one down, 8.7kgs, EF-3 monobloc, 57V rails....gets warm but nothing excessive, 3 leds strip when ON indicate unit in normal operation....glamour pics, blue is my personal trademark color for DIY builds
Attachments
Wow ! copper Heatsinked amp "porn". Nice to see this quality in the world.
Nice to see you posting again @ostripper , welcome back. We were all quite worried about you with the whole covid pandemic and all.
Thanks
My speakers are just a version of the Seas A26 kit from Madisound, with a slightly modded xover
My speakers are just a version of the Seas A26 kit from Madisound, with a slightly modded xover
Even the copper heatsink is impressed with the quality.
Attachments
Life gets in the way but I have managed to find time to review boards. Input boards soldered using horrible substance 🙂 I still have to trim all metal sticking out and give another clean before soldering the last bits. Won't do it probably until later this month, will have to finish the preamplifier first. Please have a quick look and let me know if you spot anything base.TIA
Attachments
Most likely just a reflection after fresh scrub. IPS boards are soldered with most likely lead-free solder sold as leaded
Dip the pcb's in a shallow container filled with 90% Isopropyl alcohol and give both sides a light scrub with an old toothbrush. Remove and blow off excess Iso, wipe dry the nooks and crannies with Kimtech wipes. Shiny as new 🤩
I have concerns about the solder joints. They appear to be oxidized. My solder joints with 63/37 Sn/Pb are all very shiny except occasionally when some flux remains. I've seen those types of solder joints made at too high of a temperature, or with an incompatible flux. Older solder joints (20 years and older) may show that sort of oxidation on the surface, but recent joints should not look like that.
Of course, it all could be just the lighting, but it doesn't seem like that. Or it could jut be the flux is not cleaned off.
Of course, it all could be just the lighting, but it doesn't seem like that. Or it could jut be the flux is not cleaned off.
Could be. I just looked at some commercial boards I made that had to be lead-free, and the stuff that was hand-soldered has a bit of a hazy surface. If the solder is not a eutectic it will freeze out like that. Most of my lead free work is surface mount with a reflow oven so it doesn't cool as fast and looks different. Lead-free melting points are a PITA except for the bismuth formulas.
@voxxonline
No need to worry about the dullness of the soldering joints, that's the result of the cleaning. However I do see some that will benefit from additional attention.
Replace R17 with a 1 or 2 watt type.
No need to worry about the dullness of the soldering joints, that's the result of the cleaning. However I do see some that will benefit from additional attention.
Replace R17 with a 1 or 2 watt type.
Been a while ....
I do see this amp performs as planned - actually better.
- I'm just curious how the pre-drivers are now heatsinked. It does not hurt ??
- The wolverine CCS has become an "overkill" TO-126 "beast". I guess this wont hurt , lower pF with those to-126's.
- strange addition of diodes in the cap multiplier/regulator section.
- and , the option of having the vbe closer to the outputs.
I suppose these are minor esoteric design choices ... as the resulting performance beats just about anything on the planet. Most 20K$ audiophile amps are 20-30ppm. I could beat this with a class A output stage instead of a an EF3. In fact , my next project is a Badger class A headphone amp with Jung
super-regulators and digital (Arduino) control.
Nice job , Stuart - Cheers !!
Are those tests right .... sub PPM - yikes ??
I do see this amp performs as planned - actually better.
- I'm just curious how the pre-drivers are now heatsinked. It does not hurt ??
- The wolverine CCS has become an "overkill" TO-126 "beast". I guess this wont hurt , lower pF with those to-126's.
- strange addition of diodes in the cap multiplier/regulator section.
- and , the option of having the vbe closer to the outputs.
I suppose these are minor esoteric design choices ... as the resulting performance beats just about anything on the planet. Most 20K$ audiophile amps are 20-30ppm. I could beat this with a class A output stage instead of a an EF3. In fact , my next project is a Badger class A headphone amp with Jung
super-regulators and digital (Arduino) control.
Nice job , Stuart - Cheers !!
Are those tests right .... sub PPM - yikes ??