MUSICAL DESIGN Musical Concepts

IT’S A MIRACLE……..well not really but the new Q Acoustics 5050 is something like that with a huge improvement on the already very musically involving 5040. This is a ‘big-boy’ speaker. Big sound stage, big dynamics and deep bass with great presence and projected power throughout it’s range. If you haven’t experienced ‘projection of power’ you should hear these. We are a Q Acoustics dealer. The 5050 is $2K/pair. My vote for the deal of the year.


IMPORTANT NOTICE(Phone Change)….. To call Musical Concepts and Musical Design please call us at 636-272-0040 from 10am to 4pm, M-F(12-04-23)

OUR NEW M4 AND M8 COMPLETE DRIVER BOARDS….. with all new MOSFETS work great in the Hafler SE-100/PRO 1200 too. Double-Die, high current mosfets can be used for speakers needing more oomph.

For more power: PA-8, 6 mosfets/ch, is the default Hafler SE-240/PRO 2400 replacement. The PA-8.8, 8 fets/ch, works great in the SE-240/PRO 2400 for hungry speakers. Link soon. Send any of these models for introductory pricing now. New power supply work required. Kit in planning stages. PRO versions often available at nice prices.(12-01-23)

YES THERE IS A PA-7.3……… In these modern times we all know this type nomenclature/titling - Something.improved. Okay that’s the case here too. PA-7.3 is ready in kit and installed versions. It’s much simpler to install, sounds better and priced the same as the PA-7 V2, but the V2 is now discounted. (08-14-23)

MUSICAL CONCEPTS is an authorized Q ACOUSTICS speaker dealer….. We can arrange for direct shipment from Q Acoustics USA to your door on new models(free shipping to lower USA 48 states only).* These speakers, designed in UK/Europe, are widely reviewed and very well received as reference quality.

*If you have a Q Acoustics dealer in your immediate area please support them.

We have the new Q Acoustics 5040 Santos Rosewood in house - Wow - a beautiful speaker, rock solid build quality and sublime sound! Very impressed with these $1500/pair speakers!

Q Acoustics Demo models, these are in excellent condition––

New Listing!! Q Acoustics Concept 500 pair black/rosewood, Top-of-the-Line, excellent condition, pre-owned by friend but my own listening pair now(JH), all accessories, boxes, etc. SOLD

(1pr) Q Acoustics Concept 300(Rosewood/gloss Black) with Tensegrity Stands, beautiful to listen to and look at, surprising bass reach, a long-time favorite here. Stereophile Class A speakers (SOLD)

(1 pr)Q Acoustics Concept 50(Silver) - Demo models, setting new class standards - see the great reviews –  ($2999 retail) $2499, will ship to Lower 48(2 cartons) - local pickup available.

(2) Q Acoustics B12 powered subwoofers(12” stout driver, black matte finish), can be adjusted to very seamless sound with Q Acoustics speakers and others, has auto mode, x-over frequency, volume and phase controls, well reviewed and built like a tank  – ($749 retail) $625.00/each, free shipping to Lower 48 - local pickup available

-All demos will be shipped free with all original cartons and content.-

WE HAVE A NEW CAPACITOR ……….. for our  LC-500 mod that boasts 36,000uF/100V of modern capacitor performance. They have excellent performance and long life in the large Adcom, B&K and Hafler amps. Size is 2.5 dia x 5.5” high.  They come in at $199/pr in kit.

WE HAVE MODIFIED THE FIRST B&K ST-140 AMP….. with the new PA-8BKS board and the results are excellent in every way. The ST-140 board is available installed for now - kit later. While the ST-140 has both channels on one board the ST-202 needs a different pair of mono boards, the PA-8BKM pair. These ST-202 boards are ready now.  You’ve never heard a B&K like this. New stereo driver board pictured below with PS-500SE power supply. Sweet sound indeed.  (12-07-22)

NEW SUPERB B&K AMP UPGRADE…..with new PC board replacements are here. These are all new for us. They owe their creation to the PA-7/8 modifications. They bring the exciting improvements available to Hafler owners so B&K owners can smile anew. We no longer have to tell B&K owners to get a Hafler if they want our best of our mods.

These are for amps with the ‘plastic’ TO-3P style transistors. The earlier B&K amps with the full metal can mosfets will eventually be addressed too. We welcome your comments on those early amps. As information becomes available you will see details on the B&K amp page.  (11-11-23)

Power MOSFET replacement ……… is becoming a problematic issue with the announced “END OF LIFE” status for the Exicon metal can/TO-3 style devices. If you have a Hafler amp you might want a set for your amp if they are available. We will investigate the adoption of the TO-247 size ‘plastic’ devices like we use for our PA-8 mod for application in the DH-500/XL-600.(05-09-22)

Recent feedback…..

“Absolutely amazing. Day and night difference. The sound is outstanding.” DH-500 with PA-7 Elite & PS-500 V2B, David S., FL


A NEW MUSICAL DESIGN AMPLIFIER…. new M4 power amplifier.


This is not a digital power amp, class D or familiar digital type. M4 is a full Class AB power amp owing its creation to our Musical Concepts PA-8 circuitry. We use a high bias on our UK sourced power mosfets for a silky low distortion sound. It compares more than favorably our previous, much beloved, D-75 amplifier.

Some speak to the ‘special-ness’ of a single pair of output mosfets.That quality, the distortion reduction when compared to multiple pairs of even tightly matched devices, yields a smooth, silky sound like our beloved D-75 but at the next level.




You will be wowed. You have to hear it to believe such sound is coming from this compact amplifier. It’s not magic just ear-approved engineering. To convince you we are considering a loaner program. More info and photos to come soon. M-4 is officially launching soon at $2000 (11-11-23)

SP-1/2/2B preamp upgrade changes……z….are listed here. (04-20-20)

Chameleon Phono Board Update………… is now available. There are new operating points for the gain stages and new cathode caps

 with new bypasses. Listeners report a “panoramic” quality with better micro and macro details. Also a superior octave to octave balance and clarity has been noted. A truer sense of depth and focus has been mentioned with some images closer and others deeper for a more pinpoint imaging quality, a more solid sound stage portrayal.(10-03-18)  And remember there are upgrades to the main boards and individual gain  (Active) boards too in many cases.

Musical Design D-140 and D-150 amp owners…. can now enjoy a striking upgrade in sound quality with our new 7 Series driver boards. Put those aging driver boards out to retirement. See our D-150B amp page. (08-11-18)

SP-1/2/2B Upgrade………. time is here. We have now developed two levels of outstanding upgrades. The dynamics, naturalness, clarity and bass performance is a joy to the audiophile heart. Seezz tzhe details. (08-11-18)

Check out our Hybrid Amps!……… Sweet, clean, immensely natural dynamics and definition!

SEE NEW……. power amp lineup with four new amps! See our T-100, 100W/CH Hybrid Amp!

NEW PRICING, FEATURES FOR OUR HYBRID AMPS........... Musical Design T-75 and T-100

New! Musical Design DM-100D …..…CRC multi-stage power supply - smooth, affordable. See the details.

New! Musical Design D-75D …….CRC multi-stage power supply - smooth, affordable. See the details.

New! DAC-1A Upgrade is .…….… incredibly 3D with finely sculpted imaging. It’s musical reality! Details!

Ultra Natural sounding…………. Elite and Elite Ultra option on many models!

Phono add-on board option for …………..Chameleon and legacy SP-2B model. Here!

Check out the DEMO/USED page............for some new Musical Design items.

Musical Concepts / Musical Design Modifications challenge the best new products! New components - superb sound quality, unparalleled value!