Hi,
I emailed a bit with Tomasz from Poland. He recommends the supreme audio grade transformers which definitely won't fit in the required VA rating.
So I will probably order a pair of 800VA audio grade ones and machine my heat sinks....
The R-cores are very interesting and I will try them on the next occasion but for now they just won't fit without a major rebuild as they are a lot bigger than the toroids.
I will keep you updated
William
I emailed a bit with Tomasz from Poland. He recommends the supreme audio grade transformers which definitely won't fit in the required VA rating.
So I will probably order a pair of 800VA audio grade ones and machine my heat sinks....
The R-cores are very interesting and I will try them on the next occasion but for now they just won't fit without a major rebuild as they are a lot bigger than the toroids.
I will keep you updated
William
Interesting!
I might give it a go. I'm not too concerned about a bit of noise at 600K, it's certianly worth a try.
🙂 😀 🙂 😀
Yes,
that´s true. Aiming to be able to use a smaller parking space also has some disadvantages........
William
The key is to order trafo with less than 1 Tesla induction of primary. Or even less say 0.707 Tesla.
(and with the good old EI laminations pref.)
that will give more turns on primary windings - also with same ratio more turns on secondary. That will deserve probably next bigger EI or other core because of the space
for Copper windings.
BUT that kind of trafo will run very small Io without load, will newer overhat, never hear the sound from... 🙂
.
And dont forget propper shasing grounding, and ordering the sheilds one sheild before start of primaru, other between primary and secondary.
the screws pressing the laminates should be from some non magnetic material pref. and isolated from the laminates.
.
Transformer has to be mount NOT on the chasses but on the some isolation carryng board and then to the chasses.
.
All sheilds and core thean by wires has to be tap at the chasses ground on power socket...
.
Like in old times, and like it should be.
.
These new fashion of making trafos hav only one goal - to made it low cost for material
and easyer for production - outcome is not less coast for customer but bad quality...
cheers
(and with the good old EI laminations pref.)
that will give more turns on primary windings - also with same ratio more turns on secondary. That will deserve probably next bigger EI or other core because of the space
for Copper windings.
BUT that kind of trafo will run very small Io without load, will newer overhat, never hear the sound from... 🙂
.
And dont forget propper shasing grounding, and ordering the sheilds one sheild before start of primaru, other between primary and secondary.
the screws pressing the laminates should be from some non magnetic material pref. and isolated from the laminates.
.
Transformer has to be mount NOT on the chasses but on the some isolation carryng board and then to the chasses.
.
All sheilds and core thean by wires has to be tap at the chasses ground on power socket...
.
Like in old times, and like it should be.
.
These new fashion of making trafos hav only one goal - to made it low cost for material
and easyer for production - outcome is not less coast for customer but bad quality...
cheers
Lately I order pair of trafos for the some dac (4xpcm63 dual mono, 2 chasses...)
and I measured around 17mA @ the primary Io without load. No any kind of sound, and I can not even feel with the fingers is the xformer is turned ON or OFF... 🙂 The induction of primary was 1Tesla.
and I measured around 17mA @ the primary Io without load. No any kind of sound, and I can not even feel with the fingers is the xformer is turned ON or OFF... 🙂 The induction of primary was 1Tesla.
Would the simple solution be to ask the manufacturer to build a transformer for a mains voltage about 20% higher than your own typical voltage?
i.e. I want a 500VA 230:20+20Vac transformer.
But I specify a 600VA 276:24+24Vac transformer.
When that transformer is operated on 230Vac +-6% with an effective DC blocker, it is guaranteed to not saturate.
i.e. I want a 500VA 230:20+20Vac transformer.
But I specify a 600VA 276:24+24Vac transformer.
When that transformer is operated on 230Vac +-6% with an effective DC blocker, it is guaranteed to not saturate.
If I recall correctly, Mr. Pass mentioned running dual 115VAC primaries in series (230VAC configuration) on 115VAC mains, and by choosing twice as high secondary voltages initially, he again ended up with the correct resulting secondary voltages. The goal was to minimize core saturation, if memory serves. Only works for 110/115 VAC countries of course...
That calls for twice the VA rating too. If you need a 1000VA transformer, you will need a 2000VA transformer to get away with the current draw.
Actually, I think - no.
Please take standard calc. process and start with number of turns of the primary for typical
local value of mains voltage.
And calculate for the induction of primary of 1 Tesla or less down to sort(2) if You want.
Next use little bit smaller value for current desity less than 2.55 [A/cm2] to determine, with total power requirement, diameter of primary wire.
Then with that number of turns cac for secondary and finally get the right volume core,
for space ended for windings, shields, and insulation.
.
I will try to find and post MathCad sheet for all this 🙂
Please take standard calc. process and start with number of turns of the primary for typical
local value of mains voltage.
And calculate for the induction of primary of 1 Tesla or less down to sort(2) if You want.
Next use little bit smaller value for current desity less than 2.55 [A/cm2] to determine, with total power requirement, diameter of primary wire.
Then with that number of turns cac for secondary and finally get the right volume core,
for space ended for windings, shields, and insulation.
.
I will try to find and post MathCad sheet for all this 🙂
What I seem to miss in the amp picture is ample mechanical damping of the potted Tauscher.
(Vacuum resin injection of both windings works wonders, but stuffing an entire transformer in a plastic bag is very diy. Typical Dutch is buying pants three sizes larger, at a 30% sale discount, so that it may fit perfectly in 10 years time)
Hi Jacco,
could you explain a bit further?
