Sure Electronics New Tripath Board 4*100W class-D Amplifier Board

[pheonix358]

Originally Posted by audio1st

Hi Terry,

If you think of it as an amp with a +/- 2.5Vdc supply. GND is connected to the -2.5Vdc supply. The actual 0V point is the bias cap pin. That is why you must use an input cap (dc blocker), after any input connection to GND.

The 100k resistor is not the main problem, Sure may have been able to dial out the dc from this with the trimmers?

The main problem would be shorting the terminal block inputs to GND with say a pot. If you use the rca inputs, then there should not be a problem..

Barry.

Thanks Barry, that is good to know. I was using the block inputs with a pot. Next board I would like to add more input caps, I was thinking of high grade 2.2uF, any thoughts! Should those with the current boards make any mods. Obviously from what you have said, they should add input caps if using the terminals and this is easy by just hanging them off the terminal blocks.

Once again, thanks. These are great, easy to use boards with a great form factor. They sound good and are very quiet.

Terry

[AndrewT]

post 69: is input 2 connected to the correct end of Rf?

[audio1st]

Originally Posted by obsoletemac

So, should R6,R7,R8 and R9 be removed even when using the RCA-connectors? (They seems to be located under the heat sink)

//Christian

Hi Christian,
It depends on how much dc you have at the speaker terminals.. If the dc offset has been adjusted with those resistors in place and you remove them, you may then have worse dc offset.
The dc offset trimmers I think are under the heatsink, so to re-adjust them the heatsink would have to be off. I don't know if the chips could cope with that?

If you can measure the dc offset please let use know the figures.

Barry..

[Lostcause]

Originally Posted by AndrewT

post 69: is input 2 connected to the correct end of Rf?

No... looks like the image was mirrored but not the opamp.....

[audio1st]

Originally Posted by AndrewT

post 69: is input 2 connected to the correct end of Rf?

You are probably right Andrew, but it is taken straight from the Tripath App sheet..
Input 2, Ri should connect to INV2..

[esangenisd]

My 2 cents about Tripath Board 4*100W class-D ver 1.1

This is the equipment.
Wallwart Switching PSU 24 Volts at 26 Volts.
Tripath Board 4*100W with a 12 volts fan running at 5 volts on top
B&W 685 BI AMPLIFIED
DIY Lightspeed Passive Attenuator
PC nforce 2 windows xp analog ouputs, ASIO driver , playing Mp3 and flac.

This amp Sounds really clear, and with great soundstage, crystal clear compare to my yamaha HT 5.1 receiver. The only thing I don´nt like, is that the tweeters sound a little hard, and the music sound to technical. MI think that a Gain Buffer (tube or discrete) after the attenuator will help. Any opinions? ...

[sendler]

Originally Posted by esangenisd

My 2 cents about Tripath Board 4*100W class-D ver 1.1

This is the equipment.
Wallwart Switching PSU 24 Volts at 26 Volts.
Tripath Board 4*100W with a 12 volts fan running at 5 volts on top
B&W 685 BI AMPLIFIED
DIY Lightspeed Passive Attenuator
PC nforce 2 windows xp analog ouputs, ASIO driver , playing Mp3 and flac.

This amp Sounds really clear, and with great soundstage, crystal clear compare to my yamaha HT 5.1 receiver. The only thing I don´nt like, is that the tweeters sound a little hard, and the music sound to technical. MI think that a Gain Buffer (tube or discrete) after the attenuator will help. Any opinions? ...

How long are the cables after the pre? Passive volume controls don't like much cable after them. I use none with my attenuators plugged right into the amps inputs.

[esangenisd]

I was running a feet long cable,now I change to a 3 inch long and there is a very hi difference in noise without source, almost disapear. I think the bass improve a little bit also. Next plan to solder to the amp. thanx a lot, any other idea?

[sendler]

Originally Posted by esangenisd

I was running a feet long cable,now I change to a 3 inch long and there is a very hi difference in noise without source, almost disapear. I think the bass improve a little bit also. Next plan to solder to the amp. thanx a lot, any other idea?

All of the mods from the 2X100 will apply to your board though your coils are already a bit better than what the 2X100 comes with.
Sure Electronics New Tripath Board tc2000+tp2050

[curveship]

Originally Posted by audio1st

Both problems have now been addressed.

From Sure:
Thank you so much for your mail.

We have introduced your design in the development of this amplifier board. We have removed R6,R7,R8 and R9 and replaced R12,R13,R16 and R17 with monolithic capacitors so that there will be more space.

We are grateful for your support.

I just got one of the updated boards. Not happy. The changes to my board were clearly made after the original fabrication and done very sloppily. Flux all over, sloppy solder joints, two cold joints, one lead bent over until it touches the one next to it. Yuck ...

Worse, though, is that the capacitors used to replace R12,13,16,17 are tiny little monolithic ceramics. Not the kind of thing you want to see in the signal path. They're under the daughterboard, so there's no space for anything bigger and no way to get to them to replace. Ugh