Wavebourne Edelweiss-3 Prototype Power Amp review

[MattyW 1,400]

Ok, now that I've had my Wavebourn Edelweiss-3 for a few months and it's nicely burned in it's time for me to prepare writing my review of it which I'll post here over the coming month. I'll post my impressions and experience purchasing this wonderful amp from Anatoliy Lisovskiy, who will be releasing the production series of the Edelweiss-3 power amp, an integrated amp and separate preamp over the course of this year.

 

 

As I understand it the current production version of the power amp and integrated will all be EL34 though allow and pin compatible tube to be used right through to KT120, possibly even KT150. My own amp on the other hand uses WW2 vintage CV1127 radar sweep tubes.

 

The reason I initially started looking into a lower powered amp was that 6 months ago I built my first pair of DIY speakers. A pair of shallow cabinet open back speakers which share the performance characteristics of U frame open baffles. Unfortunately the copy darTZeel NHB-108B power amp I was running at the time was far too powerful making my 101db sensitive speakers too loud for regular use so I started investigating lower powered tube amps.

 

While looking into various solutions someone on AudioKarma pointed me in the direction of Anatoliy's Wavebourn amps and I got in touch via the Wavebourn facebook group. Over the next month or so I had an interesting discussion with Anatoliy about his amps, and their suitabillity to drive my DIY speakers (Lii Audio FAST-10 full range, Aurum Cantus G3Si ribbon, Skar Audio VX1ST bullet & Lii Audio W-15 woofer) and this led to discussions of his amps variable damping factors allowing suitabillity with a wide range of speakers. A feature which I believe may well be unique to the Wavebourn amps.

 

Overall details of the amp are as follows:

 

Input: 0 dB (0.775V) RCA, 50K stereo.
Outputs: low ohm for 4-6 Ohm and high ohm, for 8-12 Ohm load.
Power: at least 6W for <1% total harmonic distortions.
Soft asymmetric saturation (inaudible clipping), negative output resistance for damping of woofers (servo-control of speakers).
Bandwidth: 10 Hz-90 KHz -3 dB, from 20 Hz full power.
 

 

Tubes:

 

Raytheon VT127 (CV1127) radar sweep power tubes.

8CB11 driver/preamp tube (twin video pentode – filament powered from rectified DC for zero audible hum.

VR150 / Russian SG4S voltage regulator (purple glow).

VR tube and solid state MOSFET voltage regulation.  The “Edelweiss” series derives it’s name from this. A beautiful flower which grows amongst hard mountain rocks.

Selectable speaker damping

 

In order to support different speaker design types such as open baffles, horns, closed and ported boxes, there’s a damping factor switch that controls output resistance of the amplifier.

 Position 1 is the first on the left.

1.       High output resistance (like pentode output with no feedback), sometimes referred to as "Current driving mode".

2.       Similar to SET with no feedback.

3.       SET with some feedback.

4.       Negative output resistance for active servo-damping of woofers.

 

With a little experimentation I soon found that I prefer the negative output resistance setting, which is actually Anatoliy's own preference. Probably the least tube like sounding setting giving tight, accurate bass where other modes seem a bit looser. This is what I've continued to use since the first week I received the amp.

Edited February 21 by MattyW

[MattyW 1,400]

I've used this amp to power the full range drivers and two super tweeters in my DIY speakers with a Behringer KM750 powering the 15" woofers. So far my experience has been that the amp is like a chameleon with very noticeable sound changes in sound signature with every change of component in front of it. Even changes of interconnects make a night and day difference with differences easily audible between them.

 

Essentially this is an incredibly transparent amplifier. Imaging, detail and tonal characteristics are wholly reliant on the quality of the rest of the signal chain. It is slightly rich tonally though overall I find it takes on the characteristics of my Linear Tube Audio MicroZOTL 3 preamp making this perhaps the most transparent amplifier I have ever run.

 

I believe the founder of Quad defined the ideal amp as being a straight wire with gain..... That said wire has it's own subtle tonal characteristics. The Wavebourn if it has a sound of it's own, is far more subtle.

 

I must fess up that I changed the coupling caps in my amp from the stock Bennic caps to Miflex KPCU-1. Anatoliy is adamant that tube and cap choice make very little difference in his circuit, and after the change I'd have to agree. The change if any is in the realm of "is it all in my head, or is there actually a difference". I do think it was slightly smoother and more detailed, though really can't be sure. Due to this, if anyone sources one of his amps, I don't believe changing any components is really worthwhile.

 

Presently the best I've heard it is either with vinyl (never used now the baby has come along) and with my modified Muji Studio DAC II. With the Muji in place everything sounds incredibly real, revealing detail in music never before heard and with this incredible surrounding  sound stage. Instruments have weight and are rich sounding, each within their own space. With movies it feels like this betters my 5.1 system downstairs, and with music it's just such an emotionally involving experience that it's brought tears to my eyes on more than one occasion.

