Sachem v.3     hi-end  power mono-block



            Please click here to read the review of a Sachem system, made by Dr. Richard Varey on the Witchdoctor hi-fi magazine.


When, after more than twenty years of glorious service, I replaced my active audio pro A4-14 loudspeakers with a pair of passive Bravo FX-04, I started assessing many top amplifier options available on the local market, but I had tremendous difficulty in finding an amplifier able to deliver euphonic sound and lightning-fast-and-wide dynamics, in order to fully release the great potential of my new speakers, obviously helped by my "immortal" sub B2-50. So, quite disillusioned, I made the brave decision to try to develop and build my own amplifier. I embarked on this very challenging adventure because I could also count on the help of my very dear friends Rino Cieri and Allen Gill. Rino, who is an Italian old friend of mine, is a hyper-talented hi-fi technician and Allen is a no less skilled technician, but with an eclectic knowledge in general electronics and digital technology. Anyway, it's been an exciting experience, even if hard and sometimes frustrating too, but absolutely interesting indeed! I have had the chance of discovering incredible things about electronic components in general and in particular about capacitors. In the end the result was more than rewarding and my new speakers fell in love with their new partners! The new "babies" have proved so good that we decided to produce a small series of 25 sets. In early 2003 the first set went on the market and was called Sachem.

Sachem (pronounced Sakèm) is the general Chief of all the American Indians, and the word comes from the Algonquian language of a tribe, who lived close to Lake Michigan. The Indians also used to bestow the epithet “sachem” as an honour on a senior warrior when he had distinguished himself with particular merits. 

The previous two versions of the Sachem have garnered critical acclaim driving any speakers, culminating in Martin Bell (the publisher of FFWD magazine at the time) calling it "the best 'sane money' power amplifier I have ever heard". Ashley Kramer, another famous name in NZ hi-fi magazines, and now editor and reviewer of the online magazine , in a Sachem review, said similar words of appreciation. It also seems that Martin and Ash really meant what they said, given that both bought Sachem for themselves. The same did Scott Bartley (head-reviewer of the late FFWD magazine), who, in my opinion, was the most serious reviewer in NZ at that times. These are not just throwaway words, as evidenced by the long customer list of those who enjoyed and still enjoy the Sachem and/or audio pro speakers and subs at home; among them some of the most well-known names in NZ audio - Greg Vincent, owner of TONE magazine; Brent Burmester, reviewer of FFWD; Michael White, publisher of TONE etc. Also TVNZ bought for its “dreaming room” a big audio pro Bravo home-theatre system and people of the technical staff of TVNZ have bought similar systems for themselves too.




                                                                                                                                       the new Sachem v.3


The success of the first lot of the original Sachem has persuaded us, a few years ago, to go on and release an upgraded version, the Sachem v.2, and now has arrived the last version, the Sachem v.3.

The v.3 version features a totally redesigned PC-board with a layout as compact as possible and a linear, great design of the cabinet, made in carved solid aluminium. Anyway, the v.3 shows a unique big difference to the other hi-end amps: it's totally wire-free.
What's more, this version features an internal micro-switch, which allows to roll the bass response off, with a slope of 6dB/oct and three selectable -3dB points at different frequencies. This is essential to properly integrate a sub into your system or, if you don't have a sub, just to render quite listenable "boomy" floorstanders (not a rarity, but almost the norm).

So, what can be said about the sound quality that the v.3 version provides? Its most evident peculiarity is that it "doesn't sound"! In fact, we do think that a perfect amplifier must not be, in its own turn, a musical instrument, adding its own “sound” to the musical program and this should be the ultimate target of any serious manufacturer of such machines!

However, to have an idea, you could start reading the "testimonials" page of this web site, but, to fully discover its superiority, and to help you appreciate what we have achieved, we highly recommend that you compare the Sachem v.3 to any hi-end amps on the market by listening, without any "inferiority complex" and any price limits (the more, the funnier) and possibly using very dynamic and well-recorded CDs. Differently to other amps, the v.3 loves very complex loads, so compare it using so called "difficult" speakers, and ... enjoy!


an overview of the Sachem v.3 mono-block and ... considerations

Please note that the text below has been partially copied from the instructions we put in every Sachem amplifier. They are useful to understand the "philosophy" of this amplifier and to learn how to solve technical and hi-fi related issues, which you will never read in any magazine and will never told in a hi-end shop.




