need ac power for amp

[Bare]

280 w That thing?? Optimistic, if not simply silly..I'd think.
Beyond that digression find a correct voltage SMPS from (where else ?) China.

 

[AndrewT]

Waow! "Colloidal Transformer": what's that, I never heard about it? Is it the latest audiophoolery novelty item?
I am eagerly awaiting for the "Colonic Irrig Transformer", that's going to be real fun...

Spell Checkers that can't read "English" !

 

[AndrewT]

read Decibel Dungeon and Elliot Sound Products
They are very good starter pages.

BTW:
you need a centre tapped transformer, a bridge rectifier and a pair of smoothing capacitors.

That is the complete AC to DC PSU (dual polarity).

Hi,

No you don't, just the transformer.

A perusal of the back of the PCB indicates to me it cannot not bridged.
(As well as a 3 wire speaker output also cannot also be bridged.)
The Mosfets are double parallel pairs, fair enough.

The suggested Apex Jr. transformer is an excellent choice IMO.

rgds, sreten.

FWIW I haven't seen the CA3046 chip for a long time, a very old
favourite, 5 matched transistors on a chip, no idea what its doing.

No thanks for your comment as a result of stripping out the relevant closing sentence.

That is the complete AC to DC PSU (dual polarity).

just the transformer.

is an AC to AC supply.

 

[cleonjr]

280 w That thing?? Optimistic, if not simply silly..I'd think.
Beyond that digression find a correct voltage SMPS from (where else ?) China.

from what I can see ,I am the only one to try this board .it just might be a shocker.but if not not much invested,$50 usd total.

 

[cleonjr]

Tip o' the hat to all that helped out on this,Apex jr is a treasure trove of electronic parts,it is enroute as I type,Steve is a great guy in my book,gonna give him all the business I can
Apex Jr.Home Page check out all the cool stuff at great discount.w

well wish me luck on my build if I have any questions I will ask,thanks guy's

 

[sreten]

from what I can see ,I am the only one to try this board .it just
might be a shocker.but if not not much invested,$50 usd total.

Hi,

Its very cheap for for all the bits you get and worth a punt.

However totally forget 280W / 560W as pure fantasy
and a power transformer to suit, it is totally wrong.

FWIW as Apex Jr basically sell audio transformers it
is not surprising most of them fit a simple the more
AC voltage the more VA is needed for amplifiers.

I'd still cheaply uprate 2 of the 4 supply caps.

rgds, sreten.

 

[sreten]

No thanks for your comment as a result of
stripping out the relevant closing sentence.

Is an AC to AC supply.

Hi,

In terms of stating the bleeding obvious your statement
was far more likely to mislead than be any use whatsoever.

What "you need" in general terms is no excuse to use
the term "you need" when it is actually factually wrong.

Which is an AC to AC supply, aka just a transformer.

rgds, sreten.

 

[JMFahey]

I don't think so, it's a 280W amplifier. It'll need something approaching a 600VA transformer into 4 Ohms.

NO WAY am amp which uses:

Input voltage::
(Recommended voltage: AC 28V * 2 is the best)

Which means +/-40VDC rails is going to put out:

Output power::
8Ω: 280W 4Ω: 560W

Think 60 into 8 and almost 100 into 4 and we can begin speaking.

And for home use, the suggested Apex transformer is fine.

For continuous Pro duty (PA, DJ, MI) into 2 x 4 ohm speakers then closer to 300VA would be fine.

 

[cleonjr]

NO WAY am amp which uses:

Which means +/-40VDC rails is going to put out:


Think 60 into 8 and almost 100 into 4 and we can begin speaking.

And for home use, the suggested Apex transformer is fine.

For continuous Pro duty (PA, DJ, MI) into 2 x 4 ohm speakers then closer to 300VA would be fine.

well for 50 dollars I think those are still good numbers.maybe later I will do some upgrades to bring it closer to original specs.

one thing ,does the transformer need to be sheilded from the amplifier?

 

[AndrewT]

No.
But there are conditions.
a.) use twisted pairs for all Mains AC wiring.
b.) use twisted triplet for PSU wiring.
c.) use twisted pairs for all signal wiring.
d.) use twisted pair/s for speaker wiring.
e.) keep all Flow and Return traces/wires close coupled, no exceptions.
f.) the transformer should be temporarily mounted in it's proposed location with long flexible leadout wires (all twisted as pairs). you can rotate the transformer to find a "null" in interference fields by measuring the amplifier/s output/s.

 

[cleonjr]

No.
But there are conditions.
a.) use twisted pairs for all Mains AC wiring.
b.) use twisted triplet for PSU wiring.
c.) use twisted pairs for all signal wiring.
d.) use twisted pair/s for speaker wiring.
e.) keep all Flow and Return traces/wires close coupled, no exceptions.
f.) the transformer should be temporarily mounted in it's proposed location with long flexible leadout wires (all twisted as pairs). you can rotate the transformer to find a "null" in interference fields by measuring the amplifier/s output/s.

ok will do.