Tc2000?
The driver chip may have died as well but there is no harm to try at this point. I ordered a replacement chip set from Sure with my last order to be ready for the inevitable.
It's 2am (get to bed!!!) and I've just finished building my amp. Still need to add the Zobel network though (the caps I had were physically too big 
).
Not going to have chance to fire it up - hopefully tomorrow. So here is what it looks like so far - kind of like lab equipment. Enjoy!
Andrew
).Not going to have chance to fire it up - hopefully tomorrow. So here is what it looks like so far - kind of like lab equipment. Enjoy!
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.
Andrew
Some thoughts:
Why the big input caps? As v-bro said, they pick up RF and make the sound go bad
Why are you powering 2 sets of speakers with one board?
What are those diodes doing there, still onboard?
I think your right channel will be shorted quickly, as I can see the copper of the wires almost touching one another.
I dont like the soldering on the potmeter.
Go test it!
Why the big input caps? As v-bro said, they pick up RF and make the sound go bad
Why are you powering 2 sets of speakers with one board?
What are those diodes doing there, still onboard?
I think your right channel will be shorted quickly, as I can see the copper of the wires almost touching one another.
I dont like the soldering on the potmeter.
Go test it!
Hi Teamacc,
Thanks for the feedback.
The physical size of the caps were not intentional. I had to hand some 4.7uF LCR metalised polypropylene caps that I know sound great. They also fit the horizontal cap clamps - keeping them mechanically fixed.
This board will never be used to power two pairs of loudspeakers (i.e. min 4 Ohm impedance rating). The two pairs of terminals per channel are used for bi-wiring purposes.
D1 and D2 are still onboard for the time-being and I can easily de-solder them later. BTW, do I also need to solder pieces of wire to bridge the D1 and D2 pads? I guess I do.
Thanks for pointing out the right channel loudspeaker connections, it's actually the camera angle. However, all the same, when I add the Zobel network I'll heat shrink these further.
With the pot, I think it is the camera angle again. Although I love the sound of this Alps pot, the issue is that it uses pins not tags. For each pin I had to tightly and neatly wrap the solid core hookup wire and then flow the solder through it. Below is part of another photo taken from a different angle on the same night - I really still need to take a proper close-up as the reality still looks better.
BTW, I have it running at a low volume (daughter asleep) right now. Already showing a nice mid band and detail. Likely to need further tweaking, e.g. pushing the PSU voltage up, Zobel & D1/D2.
Cheers for now,
Andrew
Attachments
Well spotted! Yes I realised a bit too late that I should have twisted the hookups to the pot. Maybe for a later day.
BTW, the rest of the cables are taken from some spare Linn K400 loudspeaker cable - where I extracted the cores from their massive PVC jacket.
Andrew
Supply in
I looked at the photo again and I see your power supply is coming in from the far side. That makes the path take the long way around through the diodes and then back around to the chips. If you want to eliminate the diodes you can attach the power wire to the output of the diode instead. I plan to try adding a larger tank cap and then sneaking the power wires under the heatsink to attach them to either side of c46.
Turning up voltage on the Meanwell from 24V to 27.1V has made a big improvement. At 24V things were distorting a bit in the mid range and the bass did not have the heft I like.
Now everything has a more authoritative sound, while sounding more human.
I kicked myself when reading about 32V on the power supply being optimum - about a day after I ordered the PSU
Hopefully, removing D1 and D2 will add an extra 1.2V to the supply across the amplifier itself and improve things further. I can see myself having to shell out for a 27V or 36V Meanwell...
Andrew
Now everything has a more authoritative sound, while sounding more human.
I kicked myself when reading about 32V on the power supply being optimum - about a day after I ordered the PSU
Hopefully, removing D1 and D2 will add an extra 1.2V to the supply across the amplifier itself and improve things further. I can see myself having to shell out for a 27V or 36V Meanwell...
Andrew
Hey all, I figure I may as well post a picture of how I'm getting on so far, any feedback, good or bad, will be most helpful...
A bit more info on how I've done things...
This lot of all bolted to the back of a speaker, the speaker is face down on this photo, I wanted to keep my speaker leads as short as possible.
My SMPS is on top, below the heatsink on the right I have a stepped attenuator for volume control and XLR input connector which will be connected to my source.
I'm using the heatsink for the l7805 and also a 560r resistor which I had to heatsink, as the original 560r resistor from my SMPS was originally a 2 watt resistor and got stupidly how when I turned the SMPS up to 32v.
I still need to short D1 and D2, as right now I'm getting 32v from the SMPS, but 31.7v measured across the tank caps on the sure board, but right now I think I'm pretty much done with the amp side of things.
I'm using 4.7uH Wurth XXL's on the woofer channel, as it's a 4ohm driver so an inductor which can take lots of current is ideal here. I'm using Arjen's 10uH inductors for my tweeters channel, as I'm hoping this will avoid any high frequency peaking or rolloff... I plan to crossover at 2.6KHz.
