had 6 TDA7293 chips and the torriod in it was a 2x24v 520Va ...... a simular 2.1 system with 4 chips would probably need about 300Va .....


Cheers

Well all I can find out is Z-2300 amplifier is

The amplifier uses:
i) Two STMicroelectronics Class-AB, 80W, TDA7295 amplifiers bridged together to provide a total of 2 X 80=160W for the subwoofer.[Assumed]

ii) Two STMicroelectronics Class-AB, 60W, TDA7296 amplifiers powering each of the satellites.

iii) A Japan Radio Corporation’s JRC-4565 operational amplifier required for the headphones in the control pod.

iv) Filtering of the audio signal is done by two beefy SamXon/ CapXon 10,000 uF, 35V capacitors.

v) The amplifier board have two voltage regulators/ stabilizers a 78M18 and a 79M18, making positive and negative 18 volts respectively.

So, do you think since it powers 4 TDA chips, it is 300VA rather than 120VA considering its size?

I personally believe 120VA is to less a value to provide power to the above 4 TDA chips and also when yo consider 200W RMS of power.

[Minion]

Well , if the Amp chips are Class AB and the Sub is supposed to put out 160w then you are going to need at least 300Va for that , and if the satalites are 60w each you are going to need about 200Va .....

After a Bit of Research I found that the Z-2300 Sub is 120w and the satilites are 40w each so a total of 200w or about 400Va , I"m sure logitech used a smaller one as it seems to be standard for companies to use undersized transformers to cut costs which also shortens the life of the transformer .....

[Cobra2]

Measure, and get as big as you can fit/afford...
Do the speaker terminals at the same time ;-)

Arne K