                                                                                                                            Sachem v.3  back panel view


We have spent over a year in electrical and sonic research, redesigning and compacting the PC-board and listening at length to different top components and testing small modifications of the original circuits, in order to arrive at this v.3 final version, which “sounds” as unobtrusive as possible.

To achieve this superior sonic reproduction, we have adopted and developed an interesting all-discrete circuit, incorporating the most modern, high performance, top quality components, in a totally clean and wireless layout, where the signal path has been optimised as well.
The mono-block configuration has a great advantage, for it allows you to minimize the length of your speaker cables to yield another substantial difference in sound quality. In fact, you can place the amp (in free air on a small stand or on the floor too, if not carpet) very close to each speaker.
We think (sadly in vain) that all “hi-priced” amplifiers should be built to this configuration (mono-blocks), because the use of long speaker cables, irrespective of price, make or any divine intervention, always significantly modifies the sound. A speaker is a very complex electrical load (anything but a pure resistor, unfortunately) and the cable (due to its own electrical parameters, which vary with its length) interacts to modify the electrical parameters of the total load "seen" by the amplifier. By comparison, a good quality screened interconnect (low capacitance and resistance), between preamp and power amps, does not appreciably affect the sound. Even in the very rare cases of signal degradation (some “funny” hi-end preamps, due to the high output impedance, are not able to drive long cables properly and/or using cables of very poor quality), the loss would be significantly less than that of using a long speaker cable. 

The Sachem v.3 can drive any types of loudspeakers, irrespective of their load complexity, impedance and efficiency. This peculiarity is essential to unlock the full potential of your speakers, but unfortunately it is not necessarily present in every “exclusive” amplifier on the hi-end market today! That's why amplifiers can sound so different when driving a given pair of speakers.
Regarding power, many Audiophiles believe that an 80W amplifier cannot drive a low-efficiency speaker properly, but, if the amp is a Sachem v.3, they are wrong indeed. We have tested our amps driving a pair of 82dB (1W/1m) speakers at “unusual” volumes with fantastic results: very fast transients (for what it’s possible with this kind of "conceptually wrong" speakers), and not a trace of clipping.  No miracles, this is possible because the Sachem v.3 can deliver, without strain, peak-currents of 20A, resulting in instant musical peaks (on a load of 8Ω) of more than 3000 Watt!

On the other hand, we believe it is extremely difficult, perhaps impossible, to make a hi-powered amplifier (about 200W RMS 8Ω, or more) with such a refined sound. So, we opted for a mid-powered solution, incorporating a "lightning" dynamic range and monstrous current delivery. Furthermore, with the advent of active sub-woofers in domestic settings, for driving the main speakers, there is no longer need for very powerful amps, but for well sounding and very fast ones! So, my personal advice to the Audiophile who looks for sound perfection is to buy a Pure v.2, a pair of v.3, and a very serious sub, and replace his useless power-hungry “dinosaurs” with better sounding, smaller speakers, which, differently to the "dinosaurs", always have many more chances of delivering coherent and accurate sound. In fact, if not designed by someone stupid, the smaller dimensions of their cabinets, at least, allow the adoption of interesting shapes, with a much smaller front panel, more respectful of the basic rules of physics-acoustics, for diffraction, reflection, phase etc. To know more about this topic, visit the page "school of sound".




                                                                                                  Sachem v.3  inside. Please note the stunning wireless lay-out. 



technically speaking

Each v.3 mono-block features an over-dimensioned 300VA toroidal transformer, which feeds twenty audio-grade, very low impedance and low ESR capacitors, through a 35A full-wave bridge rectifier. These capacitors provide a total capacitance of 66,000uF and are paralleled with two exceptional WIMA polypropylene caps (MKP10 series).

Differently to the v.2 version, in the v.3 we adopted a transformer with a secondary higher in voltage, in order to achieve a DC power supply for the power Darlingtons of +/- 44V, instead of +/-39V of the previous version. This way, the power stage becomes more powerful, with an increased dynamic range and a "speed" even more "lightning"!

All the resistors feature “metal film” technology, with ±0.1% tolerance and a temperature coefficient of ±15ppm/°C. For the common man, this means veeeery low noise.

