Aleph-X builder's thread.

[usekgb]

Are you getting close to finishing yours Mark? I'd love to see it. I was working on my Zen V4 today, and broke the tap off in the heat sink. . I'll have to get it out and finish it up before I can start on my AX's.

Cheers,
Zach

 

[Mark A. Gulbrandsen]

Zach,
Will all you at work today.. Getting that tap out is actually pretty easy.
Mark

 

[Nelson Pass]

However, it was a wonderful evening and I rarely pull out the old Racal 5003.... I was just way too tempted...

I understand. I like to watch my hard disk get defragmented.
It gives the illusion of progress.

 

[JCoffey]

You dont know how good that makes me feel to hear, Mr. Pass. I work with computers for a living, and I have been known a few times to watch it get the ole Defrag....

 

[andrew li]

hi power version

would anyone please inform me
how to select r2 r3 r42 r43
for different power o/p and different speaker impendance

 

[hifiZen]

These resistors should be the same as R5, R6, R41, R41... These are known as source resistors, and the calculation to find their value is explained here , under 'Calculating Circuit Values'.

The 'total bias current' needs to be known first, and you can use the spreadsheet to figure that out based on your desired power output and speaker impedance... Calculation Spreadsheet

 

[Mark A. Gulbrandsen]

"I cant wait to see results from mark's amp... i hope it goes well "

I might have some results to post tommrrow..... The first board has been completely built up since Thursday night.... Just have to wire up a temp. power supply and see what she does.....

Regarding toroids......

A friend just ordered a Victoria Magnetics toroid for his Aleph 3 project and it ran him less than 80.00 for a custom 500VA toroid. I also bought a custom VM toroid for my Mini Aleph. That was a 320 VA unit and it ran me about 60.00 shipped. These are super reasonable prices for custom trannys and the quality is as good as the best out there. You might consider getting one large unit wound for your multi channel X.

www.victoriamagnetics.com

Mark

 

[moe29]

i finished populating the second channel tonight. Now I'm just
mulling over wether to make mono-blocks or a stereo amp. Since
i hate building chassis... i'm wondering if i should just go for both
channels in one chassis, sharing a transformer and PSU. I figure
something like a 750VA transformer should handle both channels
without any problems, with 15 volt secondaries... or is this a bad idea?

 

[Prune]

The thing I like about monoblocks is that you can use shorter speaker cables.

 

[yoke]

Hi...
What is easiest way to check if mosfet ( IRFP2410 ) is broken or not...
I would like to check mosfets before I solder them down...

Thanks
Josip

 

[Mark A. Gulbrandsen]

To check a mosfet just use the same setup as if you were matching them. If you run across a broken one you will get very strange readings and it'll be quite obvious. With new mosfets I've never had one out of the tube that was bad.
Mark

 

[yoke]

Thanks Mark for replay...
But I bouth those ollready matched...so...can I just mesure some resistance betwin pins or something ?

Josip

 

[promitheus]

I have a question on the AXE-1 calculation sheet.
The voltage at the beginning is the overall voltage?
for instance when we have 30volts here does that mean that the power supply will have +/- 15 Volts?

 

[Netlist]

In your example that would be +/-30V.

/Hugo

 

[promitheus]

yeah that´s what I thought.
I did a few calculations.
What would be the lowest voltage that could be used without having to sacrifice quality?

 

[rwagter]

Anyone has experience with:

Vishay draloric's as sold by partsconnexion , they are 0.1% accurate and really cheap....

Ralph

 

[pinkmouse]

Split

I have split the IP issue off into its own thread here, it is a worthwhile subject, but we are trying to keep this thread pure and simple! Thanks

 

[leadbelly]

Re: Split

I have split the IP issue off into its own thread here, it is a worthwhile subject, but we are trying to keep this thread pure and simple! Thanks

Thank you!

 

[SGregory]

Here is the status of mine

A-X Monoblocks;
1kVA @21V dual secondaries Vic Magnetics
432,000 uF capacitance 216,000uF per Rail
CRCRC Filter Arangement 0.15Ohm R's On Sinks
Dual Rectifiers FRED 64amp from IXYS on Seperate Sink
Stacked type sink with 560Watt theoretical dissipation per side.
(calculation based on my ol fluid dynamics book) 30degree C

Will be using 16 devices per channel total with 10-12 amps bias
Theoretical Rail voltage is +/-23-24 Volts.
Total Dissapation will be 460Watts 230 per side

Any boo boo's so far?

Any Comments or Suggestions?
Regards
Scott Gregory

I will post pictures as soon as I can get them small enough.

 

[Coulomb]

Here is the status of mine

A-X Monoblocks;
1kVA @21V dual secondaries Vic Magnetics
432,000 uF capacitance 216,000uF per Rail
CRCRC Filter Arangement 0.15Ohm R's On Sinks
Dual Rectifiers FRED 64amp from IXYS on Seperate Sink
Stacked type sink with 560Watt theoretical dissipation per side.
(calculation based on my ol fluid dynamics book) 30degree C

Will be using 16 devices per channel total with 10-12 amps bias
Theoretical Rail voltage is +/-23-24 Volts.
Total Dissapation will be 460Watts 230 per side

Any boo boo's so far?

Any Comments or Suggestions?
Regards
Scott Gregory

I will post pictures as soon as I can get them small enough.

Won't 10 to 12 Amps of bias push your peak power output below 4 Ohms?

Regards

Anthony