I did also try shorting the tweeter channel's input to ground so no signal was going into the amp and the hiss was still there, so I think the hiss may be coming from the amp itself? Or would reducing the gain still reduce the hiss in this case?
The hiss isn't very loud, in fact I can't hear it when I'm around 3 ft away from the tweeter, but I'm planning to sit around 1-2ft to these speakers so I'd like to reduce the hiss really....
I've ordered some Vishay-dale 25W 8R resistors to experiment with and I'm hoping that because they are a high wattage resistor then there will be very little temperate change during use, therefore very little resistance change, so hopefully very little change in the sound (apart from the reduced hiss that is!).
An externally hosted image should be here but it was not working when we last tested it.
A bit more info on how I've done things...
This lot of all bolted to the back of a speaker, the speaker is face down on this photo, I wanted to keep my speaker leads as short as possible.
My SMPS is on top, below the heatsink on the right I have a stepped attenuator for volume control and XLR input connector which will be connected to my source.
I'm using the heatsink for the l7805 and also a 560r resistor which I had to heatsink, as the original 560r resistor from my SMPS was originally a 2 watt resistor and got stupidly how when I turned the SMPS up to 32v.
I still need to short D1 and D2, as right now I'm getting 32v from the SMPS, but 31.7v measured across the tank caps on the sure board, but right now I think I'm pretty much done with the amp side of things.
I'm using 4.7uH Wurth XXL's on the woofer channel, as it's a 4ohm driver so an inductor which can take lots of current is ideal here. I'm using Arjen's 10uH inductors for my tweeters channel, as I'm hoping this will avoid any high frequency peaking or rolloff... I plan to crossover at 2.6KHz.
I did try a few things yesterday, I tried powering the whole Sure board from a 11.1v battery, but without any adjustment to R13, 17, 25, and 31 however...
I did also try shorting the tweeter channel's input to ground so no signal was going into the amp and the hiss was still there, so I think the hiss may be coming from the amp itself? Or would reducing the gain still reduce the hiss in this case?
The hiss isn't very loud, in fact I can't hear it when I'm around 3 ft away from the tweeter, but I'm planning to sit around 1-2ft to these speakers so I'd like to reduce the hiss really....
I've ordered some Vishay-dale 25W 8R resistors to experiment with and I'm hoping that because they are a high wattage resistor then there will be very little temperate change during use, therefore very little resistance change, so hopefully very little change in the sound (apart from the reduced hiss that is!).
Tweeter?
Which tweeter are you using?
.
.
Which tweeter are you using?
.
.
Hey all, I figure I may as well post a picture of how I'm getting on so far, any feedback, good or bad, will be most helpful...
An externally hosted image should be here but it was not working when we last tested it.
A bit more info on how I've done things...
This lot of all bolted to the back of a speaker, the speaker is face down on this photo, I wanted to keep my speaker leads as short as possible.
My SMPS is on top, below the heatsink on the right I have a stepped attenuator for volume control and XLR input connector which will be connected to my source.
I'm using the heatsink for the l7805 and also a 560r resistor which I had to heatsink, as the original 560r resistor from my SMPS was originally a 2 watt resistor and got stupidly how when I turned the SMPS up to 32v.
I still need to short D1 and D2, as right now I'm getting 32v from the SMPS, but 31.7v measured across the tank caps on the sure board, but right now I think I'm pretty much done with the amp side of things.
I'm using 4.7uH Wurth XXL's on the woofer channel, as it's a 4ohm driver so an inductor which can take lots of current is ideal here. I'm using Arjen's 10uH inductors for my tweeters channel, as I'm hoping this will avoid any high frequency peaking or rolloff... I plan to crossover at 2.6KHz.
I did try a few things yesterday, I tried powering the whole Sure board from a 11.1v battery, but without any adjustment to R13, 17, 25, and 31 however...
I did also try shorting the tweeter channel's input to ground so no signal was going into the amp and the hiss was still there, so I think the hiss may be coming from the amp itself? Or would reducing the gain still reduce the hiss in this case?
The hiss isn't very loud, in fact I can't hear it when I'm around 3 ft away from the tweeter, but I'm planning to sit around 1-2ft to these speakers so I'd like to reduce the hiss really....
I've ordered some Vishay-dale 25W 8R resistors to experiment with and I'm hoping that because they are a high wattage resistor then there will be very little temperate change during use, therefore very little resistance change, so hopefully very little change in the sound (apart from the reduced hiss that is!).
Unfortunately I've unable to uncover very much info about the tweeter, apart from it physically looks like a 1" silk-dome tweeter.
The speakers I'm using are Event TR-8's which were originally bi-amped (until the original lm3886 amp module died), so I'm using the Sure board as a replacement for the original amp module.
Here's a pic, someone may recognise it as I imagine it's probably made by a 3rd party:
An externally hosted image should be here but it was not working when we last tested it.
