The 22k loads the cables (r34 r14)
More mods you could try: Really go for elcos, they are in great capacitance, and you will need them.
I dont know about the quality of your 4.7uF metallized polypro cap, but you might consider upgrading, as it makes a difference, but then again, I dont know what you are using.
Try bypassing the input cap with some small silver/mica cap, it seems to affect the performance in a great way. Stock caps are ok, but you might considering upgrading them, or at least the coupling cap.
Also, feedback resistors are for 32v, which a 24v meanwell wont put out, so upgrading to a 27/36v meanwell might add some extra hifi-ness to your setup. (if you are not upgrading, you could remove the onboard diodes to get some little extra voltage)(removing diodes is a great idea even if upgrading, though you lose the polarity check)
Make sure you get the old 4.7uH coils, as the new ones seem to kinda suck.
More mods you could try: Really go for elcos, they are in great capacitance, and you will need them.
I dont know about the quality of your 4.7uF metallized polypro cap, but you might consider upgrading, as it makes a difference, but then again, I dont know what you are using.
Try bypassing the input cap with some small silver/mica cap, it seems to affect the performance in a great way. Stock caps are ok, but you might considering upgrading them, or at least the coupling cap.
Also, feedback resistors are for 32v, which a 24v meanwell wont put out, so upgrading to a 27/36v meanwell might add some extra hifi-ness to your setup. (if you are not upgrading, you could remove the onboard diodes to get some little extra voltage)(removing diodes is a great idea even if upgrading, though you lose the polarity check)
Make sure you get the old 4.7uH coils, as the new ones seem to kinda suck.
Hi teamacc,
Thanks for the advice. Still wondering about keeping r34 and r14 as the 100k log pot should also load the input.
I got the old 4.7uH coils
Andrew
The Hi-Fi Watcher
Thanks for the advice. Still wondering about keeping r34 and r14 as the 100k log pot should also load the input.
I got the old 4.7uH coils
Andrew
The Hi-Fi Watcher
Hi Danny,
You mean a volume pot? Pretty easy. The pot can by fixed to the case and electrically sit between the phono sockets and the input screw blocks on the board. Just use the classical way of wiring a volume pot - bearing in mind the input on the board uses a shared input earth for left and right channels.
In fact, check the wiring diagram on page 139 - which should give you some pointers.
Andrew
The Hi-Fi Watcher
You mean a volume pot? Pretty easy. The pot can by fixed to the case and electrically sit between the phono sockets and the input screw blocks on the board. Just use the classical way of wiring a volume pot - bearing in mind the input on the board uses a shared input earth for left and right channels.
In fact, check the wiring diagram on page 139 - which should give you some pointers.
Andrew
The Hi-Fi Watcher
If you go for the meanwell, they dont come in 150w (except for the 24v)
The 24v does not sound nice if cranked up, so i guess you better lower the voltage aka go for the 36v supply.
Just got it, it can be turned down to 29.7, which is just over the max i was able to get out of the 150w 24v meanwell. (approx 29.2 or so)
About the pot: You might want to follow the ordinary potention meter instructions.
An externally hosted image should be here but it was not working when we last tested it.
The red wire would go to your right channel, the yellow to your left, and the black will go to the ground on both channels.
If wired wrong, it might work the other way (eg turning it to the right decreases volume) or not work properly at all (only the first few degrees turn will induce some change in volume)
Either way, remember that in the picture the pot shaft is NOT facing towards you.
I want to fit a switch to the front of my case.
one of these
IP67 Rated Illuminated Pushbutton Switch Blue - Jaycar Electronics
Its rated at 3A 250VAC, on the smps it says 200-240VAC/4.0A
How would I go about installing this? what type of relay would I use?
Cheers
one of these
IP67 Rated Illuminated Pushbutton Switch Blue - Jaycar Electronics
Its rated at 3A 250VAC, on the smps it says 200-240VAC/4.0A
How would I go about installing this? what type of relay would I use?
