**Please be sure and check out our newly launched website with additional items for sale** www.skyfiaudio.com/collections/all
Integrated amplifier with original wooden case.
This is a true survivor and the highest quality MA-5100 you are likely to find on the market. It probably looks this way because it's a one owner piece that was kept in one single place for its lifetime.
The faceplate and glass are absolutely pristine. Removing the unit from the case reveals perfect chrome work and scratch free metal work.
We replaced the display bulbs and cleaned all moving parts for perfect operation.
Passed our bench test and is producing around 50W per channel, enough to drive most vintage speakers with authority and ease.
Priced according to condition.
Link to download manual:
PREAMPLIFIER SECTION The phono and tape head preamplifier circuits in the MA 5100 have three transistors in each channel. The input selector switch connects the input jacks to the first voltage gain stage of the preamplifier. The input stage has high voltage gain and very low noise. The next stage, an emitter follower, acts as an impedance converter that matches the input stage to the second voltage amplifier. The emitter follower is direct coupled to the second voltage amplifier. Negative feedback is used around the low level section to reduce noise and distortion to an absolute minimum. The negative feedback also provides precise frequency compensation for magnetic phono cartridges and tape heads. The feedback remains in effect through the entire audio bandwidth, even at 20 Hz where gain is the highest.
This kind of careful Mclntosh engineering assures you of lowest distortion performance. The tape head input impedance is 500,000 ohms. High tape head impedance permits uniform high frequency performance from typical tape transport playback heads. The MA 5100 is ideal for tape recording. With an input signal from a phono cartridge of 10 millivolts, there is 1.4 volts available at the tape output jacks. Phono input signal overload is virtually impossible. At 1,000 Hz the phono input will accept greater than 125 millivolts without overloading. This is more than than 4 times the output from most phono cartridges when playing a low distortion phonograph record.
The phono input impedance is 47,000 ohms. This matches the impedance of magnetic cartridges. The preamplifier output is connected by the input selector switch to the tape output, the tape monitor switch, the balance control, the loudness compensation switch, and the first section of the volume control. This arrangement permits recording of the program without interruption and has the ability to monitor the recorded tape. The use of a two section volume control performs two important functions.
First, the input section of the volume control increases the signal handling capability of the tone control amplifier. Use of this arrangement makes overdriving the tone control amplifer almost impossible.
Second, the output volume control assures maximum signal to noise ratio regardless of the volume control position. The tone control stages are made up of a three stage amplifier. The first two transistors are emitter followers. The first emitter follower is driven from the output of the volume control. The second emitter follower is direct coupled to the third stage.
The third stage is a high gain voltage amplifier. Signals pass through the input emitter follower and then couple to the second and third tone control stages through the tone control network. The tone control contours are obtained by controlling the large negative feedback around the second and third transistors. This negative feedback is used to accurately shape the response.
The large amount of negative feedback also makes possible low distortion from the tone control amplifier. The output of the tone shaping amplifier drives the low frequency and high frequency filters and the second section of the volume control. The filters are designed to remove unwanted noises such as turntable rumble and record scratch. The filters remove the maximum amount of objectionable material and still have a minimum effect on the musical content of the program material. The output of the volume control is fed to a two stage voltage amplifier that has very low noise characteristics. Negative feedback is used to improve the signal to noise ratio and assure an absolute minimum of distortion.
The phase switch is part of the left channel circuit. The switch selects from two sources that are of equal amplitude but are "out of phase" to each other. In the normal position the phase is the same in both channels. When the phase switch is in the 180° position the left channel is "out of phase" when compared to the right. Out of phase program source material is easily corrected with the use of this switch.
This item will be professionally packaged and insured for safe transit to your home.
If we don’t have the original manufacture's packaging, we use heavy duty double ply corrugated boxes with Instapak expanding foam custom inserts. In many cases this has proven to be better than the original packaging. We also use high quality fiber reinforced tape to seal our packages. Lightweight items will be bubble wrapped and shipped in a high-quality box.
