diyman

[diyman]

Tranformer for Aleph-X

I have problem getting a 1KVA toroidal tranformer with suitable low voltage windings for the Aleph-X. I would probably need some extra tappings because I intend to use a regulated source for the front end and also run some protection circuits too! I have a good friend who actually manufactures regular E-I core transformers and I can get custom wound voltages for something like 30% of the price of a regular toroid.
Has anyone tried using regular 1 - 1.2KVA E-I transformers for Aleph projects? My worry would be magnetic field induced hum due to the large transformer. I have decided to put the transformer in the same casing!


ckt

[Edwin Dorre]

Originally posted by diyman

Has anyone tried using regular 1 - 1.2KVA E-I transformers for Aleph projects? My worry would be magnetic field induced hum due to the large transformer. I have decided to put the transformer in the same casing!


[/B]

What kind of transformer do you think Nelson uses in his XA200? I think it is even bigger than your 1KVA! Another example; In his X1000 are two 4KVA transformers

Edwin

[UrSv]

Originally posted by diyman
Tranformer for Aleph-X

I have problem getting a 1KVA toroidal tranformer with suitable low voltage windings for the Aleph-X. I would probably need some extra tappings because I intend to use a regulated source for the front end and also run some protection circuits too! I have a good friend who actually manufactures regular E-I core transformers and I can get custom wound voltages for something like 30% of the price of a regular toroid.
Has anyone tried using regular 1 - 1.2KVA E-I transformers for Aleph projects? My worry would be magnetic field induced hum due to the large transformer. I have decided to put the transformer in the same casing!


ckt

And why do you nedd exactly 1kVA? Why not something smaller or or using 2 at 500VA each?

[Netlist]

Originally posted by diyman
Tranformer for Aleph-X

I have problem getting a 1KVA toroidal tranformer with suitable low voltage windings for the Aleph-X.

Look at the amp in the 'Industrial AlephX' thread.
I used a 1KVA 22-0-22 which gives me about +/-28V. That's perfect for the AlephX I made, but I bought the wrong caps. Only 25V rated. Now, bye a bunch of 35V rated caps and you will be very pleased with a 1KVA 22-0-22. Of course it depends what AlephX you will build. Number of output fets?

/Hugo

[diyman]

Hi,

Thanks for the comments, guys! I stay in Malaysia and we don't have toroid transformers made here. The only sources are RS and Farnell and voltage ratings of their 500VA upwards toroid transformers start from 30V-0-30V which will give about 42 volts after rectification. My heatsink will not be able to take the extra dissipation because I intend to keep the recommended bias to optimise sound quality. Generally the regular frame type (or E-I) transformers are more lossy and hence I plan to use 1KVA to minimise heating and voltage drop. However, from my experience frame type transformers induce more hum compared to toroids. Thats why I asked whether anyone has tried the frame type transformers under high bias currents like the Aleph-X.

Regards,

ckt