Changes and Proposals to Board
I have now got the 100hrs up on the board so I have taken the opportunity to add some capacitance at the chip, a pair of 470uf/35V ESR caps soldered under the chip, (see pics) and a pair of 1000uf caps in tandem with the std ones on the top of the board. At this point I would say there is some additional tightness to the bass and better attack on notes, not a huge change but worthwhile. Time to let it run for another 15 hrs or so till the coils are added.
I am planning taking power right to the star point between the chips and the earth to the point marked on the pic. I feel the board layout is a bit of a mess and there must be return paths running all over the place in less than ideal arrangements.
I will run a separate power lead to the 5v reg so it is not passing through the board traces, this will come later.
Basically trying one thing at a time to see the results of each step, if any.
I have now got the 100hrs up on the board so I have taken the opportunity to add some capacitance at the chip, a pair of 470uf/35V ESR caps soldered under the chip, (see pics) and a pair of 1000uf caps in tandem with the std ones on the top of the board. At this point I would say there is some additional tightness to the bass and better attack on notes, not a huge change but worthwhile. Time to let it run for another 15 hrs or so till the coils are added.
I am planning taking power right to the star point between the chips and the earth to the point marked on the pic. I feel the board layout is a bit of a mess and there must be return paths running all over the place in less than ideal arrangements.
I will run a separate power lead to the 5v reg so it is not passing through the board traces, this will come later.
Basically trying one thing at a time to see the results of each step, if any.
Attachments
Suntan, interesting brand of capacitor.
It's most probably Chinese and not the common English word.
Regarding the heat, the datasheet says the quiescent current of a TP2050 is 125mA @ 28V which is pretty close to what Scott has measured (300mA for the whole amp). Assuming all that is turned into heat the datasheet numbers would mean 3.5W per TP2050, which is actually quite okay to run without a heatsink. Maybe it does not feel hot because the packaging is not made of metal.
For me, I don't like anything running over 50 degrees, call me over-cautious. So a heatsink meant for motherboard northbridge chipsets later and I'm still complaining.
On second thoughts: 3.5W might be a bit too hot for a package that small. kristleifur, possible to measure the temperature of the TP2050?
It's most probably Chinese and not the common English word.
Regarding the heat, the datasheet says the quiescent current of a TP2050 is 125mA @ 28V which is pretty close to what Scott has measured (300mA for the whole amp). Assuming all that is turned into heat the datasheet numbers would mean 3.5W per TP2050, which is actually quite okay to run without a heatsink. Maybe it does not feel hot because the packaging is not made of metal.
For me, I don't like anything running over 50 degrees, call me over-cautious. So a heatsink meant for motherboard northbridge chipsets later and I'm still complaining.
On second thoughts: 3.5W might be a bit too hot for a package that small. kristleifur, possible to measure the temperature of the TP2050?
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PSU and input caps...
Hi,
First I putted 3.2uF Philips MKT caps and 18k resistor. I was not happy with this combination. Yesterday I putted 2.2uF Wima 100v MKS4 caps and 20k resistor. It is much better combination for my system and ears. I am using Monitor Audio RS6i (89db speakers 6Ohm and FE127E diy).
Also simple PSU with two 18000uF caps is better than switching PSU. I am waiting 10uF couls to arive. Then I will continue with mods. Actualy I am very happy with results of just changing input filter.
Great board and sound. I putted in box with volume pot and PSU is in external box. I will probably put biger but passive heatsink. I dont like moving parts in amp :-(
Best regards
Hi,
First I putted 3.2uF Philips MKT caps and 18k resistor. I was not happy with this combination. Yesterday I putted 2.2uF Wima 100v MKS4 caps and 20k resistor. It is much better combination for my system and ears. I am using Monitor Audio RS6i (89db speakers 6Ohm and FE127E diy).
Also simple PSU with two 18000uF caps is better than switching PSU. I am waiting 10uF couls to arive. Then I will continue with mods. Actualy I am very happy with results of just changing input filter.
Great board and sound. I putted in box with volume pot and PSU is in external box. I will probably put biger but passive heatsink. I dont like moving parts in amp :-(
Best regards
I really should measure. I don't have any kind of usable thermometer :/ Hm ... There are some tech guys in the building, I'll check if they have a meter.
The finger test says around 50-60. When touched, it's not immediately apparent that the chip is HOT, but it does get very uncomfortable after 1-2 seconds.
Well said
I'm surprised that your heatsink is loose. All of mine (earlier, pre-fan boards) have the heatsinks glued to the chips with heat conducting glue. Perhaps you got a defective board that is missing the glue? Even if they have done away with the glue and are using paste instead, the paste should damp out vibrations. Puzzling. Let us know what you discover when you take off the heatsink.
