Parallel - continuing with "current drive" concept
My God!
Please somebody stop me! 😀
Following "Diagonal", here comes another relatively simple "current drive" design - I called it "Parallel".
Highly linear front-end, relatively low feedback loop gain (~35db), excellent stability margins, wide open loop bandwidth - hence low distortion distortion is almost constant within the audio frequency range (THD1 = 0.002%, THD20 = 0.003%).
Pretty nice harmonics profile (attached) - mostly 2 and 3 are in place.
It can be adapted to variety of rail voltages and also can be used with MOSFET output stage. Not live-tested yet.
Cheers,
Valery
My God!
Please somebody stop me! 😀
Following "Diagonal", here comes another relatively simple "current drive" design - I called it "Parallel".
Highly linear front-end, relatively low feedback loop gain (~35db), excellent stability margins, wide open loop bandwidth - hence low distortion distortion is almost constant within the audio frequency range (THD1 = 0.002%, THD20 = 0.003%).
Pretty nice harmonics profile (attached) - mostly 2 and 3 are in place.
It can be adapted to variety of rail voltages and also can be used with MOSFET output stage. Not live-tested yet.
Cheers,
Valery
Attachments
Neat. That's a lot of transistors. 🙂
I have all but the MJE15033/32 drivers. Looks like a great neutral sounding setup. Very nice.
I have all but the MJE15033/32 drivers. Looks like a great neutral sounding setup. Very nice.
Yes, the full (not simplified) Diagonal front-end has got more transistors, than resistors 😀
This one - if you go for 1 pair of HexFETs - then you need only 2 drivers - you will have 4 transistors less immediately 😉
The layout can be very compact again.
This one - if you go for 1 pair of HexFETs - then you need only 2 drivers - you will have 4 transistors less immediately 😉
The layout can be very compact again.
Luxman used this kind of topology ("parallel" current subtraction via common base cascade and current mirror at the bottom) with some variations in a number of amplifiers, but always having jFET-based LTP at the input. AD797 - never paid attention, but that's cool 😀
Yes of course,just a question.
What are you using for smd solder?
Are you using solder paste or solder wire?
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I've been using .015" solder wire lately. The paste is for reworking in an oven. Wash the boards with alcohol and apply a little liquid flux before starting. This really helps with SMD.
I'm looking for a suitable heat sink and i want your help.Please have a look here.Go through pages and help me choosing the right one.
MAR electronics - ???????? - Standard Extruded Heatsinks 1
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I'm using 12" x 6" HeatsinkUSA extrusions. With 48V rails they are hardly warming up.
SK501-200AL looks similar. 150mm versions should work.
SK501-200AL looks similar. 150mm versions should work.
Wow! That's $60/pair from HeatsinkUSA and takes a week for customs to finish admiring them here.
Diy is a very expensive hobby here especialy if you haven't good friends.
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Low cost heat sinks is the eternal enemy of DIYers. 🙁
If looks did not matter - a very low cost source of heatsinks are old aluminum cook pots. A 10in dia thick aluminum pot can probably serve as a good sink for a 250w class amp. Put some water in it and good for 2kW 😀
Other place to check are industrial building supplies where they make aluminum in scaffolding. Or aluminum extrusions for factory automation. They sell by the foot or meter. A 100mm square profile aluminum Bosch rail with channels for T nuts may also make a good sink.
Bosch Rexroth:
This profile is 25mm x 50mm x 1.82 meters long for about $40.
https://www.zoro.com/8020-framing-extrusion-t-slotted-10-series-1020-black-72/i/G6676871/
If looks did not matter - a very low cost source of heatsinks are old aluminum cook pots. A 10in dia thick aluminum pot can probably serve as a good sink for a 250w class amp. Put some water in it and good for 2kW 😀
Other place to check are industrial building supplies where they make aluminum in scaffolding. Or aluminum extrusions for factory automation. They sell by the foot or meter. A 100mm square profile aluminum Bosch rail with channels for T nuts may also make a good sink.
Bosch Rexroth:
An externally hosted image should be here but it was not working when we last tested it.
This profile is 25mm x 50mm x 1.82 meters long for about $40.
https://www.zoro.com/8020-framing-extrusion-t-slotted-10-series-1020-black-72/i/G6676871/
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There are DIY options for heatsink that work very well. I have sheet metal equipment and milling machines so it's easy for me to have excellent results, but the same can be done with a table saw and a belt sander.
DIY Heatsink
DIY Heatsink