D3:
Sure, that'll work... though I personally wouldn't use anything so nice in a power supply, as the benefits of a foil type would be mostly wasted. I'd save those for a speaker crossover. Also, with air-core inductors, you should be conscious of the stray magnetic fields. My recommendation for power supply choke would be something like the Hammond 156B.
Sure, that'll work... though I personally wouldn't use anything so nice in a power supply, as the benefits of a foil type would be mostly wasted. I'd save those for a speaker crossover. Also, with air-core inductors, you should be conscious of the stray magnetic fields. My recommendation for power supply choke would be something like the Hammond 156B.
Inductor choice
Not sure that hammonds are available in UK (not seen them available online anywhere). Just about all i have seen are loudspeaker inductors wound on plastic bobbins with 1mm wire.
Also the bias current of D3's amplifier will be 8a - will the Hammonds take that much current without saturating?
Not sure that hammonds are available in UK (not seen them available online anywhere). Just about all i have seen are loudspeaker inductors wound on plastic bobbins with 1mm wire.
Also the bias current of D3's amplifier will be 8a - will the Hammonds take that much current without saturating?
I am no expert on PS design but I understand a laminated core choke would saturate very easily at that current.Most of the hammond chokes are aimed at the tube market where current is low.
However I think the other solution is to try and cancel the DC saturation by using a double choke (is that called differential? ) wound on the same bobbin.
However I think the other solution is to try and cancel the DC saturation by using a double choke (is that called differential? ) wound on the same bobbin.
That's what I thought too, until I did some more digging in search of a better choke than the speaker crossover types - I was looking specifically for an iron-core choke which would avoid the stray fields and have a lower DCR. Turns out, Hammond does in fact make a few chokes for higher current supplies... The 156B is rated for a nominal DC current of 5A, other models in the same series are rated for 10A etc. Pricing is pretty good too, compared to most air core chokes which need a lot of copper for the same inductance. For comparison, the 156B is 1.5mH, 0.07ohms DCR... dimensions are quite small (see Hammond's website) and is available for about USD $10.
In iron core chokes, core saturation is avoided with the use of an appropriate air gap. This gap is usually quite small in most iron core devices (eg. transformers), which do not experience much DC, or at least a balanced DC flux. The 'double' chokes you mention are common-mode chokes, but they are not effective for use in pi-filters, since their AC fields will cancel, and you'll have very low inductance (theoretically none) to smooth the ripple. Where they come in handy is blocking out power line noise and other common-mode signals.
hello
http://www.colomar.com/Shavano/inductor_info.html
Question me interhook!
But it is choke coil for crossover?
Is this check for a supply?
Phill
Excuse my English
http://www.colomar.com/Shavano/inductor_info.html
Question me interhook!
But it is choke coil for crossover?
Is this check for a supply?
Phill
Excuse my English
Check out this site:
http://www.lalena.com/audio/calculator/inductor/
I made my own four 2.2 mH air-core inductors with 12 Ga wires. According to the calculation from this site, each of them measured 1.5" inner dia, 2" long (230 turns). After wound, they measured 2.03, 2.06, 2.11, and 2.14 mH (the last two were quite different because they were from a different copper supplier). The internal resistance of each was less than 0.4 Ohms. I was satisfied with the results. The calculation was quite close.
The resulting chokes were hefty monsters....Expect about 2.5 kgs of 12 ga copper for each monster!!
If you want to DIY 2.2mH air core chokes using 12 Ga wires, you can use 1.5" inner dia and, I guess, about 240 turns (which will give you about 2" long). These numbers apply only for 12 Ga wires. If you use different wire guage, you need to check out the site accordingly. Pls note that 12 ga wires are VERY difficult to bend - be careful.
Hope this helps
Pardon my English.
-Sean
http://www.lalena.com/audio/calculator/inductor/
I made my own four 2.2 mH air-core inductors with 12 Ga wires. According to the calculation from this site, each of them measured 1.5" inner dia, 2" long (230 turns). After wound, they measured 2.03, 2.06, 2.11, and 2.14 mH (the last two were quite different because they were from a different copper supplier). The internal resistance of each was less than 0.4 Ohms. I was satisfied with the results. The calculation was quite close.