The transformer is held to the frame by one big bolt, I tried to reduce the contact points to the frame and tried to avoid some kind of resonance body.
Changing the torque of the bolt didn´t change the sound of the transformer.
I also tried to put it on some rubber sheet which also didn´t change the sound.
In my X-BOSOZ power supply the humming was reduced by building a "suspension " for the 4 transformers so they didn´t touch the case, in the Aleph-X this is not an option.
When I look into other amps (non DIY) I see simple non potted transformers which don´t seem to be mounted in a special way and which are silent (F1-F6etc). I just would like one of those (transformers)
William
P.S. my 10 year old pants still fit......
Last edited:
Last I recall you were into wheel suspensions, just curious what you had tried.
I use sub-chassis and vibration dampers, buy those NOS at scrap value prices. (NOS pre-drilled aluminum sub-chassis are not only cheaper, also less work, easy to adapt)
An example I already posted a couple of times : Schwingungsdämpfer - Bauelemente / Bauteile - Mechanische Bauelemente - Montagematerial - Pollin Electronic
Some can only be found NOS nowadays, e.g. the one in the image I added below, Bürklin used to sell those up till the '90s.
(not polyurethane control arm bushings, but hey, I'm cheap)
Bit mute as I generally have R-cores for serious stuff, a lot easier with a stand-off in four corners.
The noise source is not the core (toroidal donut + DC-blocker to prevent the core from saturating due to mains phase mismatch)
And if it's not mechanically transmitted noise, only remains the windings at such high bias current levels. Makes me wonder about your Torobars.
(the Aleph-X issues continue to amaze)
I use sub-chassis and vibration dampers, buy those NOS at scrap value prices. (NOS pre-drilled aluminum sub-chassis are not only cheaper, also less work, easy to adapt)
An example I already posted a couple of times : Schwingungsdämpfer - Bauelemente / Bauteile - Mechanische Bauelemente - Montagematerial - Pollin Electronic
Some can only be found NOS nowadays, e.g. the one in the image I added below, Bürklin used to sell those up till the '90s.
(not polyurethane control arm bushings, but hey, I'm cheap)
Bit mute as I generally have R-cores for serious stuff, a lot easier with a stand-off in four corners.
The noise source is not the core (toroidal donut + DC-blocker to prevent the core from saturating due to mains phase mismatch)
And if it's not mechanically transmitted noise, only remains the windings at such high bias current levels. Makes me wonder about your Torobars.
(the Aleph-X issues continue to amaze)
Attachments
Last edited:
ook
see usual ingenious ZM Genius solution :
Babelfish J2 , pair of them , for Denmark ……. (Blast from the Past) | Zen Mod Blog
Papa’s Koan (M)2 , an amp for living room | Zen Mod Blog
see usual ingenious ZM Genius solution :
Babelfish J2 , pair of them , for Denmark ……. (Blast from the Past) | Zen Mod Blog
Papa’s Koan (M)2 , an amp for living room | Zen Mod Blog
Attachments
Hi Jacco,
still into suspensions. The problem exists not only in my Aleph-X but also happened in my Aleph-5 and my Crescendo.
The only silent amps with toroids where a few pairs of UCD´s from Hypex with almost zero load at idle and funny enough a pair of Aleph5 monos I build for a friend with some no name toroids from Pollin or Reichelt.
I tried a lot except enclosing them in a vacuum (which would help).
Suspending them only helps when the vibrations are transmitted to the case and amplified (as was the case in my X-BOSOZ power supply) but in my case the toroids are loud enough even if they don´t touch anything.
The torobars are silent.
I always thought it was the cores I heard, the noise is not always the same (but the bias is) so I think it is influenced from outside. Turning on another device (tuner, DAC etc.) makes the humming louder for a few seconds.
So for now I will try the toroidy non potted ones and see what happens. Maybe I´ve just been lucky with the ones I got until now.......
William
still into suspensions. The problem exists not only in my Aleph-X but also happened in my Aleph-5 and my Crescendo.
The only silent amps with toroids where a few pairs of UCD´s from Hypex with almost zero load at idle and funny enough a pair of Aleph5 monos I build for a friend with some no name toroids from Pollin or Reichelt.
I tried a lot except enclosing them in a vacuum (which would help).
Suspending them only helps when the vibrations are transmitted to the case and amplified (as was the case in my X-BOSOZ power supply) but in my case the toroids are loud enough even if they don´t touch anything.
The torobars are silent.
I always thought it was the cores I heard, the noise is not always the same (but the bias is) so I think it is influenced from outside. Turning on another device (tuner, DAC etc.) makes the humming louder for a few seconds.
So for now I will try the toroidy non potted ones and see what happens. Maybe I´ve just been lucky with the ones I got until now.......
William
ook
see usual ingenious ZM Genius solution :
Babelfish J2 , pair of them , for Denmark ……. (Blast from the Past) | Zen Mod Blog
Papa’s Koan (M)2 , an amp for living room | Zen Mod Blog
Nice.....if you´ve got enough space😀
will try to find some pics tomorrow.
william
I have a good experince with Sedlbauer transformers in clas A applications:
Ringkern-Transformator 2 x 115 V 2 x 12 V 2 x 20.84 A 500 VA Sedlbauer im Conrad Online Shop | 609294
- Status
- Not open for further replies.