i will get over my emotional blockade soon and get back to the patient.
you guys are right, we don't want a tpa buried alive.
Red board is like blue board, the outputfilter with 22uH and 560nF is more towards 9 ohm speakers, so could be dampening speaker, look at impedancecurve for your speakers. But electrolytics are same thing, decoupling 100nF ceramics are maybe even little further away from chippins, putting them closer restores some attack energy like in drums.
Working electrolytics, increasing size outputcapacitors, getting decoupling closer to chip. But very bad volumepot also could cause your ptoblem I guess??
I am talking about the tube pre.
I posted a link few posts before, with mods for the chinese preamp.
Mods to increase performances:
- change input resistance (to have a better gain)
- change tubes (I have russian tubes)
- change capacitors (I have russian capacitors, it works fine).
you can use a ALPS as well as output volume control. Some says it is not a best practice to have volume control at the preamp output, I think it works well with these preamp for the TPA 3116. But I have no way to compare with other systems.
Just curious, what is the source input to the transformer (I saw in the picture that it is hard wired to the source)? Could it be something related to the source output and transformer input impedances matching?
Regards,
I'll try bootstrap snubber mod for my YJ blue board. But black varnish masks everything, as I see mod consists 330pf cap &10ohm resistor to ground. According to schematic all 330pf caps connected to 0,22uf caps.
So; 0,22uf caps > 330pf ceramic > 10ohm resistor to ground?
Is this the correct implementation of this mod? Anyone got pcb layout for ground paths?
I know I'm asking silly questions
, but I want to be sure 😉
So; 0,22uf caps > 330pf ceramic > 10ohm resistor to ground?
Is this the correct implementation of this mod? Anyone got pcb layout for ground paths?
I know I'm asking silly questions
, but I want to be sure 😉
I am curious too because a -3dB loss sounds more like there is a source impedance mismatch issue. it may be that you need to change the input gain on the 3116 from default 26dB to 32dB.
I am no bat, but listening the difference between the 330uF Sepf Oscons and the 330uF FPcap NU Nichicon is very very big. You'll never mistake one for the other.
figure 2 in this document
http://www.ti.com/lit/ug/slou336b/slou336b.pdf
and post #941 in this thread have all the answers.
Hi,
Total newbie (though I've read the threads at audiokarma, audiocircle, and the more recent posts here).
I read people mentioning that the Sure 3116, unlike the other 3116's, does well with more voltage... at around KJA 2013's post, at post #4596:
If the choice were between the Astron RS-12A at 13.8V, or an average quality SMPS at a higher voltage of, say, 22V or 24V, which one do you guys think would be better for the Sure 3116?
I know linear makes a big difference (if a quality linear PSU - I read the Pyramids aren't), but it sounds like the higher voltage could in this case too. 😕
(I do know of the Meanwell RS-150-24 as a good SMPS, but am not confident dealing with the exposed AC terminals and finishing it. Was thinking of an adjustable SMPS such as Amazon.com: Prudent Way Universal Notebook & LCD AC/DC Combo 150W Power Adapter: Computers & Accessories , doesn't look overly no-name and can do 12-24V so might be good with a Sure 3110 as well if the 3110 needs less. It seems something like an Astron LS-10A, which can do 22-32V, could be best of both worlds for the Sure 3116, but it seems rare - haven't seen any on ebay.)
Thanks..
Total newbie (though I've read the threads at audiokarma, audiocircle, and the more recent posts here).
I read people mentioning that the Sure 3116, unlike the other 3116's, does well with more voltage... at around KJA 2013's post, at post #4596:
If the choice were between the Astron RS-12A at 13.8V, or an average quality SMPS at a higher voltage of, say, 22V or 24V, which one do you guys think would be better for the Sure 3116?
I know linear makes a big difference (if a quality linear PSU - I read the Pyramids aren't), but it sounds like the higher voltage could in this case too. 😕
(I do know of the Meanwell RS-150-24 as a good SMPS, but am not confident dealing with the exposed AC terminals and finishing it. Was thinking of an adjustable SMPS such as Amazon.com: Prudent Way Universal Notebook & LCD AC/DC Combo 150W Power Adapter: Computers & Accessories , doesn't look overly no-name and can do 12-24V so might be good with a Sure 3110 as well if the 3110 needs less. It seems something like an Astron LS-10A, which can do 22-32V, could be best of both worlds for the Sure 3116, but it seems rare - haven't seen any on ebay.)
Thanks..
Your pic is confusing. The right side of the Edcor board on your pic seems to be output to the amp assuming the board in the left of the pic is the amp. According to the Edcor site that should be the input side. Also 3 wires coming into the left of the transformer board per channel - is this balanced in? What device is it connected to?
