A Comparison Of Two Great Amplifiers

A wonderful power amp needs to have:

*A good sized toroidal transformer, or even better, TWO. These transformers can’t just be pulled out of a parts bin. They need to be made to a cleaner, quieter standard than generic.

*A large value of filter capacitance for its power supply. These caps should be low loss ESR in design and not come out of generic parts bin. They need to be able to withstand years of heat and abuse.

*A good number of matched output transistors. The operative here again is, the parts can’t just come out of a mass merchandise bin. They need to be used in MATCHED groups for smooth sound.

*A circuit design with minimal wire running all over the place, promulgating RFI and noise. We don’t want spaghetti running adjacent to and over/around other parts on the board.

*Circuit boards with through hole, rather than surface mount parts

Below we have two great power amps.

On Top:

On top we have an amp using two 440VA toroidal transformers. These transformers are custom made in Spain with a steel housing and absorbing case resin. This amp has a LOAD of filter caps at 84,000uF. These caps are custom made by Nippon in Japan, not a Chinese job house. You can see a dozen matched output transistors, six per channel. Yep, each has been individually tested to be sure it shares the same sonic finger prints as its brothers. Mundorf caps are house in their own silver mu-metal boxes to eliminate RFI. The circuit board is a work of art with symmetrical design and virtually no spaghetti to generate noise. It weighs 35 pounds.

On the bottom:

The amp on the bottom is much bigger and heavier. It weighs 104 pounds. It uses roughly double the size of transformer, filter caps and output transistors. One man can’t handle this big boy. The company is proud of its parts and layout, but there is clearly more running wire and solder connections than the amp on top. Given that this amp has about double the size and parts of the amp on top, it should cost approximately twice as much, right?

The Reveal

On Top is the French built, Atoll AM300, $3900, 150×2.

Or, run a pair bridged, $7800, 500w each!

3 Year Warranty

On the bottom is the Swiss built CH Precision A1.5, $40,000, 150×2.

Or, run a pair bridged, $80,000, 550w each

3 Year Warranty

We carry Atoll. The AM300 is a FABULOUS amp that competes with the best built at any price, for an affordable price. AM300 was designed to stay stable when run in bridged form. Running a pair of AM300 MONOBLOX is pushing the state of the art at an affordable price point. {Atoll also makes two less powerful brothers by the way.}

We certainly respect CH Precision. It is also a fabulous amp. It has the same power as Atoll with roughly double the parts count and same warranty. It is ten times more expensive!

Recording Change A Century Ago

Up until 1925 recordings were made direct to disc or wax cylinder by musicians playing into large horns. Recording was done acoustically. Singers like Caruso and powerful instruments like trumpets thrived.

It all changed when microphones and electronic recording gear started the studio as we know it in 1925. We started to be able to record softer singers, pianos, violins etc with far superior quality.

We’ve come a longggg way in a century.

Atohm Sirocco Speakers, New Models!

We’ve been selling the French built Atohm GT Series speakers for a few years. All of our customers are impressed by the beauty of the finish and the power of sound from relatively small cabinets with a 7 year warranty. To be clear, Atohm builds its own drivers and cabinets in house in France. They don’t buy drivers from a third party in Scandinavia or Indonesia and “assemble” speakers.

Atohm has updated its smaller and less expensive Sirocco Series models, which are commensurately impressive at about half the price of the GT Series. The new Siroccos are designated the 24 Series since they were completed in 2024. They’re available in luscious walnut, black, light oak and white.

The resolution and imaging of the new Siroccos is STUNNINGLY good. If you want definition that’s as good or better than panels, in a modestly sized speaker that’s easy to drive, please visit to hear the Siroccos. You’ll find, as we have, that you can find speakers that bash more than Atohms, but you can’t beat them for detail and spatiality.

In addition to great clarity, the new Siroccos are going to impress you with their large image

and ability to play twice as big as they look. Remember, nobody has a living room like you do in France. The Siroccos look small but you can drive them to muscular volume levels.

You are allowed to buy them just because you want GREAT resolution and imaging from modestly sized cabinets. You don’t have to hit em hard- but you can.

Thierry Comte, Atohm’s owner and chief designer, writes the most detailed white papers in our biz. Ya wanna go down the rabbit hole?

New Concave Tweeter

Dubbed the WSD20, the new Siroccos employ this cutting edge driver. It uses a concave design with .75” Silk Dome drive element. The concave wave guide is made of machined, die cast aluminum (not plastic or MDF like the other guys) to assure its precise contour and uniformity with the C150 mid/bass driver. There are several other things to make this tweeter special. It has a machined aluminum phase bullet equalizer. It uses a double neodymium ring magnet system for optimal control. It has a rear dissipation chamber within the die-cast aluminum structure. The manufacturing precision of WSD20 is of very tight tolerance. No sample will vary from the reference standard by more than a quarter of a dB. That’s twice as tight a tolerance window as the best of the rest. The benefit to you- is spot on imaging. It’s fabulous!

New Mid/Bass Drivers

Dubbed the C150, the new Siroccos employ this high performance, cast mid-bass 6” driver. It features an NBR rubber surround with low diffraction surrounding technology. The cone material itself is a unique paper composite with proprietary treatment on the front and rear (different treatment on rear!) surfaces to attain the precise stiffness Thierry wants. This design has a very linear excursion which means they can use a less complex crossover network.

Cabinet Technology

Take a look at the meticulous internal damping composition of these bass-reflex enclosures. Thierry takes great pride in tuning/voicing all Atohm speakers.

Crossovers

Sirocco crossovers use soft slope 6dB per octave structures, complemented by impedance compensation circuits to allow virtually any amplifier to run the speakers. Thierry uses top quality parts such as air core inductors, MPT (Polypropylene) caps and low resistance laminated steel inductors. Internal wiring is multi-strand OFC cable.

Tweeter Tuning Control

The Siroccos have a 3 position tweeter level switch. We all have different electronics, rooms and TASTES. Thierry lets you make the decision as to what high frequency balance you’ll prefer.

Sirocco 1.24 Stand Mounts: $2400 Per Pair

{13.6h, 7.09w, 10.25d, 88 dB, 6 ohms, 25-200 w/ch}

Sirocco 1.24 is a 6” 2-way stand mount.

Sirocco 2.24 Towers: $3800 Per Pair

{39h, 8.66w, 10.25d, 88dB, 6 ohms, 25-250 w/ch}

Sirocco 2.24 uses the WSD20 tweeter and a pair of 6s in a 2.5-way tower. In this configuration one of the C150s is used for woofer frequencies only.

Successful Songs Done In One Take

*Bill Withers, “Ain’t No Sunshine”

*Marvin Gaye, “What’s Going On”

*Stevie Nicks, “Dreams”

*Queen, “Bohemian Rhapsody”

*Bee Gees, “Stayin’ Alive”

*Stevie Wonder, “Superstition”

*John Lennon, “Imagine”

“Eagles, “Hotel California”

*Simon & Garfunkel, “Bridge Over Troubled Waters”

*Doors, “Riders On The Storm”

*Clapton, “Layla”

*Neil Young, “Heart Of Gold”

*Temptations, “Papa Was A Rolling Stone”

*Lynyrd Skynyrd, “Sweet Home Alabama”

*Who, “Baba O’Riley”

*Fleetwood Mac, “The Chain”