Quad 8 Rack Job, again,

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CJ

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how many of these have you seen already?

oh well, Soundguy dropped this 10 transistor Quad 8 pre amp, i think the 8 transistor is the 277, the 10 transostor is the 177,

i racked it and then the volume dropped in half and it sounded like crap,

bummer, but it was just a cold solder joint on one of the output transistors, somebody clipped one of the legs a little short, and the plastic spacer kept it from going all the way thru the board and the wave tank did not wik it up in there, common problem,

anyway how does it sound?

it is quiet.

very quiet.

the most quiet amp i have,

tube amps can be quiet but you always have a little hiss with the high Z enviro,

Langevin AM16 is quiet but it does not use a balanced power supply, API is quiet, has a balanced supply, but this thing has it beat.

very good high end, i am using a Jensen 1:8 mic input,

it came with a small zip loc bag with a cap and resistor, but i did an A?B test and it did nothing to improve the tone so the less parts the better,

clipped out the 4.7 input cap, soldered directly to the board as the connector was too wide for the rack, 330 ohm feedback resistor good for 40 db, external power supply,

constant phantom, no gain knob or phase switch to go bad, the gain resistor is seen under the orange tape so i can change it if i want,

easy to mount, just put longer bolts thru the tri fi output and into some 1/2 inch standoffs,

this rack used to be a Valley People experiment but he VP modules turned out to have major hiss problems, so i used this rack for the Quad and thru out the VP stuff,

the weird transformer peeking out the hole thing was to cover up an xlr hole, and the label is photoshopped until i can find a quad 8 logo to copy,

either the transformer is upside down, or the mic jack is upside down, i forget,  :eek:

supposedly these amps kick ass on the snare drum,

got some stuff in for the Fairchild so back to that,  :D
 

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nice to see people still doing DIY.
Those Quad 8 preamps what they sound like anyway?

Good luck
 
they sound great!  they yank those cards out of mixers, it is a quck rack job, that is why you see people using these cards for an 8 ch mic box,

 
Cool stuff! The Q8 stuff sounds really good, here's a quick and dirty build I did with a couple of AM10 DOAs and some QE7002 output transformers, like CJ I used Jensen inputs, mine are 1:10 i think...

7330609416_20f2fdcecf.jpg


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Matt
 
Older thread with more builds.

http://www.groupdiy.com/index.php?topic=5440.0
 
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