DRV 134
Hii Alex
Why not make drv 134 pcb too for all of us
Lets make a group buys again
make the first order from now - end of june
your pcb looks cool 😎
Give us the tools and we finish the Job
Hii Alex
Why not make drv 134 pcb too for all of us
Lets make a group buys again
make the first order from now - end of june
your pcb looks cool 😎
Give us the tools and we finish the Job
drv 134
hii alex
can you help me to buy drv 134 board alex
because i dont understand the letter 😀
or you will make this board yourself ?
so we can buy again from you
we believe 100% your design
waiting for answer
hii alex
can you help me to buy drv 134 board alex
because i dont understand the letter 😀
or you will make this board yourself ?
so we can buy again from you
we believe 100% your design
waiting for answer
I think the DRV134 is a bit old so not many stores are selling them.
Try RS online : http://www.rs-components.com/full.html
I found they have DRV134 at the HK site and their "Global Export" site under North America.
If you can't find DRV134, consider the newer (and improved) line drivers : THS4131, OPA1632, AD8138.
Or, build the balanced line driver with 2 opamps. ( http://sound.westhost.com/project51.htm )
Another option would be using transformers.
Try RS online : http://www.rs-components.com/full.html
I found they have DRV134 at the HK site and their "Global Export" site under North America.
If you can't find DRV134, consider the newer (and improved) line drivers : THS4131, OPA1632, AD8138.
Or, build the balanced line driver with 2 opamps. ( http://sound.westhost.com/project51.htm )
Another option would be using transformers.
If you are interested in OPA1632, please also have a look at the datasheet of ths4131, it has more information on how to use the chip.
e.g. Figure 38 of ths4131 datasheet is an example of a non-balanced input to balanced output circuit.
e.g. Figure 38 of ths4131 datasheet is an example of a non-balanced input to balanced output circuit.
ths4131 driver
alex, i have read the stats on the ths4131 and cmrr is approaching that of a good transformer. do you believe that rod elliots twin op amp design is much better than the standard drv setup using the 4131 chip. using the twin setup and driving each leg separate would make sense. thanks
alex, i have read the stats on the ths4131 and cmrr is approaching that of a good transformer. do you believe that rod elliots twin op amp design is much better than the standard drv setup using the 4131 chip. using the twin setup and driving each leg separate would make sense. thanks
alex, why did you choose the .2 ohm output resistor instead of .1 ohm. is the extra resistance necessary which it also robs voltage from speakers. i have just placed an order to farnell and was wondering about this. also, before i start soldering parts are there any last minute changes you would have made which i could incorporate in my build. thanks
I just learn from another forum
(http://av-forums.net/plus/viewthread.php?tid=27503&page=13&extra=page=1###)
that differential opamps like opa1632 or ths4131 themselves have low input impedence and needed to be driven by a low output impedence source. Otherwise you will get current noise. So you need to use a standard opamp to buffer the input first if your preamp is passive.
I used 0.2 ohm because I want to reduce current flow between chips. Note that Jeff Rowland used 0.5 ohm and 0.2 ohm in their amps.
(http://av-forums.net/plus/viewthread.php?tid=27503&page=13&extra=page=1###)
that differential opamps like opa1632 or ths4131 themselves have low input impedence and needed to be driven by a low output impedence source. Otherwise you will get current noise. So you need to use a standard opamp to buffer the input first if your preamp is passive.
I used 0.2 ohm because I want to reduce current flow between chips. Note that Jeff Rowland used 0.5 ohm and 0.2 ohm in their amps.
I get envious every time I see those pictures. Soon enough I shall have a similar amp of my own. BTW, I think I've decided to use the OPA1632. Maybe some others want to get in on a group buy of the boards. I'll do the layout.
that mean you are going to design a useable driver with this chip. make the boards as good as alex88 and i want some. have you noticed the neat bridges jrdg uses to transfer the output power in there amps. nice thick elevated copper covered in epoxy. nice!! if you can machine out about 75 pounds of solid aluminum for the case we could have some amps like that. otherwise 8000 dollars u.s. i am going to build my own thanks to alex boards. have fun
Haha, I am absolutely not planning on using that much aluminum in my amp. I'm doing 2 channels + seperate dual power supply using 1/4" aluminum. I have some access to a machine shop but let's not talk crazy now.
I planned on following the OPA1632 datasheet exactly. If you want in, it would be cheaper for me to order more. Any extra ideas are welcome. I will start another thread if interest continues.
I planned on following the OPA1632 datasheet exactly. If you want in, it would be cheaper for me to order more. Any extra ideas are welcome. I will start another thread if interest continues.
alexw88 said:
"Differential input sources must have well-balanced or low-source impedance." - OPA1632 datasheet p6
This isn't a problem for me but I can see why it would be nice to have additional buffering. Two opamp then, right?
1 opamp if you want to use it with single-ended input only.
2 opamps if you want to use it with balanced input as well as single ended input. I think this option has more flexibility.
I have thought of IF I would built it (ok, I won't), I will build a 3-section board that can be cut into 3 pieces and be able to use them seperately.
The 3 sections are : voltage regulation, dual opamps buffer, differential opamp line driver.
This way I can reuse these 3 modules for different applications, e.g. preamp, DAC, etc. Also this saves PCB setup cost.
2 opamps if you want to use it with balanced input as well as single ended input. I think this option has more flexibility.
I have thought of IF I would built it (ok, I won't), I will build a 3-section board that can be cut into 3 pieces and be able to use them seperately.
The 3 sections are : voltage regulation, dual opamps buffer, differential opamp line driver.
This way I can reuse these 3 modules for different applications, e.g. preamp, DAC, etc. Also this saves PCB setup cost.
haha, Thanks for the idea. That is a good one. I was thinking the same thing. I was planning on a separate +/-15V regulator board but why bother if I'm using it for here only. BTW, I was going to use my mains 25VAC and regulate down to the +/-15V with a separate diode bridge. It should be no more than a small heatsink's worth of heat for just this circuit, right?
Regulate 25VAC down to 15VAC should be ok, that's what I am doing in my amp. There is not much heat since the current is small.
new thread started for discussion of driver chips
http://www.diyaudio.com/forums/showthread.php?s=&threadid=104608
http://www.diyaudio.com/forums/showthread.php?s=&threadid=104608
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