A Purist’ Wet Dream

Wow! It has more than a year since I last wrote anything here. This is embarrassing considering I used to write every few weeks.

What happened? Well, you could see I’m still alive, kicking and soldering but more than that, I have spent more than a year improving on Discreet Monica.

I know, I know, I’m a pain in the arse but with each improvement, you learn a lot more. I improved on her layout, grounding and even incorporated a FPGA for signal processing capability.

Err, in layman’s term, I had to redo the PCB layout through a few revisions (very expensive process I tell you), learn a new (to me) programming language called VHDL (VHSIC Hardware Description Language but to me it means Very Hard Darned Language), program the FPGA to replicate what I had with 14 integrated chips previously, measure and hand match the high precision resistors (a royal pain I have to tell you) etc etc…

All this effort, so that she sounds better and she’s much easier to build. She definitely sounds so much better now but unfortunately, still tedious to build. Is there more to come? Sure there is! But save that for another day.

I then wanted to build a proper All-In-One system. You see, back when we participated in the KLIAV show way back in 2008, I built an All-In-One.

In case you don't know, I kick ass!

Back then we have the Monica3, Maggie, output transformer coupled 6GM8 and Charlize2 built in separate chassis and linked via interconnect cables, like a typical separate system.

Once built into a single chassis, the sonics gained a quantum leap!

Why so you ask? It could be lack of RCA interconnections, much shorter signal path and more crucially, the much much shorter return path (also known as GROUND) path between components. Simply put, the electrons travel in a much much shorter loop and they are happier :). And my electronics background tell me that the happier the electrons, the better the sound! And so it proved.

That was then, so I had to build something better today. Since we are going on a purist’ path here, might as well go all the way with just a single gain stage throughout the signal chain. And nothing is simpler than a one-tuber aka spud amp.

Over the years, have always wanted to build a spud and back then the popular tubes were 417, 5842 as well as 6C45. There are others but those are usually 2 stages in an envelope. I’m being purist here. I want ONE and ONE only.

The last few years, another tube gained popularity and it’s a Ruskie 6E5P tetrode. I learned a lot about this tube thanks to the fine work done by Bartola Valves as well as Romy the Cat.

Now this little fella is a like a super tube. Specs wise, everything rocks! So much so that I just have to build it!

Also, over the years, I have heard a lot about the parallel feed scheme. I’m not sure how many commercial amps out there have such a scheme. Just shows us hard core DIYers are more cutting edge than mainstream. Ha! So this is a fantastic vehicle to put in everything together.

And so, we have… A Purist’ Wet Dream.

Purist' Wet Dream

The initial idea was to build this to be mounted on to a wall but since I’m a such a pain the arse, I just can not build a simple amplifier. So 2 power transformers, 2 power supply chokes, 2 plate chokes, 2 parallel feed output transformers and 4 beer cans oil capacitors later… this whole contraption is just too heavy to be mounted on the wall. So now it has legs and it’s going somewhere!

Purist' Wet Dream

Input takes USB from your Music Machine be it Windoze or Mac and
Output goes to your speakers via the binding post

USB Input – Discreet Monica – modified Intact Audio Autoformer Volume Control – triode-wired 6E5P Magnequest Iron Parallel Feed Output – Speakers!

All in all, there is only ONE gain stage throughout.

Purist' Wet Dream

Want to know more about this Purist’ Wet Dream? Stay tuned for the next article.

6 Comments

  1. Nic June 18, 2014
  2. miso June 27, 2014
  3. yeo June 27, 2014
    • miso June 28, 2014
  4. Joe Fox March 13, 2015
    • yeo March 16, 2015
  5. Pingback: She kicks ass! - diyparadise January 7, 2016

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