Hi,
I think I spent about $500 in drivers and crossover parts for the pair. I probably spent another $120 at Homedepot for the cabs. But I first spent around $400 on woodworking tools! ( Router and bits, air compressor and nailer, and compound mitre saw )
However, I have been fixing up my house so my girlfriend actually bought me some of the tools. ( She has learned that power tools directly benefit her and the house... )
I am noticing a pattern here for the aleph x. I am ramping up on tools again, pre-project. My Fluke 8050a and variable dc power supply should arrive this week! ( Don't think she'll spring for any test gear ;-)
-Luke
I think I spent about $500 in drivers and crossover parts for the pair. I probably spent another $120 at Homedepot for the cabs. But I first spent around $400 on woodworking tools! ( Router and bits, air compressor and nailer, and compound mitre saw )
However, I have been fixing up my house so my girlfriend actually bought me some of the tools. ( She has learned that power tools directly benefit her and the house... )
I am noticing a pattern here for the aleph x. I am ramping up on tools again, pre-project. My Fluke 8050a and variable dc power supply should arrive this week! ( Don't think she'll spring for any test gear ;-)
-Luke
Small hum at AX-output solved
Hi gents,
Last day's i did some experiments with snubber circuits around the rectifier bridge(different value's and positions except...) because there was some small hum in the output signal of my AX-amp and when i looked with a scope i saw 100hz ****(see earlier mail).
After a few hours without any result i became a little angry and dismount the transformer(800va and a hell of a job) to exclude inductive coupling/radiation problems and put it in front of the chassis. ... the "hum" didn't change !!! uhhhhh
Just before a nervous breakdown i pull at some wiring and something happened.
The two massive 2,5mm wires which are responsible for the zero of the two rectifier bridges work like antenna's and radiate the line-frequentie in my system. ...oeps!
After this diagnose i change the lenght of that wiring and pull it away from the powerfetboards and other wiring(never make wiring beautiful).
The improvement is around 70% and the hum level is very,very low now.
I didn't try the rc-snubber across the secondary winding of the transformer yet maybe it's THE sollution for the last 30%.
Before the weekend i let you know.
Gr.
Johan.
Nixie said:
Hi gents,
Last day's i did some experiments with snubber circuits around the rectifier bridge(different value's and positions except...) because there was some small hum in the output signal of my AX-amp and when i looked with a scope i saw 100hz ****(see earlier mail).
After a few hours without any result i became a little angry and dismount the transformer(800va and a hell of a job) to exclude inductive coupling/radiation problems and put it in front of the chassis. ... the "hum" didn't change !!! uhhhhh
Just before a nervous breakdown i pull at some wiring and something happened.
The two massive 2,5mm wires which are responsible for the zero of the two rectifier bridges work like antenna's and radiate the line-frequentie in my system. ...oeps!
After this diagnose i change the lenght of that wiring and pull it away from the powerfetboards and other wiring(never make wiring beautiful).
The improvement is around 70% and the hum level is very,very low now.
I didn't try the rc-snubber across the secondary winding of the transformer yet maybe it's THE sollution for the last 30%.
Before the weekend i let you know.
Gr.
Johan.
Updated Aleph X parts list
Hi Guys,
Despite everyones' advice to build an easier project, I have to build the Aleph X.
I teach sound recording and get up several times a year and extol the virtues of differential balanced signal transmission.
When I read NP's white paper on the X amps, I was blown away that he applied the balancing phenominon to amplifiers...
I still am blown away...
All that said:
Does anyone know of an updated parts list for the ~40 watt version of the Aleph X?
I have been looking at Grey's original list and am just wondering if things have changed since then.
As usual thanks to everyone, especially NP.
-Luke
Hi Guys,
Despite everyones' advice to build an easier project, I have to build the Aleph X.
I teach sound recording and get up several times a year and extol the virtues of differential balanced signal transmission.
When I read NP's white paper on the X amps, I was blown away that he applied the balancing phenominon to amplifiers...
I still am blown away...
All that said:
Does anyone know of an updated parts list for the ~40 watt version of the Aleph X?
I have been looking at Grey's original list and am just wondering if things have changed since then.
As usual thanks to everyone, especially NP.
