Review of Altmann BYOB Amplifier (tube-o-latore'd version) and Attraction DAC

Altmann Micro Machines BYOB Amp and Attraction DAC

I was looking for a second amp (new or used) that was reasonably priced as something I could tinker with. I have done a few up over the years and thought it would be fun to tackle again.

Trawling through the web I came across a few reviews that pointed to Mother of Tone-BYOB The reviews mainly spoke of a DAC that a certain Charles Altmann in Germany was producing, running off an ordinary car battery. I went to the site, did some further investigation, spoke to Charles Atlmann and ended up purchasing the BYOB Amp and his DAC. The Amp is EUR 750 (about $US 940 or $AUS 1250 landed) excluding any customs or other duties. The DAC starts at EUR 750 and can be built up to include Toslink, DVD sampling and a Jitter Scrambling Decorrelator (JISCO). And of course a 12V battery. Mr. Altmann recommends the Optima Red Top 34, new this will set you back about $US 125 or $AUS 315 (someone is making extra cash in Australia). By the way its ‘tinker free’ so you can’t tinker with it!

The following is an account of what I found with my purchase and is aimed at 2 channel purists.


The Amp arrived in a small box with the DAC. A picture and some reviews can be found at so you’ll know what I am talking about. It took a few weeks from the initial order to arrival at my home, usual for ‘down under’ deliveries of this size.

Yes it is small, very small! What have I done? I recognize a pot, a few capacitors, inputs/outputs and a heat sink but the rest is a bit of a mystery. Must be digital (edit -> it's analog). People have been making 12V amps for cars for many years and I expect this little Amp to be similar in what it does, even with only 10 watts a side.

Plugged it in and turned it on, boy is it good straight out of the box. Quick and responsive with a solid bottom end. I also noticed that it had none of the ‘Solid State Sound’ that many amps can contain when mixed with the wrong gear. It had an easy listening, non-fatiguing sound but I noticed certain details were missing but it was quiet, dead quiet.

I admit I am into detail, sometimes it’s an obsession over the music. I swapped between my current system and back to the Amp and concluded that imagery front to back and the top-end octave was not as good as what I am use too. I also noticed that you had to ‘cook’ it for 30 to 40 minutes before it got better. The little heat sink does cook! I have speakers capable of producing 105db/w/m and I only needed to wind up the little pot no more than 25% of its full rotation, anymore and my ears would begin to bleed!

So back and forth I went over 3 weeks and during this time I began to hook up the DAC, swapping that back and forth. It was only in the last few days that I noticed the Amp come alive.

Listening to my current system for a week or more then coming back to the Amp was an amazing journey. Probably took about 30 hours on and off but I found most of the detail that I thought was missing.

As things progressed and the Amp ‘cooked’ some more, I was also cooking. I couldn’t believe the extra detail I was hearing and the bottom octaves became distinguishable, tighter, deeper and with pace.

The top octave became clear and present although not as detailed as I am use to. I also thought background noise was less (yes even quieter than before) so I also got better front- to-back imagery.

I found that I could increase the volume and there were no annoying ‘noises’ or distortions that can make the music sound less than real.

I was hearing music and nothing else.

This Amp could match my amp in most areas and even surpass on aspects such as musicality and speed and it cost 1/3 of the price! The battery clearly adds another dimension and nothing like some of the battery amps I have auditioned and owned in the past such as N.E.W. I think because nothing is connected to the wall whilst playing you don’t get the interference. Think what it can do for greenhouse emissions.

This little Amp is a ‘performance standard’ as Charles Altmann puts it.

I think it will give enough grunt to any speaker system 92db or above provided they are able to produce the transients without too much compression. The battery gives this Amp a shot of adrenalin whenever it’s needed which has the potential to allow a good speaker to become a really good speaker.

Listen and you will hear changes in the energy fields, the singer as do instruments move toward and away from the mic, electronic music is lightening fast. For me piano and guitar sound thrilling.

Those audiophiles with massive phallic symbols of audio nirvana beware because David has found his slingshot! I have swapped almost 35 kilos for a few kilos, what a little wonder!

Strengths: What seems to be an effortless ability to let the music in providing huge capacitance for demanding works whilst still maintaining ‘quiet’ when called for. Needless to say bass is landed with authority and depth and very distinguishable between lower octaves, piano, guitar and horns have life and voices have clear annunciation. Better (than most) instrument decay allows for greater appreciation of what’s really happening in the recording. You don’t need a pre-amp so there is less in the signal path.

