When they say 2X means 2 secondaries and 4 wires. So you can either use 2, 2 for different psus or connect the intermediate wires together and have the whole voltage across the remaining free wires. Or make +/- psus around the 0 center you created and the free wires. When they say V-0-V they mean already center tapped, you can either use whole or half or symmetric but not separate.
By twisting the intermediate wires and connecting their edges, and using only the free wires on the 2X15 you effectively get a 30V secondary that will go up to 40-41VDC. For your 28Vo needs with the specific reg, you can drop it down to 37-38Vin experimenting with small 5W resistors so you can utilize a little RC filter also, and assign some heat away from the CCS Mosfet too. As for the current ratings, there must be typos there. The cores look big enough for what they claim. Thus the electrical laws will solve the situation whatever the text on the vendors websites. 80VA/30V=2.67A, that one looks normal for the second one, and a 2X15 is what you need across secondaries to get 30VAC.
By twisting the intermediate wires and connecting their edges, and using only the free wires on the 2X15 you effectively get a 30V secondary that will go up to 40-41VDC. For your 28Vo needs with the specific reg, you can drop it down to 37-38Vin experimenting with small 5W resistors so you can utilize a little RC filter also, and assign some heat away from the CCS Mosfet too. As for the current ratings, there must be typos there. The cores look big enough for what they claim. Thus the electrical laws will solve the situation whatever the text on the vendors websites. 80VA/30V=2.67A, that one looks normal for the second one, and a 2X15 is what you need across secondaries to get 30VAC.
All the TX I am choosing have four wires so they have independent secondary windings.
I would like to use only one TX that could fit inside the existing external psu so I am inclined for the 100VA - 2 x 30v Block.
As the information in the site refer to a 0,51A rated current I was afraid that would be a problem. Besides that the Block is advertised as a "Isolating Transformer" so I was afraid it could have very thin secondary windings wires.....
I would like to use only one TX that could fit inside the existing external psu so I am inclined for the 100VA - 2 x 30v Block.
As the information in the site refer to a 0,51A rated current I was afraid that would be a problem. Besides that the Block is advertised as a "Isolating Transformer" so I was afraid it could have very thin secondary windings wires.....
So the Block is not suitable... maybe that is why they spec it at 510mA op current.
I will need two 2x15v TX than.... Of course I will need a second psu case... the end result will be a blast... imagine a riaa with two external psu cases
A really true double mono.
Now regarding the resistors to create a voltage drop from 40v plus to 36v... can I use these between the rectification and the smoothing caps ? (I just got two jensen 4 poles and would like to connect them directly to the shunts )
I will need two 2x15v TX than.... Of course I will need a second psu case... the end result will be a blast... imagine a riaa with two external psu cases
A really true double mono.Now regarding the resistors to create a voltage drop from 40v plus to 36v... can I use these between the rectification and the smoothing caps ? (I just got two jensen 4 poles and would like to connect them directly to the shunts )
Sir Ricardo some ring for you https://www.distrelec.com/ishopWebF...id=A2E8C6266CC61CF3E0B0511A2DBCE0B1.chdist141
Cool...
Some more rescue is coming my way.... Thank you nicoch46
By reading this Block link I believe it would be good... what do you think ?
https://www.distrelec.com/ishopWebF...id=A2E8C6266CC61CF3E0B0511A2DBCE0B1.chdist141
Some more rescue is coming my way.... Thank you nicoch46
By reading this Block link I believe it would be good... what do you think ?
https://www.distrelec.com/ishopWebF...id=A2E8C6266CC61CF3E0B0511A2DBCE0B1.chdist141
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ripple and noise filter
Here go two PSU Designer files. Notice the difference between shape and size of the ripple voltages. Chokes used are 50mH (0.2 ohm) common mode type. The small resistors are used to drop some voltage, secondary Rdc is guessed. Enjoy.
Here go two PSU Designer files. Notice the difference between shape and size of the ripple voltages. Chokes used are 50mH (0.2 ohm) common mode type. The small resistors are used to drop some voltage, secondary Rdc is guessed. Enjoy.
Attachments
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Without sophisticated test equipment it's a rather theoretical matter but on tube amplifiers the difference can be heard.
The Simplistic Regulator is very good. This little help might get your results a little further, as we are amplifying small signals with SE stages. I haven't listened without the CM filter but I can imagine it removes to a small extent the artifacts from the reproduction.
The Simplistic Regulator is very good. This little help might get your results a little further, as we are amplifying small signals with SE stages. I haven't listened without the CM filter but I can imagine it removes to a small extent the artifacts from the reproduction.
Yes, please Disco, tell us more. Possibly even the diode type.
Ricardo, at this point I no longer need a 30 + 30 V AC Xfrm, but an higher one to get the desired 42 V DC for the hi gain riaa. More trouble.....
I checked the Block toroid: the RT series (single 230 V pri.) specs look slight better than the RK (dual 115 V pri.) and it should be slightly cheaper.
If Farnell doesn't carry the RT series, Distrelec does.
Price differences: in Portugal F. prices the RX100/30 39.35 € + xx%Vat, in Italy 42.43 + 20%Vat
Distrelec here is much more expensive: 67,80 € + Vat for the same product! RT100/30 costs 50.70 € + Vat.
I would like to build the high gain Riaa (pcbs will follows), thus Vout must be 35V, but if I implement the filter suggested by Disco, I need a 35 + 35 VAC Xfrm. That means I must have it done on special order.
Price differences: in Portugal F. prices the RX100/30 39.35 € + xx%Vat, in Italy 42.43 + 20%Vat
Distrelec here is much more expensive: 67,80 € + Vat for the same product! RT100/30 costs 50.70 € + Vat.
I would like to build the high gain Riaa (pcbs will follows), thus Vout must be 35V, but if I implement the filter suggested by Disco, I need a 35 + 35 VAC Xfrm. That means I must have it done on special order.
guys remember that Joh curl, Ayre and Jocko Homo
don't use ring trafo because don't filter the dirty AC as wide band device.....!!!
the hammond in my phono sound better then talema ring , and peter daniel as quite critic in the component selection use the hammond split coil in the Dac....
http://www.diyaudio.com/forums/./me...file&u=4&sid=c7d3ec7d330b054e1843a521615d7ba6
don't use ring trafo because don't filter the dirty AC as wide band device.....!!!
the hammond in my phono sound better then talema ring , and peter daniel as quite critic in the component selection use the hammond split coil in the Dac....
http://www.diyaudio.com/forums/./me...file&u=4&sid=c7d3ec7d330b054e1843a521615d7ba6
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