The resulting chokes were hefty monsters....Expect about 2.5 kgs of 12 ga copper for each monster!!
If you want to DIY 2.2mH air core chokes using 12 Ga wires, you can use 1.5" inner dia and, I guess, about 240 turns (which will give you about 2" long). These numbers apply only for 12 Ga wires. If you use different wire guage, you need to check out the site accordingly. Pls note that 12 ga wires are VERY difficult to bend - be careful.
Hope this helps
Pardon my English.-Sean
Component voltages
Hi...............hope you can help, I am starting to think about populating the Aleph-X ver 1 board...............the amp I am proposing to build will have 20v rail voltages............running 8a bias through 16 fets per amp.
Q. The 10 bom xls sets out the components very helpfully....however there are a total of six caps...........what voltage should I go for??? I was considering 25v caps...does this have enough factor of safety.......If my Traffo produces a little more voltage..........so I end up with say 22v ..... will it push the caps.............and cause unreliability.......what voltages do other people use???
Q. I am going with 0.47 ohm resistors for fets.........according to spreadsheet 1 amp will be flowing............so for reliability 3watt resistors? also if the voltage is a touch higher would I need to change the fet resistors...................+ any recommendations for type/make of resistor..................
Hi...............hope you can help, I am starting to think about populating the Aleph-X ver 1 board...............the amp I am proposing to build will have 20v rail voltages............running 8a bias through 16 fets per amp.
Q. The 10 bom xls sets out the components very helpfully....however there are a total of six caps...........what voltage should I go for??? I was considering 25v caps...does this have enough factor of safety.......If my Traffo produces a little more voltage..........so I end up with say 22v ..... will it push the caps.............and cause unreliability.......what voltages do other people use???
Q. I am going with 0.47 ohm resistors for fets.........according to spreadsheet 1 amp will be flowing............so for reliability 3watt resistors? also if the voltage is a touch higher would I need to change the fet resistors...................+ any recommendations for type/make of resistor..................
I used TO-220 sockets so that I could swap pairs of IRF9610 easily. I'd like to try 2SK389 here, which would need to be paralleled. Is it reasonable to simply use 22 ohm resistors on the outputs to force matching, individual gate stopper resistors, and use it as a drop in replacement? This changes the absolute load resistor value by less than 3%.
Unless you intend to make other changes, the 2SK389 won't work--wrong polarity--you'll need to use a 2SJ109. As to the finer details, you'll need to balance the bias current against the load resistors in order to get the output stages to bias up. Watch your rail voltages.
It's not undoable...
Grey
It's not undoable...
Grey
Hi all pass-fanatics
It's time for me to order some parts for my upcoming AX. I'm going to use the chassies from my x-soz, wich can dissapate about 200W/channel.
My plan is to use my existing PSUs with CLC-filter, just add some more C.
The trafos have 15V seconderies. I once measured the voltage over the caps under load, but i completly forgot the reading.
Q: What voltage could I expect at the fets? Something like 18V, or more?
Q: I'll go with 8 fets per channel. How many do i have order to be on the safe side with matching?
Q: The power dissipation of the source resistor will be 0,73W. Is it OK to pararell 4 normal resistors? OK also with R1, R4?
I can't find any MPSA18, SST505, LM329, 1N5239B here in Europe. If you have some leftovers in your junk box I'll buy it from you
ciao // vit
It's time for me to order some parts for my upcoming AX. I'm going to use the chassies from my x-soz, wich can dissapate about 200W/channel.
My plan is to use my existing PSUs with CLC-filter, just add some more C.
The trafos have 15V seconderies. I once measured the voltage over the caps under load, but i completly forgot the reading.
Q: What voltage could I expect at the fets? Something like 18V, or more?
Q: I'll go with 8 fets per channel. How many do i have order to be on the safe side with matching?
Q: The power dissipation of the source resistor will be 0,73W. Is it OK to pararell 4 normal resistors? OK also with R1, R4?
I can't find any MPSA18, SST505, LM329, 1N5239B here in Europe. If you have some leftovers in your junk box I'll buy it from you
ciao // vit
Aleph X parts questions
Referring to Gary’s original Aleph X schematic, what brand, type (metal/carbon/wire/composite) and manufacturer should R1, R4, R44, R45 be, and how do you calculate the value, watts and ohms?
