Going with 4mH air core inductors for the above PS could be very expensive. The only way I can see to keep inductor DCR very low is to go with 12 guage foil inductors that are about $49 USD a piece.
Regards,
Dan
An externally hosted image should be here but it was not working when we last tested it.
Regards,
Dan
dantwomey said:
Hi,
I am planning to build my Aleph5 with dual mono power supply (500 VA 30 V trafo + 8 * 22000 uF/63 V for each channel)
If I use the powercircuit of Kristijan ( http://web.vip.hr/pcb-design.vip/power-5.html ) I guess I need 2 air cores of 3.9 mH for each channel (so 4 in total).
What quality must I buy? I can buy a 1.4 mm 3.9 mH air core (0.67 ohm) for 11.50 euro (about $11) at my local speaker buildingshop. Isn't that good enough?
A 2 mm air core (0.40 ohm) will cost me € 29.50 euro each
I could also buy something called "ferrocore" which will cost me euro 9.50 (1.4 mm, 0.33 ohm).
Slightly off topic. It seems that a well known amplifier manufacturer has a different point of view on dual power supplies.
"The 350A utilizes a dual mono design topology. This gives the amplifier better isolation between channels. Soundstage imaging is improved, offering true soundstage width and depth. Instrument placement and layering are more accurate. Each channel shares a common 2000 VA toroidal transformer. By using a larger sin-gle transformer, rather than 2 smaller ones as in typical dual mono designs, stronger and cleaner bass is maintained."
Regards,
Dan
"The 350A utilizes a dual mono design topology. This gives the amplifier better isolation between channels. Soundstage imaging is improved, offering true soundstage width and depth. Instrument placement and layering are more accurate. Each channel shares a common 2000 VA toroidal transformer. By using a larger sin-gle transformer, rather than 2 smaller ones as in typical dual mono designs, stronger and cleaner bass is maintained."
Regards,
Dan
Good things are very costly! $200 USD will be $320 in Canadian Tire money plus PST and GST = $370CAN.
Dan that's it For couple of Amps that should do it.
By using a larger sin-gle transformer, rather than 2 smaller ones as in typical dual mono designs, stronger and cleaner bass is maintained."
Dantwomey I will be using PLITRON 1.5kW 2 x 40V for each channel of my Aleph 4
I've read that for those old (never used) capacitors, initially you charge it up slowly or something of that saying.
Fcel Yes I will try to do the exact same thing, run the setup with resistor and DC (battery) and charge them slowly and discharge them again trough the resistor. This will do the job I hope.
Trigon
Dan that's it
For couple of Amps that should do it.By using a larger sin-gle transformer, rather than 2 smaller ones as in typical dual mono designs, stronger and cleaner bass is maintained."
Dantwomey I will be using PLITRON 1.5kW 2 x 40V for each channel of my Aleph 4
I've read that for those old (never used) capacitors, initially you charge it up slowly or something of that saying.
Fcel Yes I will try to do the exact same thing, run the setup with resistor and DC (battery) and charge them slowly and discharge them again trough the resistor. This will do the job I hope.
Trigon
trigon said:Good things are very costly! $200 USD will be $320 in Canadian Tire money plus PST and GST = $370CAN.
Dan that's it
Trigon,
If this is the case, you should seriously consider using better caps and spend your money there and not on coils. What about nice Nichicon Super-Throughs, possibly the best large electrolytic capacitor made today? This way your Canadian Tire money will be better spent and the sonic improvement will be greater too. Those inductors are nice to use in speaker networks, but overkill IMO in power supplies. BTW, I still have 4 of them sitting in my drawer (2uH).
Check http://zalytron.com/, or check this thread for info on NorthCreek coils http://www.diyaudio.com/forums/showthread.php?s=&threadid=4644&highlight=northcreek
I don't see much reason for using different wire in coils than in transformer for that stage of a circuit. So regular, air core inductors should do.
I don't see much reason for using different wire in coils than in transformer for that stage of a circuit. So regular, air core inductors should do.
basic question
Now I'm a little bit confused.
Which Voltage would you reccomend for the Aleph 5 Power Supply. Many of you have Toroids with about 30V.
Actually i have 2 x 29V Toroids with 260VA.
I wanted to use two of them for one Mono.
My Problem are my 40V Caps. I have 8 Pcs. of 47.000uF/40V and 8 Pcs. of 22.000uF/40V from RIFA.
So I decided, that I will buy new Toroids (because they are cheaper then new Caps) with 2 x 25V.
First Question:
Is this enough? I probbably would be slightly under 34V.
Second Question:
should I take 300VA or 500VA for ONE channel of Aleph5?
Thanks!!!
Martin
Now I'm a little bit confused.
Which Voltage would you reccomend for the Aleph 5 Power Supply. Many of you have Toroids with about 30V.
Actually i have 2 x 29V Toroids with 260VA.
I wanted to use two of them for one Mono.
My Problem are my 40V Caps. I have 8 Pcs. of 47.000uF/40V and 8 Pcs. of 22.000uF/40V from RIFA.
So I decided, that I will buy new Toroids (because they are cheaper then new Caps) with 2 x 25V.
First Question:
Is this enough? I probbably would be slightly under 34V.
Second Question:
should I take 300VA or 500VA for ONE channel of Aleph5?
Thanks!!!
Martin
NP's recommendation appears to be at least 3x maximum power consumption. See www.passdiy.com for guidance. So you should go for 500VA each channel with an Aleph 5 at the very least.
Hope this helps,
Paul
Hope this helps,
Paul
if "NP's recommendation appears to be at least 3x maximum power consumption. See www.passdiy.com for guidance. So you should go for 500VA each channel with an Aleph 5 at the very least." and amplifier power consumtion is 300 watts all the time, therefore wouldnt the required minimum be 3 x 300 hence 900?
You can, of course, always get away with less, and it
also depends on the conservativeness of the manufacturer's
ratings.
For example, I have used Avel Lindberg 550 VA parts for
this circuit on occasion. The 550 VA rating is continuous
at 85 deg C ambient, and appears to be very conservative.
So we see that a factor of 2 is do-able, and we find that
with power factor (comes from taking current in short pulses
on the top of the AC line waveform) figured in, it stays within
the rating.
A factor of 3 covers manufacturers that are not so
conservative (no names mentioned).
also depends on the conservativeness of the manufacturer's
ratings.
For example, I have used Avel Lindberg 550 VA parts for
this circuit on occasion. The 550 VA rating is continuous
at 85 deg C ambient, and appears to be very conservative.
So we see that a factor of 2 is do-able, and we find that
with power factor (comes from taking current in short pulses
on the top of the AC line waveform) figured in, it stays within
the rating.
A factor of 3 covers manufacturers that are not so
conservative (no names mentioned).
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