Hi folks...still trying to source a replacement toroid (300VA 50-0-50v) to go in my JLH 80W Mosfet amp...built from a Hart Kit in the 80's
Have been pointed towards Toroidy.pl and see they offer both grades!
Snake-oil aside....do I need 'audio grade' in this amp's PSU??
Be gentle with me.....and...Happy Christmas!! 🙂
Have been pointed towards Toroidy.pl and see they offer both grades!
Snake-oil aside....do I need 'audio grade' in this amp's PSU??
Be gentle with me.....and...Happy Christmas!! 🙂
Some talk about a screen between primary and secondary windings (a copper screen?).
Then there can be a mu-metal screen around the whole trafo?
Then there can be a mu-metal screen around the whole trafo?
it seems this was "audio grade" ( used in my Leach amp) - screening + epoxy potted center opening.
AA-98050-AU Ring Core Transformer 800 VA 2x 42 VAC Noratel
as far as i remember 10 years ago it was much cheaper...
due to its high power, it starts up very softly even without a soft start, as I think the core material is properly selected. much less power "general" toroidal transformer triggers my house fuses without thermistor or soft start.
AA-98050-AU Ring Core Transformer 800 VA 2x 42 VAC Noratel
as far as i remember 10 years ago it was much cheaper...
due to its high power, it starts up very softly even without a soft start, as I think the core material is properly selected. much less power "general" toroidal transformer triggers my house fuses without thermistor or soft start.
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The lineup of audiophiles waiting for the shipment to be unpacked?
If you want true quality you want Industrial or Military grade.
Yes. Another way to get a low mech noise xformer is to specify a larger core for the power you want.
And a good xformer should have at least one internal screen between prim and sec. The go-to xformers for that are medical grade xformers.
If that sort of thing is not specified, 'audio' is just a way to double the price. ;-)
Jan
The magnetic shielding around toroid is often a two-layer speciel steel (poor mans mu-metal). Also the metal disc can be a special steel which should shield better than the "standard". Those parts can be purchased rather cheap so a standard industrial toroid can be made "audio grade". Clever positioning of toroid can make a difference. Maybe in its own chassis. Also effective filtering like CRCRC or CLC etc. makes a difference. I think solutions like that is more "audio grade" than just a very expensive toroid. I have very good results following these rules using standard Talema toroids.
IMHO talema are better then Indel from Poland, but also costs more. Indel are ok, but needs soft start for power above 400VA.
I have used a lot of Iindel - the voltage of both sec. wingdings varies sometimes if you unlucky , even by 1V
Sometimes I am able to find Talema here in DK to good prices like this 625 VA, 2x18V:
Transformer 625VA 1x230V 2x18V | Elektronik Lavpris Aps
Price is around 130 Euros...….don't know if other think that is expensive for a close to 5 kg "iron" 🙂
Transformer 625VA 1x230V 2x18V | Elektronik Lavpris Aps
Price is around 130 Euros...….don't know if other think that is expensive for a close to 5 kg "iron" 🙂
I have been lucky, and have found a company (close enough that delivery is free to my work) that will custom wind toroidals for me. Shielded, potted, various windings incl. step-down trafos when I needed them. No noise from them, and quality build too. Pricing is roughly 70 Euros for a 400VA with Pri/Sec shield and centre potted and mounting hardware. 225 VA similarly is 50 Euros. Less expensive than RS and custom to boot.
I lke the idead of using a heavier core than normal. Will check and see if they will be prepared to wind onto heavier core than required.
I lke the idead of using a heavier core than normal. Will check and see if they will be prepared to wind onto heavier core than required.
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Centre potting, electrostatic screen and magnetic shielding are what's mentioned by Toroidy (oh, and the black outer tape). I've bought quite a few (standard and customer) and I have been happy with the quality. However, their standard grade transformers seem good as well and I have in some cases opted for those when the slightly smaller dimensions mattered.
The "supreme" audio grade transformers are probably nice, but they are really expensive compared to the others and usually massive in size.
..a flurry of comments since my 1st post....Thanks 🙂
Don't think I'll be getting too tied down to the 'Audio grade' thing in this instance!!😎
Has been some mention of Indel (Poland)....is this linked to Toroidy.pl..?
Don't think I'll be getting too tied down to the 'Audio grade' thing in this instance!!😎
Has been some mention of Indel (Poland)....is this linked to Toroidy.pl..?
Hello All,
It is very difficult to find good transformers.
for several years I have only been taking from toroidy.pl, and only this category
"Toroidal-transformers-SUPREME-AUDIO-GRADE-V2/99"
But is not the only one:
Toroidal transformers SUPREME AUDIO GRADE V2 - Shop Toroidy.pl
Transformer_James transformer-custom toroidal transformer|R core transformer|O core transformer|C core transformer|EI transformer
J&K Audio Design: About Us
in my opinion the 3 best quality, but more expensive
Regards and happy new year to all
Charles
It is very difficult to find good transformers.
for several years I have only been taking from toroidy.pl, and only this category
"Toroidal-transformers-SUPREME-AUDIO-GRADE-V2/99"
But is not the only one:
Toroidal transformers SUPREME AUDIO GRADE V2 - Shop Toroidy.pl
Transformer_James transformer-custom toroidal transformer|R core transformer|O core transformer|C core transformer|EI transformer
J&K Audio Design: About Us
in my opinion the 3 best quality, but more expensive
Regards and happy new year to all
Charles
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Eedjit that I am!
Bloody heck!! My bad, I meant step-up trafos (step-down😡 duh!) (no such word as idead)
you maybe better off putting together a basic psu instead.
the hart psu is complex and potentially unreliable (however, you could be lucky)
Canterbury Windings have an excellent reputation in the UK, I have purchased a few one off Audio Grade transformers wound to fit inside Naim Nac92/Nap90.3 cases, was VERY pleased with them when I received them.
Canterbury Windings Home
Click `Custom Designs` to have a read on what ingredients make up `Audio Grade`
Canterbury Windings Home
Click `Custom Designs` to have a read on what ingredients make up `Audio Grade`
Approached CW a few weeks ago as it happens...suggested I try again in the new year....busy it seems!!