Morning guys, heck I was soldering till way too late this morning... neck is a wreck... also still missing 2 resistor values.... sure I got some but I need to LOOK... else I will get some from RS on my way back from physio this afternoon... I was lucky to find some c0g caps in my bins for the values the shop also missed....
..and even FK2 Wimas for the 4n7 caps
Overall the board assembles nicely.. everything fits... thanks to eagle3d... only, some ofthe pads need to be made fatter...... or I ran out of small drills and am useing a size up from the normal....
now I need to go findthose 3 resistors... then I need to populate the transistors... and the first channel is done...
I don't have nice 27p caps.... I hope the 22p one I put in works... it actualy measured as over 23p
..and even FK2 Wimas for the 4n7 caps
Overall the board assembles nicely.. everything fits... thanks to eagle3d... only, some ofthe pads need to be made fatter...... or I ran out of small drills and am useing a size up from the normal....
now I need to go findthose 3 resistors... then I need to populate the transistors... and the first channel is done...
I don't have nice 27p caps.... I hope the 22p one I put in works... it actualy measured as over 23p
Little better.... now to swap back to the chipamp while I raid the DX for output transistors heatsinks and large caps...
I don't expect to be blown away... my vanilla DX sounds so great, since I corrected the preamp's filter situation...
Picture attached shows thermaltracking arrangement for input pairs... and how you can stack 2 bypass caps per large cap... 1 ontop of the PCB and one below...
I don't expect to be blown away... my vanilla DX sounds so great, since I corrected the preamp's filter situation...
Picture attached shows thermaltracking arrangement for input pairs... and how you can stack 2 bypass caps per large cap... 1 ontop of the PCB and one below...
Attachments
Ahh, the suspense. <chuckle> Suspense is fun, no need to rush.
Drill noise:
A while ago I eventually talked myself into buying a bench drill, just a cheap one as I was unsure of how much I would use it. Wow, it's so convenient, does most of the jobs I need, never gets lost
and is slow, slow and quiet, rumble rumble not WHINE . Even living in a flat, apartment, this thing is quiet enough that I don't need to think twice about the time of day, or night, or early morning
Drill noise:
A while ago I eventually talked myself into buying a bench drill, just a cheap one as I was unsure of how much I would use it. Wow, it's so convenient, does most of the jobs I need, never gets lost
and is slow, slow and quiet, rumble rumble not WHINE . Even living in a flat, apartment, this thing is quiet enough that I don't need to think twice about the time of day, or night, or early morning
Yep I have a bench drill too... bought it to drill holes for DX amp heatsinks..... but my house is very small.... more like a tiny flat ... and the bed is just around the corner from the drill.
Just finished vacuuming around the drill now.... as soon as the hayfever from the dust lets up, I'll be tapping away... also had to search for my drillbits.... I should realy try to finish my workshop behind the house.....
Just finished vacuuming around the drill now.... as soon as the hayfever from the dust lets up, I'll be tapping away... also had to search for my drillbits.... I should realy try to finish my workshop behind the house.....
Nice progress...
I checked the input pairs... they were fine.. so I decided to test again... sadly, no go... can only get it to draw about 170mv over the 10r resistor... offset 6v... so I would guess something further up in the amp is still unhappy... (at least no more explosions) gonna give it a rest for the evening and play some trackmania...... my rank sunk back to in the 40000s, normaly after getting the brain awake to this extend I make a killing on the track.
..b.t.w. where are all the old people this weekend?
btw I doubt I need a coil on the end... got maybe 5' of speaker cable.. probaby less...
Someone was not impressed with all the dustbunnies we blew up today...
I checked the input pairs... they were fine.. so I decided to test again... sadly, no go... can only get it to draw about 170mv over the 10r resistor... offset 6v... so I would guess something further up in the amp is still unhappy... (at least no more explosions) gonna give it a rest for the evening and play some trackmania...... my rank sunk back to in the 40000s, normaly after getting the brain awake to this extend I make a killing on the track.
..b.t.w. where are all the old people this weekend?
btw I doubt I need a coil on the end... got maybe 5' of speaker cable.. probaby less...
Someone was not impressed with all the dustbunnies we blew up today...
Attachments
Nordic, was it a VAS bjt?
The transistor that self destructed, was it part of the Beta Enhanced VAS?, the emitter follower one perhaps?. With this VAS configuration check that you dont have any shorts to ground as this will take out the small bjt at rail voltage quicker than you can blink more often than not, it happened to me twice!. This will lead to a less than optimal offset, 6v is huge but sounds about close to what I had with these problems. Id say first triple check your component arrangements, polarities and then check all traces, my problems happened because of a small sliver of aluminum and a contact from the VBE multiplier collector being grounded to the heatsink through this sliver.
Colin
The transistor that self destructed, was it part of the Beta Enhanced VAS?, the emitter follower one perhaps?. With this VAS configuration check that you dont have any shorts to ground as this will take out the small bjt at rail voltage quicker than you can blink more often than not, it happened to me twice!. This will lead to a less than optimal offset, 6v is huge but sounds about close to what I had with these problems. Id say first triple check your component arrangements, polarities and then check all traces, my problems happened because of a small sliver of aluminum and a contact from the VBE multiplier collector being grounded to the heatsink through this sliver.
Colin
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