Uncropped pic here: http://img684.imageshack.us/img684/112/tr8angleblue6ec20ea3a59.jpg
I've also found a shop selling replacements (EVENT ERSATZHOCHTÖNER - U.K. International Cyberstore) but no TS specs or sensitivity ratings anywhere which is a shame. It does seem to match the level of the woofer quite well when a 8ohm resistor is in series, but as I don't know the specs of either the woofer or tweeter then it's hard for me to know if I have a efficient tweeter or inefficient woofer!
Both
It is probably a little of both. Efficient tweeter and lowish woofer. I have some 100db compression tweeters and horns to try so my hiss problem will be even more noticeable. I hope that the amps for the tweeters will sound great on 13v supplies and that using the minimum gain that is available at the lower voltage will cut the hiss by 8db along with the output level so I can avoid using any series resistor.
It is probably a little of both. Efficient tweeter and lowish woofer. I have some 100db compression tweeters and horns to try so my hiss problem will be even more noticeable. I hope that the amps for the tweeters will sound great on 13v supplies and that using the minimum gain that is available at the lower voltage will cut the hiss by 8db along with the output level so I can avoid using any series resistor.
If was going to have a rough guess I'd say my tweeters are around 95-90db/watt, but I will be sat pretty close to them as I'm planning to use them as speakers to listen to while I'm at the computer.
When I was using TA2020 based amps beforehand, and even then the speaker hiss was louder than my computer fans, but I have gone to a lot of effort to make my computer as quiet as possible... You may find the amount of hiss is acceptable if you are far enough from the speakers, I guess you never know for sure until you plug everything up and turn it on for the first time.
My quick test with a 11v battery still gave my a similar amount of hiss but I didn't change any of the resistors, so I assume the amount of gain is unchanged... perhaps you'll have more luck them me on this.
I'll be interested to hear how you get on with a 13v supply, if it does turn out to cut the hiss then I may go for this option eventually even if will involve cutting a few PCB traces and running 2 x SMPS per board. For now I'm happy to stick with my series resistor, I know it isn't ideal but will work for the time being.
Hi all,
I've the sure board for eight months and and i modified it step by step to hear if the mod give me a real improvement between i listen a lot to be sure to have some records of how it sounds.
I'm running the Sure amplifier with :
NAD C160 pre-amplifier
Rotel RCD 961 cd player
Clearaudio emotion turn table + 640 cambridge audio RIAA preamp
Monitor Audio RS8 Speakers
At this time I focused the output filter, sure implement a strange value filter (it's personnal opnion)
The firs thing I done is to replace the 22uH by 10uH inductors (ferrite coil)
Bought at autocostruire. The result is immediatly audible with high mid and overall with high frequencies.
In a second time i replace them by air inductances bought at Autocostruire
(Autocostruire il negozio degli autocostruttori)
Again immediate result scene wider.
Then i replace with homemade single layer 0,5mm diameter wire, the result is a better precision with mid frequencies keeping clear high frequencies.
I also note that EMI has been dramatically reduced and heatsink temperature stabilised around 40° C
Last i've replace 680nF output capacitors to 470nF more details with high frequencies.
I don't implement the Zobel because its main role is to reduce the filter overshoot which is widely out of audio spectrum.
After the output filter I was not satisfied with Bass So i've implemented 2x4700uF low ESR in parallel with existing capacitor, directly soldered on it according to the power rail. The bass the are dryer and clean.
The next step is to modified the input stage of the Amplifier even if the modifications made at this time increase very much the amplifier performances
I'm running the amplier with the Tripath typical voltage recommendation 24V using a 120 W SPS (6ohm Speakers = 2x45W typical)
I've the sure board for eight months and and i modified it step by step to hear if the mod give me a real improvement between i listen a lot to be sure to have some records of how it sounds.
I'm running the Sure amplifier with :
NAD C160 pre-amplifier
Rotel RCD 961 cd player
Clearaudio emotion turn table + 640 cambridge audio RIAA preamp
Monitor Audio RS8 Speakers
At this time I focused the output filter, sure implement a strange value filter (it's personnal opnion)
The firs thing I done is to replace the 22uH by 10uH inductors (ferrite coil)
Bought at autocostruire. The result is immediatly audible with high mid and overall with high frequencies.
In a second time i replace them by air inductances bought at Autocostruire
(Autocostruire il negozio degli autocostruttori)
Again immediate result scene wider.
Then i replace with homemade single layer 0,5mm diameter wire, the result is a better precision with mid frequencies keeping clear high frequencies.
I also note that EMI has been dramatically reduced and heatsink temperature stabilised around 40° C
Last i've replace 680nF output capacitors to 470nF more details with high frequencies.
I don't implement the Zobel because its main role is to reduce the filter overshoot which is widely out of audio spectrum.
After the output filter I was not satisfied with Bass So i've implemented 2x4700uF low ESR in parallel with existing capacitor, directly soldered on it according to the power rail. The bass the are dryer and clean.
The next step is to modified the input stage of the Amplifier even if the modifications made at this time increase very much the amplifier performances
I'm running the amplier with the Tripath typical voltage recommendation 24V using a 120 W SPS (6ohm Speakers = 2x45W typical)
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