This spring, I am looking to construct a chip amp, implementing some national chips, I am still in the research phase. Right now I am looking at the power supply section and looking at different toroids. I have come across Avel and Plitron toriods, but the price difference is rather different, around 30 bucks more for the Plitron. I was just curious what this 30 bucks more is getting me, better tolerances? better efficiency? there seems to be little different in shielding.
I am looking at a 625VA with dual 25v secondaries.
My instincts say go with the cheaper on as its just a transformer, but I am just looking for different opinions on this, thanks.
I am looking at a 625VA with dual 25v secondaries.
My instincts say go with the cheaper on as its just a transformer, but I am just looking for different opinions on this, thanks.
I use an 860 VA Avel transformer in my 4 channel Leach amp. Regulation seems good, and there is no mechanical noise. I've also had good results with the Toroid of MD units in my A75s.
I haven't used Plitron, but I have heard that Pass does.
IMHO, in a class AB amp as long as it is reasonably sized (VA at least 2x output), transformer quality differences will not really be noticeable. Remember that in reality you will be using a very small part of the transformer's capability most of the time.
In a Class A amp, where you are drawing heavy current all of the time then build quality becomes more of an issue. I get a little mechanical hum in my A75s during the inrush surge, then they are silent.
I haven't used Plitron, but I have heard that Pass does.
IMHO, in a class AB amp as long as it is reasonably sized (VA at least 2x output), transformer quality differences will not really be noticeable. Remember that in reality you will be using a very small part of the transformer's capability most of the time.
In a Class A amp, where you are drawing heavy current all of the time then build quality becomes more of an issue. I get a little mechanical hum in my A75s during the inrush surge, then they are silent.
I have used quite a number of toroid brands in the past, usually because they came free or cheap.
Anything from Plitron, till stuff from Spain.
None of them were really bad ones.
Sort of like driving a dodge or a caddy, if they are in good condition both will get you there.
There is a difference in build quality between different brand toroids.
I have a lot of experience with ILP, Amplimo nowadays, because that is the standard toroidal transformer overhere for 25 years.
Plitron and Amplimo are equal quality transformers.
There are manufacturers in Great Britain that make above average quality transformers.
Holden& Fisher used to be the favorite untill they went bust, like Partridge was with Tube output transformers.
H&F was the most common used transformer in US amplifiers.
Now it seems to be Plitron that is no1.
If you do not desire the best, go for economy, is my advice.
Anything from Plitron, till stuff from Spain.
None of them were really bad ones.
Sort of like driving a dodge or a caddy, if they are in good condition both will get you there.
There is a difference in build quality between different brand toroids.
I have a lot of experience with ILP, Amplimo nowadays, because that is the standard toroidal transformer overhere for 25 years.
Plitron and Amplimo are equal quality transformers.
There are manufacturers in Great Britain that make above average quality transformers.
Holden& Fisher used to be the favorite untill they went bust, like Partridge was with Tube output transformers.
H&F was the most common used transformer in US amplifiers.
Now it seems to be Plitron that is no1.
If you do not desire the best, go for economy, is my advice.
Nelson has used the Avel's in the past.
Avels (Y23) series are now made in China, thus they can be had for a steal. For non-critical and non-aesthetic applications, AVEL's are fine. They have great after sales service and tech support.
However I do need to report, I once bought a 1kVA directly from Avel which upon installation heated up abnormally (in a class-AB Adcom 545ii) it got to 50c on idle... (the 545ii did not draw more than 20 watts at idle) while the rails were steady, this is did not jive well with me. A call to Avel got me shipped areplacement at NC to me. The replacement worked fine.
In the past year I have used / installed 16-20 800va to 1kVA Avel Y23 series with only one heating up.
The Avels do not look very professional, the windings crossover each other at places and does not sit too well.
For Class-AB amps, I have used them with little or no issues, however for a class-A amp, I'd go victoria magnetics or Plitron.
I hope this assessment was fair and balanced (FOX?
) and helps you in your thought processes.
One more thing despite the shabby build of the Avel Y23 series, they are DEAD quiet with little or no stray emissions. I put two 800va toroids on top of each other and 2 inces from the amp's input diff stages... NO hum whatsoever.
K-amps.