The power final stage is handled by 6 selected and matched Darlington devices, to achieve low open-loop output impedance and linear high-current capacity. This ensures very smooth output transitions, without any audible crossover or switching distortion, even under high-current output conditions.

The whole power supply and the Darlingtons of the final stage are so over-sized that the result is a terrific peak max transient current of 20A on the speaker, equivalent to peaks of 1.6 kW @ 4Ω and 3.2 kW @ 8Ω !!

The other four current-filtering capacitors inside the circuit feature polypropylene dielectric, while the only one in the signal path (in the feedback circuit) is a bi-polar Nichicon Muse series, top audio-grade, and, in its turn, paralleled with polypropylene capacitors WIMA MKP10 series.

It is a fact that every capacitor in the signal path affects the sound negatively and most circuit typologies require many capacitors in this area. We did things differently and, in our knowledge, the Sachem V.3 is one of the very few or the only amplifier with just one capacitor in the signal path, on the feedback (compulsory in any amp)! Furthermore, and this surely happens only in our amp, if you set up the amp for a rolled-off output (for example, when you have to join a sub to the system or just to "humanise" booming floorstander speakers), this electrolytic capacitor is by-passed and the signal "sees" ONLY polypropylene capacitors (high-speed WIMA MKP10 series)! So, having achieved our goal of using only one capacitor on the signal path, we do believe we have made an important difference in sound fidelity. The V.3's euphonic sound, the full richness of original harmonics, the incredible transparency and the silky softness of the mid-high range, the endless and lightning dynamic range and the “sculptural” quality and speed of its bass range, depend to no small degree on this.

The carefully considered grounding system and the state-of-the-art PC-board, which consents the totally absence of any cablings, eliminate internal loop-currents in the signal ground-path and assures a high level of immunity to noise and external interferences. I'd like to point out that the unique short wire in a Sachem V.3 belongs to the probe of the thermometer in the heatsink: it's impossible to avoid this wire and totally useless too, considering that the thermometer has nothing in common with the electronic circuits.

Be aware that the internal lay-out and wiring of an amplifier is the "business card" of its designer and manufacturer, and it tells you a lot about their technological level. Nowadays it's unpardonable to build an amp with messy wiring or just with a lot of wiring: there is no good reason and it could also cause problems! Nevertheless, many very high-priced amps on the market are poorly designed and built that way, not to say about the tube ones, which are even worse! So, to avoid buying one of these "jewels", my strong advice is to visit "Google Images" and check out if the interior of the amp of your dreams is as nice and clean as its external look. You don't need to be a technician to understand on the spot if the "baby" is a joke or has got the chance to be serious stuff! An astute Audiophile should always act this way before buying some piece of expensive equipment, particularly preamps.

The Sachem V.3 is temperature-compensated, and the perfect performance and sound of the amplifier is assured after a quite short warm-up period of around ten minutes or when the display of the thermometer shows 32 degrees. So, there is no need to leave these units permanently powered-up, in respect of the environment and energy efficiency.

The thermometer has got another function too: it turns off the amp when the heatsink reaches a temperature of 75 C degrees and turns it on again at 50C degrees. For normal use, even at very high volume, it's more than very unlikely to reach this temperature! We tried, but didn't manage to have it off.

The Sachem V.3 is a completely reliable amplifier. Every unit is deeply tested for 2 hours at full power into 4Ω load (1V input, 1kHz) and for 12 hours at 25W, into 4Ω load, with "pink noise".

Regarding its reliability, the first Sachem went on the market in early 2003 and we don't have any failures reported so far. Furthermore, the Sachem Guitar combo, when on stage, seems to enjoy "shooting out" more than two hours of killing sound, without any strain, and … you probably know that this kind of performance is not advisable and achievable with so-called hi-end amplifiers!




                                                                            View of the heart of the v.2 (from back to front) - Note the gain stage (operating in A Class)


Connections and Installation

On the back panel of each amplifier unit there are the connection sockets: the red input RCA socket receives the signal from your preamp. The black socket is a line output that can be used to feed the signal to other units or to drive an active sub-woofer alongside the speaker. At this point I have to introduce you to an interesting and very useful facility of our amplifier: the possibility to select a flat response or, via its passive high-pass filter, a 6dB/oct “rolled-off” response, with three selectable -3dB points at different frequencies. You must choose one of these roll-off options (possibly, the right one for your purpose), if you use a sub-woofer.

