{"product_id":"musical-fidelity-a1-integrated-class-a-amplifier","title":"Musical Fidelity A1 Integrated Class-A Amplifier","description":"\u003cp\u003e\u003cstrong\u003eA1 - Overview\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eIn Hi-Fi, the Musical Fidelity A1 has become one of the most classic designs – inside and out. First released in 1985, it quickly made waves as an absolute beast at driving some of the most difficult speakers of the time, even though it was actually a rather low-powered integrated amplifier. But: it was all done in pure Class A with excellent and expertly laid out discrete symmetrical circuitry topology and using only the highest quality components. The A1 showed people that there was more to amplifiers than just high power.\u003c\/p\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003ccenter\u003e\u003cimg src=\"https:\/\/www.musicalfidelity.com\/uploads\/images\/productpage\/A1_8.jpg\"\u003e\u003c\/center\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003cp\u003eBased on its huge success, the A1 has gone through multiple reissues and new versions over the years.\u003c\/p\u003e\n\u003cp\u003eNow, for 2023, for the first time since its initial release, we have actually kept all specifications, the appearance, and circuits of the 1985 rendition for those who missed out the first time. With an updated transformer, power supplies, and modern low noise components, we’ve revitalized the formula and are proud to reintroduce the fresh original – three decades later.\u003c\/p\u003e\n\u003ch3\u003eTechnical Talk\u003c\/h3\u003e\n\u003cp\u003eThe A1 is built around a completely discrete and symmetrical Class A topology. It‘s able to output 25W of pure Class A power @ 8 ohms load with 25A of maximum output. While the numbers here might seem rather low, the ability for the output stage to drive difficult speakers is a small miracle in itself. The amp design being dynamic class A, and if Class A standing current is exceeded, it will automatically allow more. It therefore “slides” (NOT “switches”) smoothly into class B style operation, temporarily allowing the further current draw needed.\u003c\/p\u003e\n\u003ch3\u003ePower Supply\u003c\/h3\u003e\n\u003cp\u003eThe new A1 has received an updated transformer from shared (1985 original) to more efficient “dual mono split rail” windings. The amp stages are supplied by fully independent left and right power supplies for better power handling and stereo imaging and each power amplifier now has double supply capacity resulting in reduced ripple and noise.\u003c\/p\u003e\n\u003cp\u003eThe transformer‘s noise and heat dissipation are reduced due to better efficiency and updated components. The main supplies are filtered for better regulation and reduced switch on surge.\u003c\/p\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003ccenter\u003e\u003cimg src=\"https:\/\/www.musicalfidelity.com\/uploads\/images\/productpage\/A1_2.jpg\"\u003e\u003c\/center\u003e\n\u003ch3\u003ePreamplifier\u003c\/h3\u003e\n\u003ccenter\u003e\u003cimg src=\"https:\/\/www.musicalfidelity.com\/uploads\/images\/productpage\/A1_5.jpg\"\u003e\u003c\/center\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003cp\u003eThe low noise preamplifier circuitry is the same as the original 1985 design and, as we have highlighted above, greatly benefits from the improved, fully smoothed and regulated power supplies.\u003c\/p\u003e\n\u003cp\u003eAmong the discernible alterations, one that immediately catches the eye is the addition of a new „direct“ switch at the preamp stage. With this switch you can totally bypass the gain block before the volume control, resulting in roughly 10dB less gain. This feature proves particularly advantageous when working with modern or high-output digital sources, enabling fine tuning the range of your volume potentiometer and accommodating sensitive loudspeakers.