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John Bedini's Amplifier Pages

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  • John Bedini's Amplifier Pages

    Welcome to John Bedini's Amplifier Pages
    The class "A" SE Amplifier that started it all:
    the model 10 mono parallel
    KT88 tube amplifier.

    This Amplifier used a 6SN7 low Mue driver to power the parallel KT88 tubes
    Bedini is going to bring this amplifier back into production in
    December 1- 2002
    orders can be placed at Bedini Audio

    These are some of amplifiers we were
    building in high school electric shop, 50's 60's:

    This amplifier's output was between 23 to 24 watts. This is the internal diagram of the 6N6-G tube with built in ballast resistor from what I can remember. It reminds Me of a darlington transistor," good sounding tube".

    For good output transformers. it would take us three days to wind them - but what a difference in sound because of the increase in iron in the transformer!


    Model 200/200

    This amplifier used the first
    feed forward dual diff-amp front end. the output stage was a quasi-complementary design, John Bedini and Jack Strelioff were the first amplifier company to do it with this new design you could split the sing wave into a plus and minus and put it back together again in the output , with decreased distortion. These amplifiers in the 70'swere the first to drive the Infinity QSL loudspeaker systems at ear- busting levels of over 450 watts RMS. The Amplifiers were in a "Pull out Modules" (as can be see from the picture) The front panel included , over tempeture lights and fuse lights,and a power indictor. The output transistors that were used were the RCA 1B05's. the circuit boards were mounted inside the modules connected by Molex connectors. The company lasted for about 3 years, then John and Jack split up the partnership to go their separate ways.

    These Amplifiers were some of the best that could be built at the time and are untouchable to this day in sound quality.
    What did the ad say?

    The only amplifier that can challenge the Bedini Amplifier is another Bedini. The result is always a draw because every Bedini pure class A stereo amplifier has the same "Lab Standard" specifications. Whether you're listening to the low-level model 10/10 or the newest 200/200 (both pictured) or even the 25/25, 45/45, 100,100 models, you can rely on the same performance except for the power output. Designer John Bedini 11 years of research uncovered what others are beginning to discover: negative feedback can look good on the lab bench, but it cannot make amplifier distortion (TIM. SID) go away. Negative feedback it seems, produces it's own problems, such as frequency phase shift.

    Bedini positive feedback design produces a constant source current, resulting in an amplifier unrivaled in transparency, depth of perspective, definition of inner detail and crystal smoothness of highs. Thus, Bedini's were not designed to pass sine waves in a lab. they were designed to pass musical instrumentation for musical listing enjoyment.
    To prove the point that this class A series of DC-coupled amplifiers works small miracles, try a lightweight 25/25 with a pair of Quad electrostatics, Perfecto!

    Besides its sonic achievements, the 200/200 (with top open) has impressive specifications: Frequency response at 1W is flat from DC to 200Khz and at full power: DC to 40Khz: at 200 watts per channel into 8,4, or even down to 1.2 ohms ( the unit is always stable). THD from 20 to 20Khz is no more then 0.25%. It takes a mere 1/2 volt to drive the 200/200 to a full 200 watts per channel.

    Bedini Amps: An American renaissance in amplifier design.

    The power amplifier board one channel, on the model 200/200
    17 250 Volt, 15 Amp Transistors
    Model 200\200

    The Model 100/100

    Dual Transformer Supply
    Class A Amplifier.

    This amplifier was rated at 120 watts at clipping into 8 ohms
    240 watts at 4 ohms
    5hz to 30khz at no more then .25% THD.
    This amplifier worked wonders driving Infinity speaker systems
    down to 1.2 ohms in the Bass frequencies

    This Amplifier will be produced in the "Vintage Series 100 Watt Mono Blocks"
    coming up in December 1-2002.
    The Vintage Series looks like the old Dynaco's of the 60's and 70's
    I will be putting up pictures of the Vintage Series along with all the specifications.

