sure 2x300 amp build

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thought it should go here. not speakers but a project none the less.

goal was to get the 2x300 in a case with the 48vdc power supply. i had it with the 32vdc.
case is 3/4 hickory with mitered with a bunch of poly. measures 16.5x6.25 external and has a mdf bottom.
slotted the hickory front and rear to recieve the aluminum 1/4" and the rear mdf 3/8". had to make a 1/8" insert so the imputs would fit. they were not long enough for the 3/8"
with my first one, i built everything into the bottom but it was a pain to line everything up to put the lid on. on this one i built everything into the top, mo better.
with the 2x100 board one could use screw type or rca imputs. this 2x300 only has rca so i had to secure them to the base so as not to break the board. i have the ps set at 49.9vdc with a 16000 70vdc capacitor.
in the first shot you can see two sets of high quality speaker jacks, two sets of inputs, ac in and fuse. the basic layout of the case.


i used pro mic shielded cable for all inputs through a dpdt switch for source and through the alps blue velvet pot.



continued.

[[email protected]]

Re: sure 2x300 amp build

the tangled mess on the front is 8 blue led lights around the pot. they are powered by a 5vdc walwart mounted to the floor and inline after the off/on switch.

each one has a 100ohm resistor on the positive side and they are paralelled so if one goes out the others will stay lit.

i useed big rubber feet for the bottom. holes on the top to the rear and holes on the bottom near the front for natural ventilation.

[jcpahman77]

Re: sure 2x300 amp build

Quality build Arlis. What has been your experience with the Shure boards. They boast some pretty impressive THD numbers and high power ratings for their price bracket, so I have to admit I'm a bit skeptical. Would love to hear from someone who has used them, and especially in your case this isn't your first one so it would seem you have a positive opinion of them.

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Re: sure 2x300 amp build

thanks.
i do. the first one was a 2x100 i got from china before pe started to carry them. i hooked it up backasswords and released the magic smoke. the second i got from pe and still works.
i need to find a piece of tranlucent plastic and cut it about 2 or 3 mm larger then the volume knob to radiate the blue light. kind of like the emotiva.
im getting some stadic through the speakers though. i think i need to go back through and put all the grounds together and i assume to the wall ground. does that sound right?

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Re: sure 2x300 amp build

i just realized the fan has not shut off. i dont think thats normal.

[jcpahman77]

Re: sure 2x300 amp build

thanks.
i do. the first one was a 2x100 i got from china before pe started to carry them. i hooked it up backasswords and released the magic smoke. the second i got from pe and still works.
i need to find a piece of tranlucent plastic and cut it about 2 or 3 mm larger then the volume knob to radiate the blue light. kind of like the emotiva.
im getting some stadic through the speakers though. i think i need to go back through and put all the grounds together and i assume to the wall ground. does that sound right?

Tie all the grounds to the chassis and the chassis to the wall ground. You may find that solves both problems.

i just realized the fan has not shut off. i dont think thats normal.

[ameuba10]

Re: sure 2x300 amp build

yea, jcpahman's right. tie all grounds together and then to the main wall ground on the power connector. this will eliminate any ground loops from different ground points

[tomzarbo]

Re: sure 2x300 amp build

Looks good Arlis.

I've made an amp with the Sure 2x100 board and was happy with it as well. You've got a little more going on in your case than I did. The finished amp looks very nice. Looks like you did things right with heat-shrink and shielding, etc. Getting the insides neat is tough, complexity like a crossover times 10! You pulled it off though. I really like the idea of the back-lit volume knob!

TomZ

[donradick]

Re: sure 2x300 amp build

Very nice! I've looked at those Sures a few times. Let us know how it sounds.

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Re: sure 2x300 amp build

thanks for the kudos and info. i will do that.
i have been tinkering with it every weekend for a few months. very hard to for me to figure out where every thing goes and remember it the next weekend. no electronics background at all. it really makes me appreciate what it takes to do a REAL amp or preamp kit with all those little things.
i'll let you know if it helps.

[johnnyrichards]

Re: sure 2x300 amp build

That is very impressive buddy. Also, where have I seen a pack of Reds being used for perspective..? :p

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Re: sure 2x300 amp build

That is very impressive buddy. Also, where have I seen a pack of Reds being used for perspective..? :p

all my original ideas are gleened from somewhere;)
thanks.

[johnnyrichards]

Re: sure 2x300 amp build

all my original ideas are gleened from somewhere;)
thanks.

:D Seriously though, that is one sweet amp. Now I gotta do something with my 2x100 module.

[jcpahman77]

Re: sure 2x300 amp build

A little creative tip, next time use one of these on the front instead of the strip you used so you don't have to make all those jumper wires.

[greywarden]

Re: sure 2x300 amp build

Nice looking too, great job!