Pass DIY Addict
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Very nice, Russell!
Freyahel: I think looking at 60mV of ripple is fine. Sometimes, depending on the specific construction of the amp, this can bleed through to the speakers. It all depends on how sensitive your speakers are, how well the amp topology rejects power supply ripple, and how much ripple is actually present. If you don't have any audible noise, then there probably isn't much to worry about. If you do have some noise, this suggest a possible way to reduce it.
Or, if you are just an OCD-driven tweaker (like many of us here), you'll play around a little to see what configuration reduces ripple... The worst that happens is you learn something along the way (or short something with one-too-many glasses of wine beforehand).
Freyahel: I think looking at 60mV of ripple is fine. Sometimes, depending on the specific construction of the amp, this can bleed through to the speakers. It all depends on how sensitive your speakers are, how well the amp topology rejects power supply ripple, and how much ripple is actually present. If you don't have any audible noise, then there probably isn't much to worry about. If you do have some noise, this suggest a possible way to reduce it.
Or, if you are just an OCD-driven tweaker (like many of us here), you'll play around a little to see what configuration reduces ripple... The worst that happens is you learn something along the way (or short something with one-too-many glasses of wine beforehand).
Pass DIY Addict
Joined 2000
Paid Member
But it’s also a bit relaxing when something you just built lights up without a single issue ...
I'm with you 100% there! It took me three days to work up the nerve the throw the power switch for the first time on my giant Aleph-X amps after working on them for months.
Congrats on a great looking and great sounding Aleph-J! Mine will be up and running within a few days...
Three questions here .
1.The keratherm insulators from the DIY store for the mosfets are in two layers, a kevla looking woven cloth that is stiff and a grey rubbery backing. Looking at photos it seems the grey stuff is the one to use but I'm wondering if both layers are required? If so the grey goes against the mosfet?
2.I'm using an Antek torroidal which has two each big input wires of blue and grey.
I am in Oz so it will be running on 240volts . Do I simply connect both blue to positive and both grey to neutral [or vice versa, does it matter?] or do I need a diode somewhere?
3.The output wires on the transformer are two red, two black and one blue.
Is the blue for an earth to the case?
Thanks guys.
1.The keratherm insulators from the DIY store for the mosfets are in two layers, a kevla looking woven cloth that is stiff and a grey rubbery backing. Looking at photos it seems the grey stuff is the one to use but I'm wondering if both layers are required? If so the grey goes against the mosfet?
2.I'm using an Antek torroidal which has two each big input wires of blue and grey.
I am in Oz so it will be running on 240volts . Do I simply connect both blue to positive and both grey to neutral [or vice versa, does it matter?] or do I need a diode somewhere?
3.The output wires on the transformer are two red, two black and one blue.
Is the blue for an earth to the case?
Thanks guys.
1) Keratherm is the pink rubbery stuff. The backing is removed.
2) Photos of your transformer please, as well as the sticker on it's side. I've not seen an Antek with a grey wire. No, you don't need a diode.
3) On an Antek, Red and Black are normally the primaries... Is the single blue wire purple?
Are you colorblind by chance?
Again, post well-lit-in-focus photos and we'll get this squared away.
2) Photos of your transformer please, as well as the sticker on it's side. I've not seen an Antek with a grey wire. No, you don't need a diode.
3) On an Antek, Red and Black are normally the primaries... Is the single blue wire purple?
Are you colorblind by chance?
Again, post well-lit-in-focus photos and we'll get this squared away.
Go to Antek's website and open the sales page for the transformer you bought. Dink around with the little thumbnails until you find the one which pulls up a full sized schematic of your transformer including labels which tell you what color wire goes to which transformer terminal.
Then if you want to ask more questions about the transformer, you can do a screen grab of the schematic and attach it to your post. Making it very easy for readers to know how your transformer is constructed. Even the readers who didn't happen to buy their transformer from Antek!
Then if you want to ask more questions about the transformer, you can do a screen grab of the schematic and attach it to your post. Making it very easy for readers to know how your transformer is constructed. Even the readers who didn't happen to buy their transformer from Antek!
Is this your transformer?
http://www.antekinc.com/content/AS-4218.pdf
If so, the blue-green wires are the secondaries and red-black are primaries.
For 240VAC use, you need to connect black to red. The purple is the shield,
which I believe goes directly to the chassis.
http://www.antekinc.com/content/AS-4218.pdf
If so, the blue-green wires are the secondaries and red-black are primaries.
For 240VAC use, you need to connect black to red. The purple is the shield,
which I believe goes directly to the chassis.
1.
Keratherm Transistor Insulators – diyAudio Store
2.Big BadaBoom!! if you do that . Find Antek page with adequate info , or write to them , or wait that someone with actual experience chime in
3.again - see at Antek's site ...... that wire is most probably of static shield , so you guessed correctly ....... check anyway
edit: how many Greedy Boyz are replying in same time ?
Keratherm Transistor Insulators – diyAudio Store
2.Big BadaBoom!! if you do that . Find Antek page with adequate info , or write to them , or wait that someone with actual experience chime in
3.again - see at Antek's site ...... that wire is most probably of static shield , so you guessed correctly ....... check anyway
edit: how many Greedy Boyz are replying in same time ?
