Time for some layout decisions.
I just hate drilling l-brackets for the transformers. I’m lousy even with a drill press.
Opinions on fundamental transformer placement? Umbilical between main and expansion boards will be routed along the front of the box.
I just hate drilling l-brackets for the transformers. I’m lousy even with a drill press.
Opinions on fundamental transformer placement? Umbilical between main and expansion boards will be routed along the front of the box.
Attachments
front; furthest from inputs and input side of pcbs
don't build, if you really hate any of necessary steps
do something else, which you like more/completely
don't build, if you really hate any of necessary steps
do something else, which you like more/completely
Donut in front as ZM pointed out.
Consider the umbilical in the back. See the Aleph 2 and 60 pix I did in earlier posts. I’m quite happy with the results of this config. To keep that wires short maybe move the expansion board back a little.
You may consider leaving the donut loose for testing on the bench. Put it down on the chassis floor and see how it goes. Twist it for lowest noise. If you’re happy, bolt it in. If you need to put it on an L bracket you can test with it sitting on the side without a bracket first.
What donut size? 400va? I got the Antek donut cover for the 400va I put into the A60 monos I built. That’s also a possibility of needed.
Consider the umbilical in the back. See the Aleph 2 and 60 pix I did in earlier posts. I’m quite happy with the results of this config. To keep that wires short maybe move the expansion board back a little.
You may consider leaving the donut loose for testing on the bench. Put it down on the chassis floor and see how it goes. Twist it for lowest noise. If you’re happy, bolt it in. If you need to put it on an L bracket you can test with it sitting on the side without a bracket first.
What donut size? 400va? I got the Antek donut cover for the 400va I put into the A60 monos I built. That’s also a possibility of needed.
I also mount my donuts in front and flat. There is a little bit of mains hum at full volume with no input on my Aleph 30 but not enough to bother me. I tried some rotation and gave up, if I really cared I'd try putting a rectifier on earth ground.
I see you connected the umbilical at the mid-point of the end board. Really is a swiss-army-knife layout you designed there. I may very likely use this approach.
Purple Towers of Power!
Soldered up Randy‘s CL60, snubber, and V8 CRCRC boards. This was my first PS boards and where super easy to do. Love the ceramic 3w resisters, drop them in, flip them over and away we go. Definitely took way more time to acquire, sort, run the parts through the Megatester then assemble/solder. Now if the store would just get those pesky Aleph J amp boards in so I can order up my chassis and build up an Aleph J and Aleph 30 (Aleph 30 gets the bigger caps, it’s only a matter a time before it becomes Aleph 60s).
Soldered up Randy‘s CL60, snubber, and V8 CRCRC boards. This was my first PS boards and where super easy to do. Love the ceramic 3w resisters, drop them in, flip them over and away we go. Definitely took way more time to acquire, sort, run the parts through the Megatester then assemble/solder. Now if the store would just get those pesky Aleph J amp boards in so I can order up my chassis and build up an Aleph J and Aleph 30 (Aleph 30 gets the bigger caps, it’s only a matter a time before it becomes Aleph 60s).
Attachments
Bringing the first monoblock to life, have a biasing question:
In the Aleph 60 build guide 1.0e, the example is provided to measure the bias across the source resistors for main board and expansion board, converting those measurements to milliamps, and summing them, with the example of a bias of .370v / 1R = .370 mA. Adding up that current at 6 * .370 gives us approx. 2.22A, the initial target value.
Yet if I were to add up all twelve mosfet (current source and output) source resistors, that would obviously yield 4.44A.
So I'm looking for some clarification. I assume .370mA is the ballpark of the bias we're looking at for each mosfet?
In the Aleph 60 build guide 1.0e, the example is provided to measure the bias across the source resistors for main board and expansion board, converting those measurements to milliamps, and summing them, with the example of a bias of .370v / 1R = .370 mA. Adding up that current at 6 * .370 gives us approx. 2.22A, the initial target value.
Yet if I were to add up all twelve mosfet (current source and output) source resistors, that would obviously yield 4.44A.
So I'm looking for some clarification. I assume .370mA is the ballpark of the bias we're looking at for each mosfet?
.37v / 1R = .37A
.37A x6 = ~2.2A
do this exercise for both sets of MOSFETs. Outputs & current source MOSFETs.
You’re checking for the total to add up to appx 2.2A and to see that the load is shared evenly.
.37A x6 = ~2.2A
do this exercise for both sets of MOSFETs. Outputs & current source MOSFETs.
You’re checking for the total to add up to appx 2.2A and to see that the load is shared evenly.
Me: “.370v / 1R = .370 mA”
Big old Homer Simpson “Doh!”
yep, I knew .37A but what did I write? Sheesh.
Did you finalize your donut location? Share some pix and listening impressions when you’re done!
Toad, how are your mosfet case temperatures at that setting? Getting close to 55° or staying pretty low?
I see the Red moon a-rising
I see trouble on the way
I see earthquakes, heat and lightning
I see Loud times today
Don't go around tonight
Well, it's bound to take your life
There's a Red moon on the rise
This one is on the West Side of LA... right by the 405... just North of the flight path for LAX's north runways. While parked outside, waiting for the family to come out with the doughnuts, I spent a while taking pictures of airliners "flying through the doughnut"!
There's another one in Costa Mesa. That one is closer to my house. Do you think I ought to park my Pass amps under the doughnut and plug it in? I don't think they have blue LED lights in there though.
There's a picture of Half of Randy driving down PCH in Huntington Beach. Notice the surf.... dudes!
Are those good locations? BTW, the last time we went to the West LA Randy's, there were a couple of biker gangs having a great fight at the Chevron station. I don't know, but I swear they made the stereo in the Odyssey sound better.
On Memorial Day we'll be driving by the Randy's in Inglewood.... Group Buy for doughnuts?
Last edited: