SSL 9k PSU transformer question

[jeroddumas]

Will this transformer work for the 9k psu?

http://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Partnumber=129-086.

Not sure that I understand transformers. It says center tapped, but it seems not to be dual secondary. Does the transformer have to have dual secondary to get the +/- volts?

 

[gyraf]

yes. dual-secondary means that it can be hooked up center-tapped.

 

[jeroddumas]

so the transformerabove will work?

 

[gyraf]

Dunno. I don't understand the american terminology. "18V C.T." can mean both 2x9V and 2x18V, I think..?

You will off course need 2x18V.

Jakob E.

 

[AudioJunkie]

My understanding seems to be that 18V C.T. means 2x9V.

Daniel

 

[Jonathan Hayward]

I think it would be like a 2 x 9V.
But at 5 dollars, why not get two, one for each rail.
Then you've got to find a box big enough for them, I don't think they'd fit in 1U
My other thought is that for a low-noise affair such as the 9K, I'd get a torroid to be certain.

 

[Hulk]

Maybe a really stupid question but:

I have two 2x12v 30VA torroids - can I connect them (parallel??) together for 2x24V and use them for a 9K preamp even though the 9K only uses 18-20v???

 

[rodabod]

[quote author="Hulk"]Maybe a really stupid question but:

I have two 2x12v 30VA torroids - can I connect them (parallel??) together for 2x24V and use them for a 9K preamp even though the 9K only uses 18-20v???[/quote]

If I were you, I'd buy the correct transformer. Unless you have split primaries on the 12V toroid and can get 24V out of it. Even then, you'd want to make sure your regs. were well heatsinked.

 

[Hulk]

OK thanks roda

 

[SSLtech]

Well you COULD get 24VCT by simply ignoring the centertaps and connecting the 2x 24V in series...

BUT...

It would blow the regulators to kingdom come, when 24VAC RMS gets rectified to about 34V, then rises off-load. with a slightly high line voltage, you'll be looking at approaching 40volts going into the regulators.

So to summarise:

Could you do it? -yes.

Would it work? -Perhaps, but only briefly... -But before long it'd probably be smoky and dead.

I recommend getting the right transformer.

Keith

 

[Hulk]

Thanks Keith!

 

[gosifa]

Will this transformer work for the 9k psu?

220VAC  -  24v+24v  2A

Do I have to change values ​​of any component of the PSU?

Thanks

 

[Whoops]

Will this transformer work for the 9k psu?

220VAC  -  24v+24v  2A

Do I have to change values ​​of any component of the PSU?

Thanks

Keith (SSL tech) answered that in 2006

It would blow the regulators to kingdom come, when 24VAC RMS gets rectified to about 34V, then rises off-load. with a slightly high line voltage, you'll be looking at approaching 40volts going into the regulators.

So to summarise:

Could you do it? -yes.

Would it work? -Perhaps, but only briefly... -But before long it'd probably be smoky and dead.

I recommend getting the right transformer.

Keith

 

[Whoops]

Use a 2x18V transformer:

AC voltage after being full wave rectified to DC will be aprox. 1.414 times higher

(24vAC x 1.414 = 34vDC)

look for any toroidal transformer with 30VA with 2x18V  secondaries

https://www.banzaimusic.com/Talema-TRT30218.html

https://uk.farnell.com/multicomp/mcta030-18/transformer-toroidal-2-x-18v-30va/dp/9530320?st=toroid

https://uk.farnell.com/multicomp/vtx-146-030-118/transformer-30va-2x-18v/dp/1675053?st=toroid

https://pt.mouser.com/ProductDetail/Hammond-Manufacturing/1182H18?qs=sGAEpiMZZMvwUzoUXIIvySPCJQuQgm7bFVjGbgyUPE8gEtdkrhlkCw%3D%3D

https://www.antekinc.com/as-0518-50va-18v-transformer/

 

[gosifa]

Use a 2x18V transformer:

AC voltage after being full wave rectified to DC will be aprox. 1.414 times higher

(24vAC x 1.414 = 34vDC)

look for any toroidal transformer with 30VA with 2x18V  secondaries

https://www.banzaimusic.com/Talema-TRT30218.html

https://uk.farnell.com/multicomp/mcta030-18/transformer-toroidal-2-x-18v-30va/dp/9530320?st=toroid

https://uk.farnell.com/multicomp/vtx-146-030-118/transformer-30va-2x-18v/dp/1675053?st=toroid

https://pt.mouser.com/ProductDetail/Hammond-Manufacturing/1182H18?qs=sGAEpiMZZMvwUzoUXIIvySPCJQuQgm7bFVjGbgyUPE8gEtdkrhlkCw%3D%3D

https://www.antekinc.com/as-0518-50va-18v-transformer/

Thank you and I apologize for asking the same question again. Regards