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Another B4 Thread

I take it that " heaps ! -3db/3Hz " is acceptable. The bass response of my speakers is very good indeed. This is one area where my Nj MiniMotherboard excells.
 
Under most circumstances, the ear has almost no response below 20Hz; very loud organ pipes at 16Hz are more felt than heard.

When people talk about good bass from speakers, they are usually talking about 40 vs 50 vs 60Hz; not many domestic size systems offer much output at 30Hz, let alone far below that.

-3dB at 3Hz means that even by 16Hz the B4 response will be absolutely dead flat.
 
SteveH said:
I am using it with a NAP250 and it sounds absolutely fantastic.

Cheers,
Steve
Click to expand...

I'm sure this topic has been done to death elsewhere, but how does one determine if the B4 is compatible with the amp one is using? To my ears the B4 sounds better into a 250 than, say, a Dynavector HX1.2 but don't know whether that has anything to do with an (technical/electrical) incompatibility issue or not.
 
stackowax said:
I'm sure this topic has been done to death elsewhere, but how does one determine if the B4 is compatible with the amp one is using? To my ears the B4 sounds better into a 250 than, say, a Dynavector HX1.2 but don't know whether that has anything to do with an (technical/electrical) incompatibility issue or not.
Click to expand...

I reckon the B4 will drive pretty well any power amp out there, and over a long cable run if necessary. The key issue is that it doesn't have any gain, so you need a source with sufficient output voltage. That means that most dacs (and other digital sources really) will be fine, but you'll likely need a line stage with gain for a tape or tuner output and a phono stage (and possibly a line stage as well) for records.

Mike
 
I would be very surprised if it was technical/electrical issue. The B4 should happily drive all sorts of power amps; it doesn't mind load impedance over a very range, and should shrug off all sorts of wacky cables.

I suppose the one exception would be a power amp with very low gain, that needed a big signal to drive to full power - clearly a buffer with no gain won't generate that signal. I can only think of about one design like this - one of the First Watt designs is a power buffer, with unity voltage gain, and needs a preamp that can generate about 20V!


But there may well be issues of overall system voicing; you can't simply say that one component is "better", rather that it "works better in this system context".
 
Yes i am sure that this topic has been covered many times. I take a view on it like this,
This great forum of ours is full of people with all abilities, that may be complete novice to a first rate electronics wizard. We all share the same passion ( obsession) for all things audio.
What suits one person may well not suit another and vice verse . When you build your own bits of kit, you are ultimately going to be able to fine tune for what ever sound you wish. This is where a great forum comes into its own, being able to bounce ideas around to get the results that you require.

Cheers Keith

Rs just delivered lots of stuff for the build. Time to get busy.
 
Just realised that some of my Welwyn resistors are 0.75watt. Can i use these or have they got to be 0.25 watt. Tried some in the board and some sizes fit but others will not go through the holes due to the diameter being just to big. RS don't stock most of the 0.25 welwyn types, but got all sizes in the Vishay 0.4 watt 1% types. Thanks Keith
 
The better resistors will only be of benefit if in the signal path...those are the ones where the Welwyns fit...and no problem at all being overrated for the job either.
 
Cheers Neil. So what are the signal path ones that really matter. In position R9,11,109,111 i can only get 2.67k or 2.74k welwyn RC55, will any of these be ok here. Keith
 
I haven't measured its power consumption but it has been covered before in one othe B4 threads... a 10-12 VA trafo would be ample - anything bigger is just pandering to your ego.
 
Thanks Neil. I just wanted to power it up to see if all was well. I have 2 spare power supplies
1 that a can trim the voltage between 12 and 14 volts , with approx 750mA
1 @ 12V x 2A supply.

Keith
 
Both should work for testing it out, might be a little on the low voltage side for best results if using the on board regulators. I set my on board regs for +/- 15v....so use a supply at +/- 22v to give them room to work. But the circuit should work quite happily on +/-9v
 
It draws about 10mA / channel, say 20mA in total. Almost all mains supplies of suitable voltage will be able to run it.

9V "transistor radio" batteries would do at a pinch; they should last about 24hours of running.
 
Powered the board up just a few minutes ago. Using a 14V supply, all seems well. All the Led's light up , so looks like i can check all the voltages at the points given by PD.
PD " would i be better waiting until i finished my 24V supply before doing the diagnostics".

Keith
 
No, you should be able to check that it is working either way.

Why wait!

If the voltages look sane, plug in, turn on, put favourite recording on, listen.

Best of luck.
 
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