Referring to Gary’s original Aleph X schematic, what brand, type (metal/carbon/wire/composite) and manufacturer should R2, R3, R42, R43 be, and how do you calculate the value, watts and ohms?
The FET source resistors, what brand, type (metal/carbon/wire/composite) and manufacturer should they be? How do I calculate the values, watts and ohms.
The 220uF caps, should they be Black Gate NX's? I cant seem to find any 220uF BG NX @ anything but 6 volts….what do people use?
The feedback cap should be a silver mica or maybe a polystyrene?
All other resistors should be; Metal film? Carbon? Composite? Manufacturer?
What Parts and Manufacturer’s represent good value for money for a good sound?
Referring to Gary’s original Aleph X schematic, what brand, type (metal/carbon/wire/composite) and manufacturer should R1, R4, R44, R45 be, and how do you calculate the value, watts and ohms?
Referring to Gary’s original Aleph X schematic, what brand, type (metal/carbon/wire/composite) and manufacturer should R2, R3, R42, R43 be, and how do you calculate the value, watts and ohms?
The FET source resistors, what brand, type (metal/carbon/wire/composite) and manufacturer should they be? How do I calculate the values, watts and ohms.
The 220uF caps, should they be Black Gate NX's? I cant seem to find any 220uF BG NX @ anything but 6 volts….what do people use?
The feedback cap should be a silver mica or maybe a polystyrene?
All other resistors should be; Metal film? Carbon? Composite? Manufacturer?
What Parts and Manufacturer’s represent good value for money for a good sound?
Svetlana,
On a budget, Resistors if not specified
1) Carbon film 1% resistors, all 1/4 Watt
2) Metal film 1%, all 1/4 Watt
3) Dale, Holco and some other variations 1%,
may be also 0.1% but the cost will be higher
Order 10/20 resistor of each value, and measure all to make pairs...
{Its what I have done for my A75, with very good results.}
There is a list of components, but the rest is on the schema.
And Look at the wiki page for more infos...
http://www.diyaudio.com/wiki/index.php?page=Aleph-X
Thread: http://www.diyaudio.com/forums/showthread.php?threadid=3748&perpage=15&highlight=&pagenumber=1
R1,R2,R3,R4,R5,R6, R40, R41 ... are 3 Watts, could use Panasonic for these.
Exotics would be Holco...
C1,C6 10pF silver mica's {exotics would be Teflon}
C3,C5,C6 Good quality electrolytics 35 Volts , Panasonic, exotics: BlackGate, Elna, etc.
You'll get a good sound without exotic parts in this project, after that all depends on "how big your pocket money is"!
And the final quality will depend on the assembly, the chassis, the wiring, etc., the power supply also, you can lost all gain from exotic parts by a poor assembly, otherwise, multiply the cost by 5 to 10 for building it with only exotic parts.
Regards.
Alain.
On a budget, Resistors if not specified
1) Carbon film 1% resistors, all 1/4 Watt
2) Metal film 1%, all 1/4 Watt
3) Dale, Holco and some other variations 1%,
may be also 0.1% but the cost will be higher
Order 10/20 resistor of each value, and measure all to make pairs...
{Its what I have done for my A75, with very good results.}
There is a list of components, but the rest is on the schema.
And Look at the wiki page for more infos...
http://www.diyaudio.com/wiki/index.php?page=Aleph-X
Thread: http://www.diyaudio.com/forums/showthread.php?threadid=3748&perpage=15&highlight=&pagenumber=1
R1,R2,R3,R4,R5,R6, R40, R41 ... are 3 Watts, could use Panasonic for these.
Exotics would be Holco...
C1,C6 10pF silver mica's {exotics would be Teflon}
C3,C5,C6 Good quality electrolytics 35 Volts , Panasonic, exotics: BlackGate, Elna, etc.
You'll get a good sound without exotic parts in this project, after that all depends on "how big your pocket money is"!
And the final quality will depend on the assembly, the chassis, the wiring, etc., the power supply also, you can lost all gain from exotic parts by a poor assembly, otherwise, multiply the cost by 5 to 10 for building it with only exotic parts.
Regards.
Alain.