    Copyright John Bedini Nov 18,2002.
    Bedini Electronics

    We moved! Bedini Electronics, Inc. in Coeurd d' Alene, Idaho

    Bedini is currently remodeling this building to build the Vintage amplifier series. Bedini has been asked to produce an amplifier that is affordable in price for the public, while keeping the sound quality to the highest standards. John Bedini has been working around the clock to bring the very best sounding amplifier to market. John and Gary do all the listening testing as the pro-type amplifiers are put together. John does not like pictures taken in the shop area because of some of the other designs he is working on. He feels that this is going to be the giant killer in the market place. He has said that these amplifiers are going to compete with amplifiers costing five times the price and out perform them, and from what we have seen and heard he has got the answer and the sound to do it. For years, John has developed sound processing equipment for the recording studios, BASE is a example of that on most of the CD that are recorded to this day. B.A.S.E. stands for Bedini Audio Special Environment . The process was used on movies like Star Trek, Hunt For Red October, and many others too numerous to list here. Stay tuned more coming...

    The old Bedini building

    This building was setup for the current amplifiers and has full machine shop capabilities.
    Energy Science Forum


  • #2
    The Vintage Circuit Board.

    The Vintage Series circuit boards now takes the place of the older boards with the least amount of devices in the signal path. The vintage boards give the best sound quality, because of the point- to- point wiring connections to the output stage. The Vintage series amplifier are all hand wired; there are no circuit boards in them.

    The 10/10 Class A Amplifier
    The Rarest of the Bedini Amplifiers.
    The model 10/10 class A amplifier only 35 in number. This Amplifier was given to dealers who sold Bedini products as a leader piece of equipment. If the dealer bought a mix of products then one Model 10/10 amplifier was given to them. Nothing could come close to the sonic ability of this amp except for the Vintage KT 88 tube amplifier ( pictured on the first page). I designed this Amplifier and have seen these amps selling on eBAY for as high as $800.00 or more, the original cost to the public was $375.00. The Amplifier was used by most people for STAX Headphones and in Tri-Amp systems where three Bedini amplifiers would be used, because all the input voltage levels were the same. Simple passive crossovers were the only thing needed.

    The 25/25 Class A Amplifier
    This Amplifier is going to be reproduced and available from Bedini Audio

    What did they say about the 25/25

    The Audio Critic

    Volume 2, Number 3 Spring through Fall 1980
    Since our original review in the last issue, the marvelous little model 25/25 had undergone a $195 price increase and some major changes in its internal physical layout, eliminating virtually all wiring other then the circuit boards themselves. The sound is, if anything, even better; the silkiness of the highs and the transparency of the midrange are unsurpassed in our experience, except possibly by some-- not all-- versions of the Futterman tube amplifier and one or two experimental solid state prototypes. The bottom end of the Bedini is very impressive for a 25/25- watt stereo amplifier with a single power supply, but of course there are many large amplifiers with all-out dual power supplies that will give you firmer and subjectively deeper bass, (John Bedini has been experimenting with a heavily beefed-up power supplies for a variant version of the 25/25; we have looked at a slightly miscalculated sample and found it quit promising, but for the moment this is not a commercially available product and would have to sell at a much higher price if it were marketed.)
    We want to state again that the Bedini 25/25 appears to be just about the ideal amplifier for driving the Quad electrostatic loudspeaker; the combination provides the utmost clarity, very satisfactory SPL capability and complete safety, since the largest voltage swing the 25/25 can deliver into a load of any impedance is considerably short of whatever could damage the Quad, even on a long-term basis. And that $845 price tag seems a little more tolerable in a low-powered amplifier when you can tell yourself that you're buying a Quad accessory.
    We also wish to withdraw our recommendation of the Cotter NFB-2 noise filter/buffer for use at the input of the 25/25. that was our initial lab bench determination; several months of listening experience have convinced us that real-world input signals, even the fasts, are unable to get the Bedini into any kind of audible trouble.

    The One Meg Class A 25/25

    The amplifier that blew the others away!!!
    This amplifier is the most sought after by audiophiles to this day, their is nothing in the market to compare it to in the 25 watt range. The amplifier used one of the best transistors that Motorola ever made the 2N5885, 4Mhz device at 25 amps. This amplifier is also a positive feedback feed forward circuit using a dual diff-amp front end like all Bedini amplifiers coupled to the NPN quasi- complimentary output stage. The amplifier also used modified diff amplifiers using tunnel diodes to balance the currents. This amplifier would run loads down to 1ohm with no problem, most of these amplifiers were used to run ribbon loudspeakers to high levels.
    The internal view shows that it used dual transformers in push pull wired to a power supply board with 23,000 Uf capacitors. There were 11 devices per channel, it also used a split power supply at 60 volts.

