I suppose the obvious question to ask is are you already troubled by hum and noise? Is the case completely made of metal? And if so what is the metal - aluminium?
I suppose the obvious question to ask is are you already troubled by hum and noise? Is the case completely made of metal? And if so what is the metal - aluminium?
Barry
Maple? Really?
Shielding against magnetic fields requires a ferrous material, preferably of high permeability. It shouldn't really cost three times the transformers inside.
However, un-shielded but carefully sited transformers placed well away from mains transformers can have less hum than shielded transformers simply plonked down on top of another piece of equipment.
I'm sure that for just shy of 2k for the case I could come up with something....
Adey
Sent from my Aquaris E4.5 using Tapatalk
Technics SP10 mk2
Jan Allaerts MC 1 Boron mk1 cart
Miyajima Shilabe cart
Hashimoto HM-X SUT
Siggwan (gimballed not unipivot) Cocobola 12"
Aurorasound Vida LCR Phonostage
The Truth linestage
Dave Slagle Autoformer Volume Controller
Cary 805c SET amps
Audio Note ANe-SPX speakers
Townshend Isolda speaker cables
Cardas Golden Presence interconnects
This.
When I was developing SUTs, I used Mumetal shields and I can tell you, they don't cost £2K to make or anything close!
Shielding is really mandatory for small signals subject to and sensitive to EMI, it needn't cost the earth and can be simply effected by housing the transformers within their own (potted) shielded enclosures then placing those within a secondary shielded enclosure for good measure. It's also important to get the earthing right to avoid excessive hum.
Location: Shenfield
Posts: 574
I'm Slav.
Quite often to make proper magnetic shielding more than one enclosure must be used , is quite common to use steel shield as external one because of its high saturation then use mu-metal enclosures , as mentioned earlier bending should be avoided as it lowers mu-metal properties of the affected areas.
Very good remark about positioning and earthing, this shall be your first step , do it right and you might find no need for magnetic shielding
Last edited by mac72; 04-01-2017 at 13:57.
Location: Shenfield
Posts: 574
I'm Slav.
Not necessarily, as long as diameter of the hole is smaller than length of the wave , faraday shields protect from high freq. magnetic fields , we talking radio freq. above 100kHz when thickness of material used is around 1mm.
It could protect from 50Hz EM fields as well but thickness of used material must be more than skin depth of used material , if you want to use copper for example , we talking about min 20mm of thickness .
Last edited by mac72; 04-01-2017 at 14:32.
Location: Nr Ashbourne, East Midlands, UK
Posts: 110
I'm Mike.
I looked at some of Dave's SUT too.
They are quite a bit bigger than most SUTs and I believe Dave houses them separately, which I guess goes a little towards why they are so expensive. (I believe Jeff Day has some of these...)
In the end I chose to get HM7s as they are well shielded as standard which mean building them into a box was more within my skill base...
StSt Motus DQ + SME 312 'MB Special'
Transfix Axia / HM7
Art Audio Vinyl 1 Ref
Modified Mac Mini/Weiss DAC 202
SJS Model 2
BP P20 (SJS upgraded)
Trenner and Friedl RA
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My I ask the op has he considered a head amplifier instead of an SUT? There does seem to have arisen lately a belief in some quarters that a SUT is the best way of amplifying the small signal from a MC cart and that it is a better way than a good MC input on a phono stage or a head amp.... I strongly disagree! It's yet another of those "trends", "fads" based on "old wives tales" etc that unfortunately blight our hobby
I make a high end head amp which, IMHO, is more than a match any SUT and will undercut the expensive ones as well
Arkless Electronics-Engineered to be better. Tel. 01670 530674 (after 1pm)
Modded Thorens TD150, Audio Technica AT-1005 MkII, Technics EPC-300MC, Arkless Hybrid MC phono stage, Arkless passive pre, Arkless 50WPC Class A SS power amp, (or) Arkless modded Leak Stereo 20, Modded Kef Reference 105/3's
ReVox PR99, Studer B62, Ferrograph Series 7, Tandberg TCD440, Hitachi FT-5500MkI, also FT-5500MkII
Digital: Yamaha CDR-HD1500 (Digital Swiss army knife-CD recorder, player, hard drive, DAC and ADC in one), PC files via 24/96 sound card and SPDIF, modded Philips CD850, modded Philips CD104, modded DPA Little Bit DAC. Sennheiser HD580 cans with Arkless Headphone amp.
Cables- free interconnects that come with CD players, mains leads from B&Q, dead kettles etc, extension leads from Tesco
Arkless Electronics-Engineered to be better. Tel. 01670 530674 (after 1pm)
Modded Thorens TD150, Audio Technica AT-1005 MkII, Technics EPC-300MC, Arkless Hybrid MC phono stage, Arkless passive pre, Arkless 50WPC Class A SS power amp, (or) Arkless modded Leak Stereo 20, Modded Kef Reference 105/3's
ReVox PR99, Studer B62, Ferrograph Series 7, Tandberg TCD440, Hitachi FT-5500MkI, also FT-5500MkII
Digital: Yamaha CDR-HD1500 (Digital Swiss army knife-CD recorder, player, hard drive, DAC and ADC in one), PC files via 24/96 sound card and SPDIF, modded Philips CD850, modded Philips CD104, modded DPA Little Bit DAC. Sennheiser HD580 cans with Arkless Headphone amp.
Cables- free interconnects that come with CD players, mains leads from B&Q, dead kettles etc, extension leads from Tesco
The only reason I'm considering a SUT is for exact impedance matching of the shilabe with my Vida - the Vidas high setting is 100ohms but following the general rule of thumb of x10 means the shilabe should see 160ohms, though some folks prefer higher. I wish the Vida offered a higher setting as it's performance is astonishing as is the noise floor.
Adey
Sent from my Aquaris E4.5 using Tapatalk
Technics SP10 mk2
Jan Allaerts MC 1 Boron mk1 cart
Miyajima Shilabe cart
Hashimoto HM-X SUT
Siggwan (gimballed not unipivot) Cocobola 12"
Aurorasound Vida LCR Phonostage
The Truth linestage
Dave Slagle Autoformer Volume Controller
Cary 805c SET amps
Audio Note ANe-SPX speakers
Townshend Isolda speaker cables
Cardas Golden Presence interconnects