Another Aleph-X coming up!

[pr]

They have a link to plitron, so I guess it is a plitron. Also the price suggests that: 151 Euro each.

Peter

 

[Peter Daniel]

Amplimo is a distributor for Plitron in Europe. AFAIK they don't manufacture those Plitron looking transformers.

 

[Nelson Pass]

Say Peter,

As a former owner of 5 vertical milling machines, I just want to
say that the hardware you build is an inspiration to us all, and
constitutes a real contribution to DIY. We will just have to
ignore your affair with gainclones.....

😎

 

[moe29]

hey!, i'm pulling his leg to finish that SOZ 😉

 

[Edwin Dorre]

It is finished!

Hello,

Triggered my the new Aleph-X group buy I suddenly realised that I have not posted finished pictures of my high-power Aleph-X. Here are some pictures from amp when it was not yet completely together. The picture of the frontpanel is the 'old' frontpanel which I received somehow in a weird swirl brushed kind of way. Tonight I will make some new pictures of the fully completed amp with the new satin gray front and both blue leds...

Both channels behave great. Connected with a balanced cable from a Aleph-P I have a stable 30mV of DC offset on both channels. The absolute DC offset is around -100mV to 100mV, the temperature of the room and the heatsinks are in direct relation to the absolute DC offset. The Amp sounds delicious, velvet highs with also a great precision. The bass is much better than my old Aleph 4. Tight and deep. All in all it is a more complete amp in every way in comparision to my Aleph 4.

An externally hosted image should be here but it was not working when we last tested it.

An externally hosted image should be here but it was not working when we last tested it.

An externally hosted image should be here but it was not working when we last tested it.

Have fun,

Edwin

 

[Taco]

Very nice Edwin. I will post the pictures of my baby Aleph-X when I am finished with the case. But the sound is very good.

 

[gnomus]

Really nice! Like the well organized interior.

 

[Edwin Dorre]

Hello,

the final story and pictures of my Aleph-X just made it on:

http://www.passdiy.com/gallery/alephx-p3.htm

I am so proud 😎

Have fun,

Edwin

 

[macka]

Edwin,

Very impressive and good to see another X Aleph in the Gallery.

macka🙂

 

[Leeuwarden]

Congratulations Edwin!!!!

 

[Taco]

Very nice Edwin, I am finishing mine (top-plate and the famous led ...)

 

[Netlist]

I particularly like the Vandal Proof Switch

Very nice ...and good write-up

/Hugo 🙂

 

[Edwin Dorre]

I particularly like the Vandal Proof Switch

Very nice ...and good write-up

/Hugo 🙂

Thanks,

The vandal proof switch is a good touch! It looks pretty nice and keeps the vandals away of my Aleph-X

😉

Edwin

 

[sianturi]

As I read through this thread, I learn that matching the IRF9610 is the hardest part.

So, in order to get this baby singing, how many IRF9610 should I purchase to get 2 matched ones?

Also, how big is the popolation of IRFP044 to get 2 matched ones?

I plan to purchase the FET from DigiKey. Are they selling a group of FETs with same batch?

If you guys could share your experience, I greatly appreciate it.

Thx!

 

[Edwin Dorre]

Very nice Edwin, I am finishing mine (top-plate and the famous led ...)

Hi Taco,

didn't you buy your matched IRF9610 at Ahe's??? How low or high is your DC offset with these matched mosfet's?

One pair of mine IRF9610 is not completely great (I have a kind of buzz which is generated around these mosfet's) and like to buy two match pairs from him...

Edwin

 

[Taco]

Hi Taco,

didn't you buy your matched IRF9610 at Ahe's??? How low or high is your DC offset with these matched mosfet's?

One pair of mine IRF9610 is not completely great (I have a kind of buzz which is generated around these mosfet's) and like to buy two match pairs from him...

Edwin

I bought my IRF9610's at AHE. They are matched at 2mV the offset I get is around 40 mV. (no preamp connected my unbalanced preamp will increase that value). The other pair I got was about 15 mV but unfortunately I destroyed that pair (you know the reason ... ) . I had a total of 6 irf9610's mathed together at 2 mV and I randomly picked sets of 2 and 40 mV is just fine for me. (So you can buy a set closely matched fets and match them a bit closer for your needs, as you are a perfectionist 🙂)

My amp is totaly silent the only thing I hear is a very very faint noise from the preamp. (with my ear agains the tweeter and volume cranked up, but I have to say that my monitors aren't very sensitive 85/86 db/ 1W)

 

[jrsun]

What is Ahe ? Thanks !

 

[Mark A. Gulbrandsen]

Edwin Dorre said......

"I use 10 turn bournes trimpots"
____________________________________________________

I drive past the Bourns plant(s) in Logan Utah at least once a month. Always been tempted to stop in there and see if I can get the 10 min tour, but so many buildings there...where to go?? Those pots traveled a loooooong way to get to you Edwin!

You have all inspired me to build an X... Similar to what Edwin has built. I feel there is enough data on problems collected now that anyone could probably do it.

One question I have is would it be possible to get double the power at 4 ohms and so on? A huge transformer or double trannys is no problem for me, seems like these X's built here are a bit backwards and go down in power instead of up as the impedence halves. The Pass stuff doubles as the impedance is halved.
Can anyone explain why this is.....?
Mark

 

[Edwin Dorre]

Edwin Dorre said......

"I use 10 turn bournes trimpots"
____________________________________________________

I drive past the Bourns plant(s) in Logan Utah at least once a month. Always been tempted to stop in there and see if I can get the 10 min tour, but so many buildings there...where to go?? Those pots traveled a loooooong way to get to you Edwin!

You have all inspired me to build an X... Similar to what Edwin has built. I feel there is enough data on problems collected now that anyone could probably do it.

One question I have is would it be possible to get double the power at 4 ohms and so on? A huge transformer or double trannys is no problem for me, seems like these X's built here are a bit backwards and go down in power instead of up as the impedence halves. The Pass stuff doubles as the impedance is halved.
Can anyone explain why this is.....?
Mark

Bournes and vishay are the two decent trimmers I could get here. They have a nice feel. Very easy to run the bias up and down with a 0.01A precision!

"The Pass stuff doubles as the impedance is halved." = it is all in the bias!!! It is a balance between bias and voltage. I have attached my excel sheet (which seemed to have dropped from my story at passdiy.com) to play with. And ofcourse bias comes all down to heat = heatsinks...

When you use +/-20 Volts on your rails and 10 amperes of bias, your Aleph-X will double from 81W at 8 ohm to 162W at 4 ohm... no problem. When you are building the amp yourself you can build the amp exactly in the power hungry part of your speakers. It is a trade off! My loudspeakers live in the 6 ohm area... so 25V and 6.8A puts the most power there and keep the heat in control...

Thanks for the kind words,

Edwin

 

[Mark A. Gulbrandsen]

Thanks Edwin!!

That spread sheet will be a big help in building mine. I am absolutely going water cooling and making my own copper heat sinks this time around. I will get 3/4" thick copper bar and bore lengthwise for cooling passages and then silver solder U shaped copper tubing to the holes and leave one input and one output. The bars will each be about 6" long by 3" wide. Should work out nice and not cost a fortune either....probably less than if I purchased new sinks from R Theta or M&M Metals.
I'm looking foreword to this project.
Mark

P.S. I found out that those Bourns plants in Logan are a ceramics division that makes ceramic substrates.