Thank you very much. Un lungo periodo senza sapere di te, Roberto.
PS: now I have DCB + DCBx4 in my second system, ALL with big EPCOS capacitors. I have reached the maximum attenuation of noise without dynamics loss.
How to clean the DC at mains. And ripple too.
PS: now I have DCB + DCBx4 in my second system, ALL with big EPCOS capacitors. I have reached the maximum attenuation of noise without dynamics loss.
How to clean the DC at mains. And ripple too.
Last edited:
I was about to buy Mike's first Icepower 1200AS2 kit in Audiocircle (Mivera Audio) but the great improvement I got in the sound pushed me back.
Just a few minutes ago I got another improvement, via software.
The Apolloaudio uses a cheap case. If it were mine I would add graphite sheets inside to increase the shielding with respect to atmospheric RF / EMI.
graphite sheet rf emi - Google Search
Just a few minutes ago I got another improvement, via software.
The Apolloaudio uses a cheap case. If it were mine I would add graphite sheets inside to increase the shielding with respect to atmospheric RF / EMI.
graphite sheet rf emi - Google Search
Apollonaudio uses a quite standard modu case. Also NORD uses them, they are good. Also, they use top notch internal cabling and external connectors.
Mike is somebody that once asked seriously in this forum "ok, this Putzeys guy may know something about class D, but what does he know about the Ncore modules". I would discourage anybody to buy anything from a guy asking (I repeat, seriously) this question. He has been banned from various forums.
And, yes, I am sourcing graphite sheets and g-iron or getting them to do it.
best
Roberto
Mike is somebody that once asked seriously in this forum "ok, this Putzeys guy may know something about class D, but what does he know about the Ncore modules". I would discourage anybody to buy anything from a guy asking (I repeat, seriously) this question. He has been banned from various forums.
And, yes, I am sourcing graphite sheets and g-iron or getting them to do it.
best
Roberto
Case.
Front plate, 10 mm or 4 mm, aluminum.
The other sides?
From my experience, you need more than 4 mm aluminum to avoid the RF/EMI atmospheric. I have "tons" of RF/EMI at mains and in atmosphere and others very big problems, you know.
With only 1 mm steel sheet is enough, without holes.
You can add graphite or steel sheet.
By the way, I added two pieces of steel in my amplifiers to isolate the electronics from the transformers and I noticed the improvement. Cheap and effective.
Front plate, 10 mm or 4 mm, aluminum.
The other sides?
From my experience, you need more than 4 mm aluminum to avoid the RF/EMI atmospheric. I have "tons" of RF/EMI at mains and in atmosphere and others very big problems, you know.
With only 1 mm steel sheet is enough, without holes.
You can add graphite or steel sheet.
By the way, I added two pieces of steel in my amplifiers to isolate the electronics from the transformers and I noticed the improvement. Cheap and effective.
Last edited:
3 mm the back, 10 mm the sides (but they are milled to have a nice shape, so the actual width is less), and 1 mm for the steel top and bottom cover. information from the modu web site. I think they are ok, you can add some graphite or g-iron.
The Takachi cases look indeed better from the sides.
I intend to do something similar for the main transformer of my Abrahamsen 4.0 UP power amp (a 1000VA toroid, it has a lot of leaked flux where the wires go in).
Roberto
What kind of problems? What are the symptoms?
What kind of improvement, and how much was the improvement?
Abrahamsen v4.0 inside, transformer:
Steel sheet or maybe graphite around the transformer, or both.
If you buy a graphite sheet, you can add under the sides too. 1000 VA toroidal transformer can be very problematic you know.
If you buy a graphite sheet, you can add under the sides too. 1000 VA toroidal transformer can be very problematic you know.
Last edited:
Mains: DC, RF/EMI and almost 240 Vac.
Atmosphere: RF/EMI.
There were days when it was unacceptable to listen to music, I had to turn it off how bad the excellent recordings.
This evening the sound is marvellous. You know, Saturday, weekend, festives and after 20.00 pm.
The music fills the room. It is pleasant. Very high dynamics. Bass +++. The treble is not a problem with my cheap tweaked KEF Q100 coaxial speakers. The voices are good. More 3D.
"Natural" sound, credible.
This week I have listen a very good 24/192 vinyl rip: Beethoven - The 5 Piano Concerti - Katchen / Gamba, London SO (1959-1964).
