Dynaco Dynatuner FM-3

The Dynatuner is the culmination of more than threee years intensive research on a new concept of FM tuner design. Both the tuner and the stereomatic multiplex integrator represent a totally new design so inherently non-critical, so completely stable, so accurately reproducible, and so easily aligned that the average kit builder will have no difficulty in meeting its specifications in full, without the use of any test instruments whatsoever. The Dynatuner will be most recognized for its low distortion, but it has achieved the most successful blend of sensitivity, stability and linearity yet realized.

The Dynatuner is a kit in every sense; no sections are pre-built or pre-aligned - but Dyna's proven engineering has made it the easiest of all FM tuner kits to build,, and simpler than most competitive amplifiers. The use of heavy duty XXXP and fiberglas pre-punched circuit boards assures exact placement of all components - an essential factor in critical tuner circuits. The excellent specifications of the Dynatuner are possible, and guaranteeable, unit to unit, lab model to production kit, because of the extraordinary uniformity which etched circuits provide, and the inherent stability of the Dynatuner circuit configuration.

 

The design of the Dynatuner evidences several engineering innovations. A cathode coupled RF stage, rather than a cascode input, has been refined to provide equivalent sensitivity without the disadvantages of cross-modulation (images) generally associated with the cascode design. Outstanding AM supression has been achieved,, with noticeable improvement in difficult urban reception areas, and reduced interference from multipath dispersion. Four stages of IF amplification, furnishing four stages of progressive limiting, plus careful attention to limiter design, result in superior suppression of impulse noise such as auto interference, and yield more usable low level signals than other tuners of equivalent sensitivity. We have expended some gain (sensitivity) to achieve better low level limiting, where it counts the most. The Dynatuner limits on noise alone - contributing to its low interstation noise level.

 

The Dynatuner's combination of performance 9high sensitivity, lack of drift, low noise, high selectivity, and lowest distortion) reliability (top-grade etched circuit construction, highest quality parts, conservative operation of components, ease of alignment) and simplicity of construction and operation, plus unsurpassed flexibility (with the FMA-2 and the FMX-3) make it an outstanding example of the Dynakit reputation for obsolescence-proof design.

 

Specifications

Based on IHF standard T-100

Useable Sensitivity:  4 mV for total noise and distortion 30 dB below 100% modulation

Signal-to-Noise Ratio:  70 dB at 100% modulation

Total Harmonic Distortion:  less than 0,25% at 100 % modulation

IM Distortion:  less than 0,5% from 10 mV - 100,000 mV at 100% modulation

Drift:  less than 0,03%

Frequency Response:  10 Hz - 15 kHz ±0,5 dB

Audio Output:  2 volts at 100% modulation

Output Impedance:  less than 5000 ohms

Discriminator peak to peak Separation:  greater than 900 kHz

Antenna Input:  300 Ω (balanced), 75 Ω (unbalanced)

Dial calibration Accuracy:  0,2%

Useable Sensitivity Stereo:  3 dB less than mono mode

IM or T.H.D. :  less than 1% ( including 19 kHz and 38 kHz residual)

Stereo Separation :  30 dB

Capture ratio:  5 dB

Selectivity:  54 dB

Audio Hum:  73 dB below 1 V output

AM Suppression:  greater than 63 dB

Power Consumption:  55 watts

Dynaco PAT-4 pre-amplifier

 

The PAT-4 is a solid state countrpart of the renowed PAS-3X Dynaco stereo preamplifier, providing the same superior performance with a number of added features. The PAT-4 can be used with any tube or transistorized Dynaco power amplifier or virtually any other power amplifier, tube or transistor. Available either as an easy-to-build kit for the hobbyist, or fully assembled and tested, the PAT-4 harmonizes with the Dynaco FM-3 stereo tuner and is directly interchangeable with the PAS-3X in cabinet installations.

The PAT-4 exemplifies Dynaco's long-standing reputation for excellence achieved through innovation and a constant striving for simplicity in both engineering and operation. A remarkably low level of noise and distortion has been achieved - below the level which can be measured with commercial grade test equipment - through the use of carefully selected silicon transistors in a circuit utilizing both DC and AC feedback. Frequency response is extremely wide to prevent deformation of square waves and other signals which depend on wide-band, low phase shift response for accurate reproduction. Overall performance superior to all other transistorized preamplifiers is assured.

An important specification frequently overlooked in evaluating preamplifiers is phono overload capability. The PAT-4, with its 80 mV phono overload point, cannot be overloaded by any magnetic cartridge made today. Transistorized preamplifiers in particular frequently have had poor phono overload characteristics and in the absence of any such overload specification, you have no assurance that the phono stage will not distort severely on many loud passages.

