Some compatriots of mine are working hard to mod this board.
In particular, the output stage implemented by Sure differs from the one suggested by Tripath in the related datasheets, therefore Barone Rosso decided to build the original one. Have a look at these pictures, the original thread (in Italian) is here. Google Translator might help some of you...
http://t-class.niceboard.net/ta-202...electronics-tk2050-le-modifiche-t3113-225.htm
In particular, the output stage implemented by Sure differs from the one suggested by Tripath in the related datasheets, therefore Barone Rosso decided to build the original one. Have a look at these pictures, the original thread (in Italian) is here. Google Translator might help some of you...
http://t-class.niceboard.net/ta-202...electronics-tk2050-le-modifiche-t3113-225.htm
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.
An externally hosted image should be here but it was not working when we last tested it.
Please a question.In the pdf Sure shows a Meanwell power supply with the amp ground going to -V.
Is the Meanwell power supply a single sided supply or has it positive and negative outputs?
Should the amp ground be going to the single ground terminal?
I was sent an incorrect 2 pin plug with my power supply.I assume therefore that the supply is double insulated and does not require an earth?
I'm sorry for these seemingly basic questions but I do not want to kill myself or my amp.
The Sure pdf seems wrong to me.
thanks
Paul
Is the Meanwell power supply a single sided supply or has it positive and negative outputs?
Should the amp ground be going to the single ground terminal?
I was sent an incorrect 2 pin plug with my power supply.I assume therefore that the supply is double insulated and does not require an earth?
I'm sorry for these seemingly basic questions but I do not want to kill myself or my amp.
The Sure pdf seems wrong to me.
thanks
Paul
If you are using the Meanwell power supply then COM connects to Gnd on board and +V connects to VCC on board.
The power supply case should also be earthed. Do not earth the COM terminal.
Anyone adding input caps before the board and bridging C16 & C24 as in the picture from the Italian site, must remove R14 & R34, high DC on the output will result if you don't.
Also the bass roll-off is dependent on Gain settings, more Gain = more bass roll-off.
The power supply case should also be earthed. Do not earth the COM terminal.
Anyone adding input caps before the board and bridging C16 & C24 as in the picture from the Italian site, must remove R14 & R34, high DC on the output will result if you don't.
Also the bass roll-off is dependent on Gain settings, more Gain = more bass roll-off.
col said:
On the low setting I could hear no hiss, will test again when the replacement arrives.
In the meatime I'm building a mono PA300 for this cabinet, old school class AB with 2 x MJ15004 and 2 x MJ15003.
From experience I know that the PA300 can withstand the abuse of a screaming guitar
Cost is a bit higher however, paid already 20 Euro for only the output transistors...
The speakers in the cabinet are:
2 x Celestion Vintage 30 Guitar Speaker (12 Inch, 60 Watts, 8 Ohms / 100dB)
Spec's:
http://professional.celestion.com/guitar/products/classic/detail.asp?ID=4
With the PA300 I just wire them in parralel to the output, with the Sure board each channel had it's own speaker.
2 x Celestion Vintage 30 Guitar Speaker (12 Inch, 60 Watts, 8 Ohms / 100dB)
Spec's:
http://professional.celestion.com/guitar/products/classic/detail.asp?ID=4
With the PA300 I just wire them in parralel to the output, with the Sure board each channel had it's own speaker.
Finally recieved a replacement for the faulty board and it works. Im not really happy with the sound. So what i read from this topic i need to remove C25 and C17 and replace C24 and C16 with 2.2uF capacitors? Also removing the "BJ 6CA" voltage limiters under the board improves the sound. Is that correct or am i going to do something wrong? Im a real noob with electronics and dont want to destroy my board, so im only planning on doing the easiest mods on it.
Cheers,
Lasse
Cheers,
Lasse
output stage
If the little plastic housings of the output inductors say "220", does that mean they are 22uH?
That would differ markedly from the 10uH sure put down in their schematic (and still from the 15uH as suggested in the datasheet schematic).
Also C33,36,47,50 seem to be .68uF and not .47uF (or .22)
Only C35,49 are .22uF, just as it says (datasheet gives .1)
I want to at least replace the output caps. But if I want to completely re-build the output stage as suggested by the datasheet I guess I have to replace the inductors, too.
Any recommendations on what inductors to use? Does size matter or proximity to the chip? Then SMD seems like a good choice.
Other choices?
If the little plastic housings of the output inductors say "220", does that mean they are 22uH?
That would differ markedly from the 10uH sure put down in their schematic (and still from the 15uH as suggested in the datasheet schematic).
Also C33,36,47,50 seem to be .68uF and not .47uF (or .22)
Only C35,49 are .22uF, just as it says (datasheet gives .1)
I want to at least replace the output caps. But if I want to completely re-build the output stage as suggested by the datasheet I guess I have to replace the inductors, too.
Any recommendations on what inductors to use? Does size matter or proximity to the chip? Then SMD seems like a good choice.
Other choices?
I would use shielded inductors like, http://www.vishay.com/company/press/releases/2005/050720inductors/
And keep in mind that Tripath is long gone, these chips might not be old stock but cheap chinese knock-offs. We all know about fake components coming from china, even metal film resistors turn out to be carbon ...
And keep in mind that Tripath is long gone, these chips might not be old stock but cheap chinese knock-offs. We all know about fake components coming from china, even metal film resistors turn out to be carbon ...
250mA @ 10uH doesn't sound enough
how about toroidal line chokes?
http://docs-europe.electrocomponents.com/webdocs/0241/0900766b80241d51.pdf
how about toroidal line chokes?
http://docs-europe.electrocomponents.com/webdocs/0241/0900766b80241d51.pdf
I mentioned them as example, I would check CoilCraft as well.
http://www.coilcraft.com/spt.cfm for example: SPT68H-183ML_
http://www.coilcraft.com/spt.cfm for example: SPT68H-183ML_
Missing Zobels
I don't think those are Zobel caps that are missing. My reading of the schematics says those are the HBR caps, High Frequency Bypass caps for VCC and GND to the chips. The Zobel caps and resisters are next to the missing HBR caps and are present.
The missing HBR caps should be .1uf 50V.
-Dr Vega
mravlcax said:
I don't think those are Zobel caps that are missing. My reading of the schematics says those are the HBR caps, High Frequency Bypass caps for VCC and GND to the chips. The Zobel caps and resisters are next to the missing HBR caps and are present.
The missing HBR caps should be .1uf 50V.
-Dr Vega
Re: Missing Zobels
My mistake. I mis-read the photographs. (My boards haven't arrived, yet.) Those are the Zobels that are missing.
Does anyone have recommendations for small film caps to use there (.47uF 50V)? I suppose polypropylene would be best, but they are large.
-Dr Vega
dr_vega said:
My mistake. I mis-read the photographs. (My boards haven't arrived, yet.) Those are the Zobels that are missing.
Does anyone have recommendations for small film caps to use there (.47uF 50V)? I suppose polypropylene would be best, but they are large.
-Dr Vega
Im a bit disappointed in the lows this amp produces. So im planning on changing the caps on the input, but im a total noobie in electronics. So if i remove the small smd on C25 and C17 and connect the new 2.2uF capacitor as shown in the picture on the right, will it work? Or do i have to connect the way it is shown on the left?
And how does it change the sound removing the voltage limiters on the other side of the board? Someone said it will "roll off the treble from 3.5khz", don't really understand what he meant by "roll off".
An externally hosted image should be here but it was not working when we last tested it.
And how does it change the sound removing the voltage limiters on the other side of the board? Someone said it will "roll off the treble from 3.5khz", don't really understand what he meant by "roll off".
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