Weaknesses: Well it is ugly ‘because it’s not in a box but I don’t care. It requires a watt or 2 to make things happen and could have a better handle on the mini watts (maybe it’s because my speakers are too efficient) and the top end is a little shy on intricate detail.


The DAC arrived in the same box as the Amp see for reviews and pictures. It too is small but does look like a DAC except smaller and without the pretty box. Depending on how you configure the DAC will determine how many toggle switches you have to play CD or DVD with any transport of your liking.

This also sounded great out of the box and the more I used it the better it became. The great test was to listen for a while (at least 15 hours on/off over 3 days) then go back to the sound you are used to. I did so and I did not want to go back, I ended up staying with the Attraction DAC and have not gone back since. My CD player is twice the price of the DAC; however I do use its transport.

This DAC was simply one of only 2 pieces of audio equipment I have heard play realistic music and raise goose bumps in 30 years of serious listening. The other is my Klipschorns. What a great combination I have made!

The DAC has the pleasantness and fullness of analogue, the sheer speed, timing and rhythm of a live performance and the detail digital brings. It produces lifelike music that I have not experienced before in a CD player or dac.

It’s dead quiet and even quieter with its little buddy.

As a combination they are hard to beat without spending a truckload more.

The DAC picks up where most digital players leave off, it actual adds nothing to the recording but lets you listen to what was recorded.

How can I say this? Because the music sounds like music and voices sound like voices.

You do get a sense that you may actually be listening to what the engineer had intended DDD, AAD or ADD encoded.

It’s more like sitting in a club than in an auditorium 15 rows back from the stage. It’s close and personal.

Yes you do hear the nuances that are produced from orchestral works but spatial cues are different. It is somewhat forgiving.

Music and musicians come with an added dimension and as the volume is turned up the sound just gets better and the musicians are in the room with you.

I don’t sense much ‘screaming’ that you often get with solid state when you wind it up, it has a ‘tube’ presence but with lightening attack. It reminds me of the old Marantz CD 94 II and in fact I used one of these (transport) in my listening tests and found that this was a superb addition in enhancing the sound with the Jisco on. I have not been able to notice much difference with the Cyrus CD 8, using its transport and flicking the Jisco in and out of circuit.

Well there it is. An incredible piece of kit that you must audition! I found myself playing through a huge number of CD’S listening to things I had not noticed before; this is always a good test for me. Combine with the AMP you just cannot go wrong!

Strengths: The scale of the sound is huge, rhythm, timing and overall tonality makes for lifelike presentation of artists. I feel as though the sound has become uncompressed and opens up in the room. It is free of the ‘thinness’ or ‘digital’ sounds often experienced with low Fi and even Hi Fi players. Its strength lies in its ability to present the first 9 octaves with full emotion. Affordability; just cannot think of anything that can compete with it at 5 times the price.

Weaknesses: It’s not the prettiest thing you have ever seen. It is somewhat forgiving in the top end of its response losing some of the extreme detail that some players are capable of extracting but you pay for this.

Equipment used: Muse Onehundredsixty amp, Cyrus CD 8, DVD 8 and PSX-R, 6SN7 pre-amp (purpose built A Class), Marantz CD 94II, Morrison ELAD & Klipschorn (2004) loudspeakers. All cables and interconnects are home made.

Some of the CD’S played: Diana Krall (Girl in Other Room), Dave Gruzin (Jazz compilation), Toto (Best Of), Santana (Supernatural), Eric Clapton (Unplugged), Buena Vista Social Club, Complete Beethoven Piano Sonatas (Gerard Willems), Verdi (Requiem), Mike Oldfield (Tubular Bells II), Mike Oldfield (Tubular Bells for Orchestra), Frank Sinatra (Best Of) and some Rammstein, Pink Floyd, Deep Purple and Emir Deodato.


This is a review of the Altmann BYOB Amplifier, Attraction DAC, Creation ADC, Altmann Phono Stage, , BYOB Speaker System, Altmann Acoustic Panel, Altmann UPCI (Ultra Precision Clock Injector) or Altmann JISCO (Jitter Scrambling Decorrelator). Other products by ALTMANN MICRO MACHINES.