 

The PAT-4 kit is supplied with two identical preassembled etched circuit boards which include virtually all the components except the power supply and the controls, greatly simplifying and speeding construction of the kit, and assuring operation and absolute reproducibility on completion. Each circuit board has been in circuit tested prior to shipment. An open, uncluttered chassis layout provides ready acces for assembly and trouble shooting.

Like all Dynaco products, the PAT-4 is the culmination of years of painstaking design. It has been acclaimed by renowed audio experts, like Julian Hirsch, who wrote in Stereo Review ; "in sonic quality, we would unhesitatingly say that the Dynaco PAT-4 is unsurpassed by any preamplifier we have seen, … a remarkable unit and unmatched at anywhere near its low price …"

 

Specifications

Frequency Response: 

High level Inputs :  10 Hz - 100 kHz ±0,5 dB

Low level Inputs :  20 Hz - 20 kHz ±1 dB

Distortion (at rated 2 volt output):  less than 0,05% (20 Hz - 20 kHz)

IM Distortion:  less than 0,05% with any combinaation of test frequencies

Hum and Noise:

Magnetic phono :  70 dB belowa 10 mV input signal

High level :  85 dB below a 0,5 volt input signal

Gain

Magnetic Phono :  54 dB at 1000 Hz (3mv for 1,5 V out)

High Level :  20 dB (.15 V for 1,5 V out)

Tone Control Range

Bass :  ±16 dB at 50 Hz

Treble ;  ±12 dB at 10 kHz

Maximum Output:  10 Volts into high impedance; 5 Volts into 600 ohms

Impedances:

Magnetic Phono :  47 k Ω

To tape :  from Low level inputs  600 Ω

Tape Head :  100 k Ω

High Level :  100 k Ω

To Tape : from High level inputs same as source

Audio Output :  600 Ω

Amplifier Input :  Nominal load 10 k Ω or higher

Inputs:

Low level or High level RIAA magnetic phono or ceramic phono;

NAB 7-1/2" tape head;

Special (normally microphone)

Tape amplifier

Tuner

Spare High level for TV, etc

Front panel High level

Outputs;

Tape output Ahead of controls

2 Audio outputs (one switched by front panel jack)

Front panell output

Front panel Controls

Selector switch; Volume control; balance control; 2 bass controls; 2 Treble controls;  High Filter switch at 15 kHz, 10 kHz and 7 kHz; Loudness Compensation switch; tape Monitor switch; Low Filter switch; paired (A + B) with 6 dB blend for 3rd channel output, or stereo; illuminated power switch.

Semiconductor Complement:  8 Transistors; 2 Diodes

Power Consumption:  5 watts 120/240 V 50/60 Hz AC

Dimensions (W x H x D):  13-1/2" x 9" x 4-1/4"

Weight (shipping):  4,5 kg (10 lbs)

Dynaco Dynakit Stereo 70

 The Stereo 70 is a dual 35-watt power amplifier, featuring the high quality and moderate price which has characterized earlier Dynakit amplifiers. Its electrical performance is matched only by manufactured amplifiers that cost far more.

The Stereo 70 can be used as apair of 35-watt amplifiers for stereo or as a 70-watt mono amplifier. Its power and distortion ratings are completely conservative. Its listening quality is unsurpassed. 

 Each channel of the Dynakit Stereo70 employs a 7199 triode-pentode and pair of EL-34 output tubes. The lower plate voltage used in the Stereo 70 assures long life for tubes and filter capacitors. In fact this amplifier's components are operated more conservatively than those in any other commercial amplifier we have used.

 The circuitry of the Stereo 70 is very similar to that of the older Mark II and Mark III amplifiers, except for the smaller output transformers. Somehow, the two amplifiers and their power supply have been packaged in a space not much greater than that of the older mono amplifiers, without crowding and apparently without running at a higher temperature.

The Stereo 70's frequency response is so flat that it almost seems pointless to plot it. The power response, in either mono or stereo modes, is nearly as good. The apparent discrepancy between the maximum power outputs shown in these curves and those suggested by the distortion curves is simply due to the different method of measurement. The power response shows the maximum power obtainable before some distortion of the output waveform can be seen on an osciloscope. Very small amounts of distortion can be numerical distortion values can be obtained at much higher power levels.

 The Stereo 70 will develop the eqivalent of 18 watts per channel into a 3-mld capacitive load at 10 kc, which makes it quite suitable for driving electrostatic speakers at high volume levels. It is absolutely stable and free from ringing under and conditions of capacitive loading.

