Fugly!
(hope these NTCs in plastic terminal blocks aren't those in mains ......... they're hot and , last time I checked , PTFE cased terminal blocks weren't black .........
so , to avoid your woman wearing black , use black Bakelite terminal blocks for mains NTC ...... and pull them away from metal around)
(hope these NTCs in plastic terminal blocks aren't those in mains ......... they're hot and , last time I checked , PTFE cased terminal blocks weren't black .........
so , to avoid your woman wearing black , use black Bakelite terminal blocks for mains NTC ...... and pull them away from metal around)
Thanks Zen Mod. A little unnerving to read that. I guess posting at intervals during the progress of the build would have pick it up earlier. I'll change them before the amp goes back into use.
Thanks JSA1971. It's 6mm aluminium angle. Actually cut from some heavy channel to get the size I wanted.
Where did you get the top perforated plate?
And if those are the basic GB block bridges, suggest you get a pair of those fancy Schottky ones - they're not cheap but make quite a difference to the sound - not kidding!
Perhaps add a simple mesh cover over those mains NTC assembly (to avoid possible later accidents) and maybe consider a dc trap if you have 'dirty' mains supply.
Nice build - lots of attention to details - neat and practical job on the supply
And if those are the basic GB block bridges, suggest you get a pair of those fancy Schottky ones - they're not cheap but make quite a difference to the sound - not kidding!
Perhaps add a simple mesh cover over those mains NTC assembly (to avoid possible later accidents) and maybe consider a dc trap if you have 'dirty' mains supply.
Nice build - lots of attention to details - neat and practical job on the supply
well , no mesh cover will replace thorough care and attention , when working on live amp
there are few more places with exposed mains and it's major PITA to cover them all
in last few years |I'm using small screwdriver completelly covered with insulation (nothing fancy - plastic handle , heatshrink on stub) with just tip exposed
do not ask how I come to that
and that's pretty much sole thing , besides meter probe (if possible - just one in hand , other crocodiled to appropriate point) I'm taking inside live gadget
there are few more places with exposed mains and it's major PITA to cover them all
in last few years |I'm using small screwdriver completelly covered with insulation (nothing fancy - plastic handle , heatshrink on stub) with just tip exposed
do not ask how I come to that
and that's pretty much sole thing , besides meter probe (if possible - just one in hand , other crocodiled to appropriate point) I'm taking inside live gadget
Best advice an old ham gave me, was when you are poking around in higher voltages than a D cell, keep one hand in your pocket.
yup
they taught me too , that most dangerous short circuit is that one , between two headphones
they taught me too , that most dangerous short circuit is that one , between two headphones
Thanks ichiban.
I wanted to build my own case (seemed like a good idea at the time), so I drew it up on CAD, bought the Conrad heatsinks and had the panels made locally. Lots of holes and screws and should only be tackled by those who are time rich and/or crazy. One of the reasons why I mounted the power supply this way was so that I could remove the entire PSU and give easy access to everything without dismantling the box.
It's a Mosfet version. Purchased from the DIYAudio store
Hi jameshillj,
I had the top and bottom panels CNC punched locally at about ten times the price of any country you wish to name. The front and rear were water-jet cut by and old work colleague for free to stop me sobbing.
Thanks for the hint on the Schottky bridges. The amp is currently dismantled waiting on the remaining parts for an F4 build. I'll change them then. I'll try anything for the sound, that's what it's all about.
I've taken on board Zen Mod's safety comments and will make those adjustments at the same time. I usually don't put my hands anywhere near the inside of this thing when it's on, but you never know. I changed the variable bias and offset resistors so that I can adjust from the top for that reason. (with a screw driver exactly like Zen Mod suggested).
I actually have a P5 power plant feeding this so the mains supply is clean.
Thanks for your kind words
You're welcome - I'm a generous consumer of that heatshrink material for extra insulation - I use it everywhere!
All the best ...
All the best ...
Anybody looked at doing one of these with a pair of IXFN140N20P pucks using +/-30v rails ? It would seem to be a natural way to get more power (50W at 8 ohms, maybe a 100W at 4 ohms). Only issue would be heat dissipation - I'd guess you would need two 4U chassis's to build mono blocks - similar to the SE "MOSFET Amplifier with IXFN140N20P" amplifier Pass presented at BAF a couple years ago.
Can the driver/phase splitter stage drive the input capacitance of those devices? The pucks have almost 7x more Ciss, the IXTH64N10L2 is 3x
I'm not asking the question just to make a point, can anybody shed some light here? 🙂
I'm not asking the question just to make a point, can anybody shed some light here? 🙂
Any of you major dudes got a circuit diagram with one of these HiPerFET's in the place of the IRF MOSFETs ? I have no idea how one would bias them up to 3.2A. B+ would probably be +/- 30-40 V.
I would guess the front end would look like the F6 front end using the Jensen transformer JT-123-FLPCH. (Actually, I was thinking of inserting a Pass B1 buffer in front of the transformer to make the thing more tolerant of preamp output impedance.)
BTW, anyone notice that the XA-25 brochure CAD drawing shows two HiPerFET pucks mount on each heatsink. PP N-Channel or complementary ??
I would guess the front end would look like the F6 front end using the Jensen transformer JT-123-FLPCH. (Actually, I was thinking of inserting a Pass B1 buffer in front of the transformer to make the thing more tolerant of preamp output impedance.)
BTW, anyone notice that the XA-25 brochure CAD drawing shows two HiPerFET pucks mount on each heatsink. PP N-Channel or complementary ??
Looks like the Ciss of the IXTH64N10L2 is 3650 pF vs. 7500 pf for the IXFN140N20P. Probably easier to drive.
Maybe the Ciss of these pucks is why the XA-25 has three stages vs. two......input , driver, output......just a guess.