They sound amazingly good, when you get one that works! Item Audio swapped out my first board . . . they're really PSU-sensitive (as you might expect). You'll probably experience a transformation when you can slot in a better power supply
I don't have one of these boards but looking at the diagram I see 100k resistors to ground after the input caps. This will give dc through the amp..
And no input caps via input blocks..
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.
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.
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
post 69: is input 2 connected to the correct end of Rf?
post 69: is input 2 connected to the correct end of Rf?
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? ...
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.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?
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.