Two power take-off sockets are provided to operate a pair of Dynakit preamplifiers. Each has its own heater winding to prevent interaction between channels.

Specifications

Power Output:  35 watts continuous, 80 watts peak each channel

Frequency Response:  10 to 40,000 Hz ±0,5 dB

Power response:  20 to 20,000 Hz (within 1 dB of 35 watts at less than 1% distortion)

Harmonic Distortion:  immeasurably at power of 10 watts or less

IM Distortion:  less than 1% at 35 watts (less than 0,05% at 1 watt)

Hum an Noise:  Inaudible, better than 90 dB (below 10 watts)

Sensitivity:  1,3 volts RMS input for 35 watts out

Damping Factor:  15

Output Impedance:  4, 8 and 6 Ω

Minimum Channel Separation:  55 dB

Power Consumption:  190 watts 50/60 cps

Preamp provision:  Two power take-offs with independent heater windings to eliminate interaction. Each 6,3 volts 1 amp, 350 volts Dc 10 ma

Special Features: two separate power supply sockets for preamplifier; front panel switch to parallel outputs for operation as a 70 watts monophonic amplifier

Tube Complement:  4 x EL-34; 2 x 7199; 1 x GZ-34/5AR4; selenium rectifier

Dimensions (W x D x H):  13" x 9 ½" x 6 ½"

Weight :  32 pounds

Finish:  chassis and bottom plate bright nickel plated. Cover finished in charcoal brown vinyl paint.

Dynaco PAT-5

 Dynaco PAT-5 Bi-FET Preamplifier

The Dynaco PAT-5 is the control center and preamplifier for your high fidelity stereo system, which is used in conjunction with a power  amplifier, such as the Dynaco Stereo 120 or other basic power amplifier, and pairs of speakers.

When the outputs from the amplifier are connected to the preamplifier, two pairs of speaker may be selected, and any impedance  headphones may be connected to the front panel of the preamplifier.

The PAT-5 provides flexibility and features not found in many other preamplifiers.

 Coming from Dyna, that's really news. Never before in many years has Dynaco claimed marked sonic improvements when it has introduced a new model. Every Dynaco product has been designed for the perfectionist. The simple fact that the PAT-5 preamplifier is clearly superior to previous Dynaco tube and transistor designs is history making. Until now, they were classed with the most expensive competitors.

It includes complete facilities for two tape recorders, truly useful tone controls, external processor loop, monster-amp power and speaker switching capability, extra phono gain option, low impedance headphone output, 3-stage regulated supply, and it is quiet.

Best of all, it's a DynaKIT. Easy assembly, superior parts quality, assured results from complete in-circuit testing of every fully-assembled audio circuit board.

 Circuit Description

The components in the PAT-5 are of the highest quality to protect against failure, and all parts are operated conservatively with close tolerances to assure proper operation for many years. The transistors and integrated circuits have been thoroughly researched and selected for minimum noise and distortion in sustained use, and the printed circuit boards associated with audio signals have been pretested in the circuit to ensure that every unit will meet the laboratory prototype-like specifications.

Each audio channel of the PAT-5 basically consist of three circuit elements; preamplifier-equalizer circuit, control circuit, and tone control-output circuit. The power supply is fully regulated.

The preamplifieer-equalized is a direct coupled NPN/NPN transistor pair operated at 42 volts B+. Parameters have been adjusted for optimum noise, gain, frequency response, input acceptance, stability, and distortion. All feedback is DC connected. The input stage is not affected by the source impedance of the phonograph cartridge so that the cartridge cannot alter the RIAA equalization.

The control section of the circuit, which comprises volume, balance, stereo-mono, low and high filter functions, is driven by a voltage follower containing a PNP/NPN direct coupled transistor pair at low impedance.

The tone control-output section uses a high performance operational amplifier integrated circuit as the entire gain element. DC feedback around the operational amplifier is constant in all modes; only AC feedback is altered for tone control operation. The high frequency RC filter network utilizes an active, low noise two transistor NPN/NPN configuration.

The multiple-stage power supply uses a series regulator transistor with a separate zener diode generated reference voltage for the +42 volts used for the preamplifier circuit. The ±15 volt supplies utilize shunt design zeener diode regulation for the control and tone control-output circuits, and =15 volts for the active RC filter network.  A fully regulated supply has been chosen so that variations of line voltage from 100 to 130 volts AC (alternately 200 to 260 volts) will have no effect on audio performance. This is particularly important if a very powerful amplifier is used, where its current demands can exceed the wall outlet capability. The audio circuits of the PAT-5 therefore always remain stable, because the outputs from the power supply do not "pump" or shift in voltage.