    The Model 801 Class A
    The model 801 amplifier was manufactured between June 1987 to August of 2000. The amplifier was 120 watts at 8 Ohms with less then .1 THD 20 to 20 Khz, The 801 amplifier used the 25/25 drive boards with a bigger power supply. This amplifier will also be produced in the Vintage series Mono Blocks. The more we study the construction of these amplifiers the better the chances to build any power level into the Vintage series Mono Blocks, keeping the best sound quality of all the amplifiers.

    The Model 100\100 Dual Mono One Meg
    The model 100\100 dual mono one meg
    This amplifier is in the same class as the model 25\25 One Meg using the same chassis as the model 200\200, the amplifier is gray in color only. Their is a matching pre-amp dual mono also gray in color.
    Energy Science Forum



    • #3
      The Vintage Series Amplifiers
      The Vintage Series Class A Amplifiers
      These amplifiers are designed and built by Bedini Electronics Inc in Coeur d'Alene Idaho. The amplifiers are gathered over the thirty eight years from John Bedini's private collection of the best sounding circuit designs. We at Bedini Electronics went to John's basement and started going through all the proto-type amplifiers, Pre-Amps, tubes, ect. We hooked up the proto-types KT88 tubes to theShahinian Diapason Speaker System, listening to the tube amplifiers we could not believe what we were hearing out of these 10 watt mono block amplifiers. John said that he was saving the amplifiers until the industry gave it, it's best shot and then He was going to bring this vintage amplifier out to market at a price everybody that loved music could afford. The amplifiers pictured below are the proto-types of the KT88 Mono Block that we are going to start production on, starting in December. The amplifier will only be built in the "Vintage Packaging".

      Sign wave of the model 10 Mono Block SE, notice how the sign wave looks at full power before clipping at 11 volts RMS into 8 ohms which equals 15.125 watts. The wave looks just like most of the solid state amplifiers. John explains it's the way the auto feed forward bias is connected to the tube cathode and wont give any more details about it. I have seen this amplifier clipping, and both wave forms clip symmetrical. So here is what I have done, I went and looked for pictures of sing waves of what, others considered to be the best output into 6 to 8 ohm loads and what they look like, look for yourself at what the difference is. The Tektronix is the Bedini Amplifier at full power, the other is one of the best they claim. Judge for yourself !!!!

      Notice how the two amplifiers reproduce the wave forms. Bottom picture is your typical SE tube amplifier at full power. Top picture is the Bedini SE amplifier.

      John sometimes tells the story of how He, and Saul Marantz , Stewart Hegeman use to talk for hours at the CES shows about special tube circuits and how they worked and what could be done to make the amplifiers sound the best, and I believe it after my listening to this amplifier.
      Paul Sutherland

      Shahinian Diapason Speaker System

      The Mono Block Vintage 100 Class AAmplifier

      These are the mono block 100 watt class A amplifiers, these are the proto-types, the amplifier will only be made in the Vintage Packaging only, chassis is black and gray or black and black with brass trim.

      Energy Science Forum



      • #4
        Where does the 150 mkII fit into design & timeline of the other amps?

        Was it an answer to a price point (as a 1 transformer model) or did the mkII represent a change in direction circuit wise?
        Last edited by AURAL STIM; 09-20-2013, 02:09 PM.


        • #5
          hi, wanted to know if John had considered buiding a RIFE device for healing purposes .

          I am certain that his technology would be most suitable & able to give a truely natural wave ( maybe reviving crystal technology ) .

          Please do consider as I for one would be happy to purchase it .


          • #6
            i think 150 mkII cases not consistent with the design and timing of other amps? Is that an answer to a price (as a transformer model 1) or did the mkII represents a change in direction circuit wise?


            • #7
              Originally posted by casstete View Post
              hi, wanted to know if John had considered buiding a RIFE device for healing purposes .

              I am certain that his technology would be most suitable & able to give a truely natural wave ( maybe reviving crystal technology ) .

              Please do consider as I for one would be happy to purchase it .
              how to purchase it???


              • #8
                Originally posted by Cabeceira View Post
                how to purchase it???
                Aaron Murakami

                You never change things by fighting the existing reality. To change something, build a new model that makes the existing model obsolete.” ― Richard Buckminster Fuller


                • #9
                  I think 150 mkII case is inconsistent with the design and timing of other amps? Is it the answer to a price (as a transformer model 1) or did mkII represents a change in direction circuit wise?