Cardas binding posts thread

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#41
Re: Re: Re: Cardas binding posts thread

Peter Daniel said:


Yes😉
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looks great. I love the simplicity. Does the case get very warm?

How much extra space do you have in the front of your case? By the picture above of your wiring, it looks the chassis could be half the depth. Is this so?

I picked up some strange surplus heatsinks for $1 each that I am going to try to use for mine. I am visiting parents, and will start on mine next week when I get back. I picked up some NOS Allen Bradley resistors that I am considering using if I can match them closely enough. (I am going to stick them in a convection oven for a day at my girlfriend's work at 80 degrees Celsius before matching them as read from other's suggestions [tube people])

--
Brian
 
#43
JasonL said:
Sorry to inturupt Peter what is that.? In the pic..?
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It is a gainclone [amplifier built off National Semi's LM3875 or similar chips], here is the schematic:
An externally hosted image should be here but it was not working when we last tested it.


Peter did a few mods to this schematic, but this is the basic schematic.

Here is another page by Fedde with good info:
http://home.student.utwente.nl/f.s.bouwman/audio/thor-amp.html
and his construction page:
http://home.student.utwente.nl/f.s.bouwman/audio/diy-thor-amp.html

Here is the datasheet for the LM3875, you can get samples from National's page:
http://www.national.com/ds/LM/LM3875.pdf
Samples available off this page:
http://www.national.com/pf/LM/LM3875.html

The gainclone is a copy of the gaincard, which is made by these people here:
http://www.sakurasystems.com/products/47amp.html
It costs $3,000 with power supply, and the clone can be built for as low as $50, although I suspect that Peter's costs a bit more 😉

There is a chip amp bbs that is dedicated to amplifiers like this:
http://pub4.ezboard.com/ffakeidsfrm1

Sorry to clog this thread with this info. If there is much more interest, this should be moved to a new thread.

--
Brian
 
#45
JasonL said:
Id love to have peter's skills. : O ) i like that he is so neat and tidy. Peter what do you use this amp for. ? what is the power rating.
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He did a great job. I think he is getting 25W out of it. For comparison, here is a decent pic of the original chassis for the real gaincard:

I am wondering how Peter managed to have no visible screws on the chassis. This is quite a mystery.

--
Brian
 

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#48
By the way, Peter, I also use those knock-off Tiffany RCAs, and they seem to sound just fine.

Are there really no exotic XLR connectors out there? I mean, I'm sure the Neutriks are quite nice, but aren't there any alternatives? Or, does Neutrik actually make some really great XLRs? I'm not necessarily after "industry standard" here...
 
#49
So you guys don't read the thread about Black Gates. I posted the pics there as well as some comments about the amp. This amp is so good that I've already started building another one today. For the time and money invested you won't find better deal.😉

I'm getting 40W out of it. Brian, the case could be shorter, but it acts as a heatsing so the size is right. When I play full power, it is pretty warm. Also anything smaller would not be stable enough. Original Gain Card is 0.7 size of mine.

hifiZen, I used XLO balanced connections before, supposed to be more exotic, but I like Neutrik better. You can try Michael Percy for better selection.
 

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#50
peter...!

:cheerful: :cheerful: :cheerful: :cheerful: :cheerful: :cheerful:

peter, your fine work has inspired me ones more....
your gainclone made sleepless for severel nights - i want to build some monoblocks................!
6 monoblocks drivin' my big 3-way atc 100sl's could be interesting.

BUT :

where these amps really could do some good, is in a "active system" - how about that ?

what speakers are you using ?

best regards,
troels

😉 😉 😉 😉 😉 😉 😉 😉
 
#53
Here's the pic of the inside. My aim was to get the caps as close as possible to the IC pins. With a special mounting block it was possible. You see there a Wima cap (0.1u) parallel with 220k resistor connecting positive input to the ground. Eventually the positive input was connected directly to the ground for cleaner sound. There is no input coupling cap here, but I had to add it later (4.7 BG NX), because of the DC offset, which appeared even when my DAC had 0V DC on the output.

This amp is good for any speakers (with reasonable efficiency though). I was using it with my B&W clones, which are about 91dB and I was never lacking power.
 

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#54
Peter,

I just noticed the screw heads on the screws holding the aluminum blocks to the heatsink/back plate. What kind of screws are you using?:scratch: I sure you have the 3 bladed driver for these screws as well.😀

Rodd Yamashita
 
#58
All,
just catching up with this thread so stop me if someone's already posted this.

Someone asked if the Cardas plated posts are brass underneath - see the link and you can find all kinds. Cardas make bare Cu, plated Cu and plated Brass. Just pay your money and take your pick.

I think I'll use the patented binding posts on my next project.

Regards
13th Duke of Wymbourne
 
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