Thanks again
I'll be building later in the spring, if I can get my hands on some samples. National won't send any to me, they just say that they are sorry. And it's difficult to get a hold of the 75's, the 86ers are easy to come by.
Well well
But i'm renovating my old Elektor PA300 to be put to work with my new sub.
So maybe later, but I can alwas do it all at the same time.
I'll be building later in the spring, if I can get my hands on some samples. National won't send any to me, they just say that they are sorry. And it's difficult to get a hold of the 75's, the 86ers are easy to come by.
Well well
But i'm renovating my old Elektor PA300 to be put to work with my new sub.
So maybe later, but I can alwas do it all at the same time.
national said i had to pay a premium for my samples because my email was not a corporate one, instead of using another email i just went ahead and paid the shipping. or whatever it is to get them. the price was still better than digikey or whatever.
they check the email to see if it is a public ISP and charge extra here in canada, possibly there sample program has a lot of request from your ISP and will no longer send there.
if you have a freind or can get an email which is different , re apply with that. I am pretty sure the sample program go by ISP and requests.
I hope they did not ban your whole country!! damn gainclone scroungers
they check the email to see if it is a public ISP and charge extra here in canada, possibly there sample program has a lot of request from your ISP and will no longer send there.
if you have a freind or can get an email which is different , re apply with that. I am pretty sure the sample program go by ISP and requests.
I hope they did not ban your whole country!! damn gainclone scroungers
Hey somebody' solen my picutures!
Well, I don't know where that has gone but I'll get it sorted today.
Peter, As that amp has only one PSU and some cheapo input caps, I have not done a direct comparison with my other IGC amps so I can't really say how the two circuits compare.
It is good enough to encourage me to build a pucca NIGC in the very near future though.
In fact, I have looked at your latest design and pencilled in several improvementsD ) already.
Well, I don't know where that has gone but I'll get it sorted today.
Peter, As that amp has only one PSU and some cheapo input caps, I have not done a direct comparison with my other IGC amps so I can't really say how the two circuits compare.
It is good enough to encourage me to build a pucca NIGC in the very near future though.
In fact, I have looked at your latest design and pencilled in several improvements
D ) already.
It's funny how many people tend to call me Fredde, Freddy or Filip
9.4 uF is certainly not too high! The original gaincard uses somewhere between 20uF and 100 uF. For standard electrolytic capacitors between 100 uF and 220 uF is quite common for decoupling. The distortion is said to be lower for such capacitors.
I've heard that larger capacitors obscure some detail. For LF response, anything above 2.2 uF will not make a big difference anymore...
Fedde
9.4 uF is certainly not too high! The original gaincard uses somewhere between 20uF and 100 uF. For standard electrolytic capacitors between 100 uF and 220 uF is quite common for decoupling. The distortion is said to be lower for such capacitors.
I've heard that larger capacitors obscure some detail. For LF response, anything above 2.2 uF will not make a big difference anymore...
Fedde
I was planning to make a gc but after looking at the output power vs. load resistance graph on the datasheet of the 3875 you can clearly see that it can't drive any loads below 5 ohm at any supply voltage! Too bad my speakers have a nominal impedance of 4 ohm.
Has anyone tried the GC with 4 ohm loads and how did it sound?
Maybe 2 3875's in parallel or a 3886 will do the trick?
Help please!!
I want my GC
Has anyone tried the GC with 4 ohm loads and how did it sound?
Maybe 2 3875's in parallel or a 3886 will do the trick?
Help please!!
I want my GC
Bozzz said:I was planning to make a gc but after looking at the output power vs. load resistance graph on the datasheet of the 3875 you can clearly see that it can't drive any loads below 5 ohm at any supply voltage! Too bad my speakers have a nominal impedance of 4 ohm.
Has anyone tried the GC with 4 ohm loads and how did it sound?
Maybe 2 3875's in parallel or a 3886 will do the trick?
Help please!!
I want my GC
You assume way too much from one graph. What if it's wrong? Data sheets are famous with that. Look at the next graph (bellow the one you are quoting) where it shows 4,6,8 Ohm load.
Some people report good results with 4 Ohms, but you have to use 18V-0-18VAC.
Greg
I've used my LM3875 GC using one 12-0-12 VAC 300VA toroid into my 4 ohm speakers and was pleasantly surprised at how well it performed. A LM1875 was just as useable. Makes me wonder why anyone needs amps of more than 40 or 50 watts.
I have tried the both of these GCs on a friend's really old and crappy speakers (details not known) and it required the LM3875 to drive them, so I guess its horses for courses.
I have tried the both of these GCs on a friend's really old and crappy speakers (details not known) and it required the LM3875 to drive them, so I guess its horses for courses.
Steve Eddy said:
Well Steve, I'm not completely sure, but chances are you made me start working on this
The CDP will have a footprint of approx 6.5" x 8.4". Basically the same as Amp-1. As far as I'm aware, nobody makes such a small, high end player. The TDA1543 DAC will be on board too.
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Here's another angle. The frame is made of 1" and 1.5" copper bars, hard suspention, separate PS (possibly battery operation). Brian Bell came up with control interface. Actually, such small design was possible thanks to his board.
I had a bigger design in mind initially, but working with small parts is much more satisfying.
I had a bigger design in mind initially, but working with small parts is much more satisfying.
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