Specifications

Frequency Response:

High Level Inputs :  ±1 dB, 10 Hz to 50 kHz

Low level Inputs :  0,5 dB of RIAA curve

Distortion at 2 Volts Output into 10 k Ω in parallel with 100 pf: 

THD :  0,007% or less (20 Hz to 20 kHz)

IM :  0,007% or less, with any combination of frequencies

Hum and Noise:

Magnetic Phono :  70 dB below at 10 mV input, at 1000 kHz

High Level :  90 dB below a 0,5 volt input

Gain:

Magnetic Phono (LO) to Audio Out :  75 dB at 1 kHz

Magnetic Phono (HI) to Audio Out :  63 dB at 1 kHz

Magnetic Phono (LO) to Tape Out/E.P.L. Out :  37 dB at 1 kHz

Magnatic Phono (HI) to Tape Out.E.P.L. Out :  43 dB at 1 kHz

High Level to Audio Out :  20 dB

High level to Tape Out/E.P.L. out :  Unity

Phono Input Acceptance

LO :  Greater than ±10 millivolts at 1 kHz

HI :  45 millivolts at 1 kHz

Tone Controls:

Bass :  Greater than ±10 dB at 50 Hz

Treble :  Greater than ±10 dB at 15 kHz

Filters:

Low :  -4 dB at 10 Hz, 6 dB per octave (conforms to RIAA phono playback curve)

High :  -10 dB at 10 kHz, 15 dB per octave

Voltage Output:

7 volts minimum into 10 k Ω or greater

4,5 volts minimum into 1000 Ω

Impedances: 

Magnetic Phono :  47,000 Ω in parallel with 220 pF

High Level :  50,000 ohms

Tape Output [from phono inputs/high level inputs]:  15,000 Ω / same as source

Audio Output :  less than 600 ohms

Separation at 2 volts, output into 10 k Ω; undriven input tarminated in 5K:

20 Hz :  70 dB minimum

2 kHz :  70 dB minimum

20 kHz :  45 dB minimum

Semiconductor Complements:

13 transistors; 2 ICs; 3 zener diodes; 4 diodes

Power Consumption:  12 watts, 120 V or 240 V, 50/60 Hz  AC

 Dimensions (W x H x D):  13 ½" x 4 ¼" x 11 ¾"

Weight:  5,9 kg (13 lbs)

Dynaco Stereo 120

 The  Dynaco Streo 120 is an all silicon transistor basic power amplifier for use with separate preamplifiers such as the Dynaco PAT-4 or PAT-5, or for use with tape recorders or tuners such at the FM-5 or AF-6, which have their own volume controls. The Stereo 120 contains two 60 watt amplifiers on one chassis with a common power supply.

 Although the Stereo 120 is an solid state device, containing transistors and similar semi-conductors, it has been designed to be used under normal conditions without special safety precautions, just as if it were a high grade tube amplifier. Thus it can be connected to source and speaker components and used with confidance in all conventional arrangements. There are no circuit breakers, speaker fuses, or other resettable devices to impede the use of the Stereo 120 under any reasonable conditions of use or abuse. This is achieved by using novel circuits which automatically and instantly protect the amplifier.

 The components in the Stereo 120 are of the highest quality to protect against failure, both now and for many years in the future. All parts are used conservatively with close tolerances to assure proper operation, and etched circuit modules are pretested under actual use conditions to ensure that every unit, after assembly, will meet the specifications normally associated with laboratory prototypes.

 The specifications of the Stereo 120 speak for themselves. The distortion at low levels is comparable to that of the finest tube designs, while the high power distortion remains inaudible. Specifications do not reveal all the facets of sound quality. However. In use with varying program material, the Stereo 120 justifies its design efforts to have qualities of ease and naturalness always sought and rarely achieved in solid state designs. There is no extra brightness or stridency which is unfortunately someties attributed to high fidelity sound, but rather there is an impression of limitless range and efortless handling of the highest power peaks.

 Like any precision equipment, the superior capabilities of the Stereo 120 will best be obtained when it is utilized properly.

 

Specifications

Power Output Rating:

60 watts everage continuous power per channel into 8 Ω at any frequency between 25 Hz to 15 kHz at less than 0,5% THD. Distortion decreases at lower power levels. This is in accordance with F.T.C. rating requirements, including preconditioning.

Frequency Response:

5 Hz to 100 kHz  ±0,5 dB

Intermodulation Distortion:

Less than 0,5% at any power level up to 60 watts per channel into 8 Ω with any combination of test frequencies. Distortion reduces at lower power levels.

