Cased up my sigma-11 power supply and everything is working nicely.
For anyone else who goes this route, remember that the sigma-11 has no current limiting by design, so it is necessary to power on/off with the power supply and not the amp.
BK
For anyone else who goes this route, remember that the sigma-11 has no current limiting by design, so it is necessary to power on/off with the power supply and not the amp.
BK
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
I noticed some confusion about this here and on another forum. Hopefully this will clear things up. While it's possible that SURE will correct this in the future, I'm guessing there are a bunch of them now made with the incorrect output polarity markings.
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What is a Sigma 11 power supply? I missed that somewhere. They look really nice, what is the voltage and amp rating? Slick cases.
I see you are using the SMSL 36A TPA3118D2 - do you like how those sound?
Very nicely built.
I looked at these power supplies a while back but concluded that the onboard heatsinks my be inadequate for the 3116 to otherwise very nice units. They provide instructions for higher current use and offboard heatsinks. Not saying the the onboard are not enough but if your amp is playing loudly for some time and drawing bigger current may be worth checking the temp of the heatsinks. Maybe you already have?
Just yesterday I built the same Sigma 11 supply and was very pleased with the result, significant upgrade compared to a simple transformer/rectifier/cap supply.
These don't come ready and boxed, it is a PCB which can be ordered here:The σ11 Regulated Power Supply
And I am also pleased to read hat this amp can compete with some very good transistor and valve amps, as I already assumed.
Together with input transformers, some tweaks and a good supply this is really hard to beat.
Unbelievable.
These don't come ready and boxed, it is a PCB which can be ordered here:The σ11 Regulated Power Supply
And I am also pleased to read hat this amp can compete with some very good transistor and valve amps, as I already assumed.
Together with input transformers, some tweaks and a good supply this is really hard to beat.
Unbelievable.
Chris,
Thanks for sharing the impressions.
Can you elaborate a bit on your Tubelab Simple SE config - tubes, OPT, B+ voltage, coupling caps if possible?
Well it was some years ago I built it but lets see:
Tubes are: Sovtek rectifier tube, EI 6CA7 (EL34 equivalents), Telefunken front end tube I believe (no writing visible on it). Transcendar OPTs, B+ I think was 450v, coupling caps Russian PIO (green ones).
We did compare some power tubes at one stage, the EI ones had the best balance tho I used KT88 Golden Lion (new ones) for a while which had better bass but hard top end.
xrk971 and ChrisMmm,
Jogi shared a link to the PS design. My sigma-11 is setup for 18V DC output using a 50VA shielded toroid. Amp is the SMSL TPA3118 and load is 6ohm full-range speakers for nearfield use, so the power demands are relatively low. I extensively monitored current draw and sigma-11 heatsink temps before finalizing the setup. All is good in my case. The duty cycle is low enough that the sigma-11 can easily cope. A more difficult load, continuous test tones, and/or TPA3116 might be a different story. The cases are generic Hammond enclosures from Mouser + a bit of drilling and wiring.
Earlier in this thread I outlined the 4 power supplies I (ear) tested, and the sigma-11 sounded the best to me. It was comparable to another cheaper linear regulated bench PS similar to the Astron type. All the SMPS bricks I tried were unkind to female vocals, but worked OK for lots of other stuff. Word of warning - the sigma-11 is a high-performance and no-compromise audio PS. No current limiting or other protections, so use accordingly.
As far as sound goes, the SMSL 36A Pro with TPA3118D2 is wonderful in my setup. The speakers are DIY GR Research LGK full rangers. It makes a great desktop rig. Can't comment on full-size speakers for a large room.
Now that I've had my first taste of Class D, I might need to build up my own version from scratch. Until then, any suggestions to mod the SMSL 36A Pro I have now?
BK
Jogi shared a link to the PS design. My sigma-11 is setup for 18V DC output using a 50VA shielded toroid. Amp is the SMSL TPA3118 and load is 6ohm full-range speakers for nearfield use, so the power demands are relatively low. I extensively monitored current draw and sigma-11 heatsink temps before finalizing the setup. All is good in my case. The duty cycle is low enough that the sigma-11 can easily cope. A more difficult load, continuous test tones, and/or TPA3116 might be a different story. The cases are generic Hammond enclosures from Mouser + a bit of drilling and wiring.
Earlier in this thread I outlined the 4 power supplies I (ear) tested, and the sigma-11 sounded the best to me. It was comparable to another cheaper linear regulated bench PS similar to the Astron type. All the SMPS bricks I tried were unkind to female vocals, but worked OK for lots of other stuff. Word of warning - the sigma-11 is a high-performance and no-compromise audio PS. No current limiting or other protections, so use accordingly.