This is awesome!
Ah 6L6, you got me in one. Colourblind in the extreme!
Yes it is the Antek 4218 so that's good and thankyou Dennis I now see the label and the schematic that had not been obvious to me. So black of one pair to red of the other pair then to 240V and purple to the case. Very good.
Wow I'm almost ready to assemble this big brute.
Thanks again guys you are amazing.
Ah 6L6, you got me in one. Colourblind in the extreme!
Yes it is the Antek 4218 so that's good and thankyou Dennis I now see the label and the schematic that had not been obvious to me. So black of one pair to red of the other pair then to 240V and purple to the case. Very good.
Wow I'm almost ready to assemble this big brute.
Thanks again guys you are amazing.
I remember having trouble with the secondary connections on my antek 20v trans. The way I thought it should be connected based on experience with most transformer wire colour codes was not in agreement with the diagram on the transformer.
I have the 400va 20v model with the e shield wire. This 400va is supposed to be built for audio use. I have been very happy with it in the aleph J. I am running higher than normal bias current as well as having the higher dc levels due to 20v sec. My line current readings indicate a power draw of 270va. The transformer runs quite warm but is dead silent with no mechanical buzz. This is impressive given the cost. I have had other brand name toroids that have buzzed badly when confronted with a class A power amp load. Slow Blow fuse is a must have here.
I have the 400va 20v model with the e shield wire. This 400va is supposed to be built for audio use. I have been very happy with it in the aleph J. I am running higher than normal bias current as well as having the higher dc levels due to 20v sec. My line current readings indicate a power draw of 270va. The transformer runs quite warm but is dead silent with no mechanical buzz. This is impressive given the cost. I have had other brand name toroids that have buzzed badly when confronted with a class A power amp load. Slow Blow fuse is a must have here.
OK I realized that I had probably hooked up the AC the wrong way on the bridge rectifiers so I reversed them and then it stayed on a while longer but still no LED's on the power supply. I had thought that the LED's were in the wrong way round so I changed them.
Anyway now I see I have blown the middle two resistors on the power board. They were all 1.0 ohms. Maybe I need to swap them for .47 which I have a bag of.
Here are some pics.
This was the first connection.
This is the second attempt.
Yes I foolishly hooked everything up for the first power up.
Anyway now I see I have blown the middle two resistors on the power board. They were all 1.0 ohms. Maybe I need to swap them for .47 which I have a bag of.
Here are some pics.
This was the first connection.
This is the second attempt.
Yes I foolishly hooked everything up for the first power up.
Yes they were obviously much too small. Of course I made a mistake and replaced them with even smaller ones which is probably why the LED's blew their tops.
But then I had a look at the polarity coming out of the bridge rectifiers and it was reading negative, that is, what should have read positive at the edge with the notch was reading negative, so I switched them round.Then the top blew off one of the LED's and the transformer started making a very scary noise.
So looks like new transformer and a few other bits before I try again.
This last effort was all done without the amp boards connected.
Perhaps they are still OK.
Not a great start to the new amp.
I have to say that unless one knows what one is doing with all this the actual build guide leaves quite a lot unexplained and once down the path of having spent quite a few dollars it isn't a nice feeling to still be relatively in the dark.
I will persevere but I feel there needs to be a very clear instruction tutorial instead of having to interpret and go from the power supply tutorial back to the Aleph first page and then read 290 odd pages to hopefully glean the essential bits that weren't explained in the beginning.
The trouble is once you get to a finished kind of point the test is in the power up when it all goes smoothly or not.
Anyway I'm going to order another transformer because now even unplugged it sounds like it's about to explode with the tiniest time turned on.
Then I'm going to be a total pain every step of the way till I get this thing sorted.
Damn and blast, I was hoping for a miracle I guess.
Sorry in advance.
But then I had a look at the polarity coming out of the bridge rectifiers and it was reading negative, that is, what should have read positive at the edge with the notch was reading negative, so I switched them round.Then the top blew off one of the LED's and the transformer started making a very scary noise.
So looks like new transformer and a few other bits before I try again.
This last effort was all done without the amp boards connected.
Perhaps they are still OK.
Not a great start to the new amp.
I have to say that unless one knows what one is doing with all this the actual build guide leaves quite a lot unexplained and once down the path of having spent quite a few dollars it isn't a nice feeling to still be relatively in the dark.
I will persevere but I feel there needs to be a very clear instruction tutorial instead of having to interpret and go from the power supply tutorial back to the Aleph first page and then read 290 odd pages to hopefully glean the essential bits that weren't explained in the beginning.
The trouble is once you get to a finished kind of point the test is in the power up when it all goes smoothly or not.
Anyway I'm going to order another transformer because now even unplugged it sounds like it's about to explode with the tiniest time turned on.
Then I'm going to be a total pain every step of the way till I get this thing sorted.
Damn and blast, I was hoping for a miracle I guess.
Sorry in advance.
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