Hi guys, It has been a few weeks and I finally got the power supply done. The problem is: without anything connected to the PS it's almost pushing out +- 50 V for the rails. I think this is to much for my 50 WV caps. So I need to shed 5-6 Volts. I figure I'll lose couple of volts at the thermistors, If I can find some. Both Newark and Digikey are out of them and lead time is 2 months. I'm open to suggestion, I mean please help.
Regards.
Regards.
SI said:Hi guys, It has been a few weeks and I finally got the power supply done. The problem is: without anything connected to the PS it's almost pushing out +- 50 V for the rails. I think this is to much for my 50 WV caps. So I need to shed 5-6 Volts. I figure I'll lose couple of volts at the thermistors, If I can find some. Both Newark and Digikey are out of them and lead time is 2 months. I'm open to suggestion, I mean please help.
Regards.
Mouser has some in stock. I think that this is the same part that you are looking for:
http://www.mouser.com/index.cfm?han...ductid=200724&e_categoryid=21&e_pcodeid=52703
Mouser also has no minimum order, and fairly inexpensive shipping. (no handling charges)
You could also try using some big inductors in a CLC setup.
--
Brian
Hi,
with the Aleph 2 connected, voltage will probably go down 4 or 5% so that will give you some margin.
Opinions about how much margin you need vary on this forum from 20% to 0%.
Personally I´ve got no problem connecting 50V caps to 50V DC since the manufacturer also uses some security margin. Some Caps (i.e. PanasonicFC ) can be loaded with 10% more voltage without any problems.
William
with the Aleph 2 connected, voltage will probably go down 4 or 5% so that will give you some margin.
Opinions about how much margin you need vary on this forum from 20% to 0%.
Personally I´ve got no problem connecting 50V caps to 50V DC since the manufacturer also uses some security margin. Some Caps (i.e. PanasonicFC ) can be loaded with 10% more voltage without any problems.
William
moe29 said:
If your current demands mandate the use of more than one thermistor/surge suppressor, you better hope that the additional thermistors that you put in parallel are absolutely identical. Any deviation in response curves can lead to current hogging and the possible failure of the device and damage to the power supply.
If I remember correctly, Mr. Pass addressed this issue with his AX-200 amplifier design. Check out these posts:
Parallel Thermistors
Parallel Thermsitors
And probably a better solution...
I personally like them for breaking ground loops.
Later,
Inductors will not do much to drop DC voltage in a CLC configuration. They will do some good if you use them in an LC hookup, though.
That said, I'd run the amp for few minutes to see what the actual rail turns out to be. Running a power supply with no load isn't the same as the rail under load.
Grey
That said, I'd run the amp for few minutes to see what the actual rail turns out to be. Running a power supply with no load isn't the same as the rail under load.
Grey
Hey Moe, Your email address keeps bouncing back. Here is the info you wanted.
Regards
Anthony
Hello Morris, this is the cost in Canadian. The US Cost would be $35. I will
start collecting funds when we hit 52 units ordered. Did you sign up yet?
Regards
Anthony
U.S.A. Expedited Parcel (8 business days)
Base Price: 44.15
Fuel Surcharge: 0.99
Insurance: 1.20
Total: $46.34
Regards
Anthony
Hello Morris, this is the cost in Canadian. The US Cost would be $35. I will
start collecting funds when we hit 52 units ordered. Did you sign up yet?
Regards
Anthony
U.S.A. Expedited Parcel (8 business days)
Base Price: 44.15
Fuel Surcharge: 0.99
Insurance: 1.20
Total: $46.34
Re: Re: Building Aleph 2
I put a 25 Ohm 300 watt power resistor across the rails and the was 91V across the resistor with little more then .5 f of cap in the ps. I was wondering if this is a good approximation of the actual impedence of the aleph circuit at idel.
Regards.
GRollins said:
Nelson Pass said:
2) The moment you load the circuit, the voltage will drop as
much or more than you think you want.
I put a 25 Ohm 300 watt power resistor across the rails and the was 91V across the resistor with little more then .5 f of cap in the ps. I was wondering if this is a good approximation of the actual impedence of the aleph circuit at idel.
Regards.
That's 3.6 amps. In the ballpark. after you ramp up to 4.5 A or so(if your heat sinks can stand it), you'll likely be right at +- 45V.
Anyway don't sweat the exact voltage. It'll run great anywhere from 30V to 50V.
Wuffwaff, you beat me to it.
Read this mans old post from a few years back. lots of good info on how to control AC gain and bias.
Anyway don't sweat the exact voltage. It'll run great anywhere from 30V to 50V.
Wuffwaff, you beat me to it.
Read this mans old post from a few years back. lots of good info on how to control AC gain and bias.
Arold19......
In going from an Aleph 5 to an Aleph 2 everything must be much larger. Things such as heatsinks, power transformers, wiring, rectifiers, voltage rating of capsacitors, and needless to say more output devices are all required when you upsize any Aleph. Also most build the Aleph 5 as a stereo amplifier on a single chassis and these amplifiers are normally of reasonable size. Building an Aleph 4 which is similar to having two Aleph 2's on one chassis represents constructing a really huge chassis and even larger power supply to operate both channels, although on a 4 the heatsinks and output devices stay pretty much the same as they would be on a monoblock 2. The 4 is also a VERY, VERY heavy amp when completed! The cost of building a pair of Aleph 2's is also going to be much higher than an Aleph 5.
Mark
In going from an Aleph 5 to an Aleph 2 everything must be much larger. Things such as heatsinks, power transformers, wiring, rectifiers, voltage rating of capsacitors, and needless to say more output devices are all required when you upsize any Aleph. Also most build the Aleph 5 as a stereo amplifier on a single chassis and these amplifiers are normally of reasonable size. Building an Aleph 4 which is similar to having two Aleph 2's on one chassis represents constructing a really huge chassis and even larger power supply to operate both channels, although on a 4 the heatsinks and output devices stay pretty much the same as they would be on a monoblock 2. The 4 is also a VERY, VERY heavy amp when completed! The cost of building a pair of Aleph 2's is also going to be much higher than an Aleph 5.
Mark
I think this may be simple enough for me to answer. The Aleph 5 dissipates 150 watts/channel vs the Aleph 2's 300 per channel, this requires much more heatsinking. I am in the process of building the Aleph 2 as well, the heatsinks were the most expensive parts of the project. Plus you can conceivably build an Aleph 5 in a single chassis. Most of the Alpeh 2's that i've seen are built in mono block fashion thus requiring more build time and inevitably more money.
Looks like Mark beat me to it
Looks like Mark beat me to it
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