[G.Trenchev]

My new PCM1794 DAC with XMOS.Small & compact.
 

 

[RudeWolf]

Now that's real DIY! The implementation is as seen in the Datasheet?
 
How do you like it?

 

[crispchicken]

Hey, please let me know if you go through with the digital pot, as I'm very interested in doing so myself. It'd be hugely helpful to know how someone else tackles the problem.
 
In regards to o2's... 
 
peace

 

[G.Trenchev]

Quote:

Now that's real DIY! The implementation is as seen in the Datasheet?
 
How do you like it?

It sounds much better than my AP2496.The dynamics and details are incredible.On measurements it repeats AP2496's baseline,which isn't much,but confirms a steady build.
The implementations is as datasheet - only the gain is a bit lower(1.7V at 0dB),and opamps are LME49720.
And finished:
 

 

[sceleratus]

[size=16pt]Hi,[/size]
 
 
[size=16.0pt]Don’t know how I missed this thread.  I’m pretty new to electronics, certainly theory, but I’ve forged ahead to build a valve amplifier.  [/size]I’m trying to finish it before the Los Angeles July 20^th meet.
 
[size=16pt]I'm using Tom Christiansen's boards for a 300B amp he designed.  The schematic, all the components and their DigiKey part numbers are supplied.  I started a [/size][size=16pt]build thread[/size][size=16pt], so perhaps ya’ll have seen these pictures before.  Anyway here's a few, I have a lot on the thread.[/size]
 
[size=16pt]Maida high voltage regulator (400VDC) [/size]
 
 

 
Test layout waiting for working 300B valves
 

 
 300B's arrived yesterday and one was cracked.

 

 
 
 
6.3V and 5V filament regulators
 
 
 

 
PSU board
 

 
Driver Board
 

 

 

 
Early top panel layout
 

 
0805 SMD resistor
 

 

 

[sceleratus]

Quote:

Just finished up a very special Bottlehead Crack build I call the Coppermine Crack. This guy took quite a bit of work: I mitered and routed the wood base, then copper leafed it, which is a fun experience if you haven't tried it. The plate of the amp is a 12" x 12" x 0.1" copper plate, punched and drilled. Some fun little changes from the stock unit are the 6SN7 signal tube, the excessive use of film caps for power and coupling, and a pair of bulky chokes. Hope you enjoy the pics. 
 
 
 
 

 
 

 
 
 

top shelf, very nice

 

[sceleratus]

I am new to the thread and this may have already been posted, but I think it bears repeating for noobs and others.
I have soldered off and on for years with mediocre results. I wanted to do a challenging DIY project so I sought out YouTube training.  
 
I found Dave Jones and the EEVBLOG.   He has hundreds of vids, from basic to extremely complex EE stuff. I cannot recommend his "Solder Series" enough.
 
After I watched his tutorials, I picked up a Hakko FX-888 (Amazing tool) and some 0.38mm 5 core solder.  I now feel like I can solder anything.  The components in my build pictures were the First Time I soldered surface mount components.
 
My hands have the shakes and I could still do a decent job with 0805 SMD components (2.00mm x 1.25mm) . Straight Away, no practice.  If you are new to DIY and don't know how to solder, Fear Not.  Or if, like me, your solder skills are limited and you want to brush up.  Watch the series.  You will never have a bad solder joint again.  Ok, rarely.  
 
I'm talking complicated IC's and tiny components.
 
Here are the links.  They are 30 min plus, Dave is a very animated Aussie, they are on the long side but complete and well worth watching.
 
EEVblog #180 – Soldering Tutorial Part 1 – Tools
 
 
EEVblog #183 – Soldering Tutorial Part 2
 
 
EEVblog #186 – Soldering Tutorial Part 3 – Surface Mount
 
 
EEVblog #434 – SMD Thermal Pad & Drag Soldering Tutorial

 

[crispchicken]

The latest in my line of "micro moy" boards arrived today...
 

 
 
 
 
I've stuffed one board most of the way now, I'm very excited to get the last caps that I need and try this out which shouldn't be too long now. I tidied up the design a whole lot over the last prototype, it's also running so-8 because they're so much better to solder than TSSOP. I added a second, top-layer ground plane to help further shield it, and there's decoupling caps  too.. Over all I've just tidied up the overall design a whole heap.
 
This is revision 3 of the kinda.. beta for lack of a better word. There's another PCB revision already on the way, this time I've added bass boost, and the overall design has almost reached the point that I'd consider not totally in-development anymore, which means I'll be getting a bunch of boards made so that I have some spare to sell if people are interested.
 
Here's today's work

 

[miceblue]

They look nice! What PCB making software are you using if I may ask?

 

[crispchicken]

Quote:

They look nice! What PCB making software are you using if I may ask?

It's called Diptrace. It's really pretty wonderful. It's the only piece of software I've tried that's actually intuitive in it's use. It has 4 components, that being, pcb editor, schematic editor, and editors for components for the schematic and pcb footprints.
 
I've tried altium, eagle, kicad, several others too and haven't found anything else that's as usable as diptrace.
 
I think Altium is more powerful, but it's really too hard to follow for me. Maybe I'll get into it as my skills develop, but for now Diptrace even has a free version with a maximum of 300 pins, so I'm super happy with it. This design is around 60 (it included smd pads in the limit)
 
(I'm not a shill, just a very happy customer )
 
you can get it from here if you're interested.

 

[cfcubed]

>  Diptrace even has a free version with a maximum of 300 pins
 
For non-profit / non-commercial use IOW for things you don't plan to sell.    I use Diptrace as well & for the same reasons, though for bone simple PCBs so far. 
Bought the lowest cost version in case a PCB of mine ends up in something I sell & because IIRC only the bought versions can get/apply update patches.
 
Very nice work on this CrispChicken & nice looking boards -  Think that project of yours deserves its own thread though, e.g. if anyone is interested in it or its development they'd have to comb through the Pics thread for your posts about it.   And think the pics thread is for pics & possibly brief descriptions, not full blown project development & discussion.   But I'm no moderator so what do I know

 

[sceleratus]

I am outta my mind that it  actually works !   It sounds amazing.
 
Forgive me...
I've only made 4 posts on different threads saying the same thing.
 
 

 

[crispchicken]

I do tend to waffle a bit... sorry about that. my intention was to make this project its own thread once development was at the refinement stage, right now its very much just a learning process still, which I thought would be cool to let other people in on

As for Dave's videos, I find them to be a wonderful resource and really entertaining too which isn't common in teaching electronics.

Even without good tools its very possible to produce pretty professional and work. All my stuff is solders with a cheapo “fire starter" iron and a roll of 2.99 eBay solder. Flux is the biggest trick I've ever learnt for small work

Peace

 

[DefQon]

Quote:

I am outta my mind that it  actually works !   It sounds amazing.
 
Forgive me...
I've only made 4 posts on different threads saying the same thing.
 
 

That right there is some nice tube porn. Might whack myself a kit sometime soon as I've always loved the 300B tubes.

 

[sceleratus]

Quote:

That right there is some nice tube porn. Might whack myself a kit sometime soon as I've always loved the 300B tubes.

 
Still waiting for it to go "POOF"