chuck's racks!

[mulletchuck]

So, i'm stuffing the PCBs for the power supplies now, and I am not sure if i'm missing a component or what, because Chunger's pics don't show him handling this particular spot on the PCB, yet they are filled in. 

if you look left of the 3 resistors and directly above the Trimmer, there is a 2-prong green component with the +16v, -16V, +24V, -24V and +48V silkscreened next to it.  Is that where the LEDs were supposed to connect to, in the first design?    Chunger's wiring diagram doesn't show the LEDs being connected to those holes on the PCB, so i'm unsure what is supposed to go there, as his pics show that space filled in with something green and cylindrical. 

Here's chunger's board:

Here's a closeup of the port in question:

 

[jsteiger]

Yes Chuck those are for on-board LED's. They will just stay blank as yours will be in the front panel.

 

[mulletchuck]

Looks like i'll get these two PSUs wired and fired up TONIGHT!!!

added:

WELL I CAN HONESTLY SAY IT TOOK ME LONGER TO GET THOSE WIRES FOR THE 4 REGULATORS ON THE BIG HEAT SINKS INTO THEIR RESPECTIVE HOLES THAN IT TOOK ME TO STUFF AND SOLDER THE PCBS 

 

[mulletchuck]

Finished building and wiring the AC side of rack #1.      No smoke, no sparks!!!

Everything outputs normally, except for the -16V rail, which outputs -25V.    I'll have to see what didn't get soldered completely.. 


but HURRAY!!!!!!


edit:

Problem solved!!!    One of the legs on the LM350Ts was touching another leg!    Fixed!! 

 

[mulletchuck]

Finished 1 rack!!  I had to redo the LED wiring because i wasn't paying attention to the pin length on Chunger's drawing. 

 

[mulletchuck]

and now both racks are done!

Now to build modules!!!

 

[chunger]

Sweet. .  . sorry about the mis-communication on thread regarding resistors to leave off the board.  I'm a board-populating fool, so when I see the little markings on there, I'm compelled to populate

 

[nashkato]

did you use heat shrink tube at the legs of the regulators on the big heatsink ?
it looks loke you didn´t ?
may i suggest you isolate the pins from eachother ? looks like they could easily short out .

just may 2 cents , haven´t build a 51x Rack  , and the pic is quite big to spot that .

 

[mulletchuck]

no i don't have that stuff.  ur right, as in an earlier post I said that an incorrect voltage reading was the result of the legs touching. 

 

[nashkato]

you get them at every electronics store for a few bucks .
could save you a lot of trouble in the future.

 

[mulletchuck]

couple updates!

TINY!!

WHOOPS!

TADAH!!

 

[mulletchuck]

Finished mine!  I had one or two solder bridges on the gar2520 that i had to correct.    And then, i had to leave phantom power on and let the pre run for a good 20 minutes before the pops/clicks went away as the DOA 'broke in'.

I tested it on my housemate, using a dynamic (RE20) and a condenser (414B-ULS).  Here's what it sounded like:

http://www.zshare.net/download/9495354277071b4e/ <<< Condenser

http://www.zshare.net/download/949535652b7ced61/ <<< Dynamic

The text message sound during the condenser is Jeff Steiger sending me a text saying "Awesome Job!!"  lolololololol

 

[mulletchuck]

Finished up the remaining op amps tonight!

Built 4 Gar1731s in 3 hours!  The key was to build them all simultaneously, and do one component at a time per pcb.

Next up:  VP312DI

 

[MagnetoSound]

Nice work, mr. moolay!

... i had to leave phantom power on and let the pre run for a good 20 minutes before the pops/clicks went away as the DOA 'broke in'.

I tested it on my housemate, using a dynamic (RE20) and a condenser (414B-ULS).

Interesting. What exactly needs to 'break in' on those DOAs?

And - that's totally flat, right? I have rarely heard a B-ULS sound as clear and crisp!

 

[jsteiger]

Nice work, mr. moolay!

... i had to leave phantom power on and let the pre run for a good 20 minutes before the pops/clicks went away as the DOA 'broke in'.

I tested it on my housemate, using a dynamic (RE20) and a condenser (414B-ULS).

Interesting. What exactly needs to 'break in' on those DOAs?

And - that's totally flat, right? I have rarely heard a B-ULS sound as clear and crisp!

Yeah Chuck, I meant to ask you this as well. There should be no "break in" period required with these. I am wondering how your other opamps came to life.

 

[mulletchuck]

I don't know what could've needed to be broken in lol.  But it took that long for the clicks and pops to disappear.  Everything is alright now.  This was only when the phantom power was engaged, mind you. 

Yes, that's a totally flat recording.  414 -> vp26 -> motu traveler via the Mic inputs (no gain).

I'm going to test later with the 1731s.  Strange enough, none of the other op amps needed to burn in.  So maybe it was something else in the circuit.  Oddly enough, I'm not too excited about the sound on sax.  But I'm hoping to get a better Mic soon to rectify that (cv4).  However, I'm dying to know HOW the 2520 works.  Any articles that break it down stage by stage?

 

[jsteiger]

Chuck, are your shunt jumpers set to couple the input's shield to pin 1? That is the correct way for phantom. Does this pre/opamp combo crackle in all slots or just that particular one?

Google "discrete op amp" and search around Prodigy. You will find a lot of info that describes the different stages.

 

[mulletchuck]

it doesn't crackle anymore.  just the first time I powered it up with phantom power turned on   Everything sounds great now (as you heard in those sound clips)

 

[gemini86]

Is it possible some rosin was causing some of the noise, maybe the conduction kindof burned off?

 

[mulletchuck]

here are some 312 pics!





Here's how i've got my rack set up to swap out op amps/plugins and also trim pots on the Modules
that will have trimmers