Analogue revived !



The big JBL horns on top of the Greenvalve 5940.

The big JBL horns on top of the Greenvalve 5940.

It is hard to make a speaker that the bass has the same efficiency as the horn. These are close. Simple crossover.


Lytro picture of the Greenvalve modded Eastern Electric ES9018 DAC

Click to focus, Double click to zoom.


Greenvalve Luddite Maxim Monoblocks

Greenvalve Luddite Maxim Monoblocks

Burning the 4A constant current filament supplies through the night. Toasty 😉

See the Maxim in operation here: YouTube Video

10 IT 801A

Practical application of the SMPS B+ idea upon a tested amp design. Here is the very simple schematic:

YouTube videos of my experiments. Wear headphones 😉


SMPS for B+?

People hate SMPS. “Too noisy”, “All that hash will kill the music”. It is time to see if they are right. Show me another supply that can provide over 300mA of current at 800V+ all while having an output impedance of less than 10 ohms!

Here is a video of the SMPS supplying 770V B+ and -96V bias for my 826 IT GM70 breadboard amp. YouTube Video

EDIT: Well, once again I am late to the party. Way back in 2009 Ed Brown of had the same idea. He didn’t stack as many, but the concept was proven valid with just six units in series. See more HERE.
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The future?

The DACmini CX is my new 24bit 192khz source. So far the sound is excellent… all it needs is a little tube love 😉 It may be too tight inside for an all in one source / tube amp, but there is plenty of room to make it into an optocoupler volume control LC 26 tube preamp.


After using the CEntrance DAC for a while I am convinced it is an outstanding value. Not just because of its excellent sound, ability to play 24/192 files via optical or coax and 24/96 files via USB, but because of its stability and isolation from noise. Now it’s time to see just how transparent the Asahi Kasei AK4396 DAC chip really is. Bypass everything and run the balanced DAC output right from the AK chip, into high quality 1:4 step up transformers, then directly to the Hornshoppe Truth buffered preamp. This sounds astonishing! Even better than directly coupling the DAC to the grid of a preamp or driver tube. The dynamics feel decompressed, headroom limitless. It must be the synergy of the interstage transformers being given what they love and the exponential expanding dynamics from the step up transformers creating the most exciting, real and dynamic presentation I have ever heard. Yes, maybe even better than vinyl. 😉 Pictures of the mod follow:

Don’t do this unless you have the steady hand of a surgeon, which is why my solder joints look as poor as they do. Each of those wires is only slightly larger than a human hair. 🙂

The power, USB, optical and coax inputs. On the back is an analog input as well.

The CEntrance DACmini CX has been ‘dechassified’ and wedged into the Hornshoppe Truth chassis. Still plenty of room left for the interstage transformers…

Introducing the True Green DAC. 😉 The final product has all the conveniences of a modern DAC. It is amazingly quiet, has a remote volume control, balance control, and plenty of gain. It is the perfect source for my powerful SMPS GM70 amp.

This post may not seem too interesting, but trust me… you will enjoy listening to this source at Hornfest.

This thing REALLY rocks!

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Perpetuum Jazzile – Africa

Have you seen this yet? Awesome!
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A worthy digital source!

Eastern Electric MiniMax DAC

Eastern Electric MiniMax DAC / JBL Horn Speakers

In the teaser photo: My modified Eastern Electric MiniMax Sabre32 DAC with RCA 210 tubes, transformer output, and Optocoupler / Light Dependent Resistor (LDR) Volume control. Used to drive all IT coupled 10 > 45 > GM70 monoblocks with Onetics Output transformers. Although my favorite music is from vinyl, this DAC sounds incredibly natural with 24/96 files.

Hornfest 2010

As always, Ed Schillings ‘Hornfest’ is a delight to the ears (if not the eyes). This year I took my Behringer 2496 DEQ along for the ride. When we measured Ed’s listening room I was shocked how different it was from my own. I was even more surprised that my open baffle speakers needed NO digital equalization in Eds room. This was disconcerting, since I had spent so much time and energy pursuing a digital solution.

We ended up running Joels tubed Jolida CD player directly into Ed’s ‘Truth’ buffered LDR preamp and finally into the awesome Dowdy Llama 826 / GM-70 amp. This resulted in stunning presence, incredible speed and dynamics on the baffle-less  speakers. How can digital equalization sap so much life from music? Certainly, more research is needed.

Here is a link to a video of that setup…

Open baffle speaker by Greenvalve Audio at Hornshoppe Hornfest 2010 Dowdy GM-70 Amp

6C45Π / 6s45p Spud amp / preamp

Cool huh?

A fun little amp that sounds great. The

6C45Π doesn’t have the thoriated magic on the top (like the VT-25) but having only 1 tube for amplification gives a lot of detail and transparency. Here is a link to a video about it.  Look at the plates on these tubes. They are rumored to be solid carbonized titanium, and the grid wires solid platinum. WOW!

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