Top ten ways to a better Aleph?

[Zen Mod]

it'll work , as long you are using parts up to voltage , and having enough in heatsinking

no more than 35W of dissipation per output mosfet , if you want long and prosper 😉

 

[Mark Allen]

All you need is a CL-60 current limiter... Is about a two dollar part from Mouser or Digi-Key. I am pretty sure this is standard in every Aleph amplifier ever built at Pass factory. It limits inrush current but is effectively out of circuit once inrush is gone. Also use one from AC ground to chassis! I have them in all my amplifiers, not just Pass!

Mark

 

[Danger Mouse]

this was fast.

Only PSU will be bigger. the rest will be stock like recommended in SM.
Heatsink should be ok if Heatsinkmanufacturer have correct data to his products. And ive put in some safety margin too.

If Heatsink should not be enough (hopefully i dont need this part)
Decrease the Bias would be ok?
Or should i delete a some irfp`s and let the bias per Transistor at same level?
What will be the better way?

thanks

 

[Mark Allen]

You can go to a bigger CL then, but I bet CL-60 will be fine. There is an entire range of them available. It is easiest and most reliable solution.
CL-60 Amphenol Advanced Sensors | Mouser

Just put in series with hot leg of AC going to transformer primary.

 

[Danger Mouse]

Yes CL60 i`ve also used in my previous pass builds. -to Limit the inrush cuurent-
Dont know why... but i thought i have to do more when i double the capacitance i thought normal CL60 will not be enough.
But when the solution is so easy...

Thanks a lot 😀

 

[Mark Allen]

My Aleph 2's have 160K capacitance on each rail. Lights in room only dim very briefly on power up and they are 12 years old now! Only one CL-60 per amp and one from AC ground to chassis too.

Mark

Here is link to chart of entire CL range for your refrence... http://www.ge-mcs.com/download/temperature/920_325a.pdf

 

[Mark Allen]

Also on larger Pass amplifiers they put one CL-60 in both primary leg of power transformer. So that is also an option. Not two in series but one in hot and one in neutral.

Mark

 

[Zen Mod]

isn't that the same

 

[Mark Allen]

It should give more current limiting. Otherwise why would he be putting in two?

 

[Zen Mod]

certainly 2 x 10R is more than 10R

however , I was asking about

Not two in series but one in hot and one in neutral.

sometimes hot is called hot , and neutral is called return , not without the reason

whatever - you meant good , but didn't wrote clear enough , so I'll try .....

Papa is making arrangement like that for years now , as part of clever mains voltage selector arrangement , re-positioning NTCs in appropriate positions on mains pcb

that way , when donut is having two 110V primaries , each of them is having own dedicated CL60

when connected for 110V operation , they're (CL60+one primary combo ) connected in parallel , while - when connected for 220V operation , everything is practically in series

 

[Mark Allen]

This is a good point Zen because Damger Mouse is in Bavaria and likely has 220 volts. He may be better off with a CL-60 in each leg of the transformer. Granted current draw on 220 volts is likely going to be half but the inrush is going to be the same.

I am lucky enough to own a device capable of measuring DC inrush current. I will have to post a picture tomorrow. I normally use it for verifying inrush from xenon rectifier when xenon lamp is ignited as that is critical to the life of the lamp. It just happens to also work on power amplifier supplies too!

Mark

 

[Hylle]

This CL60 component, couldnt you use it on the secondary side of the transformer, then It does not matter if it is 115V or 230V powersupply?

 

[Zen Mod]

naah

 

[zeepup]

I'm currently running 4 aleph mini's with rail voltage of 21V + & - I've been running these awesome beasts for years with no issues. However id like to gain a little bit more power.

I'm wondering what the max rail voltage is and what i can get out of this aleph mini for power..

I'm estimating 20watts right now..

I have matched outputs & IRF9610's, dale resistors & running a CRC psu..

 

[Zen Mod]

for xformer with dual 24Vac secondaries , you don't need any change in parts values

for more , there is need for that , also change to IRFP150 , allowing for more dissipation