Cheers
Guys, whats the optimum SMPS's rated power to suit Sure 2x100 amp ?
I can buy 30v 240W 8A for a reasonable price here in Poland.
My thinking is that 2x100W=200W, so 240 should be ok
Sure sells the amp in KIT'a now with 24v 150W SMPS.
What do you think of it ?
One more thing some MeanWell's units have switching frequency 25khz and others are 96khz. Does it make any difference ?
I can buy 30v 240W 8A for a reasonable price here in Poland.
My thinking is that 2x100W=200W, so 240 should be ok
Sure sells the amp in KIT'a now with 24v 150W SMPS.
What do you think of it ?
One more thing some MeanWell's units have switching frequency 25khz and others are 96khz. Does it make any difference ?
30v
30v/ 240 watt should be good on paper. No way to know how it will sound until you try it. I have only seen 25KHz ever listed for the switching rate of the MeanWell.
Guys, whats the optimum SMPS's rated power to suit Sure 2x100 amp ?
I can buy 30v 240W 8A for a reasonable price here in Poland.
My thinking is that 2x100W=200W, so 240 should be ok
Sure sells the amp in KIT'a now with 24v 150W SMPS.
What do you think of it ?
One more thing some MeanWell's units have switching frequency 25khz and others are 96khz. Does it make any difference ?
30v/ 240 watt should be good on paper. No way to know how it will sound until you try it. I have only seen 25KHz ever listed for the switching rate of the MeanWell.
Hi, I hate to bring up R34 and R14 again, but I just want to check I've got everything right while the the Sure boards are being soldered...
Right now I'm leaving R34 and R14 in, and I've removed both 1.0uF and 0.22uF parallel input caps. I'm planning to use a 4.7uF input cap, and I've wired it using the existing holes for the 1.0uF cap.
I was comparing the Tripath and Sure datasheets, and couldn't work out 100% what sure have done with the input side. Will leaving the R34 and R14 in place be the best thing here?
Right now I'm leaving R34 and R14 in, and I've removed both 1.0uF and 0.22uF parallel input caps. I'm planning to use a 4.7uF input cap, and I've wired it using the existing holes for the 1.0uF cap.
I was comparing the Tripath and Sure datasheets, and couldn't work out 100% what sure have done with the input side. Will leaving the R34 and R14 in place be the best thing here?
I do plan to run a pretty similar set up to Scott so I think I'm going to leave r14 and r34 in the circuit for now.
My planned configuration for each Sure board is:
AK4396 DAC -> 2.2uF or 4.7uF coupling cap -> 4 ft interconnect -> 3.9K shunt stepped attenuator -> 6 inch wire -> Sure amp module -> speakers
Also, I forgot to ask before, how well is everyone managing to solder the Wurth XXL inductors to the PCB? Right now I'm using a 50W iron turned up to maximum heat, and using a medium size tip, and soldering them from the side. I find if you tin the inductors before you put them on the PCB then this makes things work better. I also add a little extra solder to the PCB tracks but I'm not sure if this helps or hinders things...
I do find things can get a little cramped when adding the final inductor however, has anyone else had this problem? Are there any easier ways of doing it?
Second cap
I think you will find that you need a second cap. One at the dac and one at the stock location on the amp to keep the 2.5v input bias from shorting back through the attenuator or R14/34. With the attenuator loading the dac you may get better sound after removing R14/34. I have been doing my critical listening using digital volume control without the attenuators. This sounded better with the resistors in place to load the dac and cables. I am soldering the coils the same way as you. It is much easier on the new style amps as the heat sink clips right off. Then there is plenty of room.
I think you will find that you need a second cap. One at the dac and one at the stock location on the amp to keep the 2.5v input bias from shorting back through the attenuator or R14/34. With the attenuator loading the dac you may get better sound after removing R14/34. I have been doing my critical listening using digital volume control without the attenuators. This sounded better with the resistors in place to load the dac and cables. I am soldering the coils the same way as you. It is much easier on the new style amps as the heat sink clips right off. Then there is plenty of room.
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