Doing so will create the correct crossover point between the sub and your main stereo pair, so that the bass will be clean and free of boom. Furthermore, the dynamic range of the main speakers will increase, and their distortion decrease, because they will no longer struggle to reproduce (in vain) the low frequencies your sub is better qualified to manage. Image and clarity in the mid and high-range will improve because of the lower general distortion of the loudspeaker.

NOTE: if your speakers are floorstanders and tend to “boom” (it's in the "DNA" of this kind of speakers), try the roll-off option and you will probably be amazed about the transformation in the bass department and in the rest of the audio band too. Please call us for a better explanation of this powerful facility. However, as standard, every Sachem V.3 leaves the factory setup to deliver the full signal range (flat response).

For safety reasons, you are not allowed to open the amplifier, so, if you wish to change the default settings, you will need to contact us to have the job done (free of charge).




                                                                                                        internal view (from front to back) and the power suppy


Now we would like to digress and give you our point of view about the much-discussed subject of sub-woofers.

Given for sure that bass instruments do not deserve to be treated like ugly ducklings (they are the foundation, and an essential part, of a musical composition), we do recommend the use of high-quality subwoofer/s with any system. People usually forget that, by definition, a hi-fi system must reproduce frequencies across the whole audible range, from 20Hz to 20kHz ± 3dB.  So, if you like to listen to a genuine hi-fi system, you must have a dedicated subwoofer, as NO traditional, passive, full-range speaker can achieve decent infra-bass.

Many esoteric hi-fi lovers believe that a sub will muddy the sound of a good system, and they are very often right, but this usually happens because of poor integration of the sub, so that “booming” bass from the main speaker pair is only worsened by the sub’s additional output. The second reason is that the large majority of these sub-woofers do not have acceptable sound-accuracy (no matter the noble brand, the "galactic" price, and the astonishing review of some inept or biased reviewer). We only use and recommend audio pro sub-woofers, which, thanks to their patented ACE-bass technology, achieve a completely “unusual” infra-bass reproduction. When an audio pro sub is correctly tuned alongside the main speakers (properly cut and possibly driven by a Sachem Pure v.2), low frequencies are very deep and almost undistorted (virtually carved out of the air) and there is no trace of “booming”.




                                                                                                                           A Class driver stage of the v.2


Back to the previous subject, if you plan to bi-amp your speakers with a second pair of Sachem V.3, connect your pre-amp to the red RCA input of the amps driving the low spectrum, then connect their black socket to the red socket of the mono-blocks handling the mid-high. In this configuration, you must cut the bass response in the mono-blocks used for the high frequencies, setting up the highest possible roll-off point (350Hz  -6dB).

With each V.3 mono-block you will find a metre-long speaker cable terminated in a NEUTRIK Speakon plug. The cable provided is NORDOST 2 FLAT.  Although we are not the importer of this brand, in all our trials of speaker cables up until now, we have found this to be superior to all others (some indecently expensive too) in clarity, bass control and speed. We reckon that this cable is the best (or amongst the best) choice to fully transfer the Sachem's huge potential to your speakers and … the price is not crazy at all!

Anyway, you are free to try other brands/types of cable, but whatever cables you decide upon, keep them as short as possible.

Connecting them to the amplifiers is straightforward via the professional NEUTRIK Speakon connectors, with an electrical current/contact rating of 30A RMS – just the best. If you want to change the cable, you should open the NEUTRIK connector to reach the screws which lock the wires. Please, be totally sure to connect the new cable exactly the same as in the original, in order to maintain correct polarity and phase.

To discover the polarity of the accompanying Nordost cable, you have to look carefully at the external white plastic cladding. You will note that the plastic cladding of one wire is completely smooth and that the other one carries a line in relief along the middle - this marked wire is the positive and the smooth one, the negative. Obviously, to connect the cable to the speaker with the correct polarity, connect the marked one to the red (+) binding post of the speaker and the smooth one to the black (-). To finish, you must test the cable for a possible short-circuit, which will “kill” the final stage of your amplifier instantly!

