Edcor shielding Question
Question for those who have fitted mu metal shields on the Edcors: What thickness of material did you use? Is the 4 mil (.004) sheet available on ebay sufficient?
Its hard to judge from pictures how thick the material actually is.
Thanks!
Greg
Question for those who have fitted mu metal shields on the Edcors: What thickness of material did you use? Is the 4 mil (.004) sheet available on ebay sufficient?
Its hard to judge from pictures how thick the material actually is.
Thanks!
Greg
I bought 0.01" from McMaster, and if I recall correctly NP said that's what he tried.
BK
DC offset
I noticed that DC offset at the speaker terminals goes temporarily over 1V when I switch on the amp from cold. Then it goes down to about 50-30mV and slowly to 0mV when the amp warms up. Is that something I need to worry about?
I noticed that DC offset at the speaker terminals goes temporarily over 1V when I switch on the amp from cold. Then it goes down to about 50-30mV and slowly to 0mV when the amp warms up. Is that something I need to worry about?
So, I boxed Edcors using TEKO 3710 with some mu metal glued in and most of the noise is gone, but the sound of the amplifier changed to much worse. Bass gone, mids hidden, dominant upper frequencies, quite sandy. As soon as I take TEKO lids off it starts sounding better. Any idea why this is happening?
The difference is also measurable - without TEKO boxes THD+N is about 0.08%, THD about 0.04% (at 1W, 1kHz, 8Ohms), with TEKO boxes both THD+N and THD raise to almost 0.2%.
I think I will get rid of TEKOs and try to build boxes from mu metal sheet.
Maybe I will also shield power transformers with some steel.
regular shielding strip around donut is a must with M2
That's why I'm constantly repeating that Modushop 4U/400 is swiss knife case solution for all FW format amps - enough Alu , enough space
300 deep is cramped , for Sissies
OK , 400 is for Sissies , too
I'm pleading to Store to include both Dissipante 4U and Dissipante De Luxe 4U - 400 deep
That's why I'm constantly repeating that Modushop 4U/400 is swiss knife case solution for all FW format amps - enough Alu , enough space
300 deep is cramped , for Sissies
OK , 400 is for Sissies , too
I'm pleading to Store to include both Dissipante 4U and Dissipante De Luxe 4U - 400 deep
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regular shielding strip around donut is a must with M2
That's why I'm constantly repeating that Modushop 4U/400 is swiss knife case solution for all FW format amps - enough Alu , enough space
300 deep is cramped , for Sissies
OK , 400 is for Sissies , too
I'm pleading to Store to include both Dissipante 4U and Dissipante De Luxe 4U - 400 deep
Yes, you are right. I am reusing 4U/300 chassis, which I have bought quite a few years ago (4U/400 was not available at that point). Now I would definitely go for 400.
M2 'only' dissipates ~160w - not a lot around this corner of the forum 🙂
Why not put the amp in a smaller chassis, and the PSU in another? There will be silence when you want silence.
This makes sense especially for someone making their first FW amp, and reusing the PSU for subsequent builds.
I sound like a broken record
Why not put the amp in a smaller chassis, and the PSU in another? There will be silence when you want silence.
This makes sense especially for someone making their first FW amp, and reusing the PSU for subsequent builds.
I sound like a broken record
Yes, great idea as well, but not feasible for me due to limited space in my living room...
Any chance the TEKO box or its lid makes contact with the Edcor core laminations, thereby inadvertently grounding them ?
As far as I understand, the TEKO box should be grounded, but the transfomer laminations themselves should not. That's the way I have built the amp boards.
Best regards,
Claas
No, I don't think so. TEKO boxes are grounded as I mounted them on the same bolts which hold PCBs to heatsinks, but they don't touch Edcors at all.
ZM: What material are you referring to as "regular shielding strip"? I have some 0.01" Mu Metal (equivalent) sheet on order from McMaster Carr. I'm wondering if that would be up to the task of shielding the toroid.
frankly , all I know about is what I saw in amps I repaired - ring made of 2 or 3 full windings of metal strip , wound around perimeter of donut
material looks grainy on edges , fine surface ....... pretty much the same looking as xformer lamination
it can be mumetal , or something else , but certainly having decent magnetic characteristics
material looks grainy on edges , fine surface ....... pretty much the same looking as xformer lamination
it can be mumetal , or something else , but certainly having decent magnetic characteristics