This item is available for pickup in Ridgewood, NJ or Union Square, NYC (with convenient parking in the building).
NJ Residents or anyone picking up without a resale certificate will need to pay NJ Sales Tax.
Use the Buy It Now button and we will cover the PayPal fees.
Thanks for looking and be sure to call or text 646.852.2073 with any questions.
Please also be sure and visit our Audiogon e-store to see the rest of the items we have for sale www.audiogon.com/stores/skyfi
**And be sure to check out our newly launched website with additional items for sale** www.skyfiaudio.com/collections/all
WHO WE ARE
Skyfi Audio is a small startup business specializing in the purchase, reconditioning, and reselling of select high end audio equipment. We only buy equipment the we admire and are passionate about. No mid-fi, no gimmicks, and no junk.
Each piece of equipment is cosmetically restored and fully tested in our well-equipped lab by an engineer with 30+ years of experience in the HiFi world. If it does not meet or exceed the original manufactures specifications, it will not be sold. We are very selective about the equipment we purchase, focusing on mostly analog, high-build quality, American, and European built units.
Through our sister company, which is an authorized dealer for McIntosh, Audio Research, Sonus Faber, ClearAudio, Project, and Sony ES, we have access to OEM parts, service, and support. If you are local and are looking for any new equipment for the above-mentioned manufacturers, please drop us a line as we can arrange both sales and professional installation in the tri-state area
We do not accept or review any offers that do not go through the official Audiogon system. We have too many items for sale and its nearly impossible to keep track of offers outside of the official system. Please don’t message, email, or text any offers.
If you do not see a “Make an Offer” button, it means we are not considering any offers on that item.
We prefer working through PayPal, which allows you to use a credit card or bank transfer. We do not charge extra for any payment fees if you purchase the item at the asking price. You can also send us a personal check (which will need to clear before shipping), certified check, money order, or wire transfer. International clients without access to PayPal should use a bank wire transfer.
If you are picking up an item, we do not accept PayPal. You must pay in person with cash, certified or bank check, or wire transfer. If you make a PayPal payment and are picking up the item, it will be returned.
TRADE IN POLICY
We accept trade-ins of equal or lesser value under certain conditions. Simply ask and let us know the exact model, condition, and the accessories that are included. Such as the original box, remote, manual, etc. We will only consider high-end equipment from mainstream manufacturers such as McIntosh, Mark Levinson, Audio Research, Krell, etc. and will typically pass on displays, projectors, receivers, dated processors, and mid-fi equipment of any type. We will offer a fair value for your equipment, but keep in mind we are running a business and will need to be able to resell the equipment at a profit after investing a great deal of time and resources in testing, certifying, repairing, cleaning, and packaging the incoming equipment. If you are looking for top dollar we suggest attempting to sell it directly to an end user on your own.
SELL US YOUR GEAR (Working or Broken)
We will also purchase your used or broken gear and arrange pickup if you are in our local market. Just drop us a note for a quote but be sure to include the condition and what is included.
HOW TO VISIT US
We are currently operating from a residence in Ridgewood, NJ. You are welcome to make an appointment if there is a piece of equipment you would like to see in operation before or after purchase. We have a well-equipped, dedicated listening room with tons of equipment of all makes and models. We are not a store, so please don’t make an appointment if you are just curious as to how a speaker or piece of equipment sounds. In essence, no tire kickers please.
If you are in NYC and cannot make it out to Ridgewood, we can arrange pickup in Union Square (14th Street) after the purchase. You can call or text 646.852.2073 with any questions or to schedule an appointment. We can also arrange to install, calibrate, and tune the gear in your listening room if you are local to the area. This is super useful when purchasing large speakers or heavy amplifiers. It is also great for ensuring your new turntable is setup correctly in its final resting place.
Thanks for looking and please send us your email address if you would like to receive a list of the equipment we receive from time to time. We promise not to bombard you with junk email.