As far as sound goes, the SMSL 36A Pro with TPA3118D2 is wonderful in my setup. The speakers are DIY GR Research LGK full rangers. It makes a great desktop rig. Can't comment on full-size speakers for a large room.
Now that I've had my first taste of Class D, I might need to build up my own version from scratch. Until then, any suggestions to mod the SMSL 36A Pro I have now?
BK
That SMSL amp has all the fixin's as far as I can tell. If it doesn't have 330uF 25v Panasonic SEPF OSCON's that would be it. It appears to have good bootstrap caps, big input film caps, bootstrap snubber, good inductors, lower 20dB gain? Oh, if you went the transformer input to skip input caps that might be the next big step up.
Awesome power supply you have there - those look like formidable projects in themselves.
Awesome power supply you have there - those look like formidable projects in themselves.
Awesome - thank you. Already have the 330uF 25v Panasonic SEPF OSCON's on hand and waiting to go in. I'll see where that gets me.
AMB designs good stuff. The biggest hassle by far was hand drilling several hundred precision holes for ventilation!
BK
Thanks, thats good to hear, with lower current demands all sounds fine which is handy to know. I agree that PS/regulator circuit looks very good.
Now I know how well these amps compare with other designs I think spending a few more bucks on the PS is definitely warranted.
I use Hammond cases a lot myself - well made and easy to work on.
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Here's a temperature datapoint from my sigma-11. 4hrs continuous play at moderate volume with the arrangement as shown in the earlier pic. Snaked a Fluke thermocouple into one of the vent holes and measured the surface temperature at the top of the heatsink @ 40.4C with ambient (room) temp 26.3C. Running nice and cool!
Hammond cases are great. Nice for drilling and thick, long-lived, good looking anodizing. If I needed a much larger trafo I might look at the modushop galaxy line.
BK
Varying opinions I think. But for me lower gain gives higher input impedance which is definitely a good thing.
Yeah, I was a little surprised as well for the reduction in volume. I wonder if this is because the reduced in harshness fooled me thinking into less volume. I did use the 330pf/10R combo. I didn't calculate the impedance of this circuit at the switching frequency either so I can't tell if there was too much shunting. I also have the output coils changed so I think this may be a combo of several things. Maybe the new output coils are not the right match with the snubber circuit. But I remember the first impression of the snubber mod was an over-tamed feeling and the amp was a little quieter overall and in the bass as well (very unexpected). I had to turn up the volume a little bit, say from 10am position to 11:30am or 12 position to make it up to the same volume as before. Now without it, its back to the normal 10 am position that I usually set to (before getting too loud for the wife's liking).
I have a solder vacuum pump but I didn't use it much because I didn't want to leave the soldering iron tip too long on the track and damage it (screwed up many times before). I ended up using a sewing pin to poke through the holes while I soldered the holes on other side. Works for me.
-AC
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Here was my weekend project: putting together a little amp using the new Sure tpa3110 board. The original Sure tpa3110 board got me started down this rabbit hole of intrigue and obsession.
Nothing special about this build, just thought some might enjoy the pics. The board is stock (except for the screw terminal blocks I added). I intend to replace the stock electrolytic caps with the OSCONs (soon as they are delivered).
Have only done a minimal amount of listening so far, but I really like what I hear. I always liked the original Sure 3110 board. Might just be a case of "new gear syndrome", but right now I'd have to give this one the nod over my modded YJBlue 3116. Can't really put my finger on it, but the best analogy would be that this amp has the "blacker blacks" if we were talking plasma TVs. My only complaint with this board is that there is a power-off pop. To address that, I'm going low-tech and will just add a little rocker switch to connect the "SD" and "GND" pins. Using a paper clip right now, while I wait for additional screw terminals and a switch to be delivered.
Nothing special about this build, just thought some might enjoy the pics. The board is stock (except for the screw terminal blocks I added). I intend to replace the stock electrolytic caps with the OSCONs (soon as they are delivered).
Have only done a minimal amount of listening so far, but I really like what I hear. I always liked the original Sure 3110 board. Might just be a case of "new gear syndrome", but right now I'd have to give this one the nod over my modded YJBlue 3116. Can't really put my finger on it, but the best analogy would be that this amp has the "blacker blacks" if we were talking plasma TVs. My only complaint with this board is that there is a power-off pop. To address that, I'm going low-tech and will just add a little rocker switch to connect the "SD" and "GND" pins. Using a paper clip right now, while I wait for additional screw terminals and a switch to be delivered.
I really like these two new boards from Sure, especially the 3116. Here's what I did with mine. With only a set of Oscons a good home made power supply, quality wire and hardware, this board has fast become my favorite by a good margine. These dark boards with dark solder mask make it hard to see exactly how everything is being implemented... maybe it's just a better match with my speakers....whatever it is, I like it a lot.
