Attached is a photo of an Aleph 30 that I am building for a friend....
Hi Lyndon!
This layout worked pretty well for my Aleph 2's but I am open to suggestions to improve what ever might be......
The specs are as follows....
Transformer: Victoria Magnetics 500 VA feeding dual bridge rectifiers and 84000 mfd of caps..... through the 6mh torodial chokes and then another 42000,mfd of caps.
Lots of heat sinking! way more than the original 30 had so we can bring up the bias considerably.
Boards by Mike W.
Back panel will be home to Neutrik XLR jacks, Cardas posts, an IEC AC socket, Fuse holder, AC switch.
Chassis: All black hard coated 6061-T6....1/8" alumnium bottom and rear plate, Perforated alumnium top cover. 3/8" alumnium tooling plate front panel (Hard coated Pewter) will get a blue LED some where and there is a blue LED on each PCB inside the amp so there is a little internal glow. Its weight so far is 38 lbs!
Mark
Hi Lyndon!This layout worked pretty well for my Aleph 2's but I am open to suggestions to improve what ever might be......
The specs are as follows....
Transformer: Victoria Magnetics 500 VA feeding dual bridge rectifiers and 84000 mfd of caps..... through the 6mh torodial chokes and then another 42000,mfd of caps.
Lots of heat sinking! way more than the original 30 had so we can bring up the bias considerably.
Boards by Mike W.
Back panel will be home to Neutrik XLR jacks, Cardas posts, an IEC AC socket, Fuse holder, AC switch.
Chassis: All black hard coated 6061-T6....1/8" alumnium bottom and rear plate, Perforated alumnium top cover. 3/8" alumnium tooling plate front panel (Hard coated Pewter) will get a blue LED some where and there is a blue LED on each PCB inside the amp so there is a little internal glow. Its weight so far is 38 lbs!
Mark
Attachments
wuffwaff ,
I am not familiar with calculating anything to do with chokes. I installed these in my Aleph 2's and it got rid of every last but of ac riding on the rails. Now all thats on the rails is a wee bit of noise. These are 6mh torodial chokes wound with 12 gauge wire. Perhaps if you have a couple of minutes you might be kind enough to enlighten me on info about saturation and such. I'd be very appreciative!!
Mark
I am not familiar with calculating anything to do with chokes. I installed these in my Aleph 2's and it got rid of every last but of ac riding on the rails. Now all thats on the rails is a wee bit of noise. These are 6mh torodial chokes wound with 12 gauge wire. Perhaps if you have a couple of minutes you might be kind enough to enlighten me on info about saturation and such. I'd be very appreciative!!
Mark
Hi Mark,
to enlighten one must be enlightened, the problem is that I am not........
I´ve got some 2mH torobar chokes from intertechnik I want to use in my Aleph-X but can´t get any decent info if they will saturate or not (at 8-10A bias). Even wrote to intertechnik but no answer.
It should be easy to see though just by looking at the ripple before and after the choke. In case of saturation it should work as a simple resistor. The problem is that when noticing this it is already too late
William
to enlighten one must be enlightened, the problem is that I am not........
I´ve got some 2mH torobar chokes from intertechnik I want to use in my Aleph-X but can´t get any decent info if they will saturate or not (at 8-10A bias). Even wrote to intertechnik but no answer.
It should be easy to see though just by looking at the ripple before and after the choke. In case of saturation it should work as a simple resistor. The problem is that when noticing this it is already too late
William
I don't claim to be enlightened myself in this regard, but I don't think totiod inductors are ideal as high DC saturation types. DC inductors usually have an air gap to prevent (or postpone) saturation.
But that doesn't mean they wont do a lot of good to smooth out psu...even if they are well into saturation. They will still pruduce a back EMF untill they saturate, and produce voltage as soon as the current starts to fall. It just falls short of what the simulated ideal when it goes into saturation.
I'm interested in anyone elses info on this subject.
Looks nice and I wouldn't hesitate to put the toriod chokes in my amp if I had them. They'll work much better than a resistor (at smoothing ripple) and not make heat.
But that doesn't mean they wont do a lot of good to smooth out psu...even if they are well into saturation. They will still pruduce a back EMF untill they saturate, and produce voltage as soon as the current starts to fall. It just falls short of what the simulated ideal when it goes into saturation.
I'm interested in anyone elses info on this subject.