Avels (Y23) series are now made in China, thus they can be had for a steal. For non-critical and non-aesthetic applications, AVEL's are fine. They have great after sales service and tech support.
However I do need to report, I once bought a 1kVA directly from Avel which upon installation heated up abnormally (in a class-AB Adcom 545ii) it got to 50c on idle... (the 545ii did not draw more than 20 watts at idle) while the rails were steady, this is did not jive well with me. A call to Avel got me shipped areplacement at NC to me. The replacement worked fine.
In the past year I have used / installed 16-20 800va to 1kVA Avel Y23 series with only one heating up.
The Avels do not look very professional, the windings crossover each other at places and does not sit too well.
For Class-AB amps, I have used them with little or no issues, however for a class-A amp, I'd go victoria magnetics or Plitron.
I hope this assessment was fair and balanced (FOX?
) and helps you in your thought processes.One more thing despite the shabby build of the Avel Y23 series, they are DEAD quiet with little or no stray emissions. I put two 800va toroids on top of each other and 2 inces from the amp's input diff stages... NO hum whatsoever.
K-amps.
Jacco,
Both are very good. I prefer Victoria because a 1kvA custom victoria costs $95 here in the US, Plitron standard (no custom) 1kva costs $113 plus shipping to US so about $140. Not big difference but the fact that I can get custom primaries for no extra charge etc makes me go to Victoria.
However Victoria is a small shop, they sometimes dont have the cores and they may not be able to fulfill the order for 3-4 weeks depending on the load. Plitron can send you as many as you want. So manufacturers tend to go Plitron. It is less expensive than Hammond and some other makers and very good quality. My krell has a Plitron. Nelson (and the Canadian dudes) also use Plitron.
K-man.
Both are very good. I prefer Victoria because a 1kvA custom victoria costs $95 here in the US, Plitron standard (no custom) 1kva costs $113 plus shipping to US so about $140. Not big difference but the fact that I can get custom primaries for no extra charge etc makes me go to Victoria.
However Victoria is a small shop, they sometimes dont have the cores and they may not be able to fulfill the order for 3-4 weeks depending on the load. Plitron can send you as many as you want. So manufacturers tend to go Plitron. It is less expensive than Hammond and some other makers and very good quality. My krell has a Plitron. Nelson (and the Canadian dudes) also use Plitron.
K-man.
G4ME said:
625VA ?? How many chips did you have in mind? The LM3886 plays VERY well with 125VA, so 625VA will get you 5 HEAVILY powered chips..
Even if you where building a stereo pair of BPA-200's, 500VA would be sufficient.
I am a firm believer of over engineering, but since you mentioned you were "researching" I didn't want you to think 625VA was a requirement.
Only kidding, KBK.
Of course i know the Canadian Brands.
In the early 90s i had a Classé DR3, for a short while.
Secondhand, the high current version, vhc, loved the layout with separate output boards of that power amplifier.
I am even aware that Canada has a large producer of big capacitor cans for amplifiers in Ontario.
Shoot, it is even my fav. brand.
However, i wonder how many are still Canadian owned ?
Of course i know the Canadian Brands.
In the early 90s i had a Classé DR3, for a short while.
Secondhand, the high current version, vhc, loved the layout with separate output boards of that power amplifier.
I am even aware that Canada has a large producer of big capacitor cans for amplifiers in Ontario.
Shoot, it is even my fav. brand.
However, i wonder how many are still Canadian owned ?
The Shaman said:
You can get away with 80VA per chip if they are not to be used full volume for extended periods.
125VA will power one(1) chip to full potential under most circumstances.
I used Apex.jr's http://www.apexjr.com/images/NewTorid.JPG x-former for a stereo amp consisting of BrianGT's premium LM3875 amp kit. I used it on my B&W 805's and a friends Madisound Thor kit. That is 100VA shared between 2 chips.
EVERYONE remarked how the little kit had better bass than his 300wpc Adcom GFA-8500(?).
K-amps said:
Thanks, K-amps.
Overhere they do $200 and +$300 for regular windings, having custom made swim across should be even more attractive.
I gathered that price levels will be rising due to increasing copper
and steel prices.
I saw the Rockna homepage some time ago, they probably just started in Romania.
I'm in for a couple of their 5000VA models, if the quality is ok.
I requested a quote on 5000VA toroids at a company that does those in the tulip flats, dont even ask.
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