-Luke
Luke, Here's the thread regarding a high-powered version.
http://www.diyaudio.com/forums/showthread.php?s=&threadid=8933
-David
http://www.diyaudio.com/forums/showthread.php?s=&threadid=8933
-David
I consider the original Aleph-X to be a decent intermediate to advanced project. You want to build it for a first project? That's fine by me. As far as I'm concerned, the original schematic and Bill Of Materials stand, with one exception. I recommend the addition of Ian MacMillian's resistors from the outputs back to the front end CCS.
That's not to say that you can't find other things to modify, but then you quickly get swamped in permutations that may or may not actually make the amp sound better. For instance, if I were to start with a clean sheet of paper and design the amp today, I would probably use a series resistor and pot instead of the two resistors and a pot in the original front end CCS. Would the amp sound different? No. But in the event that the pot failed open, it would be less disruptive.
There are other things that I might do, but then again I might just hold them in reserve for another project. I've got power JFETs to play with now, you know.
Grey
P.S.: I consider the addition of a straight cascoded JFET to the outputs of an Aleph-X to be a trivial project. I'll let someone else do it.
That's not to say that you can't find other things to modify, but then you quickly get swamped in permutations that may or may not actually make the amp sound better. For instance, if I were to start with a clean sheet of paper and design the amp today, I would probably use a series resistor and pot instead of the two resistors and a pot in the original front end CCS. Would the amp sound different? No. But in the event that the pot failed open, it would be less disruptive.
There are other things that I might do, but then again I might just hold them in reserve for another project. I've got power JFETs to play with now, you know.
Grey
P.S.: I consider the addition of a straight cascoded JFET to the outputs of an Aleph-X to be a trivial project. I'll let someone else do it.
Banned
Joined 2002
4,7K is the proposed value from the start, but later it was suggested that a lower value might be better so I guess you are on track.
How is your AX's doing? Mine takes forever to finish, it has been a huge work on these amps for me but now I think I can safely say
that the A-X's are finally getting close to the finish
All I need to do now is make the connections to the boards and adjust Hope it goes smoothly Well have a peek at the monoblocks. They are small powerplants Steen
Attachments
Hi Steen,
Yes, definitely get a variac for turn on. My first Aleph-X monoblock had the main rectifier diodes wired backwards. I had even checked all the wiring three times before initial turn on. I always first turn the variac on very very slowly with a multimeter on the first PS filter cap and never let the voltage get above a few tenths of a volt. This time it paid off. I remember not believing what I was seeing and checking the meter leads and all kinds of other things before forcing myself to go back to square one and start rechecking from the very beginning.
Use a variac.
Regarding the MacMillan resistors, 4.7K was the nominal vaue established in the Aleph-X thread. Several builders preferred 2K and 1K values but I don't recall anyone doing more than a cursory listening test. At the time NP said something like you could go as low 5K without things "going to hell". That's not a very promising statement. I intend to do some listening tests on this resistor value over the next few months. I think the optimum value is going to be larger - like 10K+.
Cheers,
Graeme
Yes, definitely get a variac for turn on. My first Aleph-X monoblock had the main rectifier diodes wired backwards. I had even checked all the wiring three times before initial turn on. I always first turn the variac on very very slowly with a multimeter on the first PS filter cap and never let the voltage get above a few tenths of a volt. This time it paid off. I remember not believing what I was seeing and checking the meter leads and all kinds of other things before forcing myself to go back to square one and start rechecking from the very beginning.
Use a variac.
Regarding the MacMillan resistors, 4.7K was the nominal vaue established in the Aleph-X thread. Several builders preferred 2K and 1K values but I don't recall anyone doing more than a cursory listening test. At the time NP said something like you could go as low 5K without things "going to hell". That's not a very promising statement. I intend to do some listening tests on this resistor value over the next few months. I think the optimum value is going to be larger - like 10K+.
Cheers,
Graeme
Thanks for advice, Graeme Well, I crossed my fingers and tested the psu's allready. Both worked as they should. They put out +/- 24,8V, only loaded with a bleeder resistor of 2,7k. So I guess they will end up around the +/-22V that was the target under load. The psu is a CLC filter. I used Bigparsnips rectifierboards as on the pic. I just noticed that he actually has some left, see the marketplace.
Steen
Well, I crossed my fingers and tested the psu's allready. Both worked as they should. They put out +/- 24,8V, only loaded with a bleeder resistor of 2,7k. So I guess they will end up around the +/-22V that was the target under load. The psu is a CLC filter. I used Bigparsnips rectifierboards as on the pic. I just noticed that he actually has some left, see the marketplace.Steen