In this connection, be aware that Sachem V.3 is NOT protected against speaker cable shorts. Invariably protection measures introduce sonic compromises, so we have refused to adopt any, in the reasonable expectation that our customers - who are unlikely to be “hi-fi beginners” - will connect their speakers with the requisite care. Anyway, before disconnecting the speaker cables, always ensure that the amplifiers have been switched OFF for at least 30 seconds. We also recommend disconnecting the Neutrik Speakon plug before the speaker ends. Please note that the warranty will NOT cover the cost of addressing any problem caused by a short on the speaker cables.

Safeguarding the Sachem V.3 from overheating is simple. Do not place the amplifiers within an unventilated enclosure, such as a closed cabinet or cupboard. The amplifiers are best kept out in the open, on a hard surface, not a carpet or other yielding surface that might block or even just restrict the underside vents. Finally, and most importantly, ensure that the V.3 is kept out of direct sunlight.

If these conditions are not met, there is the risk that the amplifier will not run at its optimal temperature and it may suffer “thermal runaway” and automatically turned off at 75C by the thermometer (fortunately)!

Anyway, it could also happen that a fuse on the power supply blows. This can happen and it's normally due to a power surge (quite common in NZ). The fuses are inside the amplifier, so you must bring or send back to us the unit: we’ll replace the fuse(s), but we’ll also check the amp, to be sure that nothing else has happened.

A general rule is: if the amp stops working or you just note something unusual, you MUST turn the unit off as soon as possible and disconnect the power cable too. In a second time, contact us, to discuss the problem and what to do.

However, if you decide to open the amplifier (to check and eventually replace fuses, or for any other reasons) be warned that WE DO NOT agree and that WE DO NOT take any responsibilities for the consequences: you do that at YOUR OWN RISK and the warranty will become void. Anyway, if you still want to do that, BEFORE OPENING THE UNIT, you MUST DISCONNECT THE POWER CABLE!




                                                                                                                  RC snubbers and service power supply of v.3


We hope you now feel ready to use and care for your new stunning amplifiers, and we are confident you will enjoy the improved performance of your hi-end system.

Please remember, though, that a pair of Sachem V.3 will not perform miracles! These amplifiers will mercilessly reveal any weaknesses in your hi-fi chain, and, in turn, their full potential will be “obfuscated” by any other component(s) of poor selectivity, speed or sound-clarity. Until all your components are as good as your new V.3 amps, your quest for sonic perfection will remain unfulfilled.

Please do not hesitate to contact us if you need assistance or advice with the installation and use of our products, or ... just if you have any general curiosities or questions.





Rated continuous power (RMS)   8Ω  (20Hz ~ 20kHz)                                                        >  80W

Rated continuous power (RMS)   4Ω  (20Hz ~ 20kHz)                                                      >  145W

Rated not continuous power 2Ω                                                                                        >  220W

Peak max. transient current on load  -  see note below (**)                                                 >  20A  

Input sensitivity                                                                                                                     ~ 1.3V

Input impedance                                                                                                                     13kΩ

Internal impedance                                                                                                             <  0.1Ω

Power bandwidth @ -3dB  (top-band limited by input passive low-pass filter)        2Hz ~ 240kHz

Audio-band linearity   5 ~ 200kHz (@ rated power)                                                         +/-0.1dB

Phase deviation  20Hz ~ 20kHz                                                                                              <  3º

THD @ rated power  8Ω  1kHz                                                                                        <  0.03%

Crossover distortion                                                                                                         NO trace

Hi-pass filter slope  (see instructions)                                                                6dB/oct @ xxx Hz

Maximum power consumption                                                                                              250W

Overall dimensions  (W-H-D)                                                                         300 – 165 – 410 mm

Shipping weight                                                                                                                  13.2 kg

(**)  Please note that a current of 20A is equivalent to peaks of 1600W @ 4Ω and 3200W @ 8Ω



Sachem v.3 (or v.2) is on display at the following dealers:


Signals - Auckland

HiFi Auditions - Hamilton

Soundhaus by Schuler - Napier

Tone Electrical - Paraparaumu

(you'll find their contact details in the "partners" page)


PLEASE NOTE:  If you are not living in an area covered by one of our local dealers, please contact us and we will "invent" an alternative solution, in order to let you experience and enjoy the Sachem "difference".