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Old 3rd November 2012, 04:41 PM   #901
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Quote:
Originally Posted by The Space Egg Corp View Post
Arrh !

You make 26 as well Felipe ! yes

I looked at this also...
...good with attenuator between Itch & 26 maybe.

Felipe...You told me a year ago...but I forget...
...You are using 'balanced amps'...yes ? yes
..I think you built yourself Nelson something ( F? ).no, I use Erno Borbely pre amp & power amp both full balanced

What line-stage do you use/build ?
This is what you listen to 'Itch' with now...before amps/s ? Simplistic NJFET RIAA

Si.

Hope that makes sense.

( nice grommets !!! ) thanks to massimo
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Old 3rd November 2012, 07:56 PM   #902
Salas is offline Salas  Greece
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Originally Posted by merlin el mago View Post
I need to change for other more thick?
Not the matter, only mA here, I was wondering about its insulation rating and long time safety. Fuse the live of mains going to transformers. Fuse for as much total VA/230V with 6x32mm glass or 5x20mm ceramic fuse 250V for good interruption not arcing. Fuse +line somewhere along the way to SSHV2 with 6x32mm 380V 200mA ceramic fuse also. If you are to keep and use take care of it. Is the sink well insulated to the IRF840? Much chassis metal near, must be safe too.
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Old 3rd November 2012, 08:07 PM   #903
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Originally Posted by merlin el mago View Post
Changed interstage caps 47nF 600VDC MKP to 47nF 1000VDC teflon film & tin foil
Had the first model blue SCR branded only, Teflons without tin, few years back. They were very fast and very clean, maybe not that forgiving also. How are the Teflon Foil SCR for Obbligato in the Itch VS the MKP you changed?
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Old 3rd November 2012, 08:22 PM   #904
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You will buy proper as I described, fast only. A fuse has to have the voltage rating and interruption current rating proper. So it does not blow ugly or arcs, especially in the HV line.
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Old 3rd November 2012, 08:23 PM   #905
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Quote:
Originally Posted by Salas View Post
Not the matter, only mA here, I was wondering about its insulation rating and long time safety. Fuse the live of mains going to transformers. Fuse for as much total VA/230V with 6x32mm glass or 5x20mm ceramic fuse 250V for good interruption not arcing. Fuse +line somewhere along the way to SSHV2 with 6x32mm 380V 200mA ceramic fuse also. If you are to keep and use take care of it. Is the sink well insulated to the IRF840? Much chassis metal near, must be safe too.
I have only 5x20mm, no ceramic only glass, I have 200mA 250V fast and 250mA 250V slow. Wich fuse before the mains transformers?
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Old 3rd November 2012, 08:26 PM   #906
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Told you add all your transformers VA then divide by 230V, that is ballpark proper. Only fast for mains in a preamp.
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Old 3rd November 2012, 08:29 PM   #907
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Quote:
Originally Posted by Salas View Post
Had the first model blue SCR branded only, Teflons without tin, few years back. They were very fast and very clean, maybe not that forgiving also. How are the Teflon Foil SCR for Obbligato in the Itch VS the MKP you changed?
Yours blue SCR are teflon film metallized, foil have more body also are very fast, very clean & open. I prefer not forgiving caps. Surely is the easy tweak with better result to do in the Itch.
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Old 3rd November 2012, 08:36 PM   #908
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Told you add all your transformers VA then divide by 230V, that is ballpark proper. Only fast for mains in a preamp.
I don't know VA rating of B+ transformer, surely is aprox. 240V x 0.020A = 4.8A because Audionote uses it for DAC I/V output with 2 tubes 6922, each heater 12V 5A = 36VA

4.8A + 36VA + 36VA = 76.8VA : 230V = 333mA it's ok 400mA 250V or better 500mA?

Between PSU & SSHV2 6x32mm 380V 200mA ceramic?
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Old 3rd November 2012, 08:45 PM   #909
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400mA should do. If it ever blows in start up inrush only then go 500mA.

Yes, 200mA ceramic, so if something happens in the HV line or under the plate in the phono B+ it will protect from fire. But now you say your HV transformer is too small. So use 100mA which is the SSHV2 ~max CCS.
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Old 3rd November 2012, 08:55 PM   #910
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I'm not really sure how many mA have the B+ tx, I said 20mA because is the max current that I can adjust with SSHV2, I think the right way?

About floor metal chassis I use bitumen self adhesive to isolate the heatsink of the SSHV2 of the chassis, I can do the same for the rest of floor metal chassis.

Last edited by merlin el mago; 3rd November 2012 at 08:58 PM.
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