Questions about the Aleph 5

Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
Hello,

Sorry, I use a translator because my English is not at the top

Just a few years I realized the aleph p 1.7. I finally launches in achieving the aleph 5.

I currently have two ilp 500VA transformer but 2x35 Volt. My question is what is the impact on the final assembly? Knowing that Mr Nelson PASS (my god) recommends tension to 34V.
What should I monitor tensions in particular and what will be my Current? 1.8 or 2A or more

Thank you for your answers
 
Hello,

Thank you for your answers.
I currently own two large heatsinks 0.16 °/W. Do you think that will be enough for a channel or does it necessarily make mono block?
I wanted to make one box combining both channels
By my calculations, for my 150w dissipated through heat sinks are just ready to 24 °.
With 2x35v I think beyond this temperature.
- Do you think it's reasonable to mount the 6 irfp240 on one sink?
- The bias should always be between 1.8 and 2A or stronger or weaker?

Thank you
 
Last edited:
Just to confirm. Your transformer has 35 V AC secondary windings?
If so, you will have well over 40V dc (approaching 50V).
With rails that high I wouldn't use anything less than 5A.
May as well make it 6 A.
That's a lot of heatsinking.
Edit:You don't have to do this, this assumes you want close to full power into 8Ohms. You could do less if you know you're never goint to need more than 3A, just a bit unconvetional for such high V rails.

If that is sounding too much it might be cheaper just to buy another set of transformers with 24V secondaries.
 
Last edited:
2 picoDumbs
Yes I confirm that the secondary is 35V.

I also has 2 transformers 300VA 2x24V

- I realize is the aleph 5 with 300VA 2x24V
- Either I realize the apeph 2 with 500VA 2x35v but I need two new heat sinks
- I realize is the aleph 5 with 500VA 2x35 with a regulated power supply. Do you know a good regulated power supply?
 
Official Court Jester
Joined 2003
Paid Member
regulated supplies for that sort of beast , just to waste few volts of rails, are as knife to kidney

- it still demands proper (read- more) heatsinking
- it still demands proper educating of OP , who evidently isn't capable to choose by himself

so - back to start - to OP :

1.do you need that sort of power you get with 35Vac secondaries ?
2.if yes , you need to cover resulting rails with appropriate standing current (Iq , bias , call it as you wish) ........
3. to decide what's proper number of outputs and appropriate standing current , we need to know what's worst case scenario , regarding speakers impedance , then
4.we can calculate what's sum dissipation , and only then we can calc what's size of Al chunk you need to attach to output mosfets , with or without forced cooling ( I know, another possible decision you need to make )

as Al sez .......... Whoo Ah!
 
my speakers have a sensitivity of 93 db

I think to start an aleph 5 and 300VA would be good. I have almost all the components to build it. I miss the resistance of 453 ohm, the MPSA 18 and resistance for CRC.

I keep my two transformers of 500 VA to produce mono blocks aleph 2 thereafter. I would buy two extra heat sinks and I would adapt my existing installation since it can operate between 42 and 50v.

for CRC, what type of resistors should I use?

I 4x22000μf 63V per channel, so 22000 / *** x 25w / 22000
 
Last edited:
I bought Vishay .47ohm 5watt and 1 ohm 5watt. all are CRMF55 vishay resistance and IRFP are paired. 2200μf Silmic and 22000μf Aerovox

do you best to use Panasonic resistors 3 W instead of reésistance wirewound 5 W? is it better for sound?
for some uses CRC supply 2.2mh. May have replaced them with resistance? and what value to use?
 
I bought Vishay .47ohm 5watt and 1 ohm 5watt. all are CRMF55 vishay resistance and IRFP are paired. 2200μf Silmic and 22000μf Aerovox

do you best to use Panasonic resistors 3 W instead of reésistance wirewound 5 W? is it better for sound?
for some uses CRC supply 2.2mh. May have replaced them with resistance? and what value to use?
You can use whatever you want for R in CRC as long as it is appropiately rated for power dissipation and keep it below 0.2 Ohms total effective resistance.
 
Last edited:
Hello,

Thank you for your answers. The choice between Aleph5 and Aleph2 is not easy. 100w may not be useful for my current installation, but some progress.

I would share with you my choice quickly
The Aleph 2 is certainly a fine amplifier but the best amplifier will be one custom designed for your speakers. Some simple measurements would go a long way in designing the right amp.
I'd also go with Zen Mod's pcbs so you can utilise jfets at the front end.
 
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.