-dr_vega
Hi DV, I took the heatsink off this morning it just clips out, there was paste under the sink, but I added a little more. I tied some copper wire around the nylon clip on the underside of the board and increased the pressure a bit but have not tested it for fan noise/vibration though I have since ran the amp for another 8 hrs. It has 108 hrs on it now.
At this point I would say the amp is very smooth and nicely balanced, there is still some micro grain in the mids which I suspect will disappear once the coils are added. There is certainly no issue with resolution, quite superb in that area.
I have star wired the power supply this evening and will fire it up before I go to bed to check. Currently have one of the Helder 2020 mk 3s burning in, actually it sounded sweet from the first minute!
I won't split off the 5v regulator supply till I have fully tested the current set-up. I expect there may well be some gains to be made there, possibly a pre-regulator down to say 7.5v and remote cap bank could help.
At this point I would say the amp is very smooth and nicely balanced, there is still some micro grain in the mids which I suspect will disappear once the coils are added. There is certainly no issue with resolution, quite superb in that area.
I have star wired the power supply this evening and will fire it up before I go to bed to check. Currently have one of the Helder 2020 mk 3s burning in, actually it sounded sweet from the first minute!
I won't split off the 5v regulator supply till I have fully tested the current set-up. I expect there may well be some gains to be made there, possibly a pre-regulator down to say 7.5v and remote cap bank could help.
Paste
The third version heatsinks are assembled with the superior heat paste instead of the rubber glue. I am going to measure the temp with the fan disconnected. The new heatsink is actually pretty large.
The third version heatsinks are assembled with the superior heat paste instead of the rubber glue. I am going to measure the temp with the fan disconnected. The new heatsink is actually pretty large.
The heat sink never gets even warm with the fan on, I have not tried it with the fan disconnected but I doubt it would get hot unless pushed at higher V. Be interesting to see however just what sort of temps are involved, I suspect Sure may have over-compensated a bit because of the problems with the early boards.
Thanks wwenze for the tip on the paste.
Thanks wwenze for the tip on the paste.
Well, I can report that the fan noise is quite terrible (later blue fans) and is now totally gone. The problem here was running two boards off the one PSU. Disconnecting one amp made the other amp's fan noise silent, reconnecting the fan noise restarted. Now have two PSUs and all fan noise has gone. Also the rating and make of PSUs had nothing to do with this, seems to be some earth loop problem. Hope this helps some of you out.
Hi Scott, not forgotten your recommendation for these, but they are still out of stock over here:
WUERTH ELEKTRONIK|7447709004|CHOKE, SMD, 4.7UH | Farnell United Kingdom
On the fan and heat. I tried running the amp sans fan but the heat builds up after about 10 mins, certainly not very hot however in the interests of having a long living amp I feel the fan should be retained or a really large heatsink used.
I have now powered the 5V through a separate cable still from the same battery, interestingly it does seem to make a change to the bass, a bit tighter and fuller, I must say though I have no idea why and did not expect it to do this, overall it just seems a little more dynamic.
I feel the amp would probably benefit from a ground plane below the board, this I feel will lower noise. I have a Helder 2020 mounted on a copper ground plane it is utterly dead quite, no hiss or anything else, I know from experience with other amps and dacs that a close coupled ground plane has benefits so that is what I will do next.
Still no coils added, I want to square everything else away first.
I have now powered the 5V through a separate cable still from the same battery, interestingly it does seem to make a change to the bass, a bit tighter and fuller, I must say though I have no idea why and did not expect it to do this, overall it just seems a little more dynamic.
I feel the amp would probably benefit from a ground plane below the board, this I feel will lower noise. I have a Helder 2020 mounted on a copper ground plane it is utterly dead quite, no hiss or anything else, I know from experience with other amps and dacs that a close coupled ground plane has benefits so that is what I will do next.
Still no coils added, I want to square everything else away first.
Dr Vega,
Would you mind posting a picture of your air-core inductors with paper and tin foil shields? In fact any pics of your amp would be cool. Also, bypassing the PIOs with the Daytons means you are running them in parallel?
Regards,
Free
hi
Thanks guys.
Im novice just trying to learn a bit from this excellent forum.
Yes i did try stopping fun but there is no difference.
I just got the board and using 12v power supply from my tripath.Still looking for power supply.
And also with modes ,i have that updated version so called.
Should i do some changes ?.
There were lots of photos at the beginning of the forum but most of it don't work anymore.
thanks
Thanks guys.
Im novice just trying to learn a bit from this excellent forum.
Yes i did try stopping fun but there is no difference.
I just got the board and using 12v power supply from my tripath.Still looking for power supply.
And also with modes ,i have that updated version so called.
Should i do some changes ?.
There were lots of photos at the beginning of the forum but most of it don't work anymore.
thanks
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