\u003c\/p\u003e\n\u003cp\u003eFurthermore, a notable upgrade has been made to the volume potentiometer itself, now replaced by a premium ALPS RK series potentiometer. This high-quality component ensures superior performance and enhanced precision. Additionally, the potentiometer is now motorized, granting you the convenience of adjusting the volume from the comfort of your couch, courtesy of the new included remote control.\u003c\/p\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003ccenter\u003e\u003cimg src=\"https:\/\/www.musicalfidelity.com\/uploads\/images\/productpage\/A1_4.jpg\"\u003e\u003c\/center\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003ch3\u003ePhono Stage\u003c\/h3\u003e\n\u003cp\u003eThe A1 employs a discrete current-mode input stage for the lowest noise amplification of MC and MM cartridges. A low-noise current-to-voltage conversion stage is used for further amplification and RIAA equalization. Automatic input impedance matching for the selected MC input, along with increased gain, increases the versatility of the A1‘s phono stage.\u003c\/p\u003e\n\u003ch3\u003eThe return of a true Hi-Fi classic\u003c\/h3\u003e\n\u003cp\u003eThe A1 has one secret. This secret is simple: it makes music. It sounds sweet and fluid, creating a beautiful atmosphere around natural instruments. Especially in small to mid-sized rooms, carefully set up with a pair of great two-way speakers. It is not a powerhouse, but music lovers will cherish its abilities.\u003c\/p\u003e\n\u003cp\u003eIt's also not a product you'll want to hide. A perfect example of form follows function. The oversized heatsinks define the A1‘s look, but they are essential for its operation. Truly unique, inside and out.\u003c\/p\u003e\n\u003cp\u003eThe A1 has a sweet, warm, complete, and exciting sound. No harshness. No grain. Just pure music. It doesn‘t get muddy, and despite its lower power, it drives difficult speakers with ease. It remains clean right up to its power limit. To hear what the A1 does is to listen to what Hi-Fi is supposed to do: it makes music, pure and simple.\u003c\/p\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003ccenter\u003e\u003cimg src=\"https:\/\/www.musicalfidelity.com\/uploads\/images\/productpage\/A1_6.jpg\"\u003e\u003c\/center\u003e\n\u003ch3\u003eThe A1 through time - Improvements to the original\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eUpdated transformer to more efficient “dual mono split rail” windings\u003c\/li\u003e\n\u003cli\u003eHigh-quality and updated ALPS RK series potentiometer as volume control\u003c\/li\u003e\n\u003cli\u003eIR remote control has been added for volume\u003c\/li\u003e\n\u003cli\u003eGain block before volume control is totally bypassable using “the direct” switch (-10dB)\u003c\/li\u003e\n\u003cli\u003eAll transistors, including output devices, are carefully selected modern equivalents.\u003c\/li\u003e\n\u003cli\u003eAll capacitors in signal path are polypropylene (PP) type\u003c\/li\u003e\n\u003cli\u003eResistors are modern low-noise metal film types\u003c\/li\u003e\n\u003cli\u003eCare and attention were taken not to change any component specification from the original but to update them to modern equivalents with a long lifespan.\u003c\/li\u003e\n\u003cli\u003eThe layout faithfully follows the original within circuit sections on the circuit board.\u003c\/li\u003e\n\u003cli\u003eCircuit sections are better laid out, in particular, the separate supplies and power amplifiers.\u003c\/li\u003e\n\u003cli\u003eThe phono stage and preamplifier were improved for less noise and hum.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003ccenter\u003e\u003cimg src=\"https:\/\/www.musicalfidelity.com\/uploads\/images\/productpage\/A1_1.jpg\"\u003e\u003c\/center\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003ch3\u003eThe A1 in Brief\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e25W Pure Class A power @ 8 Ohm\u003c\/li\u003e\n\u003cli\u003eDiscrete symmetrical topology\u003c\/li\u003e\n\u003cli\u003ePlanar Audio transistors with 25A maximum output\u003c\/li\u003e\n\u003cli\u003eDynamic class A, slides (NOT switches) smoothly into Class B, allowing more current as needed\u003c\/li\u003e\n\u003cli\u003eTherefore, it drives