New Tube DAC TDA 1543

Actually I guess that one would be described as in 'series'.

Here is a 'parallel' example.

https://i.ibb.co/Dp94hdM/s-l1600.jpg

Gives a whole new meaning to 'a portion of chips'! :)

Ah - I understand now. Not heard of that technique for complete ICs, but it is commonly used with transistors (and even valves) to reduce thermal noise.

The noise is reduced by the square root of the number of devices in parallel, so for 8 of them the noise will be reduced by a factor of 2.83 (or 9dB). There is no advantage in using more than 8, as the increase in the Miller capacitance will start to be a problem.

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Originally Posted by Barry

Ah - I understand now. Not heard of that technique for complete ICs, but it is commonly used with transistors (and even valves) to reduce thermal noise.

The noise is reduced by the square root of the number of devices in parallel, so for 8 of them the noise will be reduced by a factor of 2.83 (or 9dB). There is no advantage in using more than 8, as the increase in the Miller capacitance will start to be a problem.

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Makes sense, there are some advertising the use of 16 but seems the point of diminishing returns has been well reached.

Do you think the transformers will be able to handle the extra load?

I think I might order 8 just to give it a go, then if I mess it up or it doesn't work I can just put the X 1 back in (assuming it's not going to damage anything within the circuit path). I would assume we're not talking voltages that are likely to do damage to any components downstream?

You would have to look at the specification for the chip to see what the current consumption is. Then multiply that figure by the number of chips to see if it lays well within the current capability of the transformers (and of the voltage regulation circuitry).

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Originally Posted by Barry

You would have to look at the specification for the chip to see what the current consumption is. Then multiply that figure by the number of chips to see if it lays well within the current capability of the transformers (and of the voltage regulation circuitry).

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Thanks Barry, some DIY research coming on I feel.

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Originally Posted by Opti-cal

PM'd you Brian.

Still enjoy my LP5 practically everyday!

Mine now wears a cork mat, seems to work better in my system.

Cheers

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Thanks Chris, replied. Yup, still enjoying the LP5x very much. I have a cork mat here and will give it a go. Thanks for the links etc. :)

TDA1543 typical current consumption is 50mA.

So you need to assess or test that the 5V supply can provide 400mA.

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Originally Posted by Firebottle

TDA1543 typical current consumption is 50mA.

So you need to assess or test that the 5V supply can provide 400mA.

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Thanks Alan, the supply is 9V (9v/115v X 2) I believe and a lot of people have had success using 7/8v supplies. It has a Secondary Current rating of 833mA so even split between the two outputs it should meet the specs. Is that right? I've literally just guessed at most of that?!

As it happens there is a school of thought that just having 1 chip gives a purer 'sound' (which does make sense) but if there is space in the unit I think I might still give it a try as it's cheap to find out.