A while ago I could not resist and I had to get up from the chair and start directing the orchestra:
B1 Piano Concerto No.1 in C major Op.15 - 3. Rondo (Allegro scherzando)
A word: EMOTION.
Before I was desperate and now I get excited with some excellent recordings. Does the difference seem little?
Few years ago I decided that I would spend up to 2000 euros on a new amplifier but it was illogical if I did not solve my problems before. And just when I was going to spend just over 900 euros (kit, shipping from Canada to Spain, taxes) I got another substantial improvement.
Right now I am listening to french opera live? from Radio Clásica de RTVE and I am amazed. From the FM tuner of my cheap tweaked and second hand (€115) AV Marantz SR4500.
Radio Nacional en directo - RTVE.es
BBC, December 24 2016
Offenbach's Les Contes d'Hoffmann
BBC Radio 3 - Opera on 3, Offenbach's Les Contes d'Hoffmann
Les contes d'Hoffmann
The Tales of Hoffmann - Wikipedia
Few years ago I decided that I would spend up to 2000 euros on a new amplifier but it was illogical if I did not solve my problems before. And just when I was going to spend just over 900 euros (kit, shipping from Canada to Spain, taxes) I got another substantial improvement.
Right now I am listening to french opera live? from Radio Clásica de RTVE and I am amazed. From the FM tuner of my cheap tweaked and second hand (€115) AV Marantz SR4500.
Radio Nacional en directo - RTVE.es
BBC, December 24 2016
Offenbach's Les Contes d'Hoffmann
BBC Radio 3 - Opera on 3, Offenbach's Les Contes d'Hoffmann
Les contes d'Hoffmann
The Tales of Hoffmann - Wikipedia
Last edited:
Any way you could describe the issues in any understandable way, such as "there was hiss in the quiet passages" or "the top end sounded clipped" or anything like that?
Funny to read this.
My take is: when the amplifier only performs best when certain conditions are met, and apparently the power supply transformer is responsible, throw it out.
Why on earth audiophiles presume that everything should be OK when the transformer is round, eh... toroidal?
Toroidal transformers have advantages and potential drawbacks. Not because they are "toroidal", but too often not optimally designed because economics "rule".
Advantages: small dimension; low strayfield.
Potential drawbacks:
1. many commercial toroidals work too near to core saturation, which means that line overvoltage causes core saturation;
2. because of core geometry very sensitive to DC garbage, again causing saturation;
3. because of winding geometry (high bandwidth) very sensitive to HF garbage;
4. potential resonance; this can be a combination of high core excitation and "randomness" of windings, or caused by one of these.
Most of these drawbacks can be handled with a good design:
1. lower core excitation (preferably not over 1T); this cures malfunction because of line overvoltage; transformers need to be larger though, and therefore less economic
DC immunity is improved at the same time, though the core geometry is problematic (EI and c-cores with some airgapping are better);
2. good electrostatic shielding, preferably a double shield between primary and secondary (EI and c-cores again better because of lower bandwidth, in other words the worse coupling is an advantage here).
IMO toroidals are not the optimum choice in high end gear, but I realize that it's "cursing in the audiophile church". Funny again to see how people fight the problems caused by sub optimal toroidal power supply transformers by DC blockers, extensive shielding, and apparently waiting to enjoy the amplifier when line voltage is "normal"
It is perfectly possible to tackle these potential problems at the source by applying better transformers.
Last edited:
I suppose it will also influence that the USA electric grid, like the rest of the world, is increasingly contaminated by the use of cheap SMPS, deficient electric motors, cheap air conditioners... manufactured in Asia.
European regulations have hardened but it seems that the authorities look the other way with chinese imports and in the end is the consumer who suffers his neglect.
European regulations have hardened but it seems that the authorities look the other way with chinese imports and in the end is the consumer who suffers his neglect.
Last edited:
Found it on Tidal:
Piano Concerto No. 1 in C Major, Op. 15: III. Rondo. Allegro
London Symphony Orchestra, Piero Gamba, Julius Katchen
Beethoven: Piano Concertos Nos. 1, 2, 3, 5 & Rondo, WoO 6
PCM VBR, FLAC
First class playing. Sounded just a little harsh in forte sections compared to the best modern recordings. Good "room" and stage. I can see why you stood up
//
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.