difficult speakers with no problems\u003c\/li\u003e\n\u003cli\u003eUpdated transformer to “dual mono split rail” windings\u003c\/li\u003e\n\u003cli\u003eFully independent left and right power supplies\u003c\/li\u003e\n\u003cli\u003eEach power amplifier now has double the supply capacity\u003c\/li\u003e\n\u003cli\u003eTransformer noise and heat dissipation are reduced\u003c\/li\u003e\n\u003cli\u003eFiltered main supplies\u003c\/li\u003e\n\u003cli\u003eGain block before volume control is totally bypassable using the “direct” switch\u003c\/li\u003e\n\u003cli\u003eHigh-quality and updated ALPS RK series potentiometer\u003c\/li\u003e\n\u003cli\u003eLow noise TL071 JFET preamplifier circuitry\u003c\/li\u003e\n\u003cli\u003eDiscrete current-mode MM\/MC phono input stage\u003c\/li\u003e\n\u003cli\u003eLow noise current to voltage converter for further amplification and RIAA equalisation\u003c\/li\u003e\n\u003cli\u003eAutomatic input impedance matching (1K nominal) for MC, along with increased gain\u003c\/li\u003e\n\u003cli\u003eOriginal (1985) A1 appearance and circuits with modern improvements\u003c\/li\u003e\n\u003cli\u003eA remote control has been added for volume\u003c\/li\u003e\n\u003cli\u003eModern updated low-noise components\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2\u003eSpecifications\u003c\/h2\u003e\n\u003ch3\u003eAmplifier\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003ePower: 25 Watts per channel into 8 Ohms\u003c\/li\u003e\n\u003cli\u003eVoltage: 42.5 Volts peak to peak\u003c\/li\u003e\n\u003cli\u003eCurrent: 25 Amps peak to peak\u003c\/li\u003e\n\u003cli\u003eDamping Factor: 150\u003c\/li\u003e\n\u003cli\u003eGain (volume max): 32dB (Direct Mode), 42dB (Normal Mode)\u003c\/li\u003e\n\u003cli\u003eOutput devices: 2 per channel\u003c\/li\u003e\n\u003cli\u003eSignal\/noise ratio: 82dB\u003c\/li\u003e\n\u003cli\u003eChannel separation: 85dB\u003c\/li\u003e\n\u003cli\u003eFrequency response: + 0, –1dB, 10Hz to 40 kHz\u003c\/li\u003e\n\u003cli\u003eLine level sensitivity: 300mV rms nominal, 8V rms max\u003c\/li\u003e\n\u003cli\u003eLine level inputs impedance: 25k Ohms\u003c\/li\u003e\n\u003cli\u003eTape Out impedance: 220 Ohms\u003c\/li\u003e\n\u003cli\u003ePre Out impedance: 100 Ohms\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003ePhono Preamp\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003ePhono RIAA response: +\/- 1dB\u003c\/li\u003e\n\u003cli\u003eMM sensitivity: 5mV nominal\u003c\/li\u003e\n\u003cli\u003eMM capacitance\/impedance \/ gain: 100pF \/ 50k Ohms \/ 40dB\u003c\/li\u003e\n\u003cli\u003eMM signal\/noise ratio: 75dB\u003c\/li\u003e\n\u003cli\u003eMC sensitivity: 450μV nominal\u003c\/li\u003e\n\u003cli\u003eMC impedance\/gain: 1k Ohm \/ 60dB\u003c\/li\u003e\n\u003cli\u003eMC signal\/noise ratio: 70dB\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eInputs\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e1x phono RCA MM\/MC, 5x line RCA\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eOutputs\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e1 x line level RCA fix TAPE OUT\u003c\/li\u003e\n\u003cli\u003e1 x line level RCA var PRE OUT\u003c\/li\u003e\n\u003cli\u003e1 x 4mm banana\/binding posts SPEAKER OUT\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eGeneral Information\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eDimensions (WxHxD): 440 x 68.3 x 283.3 mm\u003c\/li\u003e\n\u003cli\u003eMain voltages: 230V\/115V Internally set or 100V optional\u003c\/li\u003e\n\u003cli\u003eMax. Consumption: 130W, 0W in standby (=Power Switch OFF)\u003c\/li\u003e\n\u003cli\u003eWeight: 10.5kg\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"The Music Room","offers":[{"title":"Default Title","offer_id":51268131094809,"sku":"0456newMUFI","price":1999.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0844\/4225\/1545\/files\/Musical_Fidelity_A1_Integrated_Class-A_Amplifier_1.jpg?v=1768043470","url":"https:\/\/tmraudio.com\/products\/musical-fidelity-a1-integrated-class-a-amplifier","provider":"The Music Room","version":"1.0","type":"link"}