My first chip amp

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Just finished 2 channels of my first gain clone. I am pretty excited. I used a PS that BrianGT had to test it out and it worked great. Sounds great so far. Now I have to finish the case and the PS.

I just had to share it with someone else since this my first real electronics/soldering project.

Not to bad eh?
 

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Yes, you are correct. I started using the schematics off of National's site, then I worked Peter's design into it.

The clear stuff is Teflon to protect the wires when I ran them across one another.

To tell you the truth, I really was not sure that it would sound great but it did.
 
Retired diyAudio Moderator
Joined 2002
ENIGMA said:
Just finished 2 channels of my first gain clone. I am pretty excited. I used a PS that BrianGT had to test it out and it worked great. Sounds great so far. Now I have to finish the case and the PS.

I just had to share it with someone else since this my first real electronics/soldering project.

Not to bad eh?

Looks good :) Pretty good amplifier to build in 6 hours. We will tackle the chassis next.

--
Brian
 
diyAudio Editor
Joined 2001
Paid Member
Hey , you guys should have an amp Build-a-Thon.
Put up posters and get payment in advance. Maybe some official endorsement by the dept. or club so people don't worry about getting ripped off. Put together say 20 kits- a single transformer for 2 channels, Dale resistors, Panasonic caps, plastic knob terminals, surplus CPU heatsinks. They bring a (cookie tin?) enclosure about the size you specify.

All the potential DIYers put 'em all together one night til 2 am under your direction. Get a few extra parts for those that fry something.

A lot of fun seeing people so excited about making something so great "all themselves" You could guarantee success-I mean the worst case is you have to rebuild someones botched effort.
 
Looks very motivating to try this out. I had always wanted to build it but I guess this one is the final nail in the coffin! I will buy the stuff and start building the clone.

Can you post the schematics for it and also the power supply schematics.

I have access to Farnell and was looking at the Toroidal power supply. 0-18V, 0-18V 160VA. Is this sufficient for 2 channel for a start? I wanted to built the LM3875. I can purchase a another toroidal if necessary for the other other channel.

Inputs from all the experts are appreciated.


Regards,
 
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Joined 2002
As for the setup that this chip was used on. Both chips were screwed to a 3"h x 10"l x 1/2"w piece of aluminum, which was the side of my chassis. They were powered by a 320VA 2x25vac transformer through a standard bridge rectifier. The final version will use discrete MUR860 diodes for the rectification.

As for getting warm, the side of the chassis I made worked just fine. It got only a little warm. Aluminum oxide insulators were used along with silicon compound for attaching to the heatsinks.
Link to insulators

--
Brian
 
Ok...

here is the silly question but I really want to make sure. How can I have the negative supply voltage since all the trafo is rated as 0-25V, 0-25V.

How do get the -25V from this trafo. Also is there any power supply filtering like CRC or do we simply feed the recitifer output and feed it directly to the chip?

Thanks.
 
my very first

stereo gc was fed by very very cheap and very low power trannies.
item no: pwr1013 (Basler) from bgmicro.com

i used 2 per channel they cost $2.95 each.

not powerfull, as i said, but the sound is very very very nice!

I learned in this forum how to prepare them for a gc channel!

there is absolutely no humm at all from these transformers, they stay cold even after I let the gc's play for hours and hours ....

my guess is that they put out some 5 watts maybe a bit more but the sound is rich, clean and every detail is presented.

J-P

i am not affiliated nor do I work for bgmicro, i just like to diversify my purchases as much as possible!
 
enclosure?

Enigma'
Congrats!
I'm starting my first gainclone. I admire the use of perfboard and board mount terminals. I will incorporate them.
Here's something to consider: Fair Radio offers an enclosure listed as a modem. For $15 plus ship you get the box containing a 5 & +/- 12V power supply, other stuff for the parts bin AND 6 pair of mil-spec binding posts. I'm adding some .063 alum. sheet to incease the height to accomodate my tranny and capacitors. Using the case for a heat sink is an option.
Thanks So Much

Ed
 
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