Hey,
I’m building some amplifiers that require 20 va xfmr’s. I’m hesitant to use eBay or aliexpress as I’ve had issues with them before. So, where can I get these from a reputable retailer? I’m in the USA which apparently has limited options. Please advise.
Regards
I’m building some amplifiers that require 20 va xfmr’s. I’m hesitant to use eBay or aliexpress as I’ve had issues with them before. So, where can I get these from a reputable retailer? I’m in the USA which apparently has limited options. Please advise.
Regards
What volts?
R core is a modified toroid, very common for 12V 50W halogen lamps in shops.
Or simply use regular toroidal transformers.
R core is a modified toroid, very common for 12V 50W halogen lamps in shops.
Or simply use regular toroidal transformers.
20VA is quite a small rating.
Are you sure about it?
R-Core transformers were replaced by switching supplies here for halogens, later they were replaced by LED spot lights.
You can try laptop bricks, they might work.
And yes. toroidals are easier to source, here in India the R-core is out of production for the most part.
Are you sure about it?
R-Core transformers were replaced by switching supplies here for halogens, later they were replaced by LED spot lights.
You can try laptop bricks, they might work.
And yes. toroidals are easier to source, here in India the R-core is out of production for the most part.
I was mistaken
I need a 300va transformer for an amplifier I’m building
I’m not sure if r-core is appropriate
Probably use a toroidal
Thanks for your help
I need a 300va transformer for an amplifier I’m building
I’m not sure if r-core is appropriate
Probably use a toroidal
Thanks for your help
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Unlikely that you will find that rating in R-Core.
Some people here have rated Antek toroids highly, there are some other suppliers in Poland.
Use a higher than needed rating, it will not sag under load, the price difference is not so much.
Look around, best wishes.
I have no ties to any above named suppliers.
Some people here have rated Antek toroids highly, there are some other suppliers in Poland.
Use a higher than needed rating, it will not sag under load, the price difference is not so much.
Look around, best wishes.
I have no ties to any above named suppliers.
R-core transformers are superior to toroids. R-core win hands down when wound correctly as their stray field is incredibly low. You can use them millimeters from sensitive electronics without issue (still don't do that). I did a project here and tested many and haven't found a single one that hummed. They were used in the better Japanese amplifiers as well which may be convincing. That (insert famous name of brand or designer here) doesn't use them is simply a matter of cost.
Toroids are often very wideband and therefor don't filter pollution on the main voltage and they can hum as they are often allergic to any small DC component. They are available everywhere which is the reason for their popularity. They are cheaper than E core/R core/C core transformers, they're available and easy to mount. They pushed other more costly types out of the nest and people repeat their positive properties which makes it a self fulfilling prophesy that they are king of the hill. Try to find anything else! There are quality difference so industrial types are preferred.
Laptop bricks are SMPS and external. Nuff said. It is all a choice of wanting to put some effort in matters and choosing between cheap and quality.
https://www.audiophonics.fr/en/r-core-transformers-c-6354.html
The choice for cheap will possibly add costs for either post filtering and/or mains filtering, DC blocking and shielding.
Tip: amplifiers need voltage and current which makes power. If you mention the required voltage and which current (or power) the search will be slightly easier. So let's say 2 x 22V 300VA or 2 x 22V 6A. After rectification and filtering the DC voltage will be higher like 2 x 30V.
Toroids are often very wideband and therefor don't filter pollution on the main voltage and they can hum as they are often allergic to any small DC component. They are available everywhere which is the reason for their popularity. They are cheaper than E core/R core/C core transformers, they're available and easy to mount. They pushed other more costly types out of the nest and people repeat their positive properties which makes it a self fulfilling prophesy that they are king of the hill. Try to find anything else! There are quality difference so industrial types are preferred.
Laptop bricks are SMPS and external. Nuff said. It is all a choice of wanting to put some effort in matters and choosing between cheap and quality.
https://www.audiophonics.fr/en/r-core-transformers-c-6354.html
The choice for cheap will possibly add costs for either post filtering and/or mains filtering, DC blocking and shielding.
Tip: amplifiers need voltage and current which makes power. If you mention the required voltage and which current (or power) the search will be slightly easier. So let's say 2 x 22V 300VA or 2 x 22V 6A. After rectification and filtering the DC voltage will be higher like 2 x 30V.
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He first said 20 VA, then 300 VA...
Small R core should be available in 20 VA, but 300 is unknown for me.
Also, no mention of amp details, becomes a little difficult to say more.
Small R core should be available in 20 VA, but 300 is unknown for me.
Also, no mention of amp details, becomes a little difficult to say more.
The 20 va transformer is meant for use in a preamp for which I will use an r-core. The 300 va is for an amplifier (100w) for which I will use a toroid.
I have not seen an r-core that is capable of 300 va.
I do like audiophonics but shipping to the USA is expensive. 25€ for a 32€ 30 va r-core
My apologies for the confusion but thank you Naresh and Jean-Paul
I have not seen an r-core that is capable of 300 va.
I do like audiophonics but shipping to the USA is expensive. 25€ for a 32€ 30 va r-core
My apologies for the confusion but thank you Naresh and Jean-Paul
Have anyone seen any regulatory approval on these Asian supplies R- core transformers? I’d be cautious or even disqualify any AC line device without approvals. It’s a safety issue, buyer be ware
Pfff if that is a big risk what about SMPS? Had numerous defective ones even melting and smelling ones.