 

Recently I've had some issues with the Muji (one of the legs of the TDA1541 S1 is shorter than the others causing issues) so I've an inexpensive Lamp Audio TDA1541A based DAC filling in. Sound stage has collapsed and while the TDA1541 tonal characteristics are evident, it is what I'd classify as typical stereo sound. The richness of the sound is gone and sound stage is altogether flatter. Less overall detail is revealed from the mix. The chip used doesn't make the DAC, though rather the implementation and materials used in conjunction with it. Nothing will ever change that.

 

Likewise, changing RCA leads between my LTA MZ3 preamp and the Wavebourn showed huge differences. All cables tried were sourced from Geoff at Aurealis Audio.

 

Neotech UPOCC, Amphenol connectors - Smooth and rich sounding with a pronounced mid-bass hump making it richer and fuller sounding. Very refined

Litz copper, unshielded with Amphenol connectors - Large sound stage, detailed and layered witha good weight to the sound top to bottom. Very even handed.

Litz silver and copper hybrid - Huge enveloping sound stage with incredible detail. Very transparent though less weight and body to the sound.

 

While I do not mean this to be a review of different cables or components I do think that sharing this information is valuable in showing just how transparent this little amplifier is. It must be noted that it is paired with the Linear Tube Audio MicroZOTL 3 which is itself know to be an incredibly resolving and transparent component. That said I've always felt that the said transparency of the MZ3 is itself a colouration. The Wavebourn goes beyond this and simply takes on the characteristics of the source, interconnects and preamp before it.  I really can make no higher recommendation than that.

 

Having said that, I think my system a little too transparent just now..... It really does show up the deficiencies of my temporary Lamp Audio DAC. The Muji Studio will be getting looked at by my friend @muon* in the coming months and restored to active duty, though likely in my second system downstairs as I've a new DAC and phono stage being hand made for me by Abbas Audio in the Ukraine. Abbas Audio share their circuits with SW1X Audio in the UK and are indeed affiliated, though each take a very different approach to component and build choices. Abbas comonent choices are more in line with the vintage parts used in Killer DAC's whereas SW1X are more in line with Audio Note. I very much look forward to using them in this system as I know that the Wavebourne amp will let every nuance through in its full glory. 

 

Here is a link to a video I made when my Muji was working correctly. I must apologise in advance as recording quality with my Pocofone F1 is substandard, and volume is set quite low as that I how I tend to listen to most music. I don't feel I'm left wanting for tone, detail or nuance at this volume though it seems my phone simply wasn't up to it:

 

https://photos.app.goo.gl/9N8YgER1kCJTFrkc8 

 

Another benefit I've noticed with this amp may not actually pertain specifically to this amp though rather all low wattage class A amps vs their higher powered brethren, and it doesn't pertain to sound quality as such. I've found with higher powered class AB push/pull tube amps that listening can be something of an unpleasant experience during summer. Brisbane being quite hot and humid during summer, the added heat of a 45WPC push/pull tube integrated can leave you sitting on the couch in your boxer shorts, shirtless and sweating like a pig. Even more unpleasant when you need to get up and find yourself stuck to the leather couch.

 

My current the little Wavebourn + MZ3 generate very little heat and do not make the experience any worse than when the sound system is powered off. On the sound front, while less punchy the a push-pull KT120 amp it's also far more natural sounding, a characteristic which is shared by other single ended amps I've tried. An amp should not sound punchy (no matter how enjoyable that can be) unless that is what is recorded in the music. The little Wavebourn gets that just right 

 

Edited February 21 by MattyW

[Ian McP 4,120]

MattyW, truly an impressive effort! Care to describe the speaker design in a little more detail, crossovers etc?

regards Ian

[MattyW 1,400]

@Ian McP The speakers have the full range wired in parallel with the two super tweeters, which are wired in series with each other. The Skar Audio VX1ST bullet is firing up at the ceiling and the Aurum Cantus G3Si forward facing. There is a 1uf Duelund Rs-Cu with 0.47uf Arizona Blue Cactus cap wired in parallel with it for a total of 1.47uf on on the super tweeters. Internal wiring uses Duelund stranded tin plated copper cotton covered oil impregnated wire which is great once burned in. Like most tinned copper wire it can be a little harsh prior to burn in.

 

A very very simple speaker with minimal crossover components..... I'm really only limiting the super tweeters with full range and woofer run full range. The woofer is run off the Behringer KM750 with left and right volume knobs set to 50%. I know this probably wouldn't suit most purists however the sound signature of both drivers is identical as they both Lii Audio drivers and as such they blend seamlessly without need to limit either of them in any way. Lii Audio developed the W-15 woofer specifically to supplement the bass of their full range drivers in open baffle configurations and I believe it does rather well.

 

I've used Karri FJL panels from Bunnings and affixed everything using little L brackets..... Liquid nails and wood putty used to seal everything. This a first (and likely last) DIY efford for me so it is a little rough though overall I'm very very happy with the appearance and even more importantly the sound. So far the best I've experienced. 

 

 

 

 

 

The caps installed have changed since this photo.  I went through a few different cap combinations before finding the one that sounded best to me.

 

Edited February 21 by MattyW