Sure3116 is 400khz like the other 3116ampboards I have, so that isn't a reason for running hotter then others. Modulation selected is also normal BD mode. On 14V it doesn't need heatsink any more then any other 3116 btw, I have heatsink not mounted. If it runs hotter then others on higher voltages I wouldn't call that better btw if basic operations are the same.
All added parts on bottom side pcb except the 4 bootstrapsnubbers (4 caps and 4 resistors) so all other capacitors are filtering/decoupling DC, they follow edge of DC positive trace crossing the board to other side, 28 smd ceramic caps do that there, all are between positive DC and ground. Near tpachip there are 2 ceramics on each side to decouple, total capacitance of these 32 smd ceramics is ~25uF.
Forgot to mention this earlier 🙂
All added parts on bottom side pcb except the 4 bootstrapsnubbers (4 caps and 4 resistors) so all other capacitors are filtering/decoupling DC, they follow edge of DC positive trace crossing the board to other side, 28 smd ceramic caps do that there, all are between positive DC and ground. Near tpachip there are 2 ceramics on each side to decouple, total capacitance of these 32 smd ceramics is ~25uF.
Forgot to mention this earlier 🙂
Chris, im going to switch the connections and see if that helps. It looks like the Edcor is assemetrical, but i could be wrong. Each ch is +,-, plus center tab is 3 wires. So that is 6 total from amp to Edcor. From Edcor it goes to audio source, which in this case my computer. But ill reverse the Edcor, and post the results.
Also maybe try amp to Edcor with no enter wire - i.e. just + and - inputs to pins 5 and 7 respectively as an alternate way of connecting. Pins 1 and 3 being the input.
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Thanks everyone for the informative thread... I've decided to get the iron out in this little YJ blue board. Have gone for the oscon dc power caps from mouser uk.
Also ordering the .22uf x7r's for the topside bootstrap capacitors...
BUT I also want to do the bootstrap snub mod on the underside of the board but my confidence and eyesight is going and I hear you have to scape off varnish to find the ground... is this really an easy mod for me? I'm slightly concerned, can someone explain where exactly you would 'scrape' and then does one simply drop solder on the resistor to the underside of the board?
And if anyones feeling generous with their time could you point me in the right place on Mouser Electronics - Electronic Components Distributor for the capacitors and resistors for the bootstrap snubber mod...
stu
Also ordering the .22uf x7r's for the topside bootstrap capacitors...
BUT I also want to do the bootstrap snub mod on the underside of the board but my confidence and eyesight is going and I hear you have to scape off varnish to find the ground... is this really an easy mod for me? I'm slightly concerned, can someone explain where exactly you would 'scrape' and then does one simply drop solder on the resistor to the underside of the board?
And if anyones feeling generous with their time could you point me in the right place on Mouser Electronics - Electronic Components Distributor for the capacitors and resistors for the bootstrap snubber mod...
stu
I re-looked at the chip schematic. I had the pins 4-5 & 10-11 reversed from amp in relation to the Edcor. So after i fixed that I knew I had resolved the problem. Immediately it sounded better which would be expected, but the volume loss was still the same 🙁 So I removed the center tab connection from Edcor coming from Amp. And waaalaaa, presto! that was the issue, but I dont know why. So now I was anxious to listen to a few tracks and test by switching from source to edcor then from source to amp. I can now say the detail is better, more accurate and its slighly more musical. Its not a night and day difference but its an upgrade that can be noticed. If i were to quantify in terms of %. Its from 20% on the low to as high as 30% depending on the type of music. The 30% would be with music that has alot different kinds of percussion. 20% would be in accuracy and musically. Perhaps it will even get better as it gets burned in. If you listen to heavy metal or similar, I dont think the Edcor would help much. But Jazz, classical, Orchestra, Blues, etc more complex types of music, it might be worth looking into. I dont have a center tab connection from my laptop as its plastic to the Edcor. But I did have a center tab from the amp to the Edcor. I wonder if I had a cd player with a metal chassis that I could hook up to that, then to the Edcor input side, I wonder if that would cancel out the db loss, and improve the audio performance even more. I dunno----Thanks Chris and also to KJA2013 who was helpful. Im listening to it right now as I edit this post, and it brings a pleasant smile. But now it makes me wonder more then ever. How will the Cinemags compare now ......hmmmmmm
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Most of the area on the underside around where the mod is done is the ground-plane so you can scratch away the varnish wherever your components are best placed. Yes, just scratch away a small "pad", try to make it as clean of varnish as possible, and apply some solder. This really is one of the easiest mods to do as well as cheap and very worthwhile.
Good luck