Looks nice and I wouldn't hesitate to put the toriod chokes in my amp if I had them. They'll work much better than a resistor (at smoothing ripple) and not make heat.
Chokes should be fine for a 30
They look to be 8 - 10 amp judging by the size of the cores. They should be wide bandwidth also. I picked up some 2.2 ufd 6 amp toroids that are about 1/4 the size.
I have been using framed chokes for power supply filtering lately. They do a good job of knocking hum.
Good Luck, looks great so far.
George
They look to be 8 - 10 amp judging by the size of the cores. They should be wide bandwidth also. I picked up some 2.2 ufd 6 amp toroids that are about 1/4 the size.
I have been using framed chokes for power supply filtering lately. They do a good job of knocking hum.
Good Luck, looks great so far.
George
They definately make a difference in the Aleph 2's rail noise level and they were just a few dollars each. They barely get warm after being powered up all day. I would think they'd work just fine in the Aleph 30 operating at the lower current level involved there.
One test that might be intresting would be to look at the waveform thats developed across them and see what kind of stuff is going on while its reproducing music.
Mark
One test that might be intresting would be to look at the waveform thats developed across them and see what kind of stuff is going on while its reproducing music.
Mark
Here the transformer choose I have for Aleph30 power amp. From Plitron.
I don't want to use any choke or Resistor in the power supply
400VA 20V
400VA 22V
If I go to a more powerful transformer (500VA), I have to take a 24V output, this is probably to much ??
so wish of this 2 transformer is the best?? 20V or 22V ??
thank you !!
I don't want to use any choke or Resistor in the power supply
400VA 20V
400VA 22V
If I go to a more powerful transformer (500VA), I have to take a 24V output, this is probably to much ??
so wish of this 2 transformer is the best?? 20V or 22V ??
thank you !!
Really, neither of those trannys comes out at 25 volts on the rails... the 22 volt tranny ends up at about 30 volts and the 20 volt tranny ends up at about 28 which are both too high unless you want a tad bit more power... but then you would also need to add some heat sinking and perhaps another set of devices per channel to keep things reliable.
Or... get your tranny from Victoria Magnetics instead. Same high quality as Plitron and they are less expensive and ship LOTS faster.
www.victoriamagnetics.com
Mark
Or... get your tranny from Victoria Magnetics instead. Same high quality as Plitron and they are less expensive and ship LOTS faster.
www.victoriamagnetics.com
Mark
Well I've been enjoying this really fine amplifier for most of the day today. What it does is beyond belief!! I have a pair of Aleph 2's that I built a couple of years back and I'd have to say that the 3 is much more musical than the 2's are. This is a magical amp that without doubt lives up to everything I've heard about it.
Here is a pix of the almost completed amp... Still need to mount inductors and finish the front panel, top cover. Then I have to give it to the guy I'm building it for.....
... and then atart another one for myself......
Thanks Nelson for putting your heart and soul into this design.... and making it available to us to build.
Mark
Here is a pix of the almost completed amp... Still need to mount inductors and finish the front panel, top cover. Then I have to give it to the guy I'm building it for.....
... and then atart another one for myself......Thanks Nelson for putting your heart and soul into this design.... and making it available to us to build.
Mark
Attachments
One more photo of the heat sink wiring detail......
Each channel is easily removable for repairs if need be. Wiring this way is a breeze, about half of it is P to P using turrett terminals. All Teflon covered silver plated OFC wiring is used.
An all P to P using those turrett terminals would be fun and make the thing much sturdier and easy to repair......
Mark
Each channel is easily removable for repairs if need be. Wiring this way is a breeze, about half of it is P to P using turrett terminals. All Teflon covered silver plated OFC wiring is used.
An all P to P using those turrett terminals would be fun and make the thing much sturdier and easy to repair......
Mark
Attachments
Brian is correct in what he says. If you don't install the CL-60 in series with the hot lead of the AC line then you will blow alot of fuses or you may require a larger than normal rated fuse to sustain the turn on inrush..... while a lower rating fuse is whats really needed for normal operation. The larger rated fuse would pose a serious fire risk if some internal component were to short out. If you can't get the CL-60's where you live then using a resistor of about 10 to 15 ohms/50 watts in series with the hot lead is fine. Use a 1 second time delay relay to short out the resistor after turn on. This will give you the same end result of limiting the inrush current.
Hope this helps you....
Mark
Hope this helps you....
Mark
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