2 transformers per channel

[chanmalichan]

hi, does anyone know if there is any benefit or downside to using 2 transformer per channel for an amplifier. one transformer for +ve rail and another transformer for -ve rail.

I am trying to have full wave rectification with 2 bridges per channel and i have readily centretapped transformer 28-0-28. So i thought 1 of these per rail will be what i need to achieve the setup.

I am not too sure if there is any issue with the 2 centretap from the transformers sharing the same ground (any current or phase problem?).

[bob91343]

It doesn't really matter. With two transformers, each can be lighter but the sum of the weights (and sizes) will be roughly the same. The regulation will be the same, more or less. I guess one advantage of two units is you can mount them in such a way as to balance the weight. The only way to do that with one transformer is to mount it in the middle.

[tomes]

Hi Bob,
What about different type of tran?I have 4 tran. two troid&two EI with 24-0 only,so i thinking use one troid for +v and Ei for -v same go other channel,try to use what in hand for a class a amp.the troid is 4a and EI is 3a.

[AndrewT]

Hi,
a pair of 300VA transformers compared to a single 600VA (and this applies all the way through the VA range) will be:
more expensive
heavier
bulkier
worse regulation.

The two bridge rectifier does indeed need separate secondary windings.
The centre tapped that you have may be convertible to dual secondary.
Check to see if the secondary is wound on the outside of the core.
Remove the insulation where the secondary tappings come to the outside.
Find the centre tap with it's 1 wire coming to the outside and two wires from the winding. Disconnect the two winding that meet at this tapping connection.
Attach a fourth tapping wire to the spare secondary winding. DO NOT remove any windings.
Carefully insulate the two tappings, secure them to the outside of the whole secondary in the same manner that you found it.
Re-wrap the secondary insulation.
Bring all 4 wire ends out. You now have a dual secondary transformer.

If the centre tap is buried beneath other windings then it is extremely difficult to convert from centre tap to dual secondary.