If the output traces/cable from the LED/LDR attenuator have very low capacitance and the RF filters on the paralleled inputs of the power amps are designed to suit the LDR output impedance, then you won't have any problem feeding the paralleled inputs.
It's the high capacitance after the LDR output impedance that causes the problem of loss of treble content. This can be solved by adding a Buffer after the LDR to feed the cables and higher capacitance loading.
It's the high capacitance after the LDR output impedance that causes the problem of loss of treble content. This can be solved by adding a Buffer after the LDR to feed the cables and higher capacitance loading.
Changing input impedance of the amp to 50K will increase DC offset, depending on chips you have, it may be still fine, or the offset may become excessive. More info on the issue here: http://www.diyaudio.com/forums/audi...-kit-building-instructions-5.html#post1524877
Many thanks peter, I really do have loads of options then, chassis has arrived so I will report back when ive got a working amp.
Cheers Andrew, if I get right into the build I have a lot of choices, Ive ordered a transformer for my buffer so I should have everything I need to create something decent.
Many thanks Peter, I have a case I was going to use for a pre a long time ago, same range so they match up, theres no real room to include heat sinks for the DCB1 and i am going to run it hot!
![URL]](/community/proxy.php?image=http%3A%2F%2F%5BURL%3Dhttp%3A%2F%2Fs741.photobucket.com%2Fuser%2FDawgno1%2Fmedia%2FGC%2F20151218_153010.jpg.html%5D%5BIMGDEAD%5Dhttps%3A%2F%2Fi741.photobucket.com%2Falbums%2Fxx59%2FDawgno1%2FGC%2Fth_20151218_153010.jpg%5B%2FIMGDEAD%5D%5B%2FURL%5D&hash=b47dee21e7ddc8d4156d4290a0c42b91)
Right Im off line till tomorrow, off to wembly arena, thanks for the advice again!
First of all Happy New Year!
Now my question:
I intend to make LM3875 for 2 small PC desktop speakers uFonken.
I had decided to make the stereo version, would it be better to make 2 mono versions or would it be too much for these small speakers? Would it sound better with 2 mono amps?
Thank you!
Now my question:
I intend to make LM3875 for 2 small PC desktop speakers uFonken.
I had decided to make the stereo version, would it be better to make 2 mono versions or would it be too much for these small speakers? Would it sound better with 2 mono amps?
Thank you!
Thank you for replies!
I think that I will build the stereo amp, to avoid the extra weight and box needed for only a small improvement.
Now trying to select the components, I would like to ask about the potentiometer, a 25k or 50k is suggested, it seems that I will buy an ALPS blue velvet, because I can find them at a dealer in Greece. Values to choose from are 20k or 50k. Should I select 50k? Any other suggestion?
And about the cables, what kind of cables should I choose for the internal wiring?
Thank you!
I think that I will build the stereo amp, to avoid the extra weight and box needed for only a small improvement.
Now trying to select the components, I would like to ask about the potentiometer, a 25k or 50k is suggested, it seems that I will buy an ALPS blue velvet, because I can find them at a dealer in Greece. Values to choose from are 20k or 50k. Should I select 50k? Any other suggestion?
And about the cables, what kind of cables should I choose for the internal wiring?
Thank you!
select based on compatibility with your equipment.
We can't guess at what you have.
It would be nice if all your future equipment would be compatible with what you choose.
The vol pot is a Receiver that your Source/s see. It must work as a Receiver.
The vol pot is a the Source to whatever comes next. It must work as a Source.
You have to make BOTH functions, Source and Receiver, work by selecting a compromise value that works.
)
I'd go with 20K pot. As to wiring, you'll find info here: http://www.diyaudio.com/forums/audi...-kit-building-instructions-2.html#post1514854
im thinking on making another one of these but was wondering if a single 200va 22-0-22 transformer would be enough for a stereo set up. i hear they are rated for 50hz so supposedly it would make more?
im thinking this antek -2222 (22v output)
AN-2222 - 200VA 22V Transformer - AnTek Products Corp
or would a higher volt out like the antek 2225 (25v output) be better?
AN-2225 - 200VA 25V Transformer - AnTek Products Corp
my first one was made with a 300va 22-0-22 i think.
im thinking this antek -2222 (22v output)
AN-2222 - 200VA 22V Transformer - AnTek Products Corp
or would a higher volt out like the antek 2225 (25v output) be better?
AN-2225 - 200VA 25V Transformer - AnTek Products Corp
my first one was made with a 300va 22-0-22 i think.
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