I'm confused as to what the LED is indicating.
At IDLE the Cathode will be at approx 0V so the LED will be ON.
With a large signal the Cathode will vary between close to +Vcc and -Vcc so the LED will appear to FLASH with the music.
Should the Cathode not be connected to 0V to indicate POWER ON ?
At IDLE the Cathode will be at approx 0V so the LED will be ON.
With a large signal the Cathode will vary between close to +Vcc and -Vcc so the LED will appear to FLASH with the music.
Should the Cathode not be connected to 0V to indicate POWER ON ?
Power Supplies
At long last I've completed the Power Supplies.
I don't know how I'm going to lift this beast once it is complete. The Heatsink Assembly is almost too heavy to lift and this Power Supply is positively hernia inducing.
Interesting in the diagram that I am working to, there are no PSU chokes. I'm only using them as the KK-PCB Power Supply includes them.
Would I be better removing them and allowing the PSU rails to increase to +/-45V.
At long last I've completed the Power Supplies.
I don't know how I'm going to lift this beast once it is complete. The Heatsink Assembly is almost too heavy to lift and this Power Supply is positively hernia inducing.
Interesting in the diagram that I am working to, there are no PSU chokes. I'm only using them as the KK-PCB Power Supply includes them.
Would I be better removing them and allowing the PSU rails to increase to +/-45V.
Attachments
It will dissipate the most heat at idle. When it's working some of the heat is being handled by the spkrs.
You need to add some vent holes in your baseplate so it's not an oven in there.
Best, Bill
All is not well in the Freestone Aleph 4 household.
Andy f****d up and is paying the costs.
With everything wired up and the PSUs tested correct it was time to try the amps.
Left Channel has already been tested and is perfectly OK, the Right Channel was still virgin.
POWER ON and RH channel had a smoking Source resistor in -VE leg, DC output offset was also high at 8V.
FOOLISH ME I had inadvertently reversed the connections to GATE and SOURCE SENSE. The DRAIN and OUTPUT connections were correct. I'd done this on both +ve and -ve FETs.
Briefly looking at the circuit diagrams it would appear that no harm should ensue from this ****-up.
I then smartly reconnected the FET boards - correctly this time.
I powered ON and watched the DC OFFSET to see if my ****-uop correction had worked. It did, output offset was now in the millivolt range.
I was just clapping my hands when the -ve bank started to smoke again and the +ve Bridge Rectifier (35A) went up in smoke.
The transformer survived but it got mughty warm in the 20 seconds or so that it took the amp to go into self-destruct.
Andy f****d up and is paying the costs.
With everything wired up and the PSUs tested correct it was time to try the amps.
Left Channel has already been tested and is perfectly OK, the Right Channel was still virgin.
POWER ON and RH channel had a smoking Source resistor in -VE leg, DC output offset was also high at 8V.
FOOLISH ME I had inadvertently reversed the connections to GATE and SOURCE SENSE. The DRAIN and OUTPUT connections were correct. I'd done this on both +ve and -ve FETs.
Briefly looking at the circuit diagrams it would appear that no harm should ensue from this ****-up.
I then smartly reconnected the FET boards - correctly this time.
I powered ON and watched the DC OFFSET to see if my ****-uop correction had worked. It did, output offset was now in the millivolt range.
I was just clapping my hands when the -ve bank started to smoke again and the +ve Bridge Rectifier (35A) went up in smoke.
The transformer survived but it got mughty warm in the 20 seconds or so that it took the amp to go into self-destruct.
The ALEPH 4 lives
In my impatience to get some NELSON music I overlooked the DIYers GOLDEN RULE.
CHECK, CHECK, CHECK AGAIN.
The second channel had a dry joint on its -VE supply.
The second channel had its D-S connections to both legs transposed.
I'm amazed that ONLY the bridge rectifier blew.
It's now running and producing the most glorious sound that I have heard.
The only fuse in the beast is a 10A Mains Fuse, that didn't blow.
In my impatience to get some NELSON music I overlooked the DIYers GOLDEN RULE.
CHECK, CHECK, CHECK AGAIN.
The second channel had a dry joint on its -VE supply.
The second channel had its D-S connections to both legs transposed.
I'm amazed that ONLY the bridge rectifier blew.
It's now running and producing the most glorious sound that I have heard.
The only fuse in the beast is a 10A Mains Fuse, that didn't blow.
Attachments
I just can't turn it OFF.
Well, the technical bit has been done and its soak testing after my disasterous mistake. I still can't believe that I didn't do more damage.
The test system is
ARCAM FMJ CD36
SHUNTKY / PUMPKIN Pre-Amp
PASSIVE 100K LADDER ATTENUATOR
B&W DM683 Speakers
The results are STUNNING
There is absolutely no audible noise when there shouldn't be.
BASS SLAM is amazing - no need for the subs anymore, not that the 683s are shy on BASS at all.
The 683s share a lot of technology from the Nautilus (the surroundless Midrange and the Nautilus Tweeter). The Aleph 4 controls these extremely well and the sound is both beautiful and lovely to listen to. I've got them bi-cabled with QED Qudos cables but 15A ring main cable is very good as well.
There is no audible sibilance. Piano sounds like a piano.
I've got these biassed at 2.4A and the heatsinks are comfortably warm.
Total draw from the 240V mains is 1.6A (so 380W)
When I can stop listening to it I'll get around to fitting the top cover and painting it.
No-one's going to pinch it - It weighs 48Kg.
It's getting near to my "Granny" neigbours bed time, I'll have to turn it down soon, but it's only running at (Nelson's Sweet Spot) around 1W or so. 5W with the 683s is LOUD. I haven't even attempted 50W as its just too loud to listen to. It's nice to have the headroom though so that the sound is both musical and unrestrained.
I haven't bothered with low value caps across the CLCC PSU. I don't think it needs them and the circuit that I have been using doesn't show them.
If it sounds as lovely as it does "out of the box", what improvements can be made ?
Well, the technical bit has been done and its soak testing after my disasterous mistake. I still can't believe that I didn't do more damage.
The test system is
ARCAM FMJ CD36
SHUNTKY / PUMPKIN Pre-Amp
PASSIVE 100K LADDER ATTENUATOR
B&W DM683 Speakers
The results are STUNNING
There is absolutely no audible noise when there shouldn't be.
BASS SLAM is amazing - no need for the subs anymore, not that the 683s are shy on BASS at all.
The 683s share a lot of technology from the Nautilus (the surroundless Midrange and the Nautilus Tweeter). The Aleph 4 controls these extremely well and the sound is both beautiful and lovely to listen to. I've got them bi-cabled with QED Qudos cables but 15A ring main cable is very good as well.
There is no audible sibilance. Piano sounds like a piano.
I've got these biassed at 2.4A and the heatsinks are comfortably warm.
Total draw from the 240V mains is 1.6A (so 380W)
When I can stop listening to it I'll get around to fitting the top cover and painting it.
No-one's going to pinch it - It weighs 48Kg.
It's getting near to my "Granny" neigbours bed time, I'll have to turn it down soon, but it's only running at (Nelson's Sweet Spot) around 1W or so. 5W with the 683s is LOUD. I haven't even attempted 50W as its just too loud to listen to. It's nice to have the headroom though so that the sound is both musical and unrestrained.
I haven't bothered with low value caps across the CLCC PSU. I don't think it needs them and the circuit that I have been using doesn't show them.
If it sounds as lovely as it does "out of the box", what improvements can be made ?
Attachments
Last edited:
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