Post pics of your builds.... - Page 252

Sorry, I cannot reveal the price.

PPA v1 in a 1U rackmount (re-used) case. PS is internal.

for your viewing pleasure I present to you a work-in-progress.

my first PPA(v1) amp:



details:





and this is how that old box started out in life:



I went to a used music store and they had this semi-cheap rackmount there that I thought I might be able to use. this was something like $15 (they said it was working but the unit didn't work when I tried it at home).

no matter, I used the box and some of the nice red wima's - I stole those from the board, and those nice TRS jacks, too. stole all I could from that board and then left it for dead

I don't have the bass boost hooked up yet on the PPA. there's a control for it, as you can see, but nothing connected. there's also MOTOR POTS but no motor control. yet. and that would also mean some kind of remote control. soon...

there aren't even rear jacks mounted yet. just pigtails of rcas in fake gold but its 100% functional and sounds great!

the power supply is a TREAD and its using some overkill of a torroid. found it at a local junk shop for a song (ha, that was a joke). its 17vac per winding and I'm using 1 winding to get a bit over 20v into the PPA.

oh, there will also be a crossfeed board installed. somewhere. eventually.

the box was used except for the front panel. for that I removed it, took it to TAP plastics and had them cut a few 1U rack sized fronts from cheap easy-to-work plastic. its VERY easy to work. shows no fingerprints and even hides a lot of mistakes. good for prototyping. the panels costed me $1 each and they cut them to size while I wait. eventually I'll go with front panel express but for now, $1 plastic fronts are just fine.

what really amazed me was how the PPA fit into this 1U pro-audio rack box with NO room to spare. wow.

the pot wiring was kept short. I lucked out with my knob positioning. the power supply is also very short as I put the TREAD close to the power-in of the PPA.

the case is set at audio-in ground even though I have a green-wire (3rd wire) ground available thru that IEC socket. not sure what to do but my gut says to float all connectors and green-ground the chassis. I might do that.

all that took me the better part of today. I had the PPA assembled a day before (took most of THAT day, too).


update: new status:



its not at v1.0 level (by my version numbering). all manual features work, including volume and bass. I love that bass control - it changes enough of the lower end to really balance out my hd-580's and give a lot more warmth to them!

there are now gold rca jacks on the back instead of the wire hanging out the rear these were MTG-12 and were directly chassis mounted (to metal). I decided to go for audio-in as chassis ground.

so, currently, v1.0 is a basic PPA. all boxed up and wired and fully working.

v1.1 will have a crossfeed board (tangent's) installed.

v1.2 will have some kind of motor control over IR or possibly RF.

so, stay tuned for more...

update again: cut down the pot shafts so they don't stick out and the knobs now hide the mounting nuts.

also did some hand lettering (datak rub-on dry transfer letters) just to dress it up a bit. each letter was transferred one by one! quite laborious. I really wish the labelling part was a bit easier..

shown in my stereo cabinet along with my re-faced behringer a500 amp (bottom) and not-yet-refaced rane active crossover.

Why does it seem I always post right next to the giants?

My Millett Starving Student built as a cathartic distraction from school.



Notice the fine attention to detail and overall neatness of the layout.

This is the proto Bijou finally cased up. I second linuxworks approach for re-using chassis and picked up a router case from a surplus store, harvested the perforated section from a power supply which I hacked up and it just took me an awful long time to give this gem it's dues.

Still a little work to be done but this is the general idea



PSU section open



back



innards



- stepped attenuator wrapped in rubber sheet to prevent unwanted shorting with the case which is not very deep.


..dB

The wood is a nice touch. Got any bigger pics ?

I think you should just leave the PSU naked on that Bijou. Did you consider staining/finishing the wood?

no its not. that's my soldering iron in the background!

yeah, I noticed that also, mine was having a lot of intermittent problems. replacing the pot was cheap and easy to do. and no, no audio-taper is needed on the LED soldering iron pot just wish that iron was more reliable - I have to fight with it all the time. price was right, though, on that iron.

as for your build (grin) - I agree, add some stain to the wood. I assume you plan to?

AWESOME!

Wood has already been stained in light oak - last thing I did last night.

as for leaving the psu open - not likely with those voltages floating around. Kids and pets don't get that some things shouldn't be touched. The amp is is also not going to be staying with me, it is for a friend who has been patiently waiting while I got my act together.

curious - mine has been a solid performer for the past 5 odd years. The tip is finally showing signs of wear but other than that, I have had no problems with it at all.

..dB

Finally there is someone who is slower than I am in finishing the casework for his proto Bijou.
Well done, BTW.

I just finished my SOHA II. I used the straight BOM, no boutique parts. I used a hammertone paint. I didn't expect the birdseye effect, but I liked it once I saw it.

Wellcome to Head-Fi. A bit unsusual but very nice painting work.
Hope you enjoy the SOHA II sound too.

congratulations, I too like that paint effect..dB

The Silver Ghost

I finished my project.



This amp has been "brewing" in my mind for quite some time. I finally decided to build it, and am happy with the hour or so of music it has put out thus far.

It is fully balanced from input to output. The pot is a 2-deck noble in a balanced shunt configuration. I finally got the attenuation "right" and can swing the pot way past 9'o-clock comfortably. pots are not well balanced chan-chan below 1/3 swing...

The gain stage is a long-tail-pair with a CCS for the tail. At the moment, the plate resistors are SLIGHTLY lower impedance than what I should have used.

The output stage is a white-cathode-follower with external phase splitter.

For various reasons the amp MUST have at least 1pr of 6sn7 in it (the tubes in the way back) but there is some flexibility for the others.

The power supply has a big-fat 20 henry choke in it, and is a fake-dual-mono, with many duplicated stages.

EDITED:
all of the output jacks work.
the 4-pin for those of us with the superior connector
2X3-pin for those of us with the "other balanced connectors.
the "left" 1/4" TRS is straight, 0-ohm output.
the "right" 1/4" TRS is a 120-ohm output.

Congrats Ari, looks GREAT! I hope to give it a listen in NYC in a month or so.