Noise:

95 dB below rated output unweighted with shorted input; 100 dB down by IHF standards

Damping Factor:

Creater than 40 from 20 Hz to 20 kHz

Separation:

More than 70 dB from 20 Hz to 20 kHz

Input:

100 k Ω, 1,5 volts for 60 watts output

Semiconductor Completed:

15 transitors; 15 diodes

Power Requirements:  100, 120, 220, 240 V 50/60 Hz

Power Consumption:  400 watts

Dimensions (W x H x D):  13" x 4" x 10,5"

Weight:  20 lbs

Dynaco SCA-35

 The SCA-35 is a one piece combined pre and power amplifier. It is the best value of all the Dynaco components and can deliver half again as much steady-state power at the audio extremes as many other units adbertised at twice the wattage.

 Features

1) Input selector for phono, tape head and three high level sources

2) Exclusive bandpass filter eliminates rumble and scratch without destroying the musical balance

3) Functional, easy to understanad controls make it easy for the whole family to use, with sufficient flexibility for the enthusiiast's subtle adjustments.

4) Speaker terminal connectors provided for driving a center speaker, no other amplification required.

5)Inputs for low and high output magnetic cartridges as well as ceramic cartridge provided

6) Three preassembbled etched circuit boards reduce assembly time, no adjustments of any kind are required

7) Specially engineered Dynaco output transformers have phase reversal frequency in excess of 300 kHz to provide complete stability regardless of speaker load.

8) 120/240 V AC power transformer available on special oreder for overseas use.

 The SCA-35 is a completely proven amplifier. Since its introduction in 1963, literally tens of thousends have been built from kits or acquired factory assembled. Even though an integrated amplifier, it maintains Dynaco's reputation for easy -to-build kits, as attested by High Fidelty Magazine: "Building the SCA-35 offered no problems, and several hours of pleasant diversion, to the kit enthusiast. The printed circuit boards are supplied with parts already mounted, and wiring to them and to the rest of the chassis is fairly simple because of the happy absence of crowded areas. The instruction manual is clearly written and excellently illustrated. Total working time was eight hours."

  The result, the magazine went on, "… is, in a word, an excellent amplifier - especially so in view of its cost"   Kit price in 1971 was $ 99,55 for East and $ 104,95 for West.

Specifications

Power Output: 

35 Watts RMS both channel driven at 1000 Hz

28 Watts RMS both channel driven at 20 - 20,000 Hz (either channel alone 17,5 Watts RMS from 20 - 20,000 Hz)

Harmonic Distortion:  under 1% at rated output

Intrmodulation Distortion:  under 1% at rated output

Both Harmonic and IM Distortion (decrease as power is decreased): blelow 0,2% at average listening levels.

Frequency Response:  20 - 20,000 Hz ±0,25 dB

Tone Controls:  ±12 dB at  50 Hz and 15 kHz

Input Signal Required (for rated output at 1 kHz):

Phono Magnetic : 4 mV

Tape : 2,5 mV

High Level : 1 V

Hum and Noise:  70 dB below 10 mV on low level inputs; 80 dB down on high level inputs

Front Panel Controls:  Selector, Volume, balance, Bass and Treble

Front Panel Switches:  Stereo/Mono; Loudness compensation; Bandpass filter; Power

Rear Panel Inputs:  RIAA magnetic phono (high and low level); NAB 7½" tape head; Radio; Tape and Spare

Rear Panel Outputs:  8 and 16 Ω speaker; Tape output (unaffected by balance tone and volume controls), Center channel output (no auxiliary amplifier needed), provision for headphone connection, two AC convenience outlets.

Rear Panel Controls:  Dual hum balancing pots

Tube and Semiconductor Complement:  2 x 12AX7, 2 x 7199, 4 x 6BQ5, 2 silicon diodes

Power Consumption:  100 Watts at 120 V, 50/60 Hz (120/240V powertransformer available on special order)

Dimensions  (W x D x H):  13 ½  x 10 ½ x 4 ¼  inches

Weight (shipping):  20 lbs (9,1 kg)

Cover Included:  Charcoal brown baked vinil cover

DYNACO SCA-80Q (1969)

The Dynaco SCA-80Q is an all silicon solid state stereo control amplifier of exceptionally high quality. It functions as the control center for all mono or stereo signal sources, such as a record player, radio tuner, tape recorder, television sound, etc., and provides output connections from two 40 watt power amplifiers for either two or four loudspeakers, as well as a front panel jack for stereo headphones. Thoughtful planning has provided exceptional flexibility with remarkable ease of operation.
The SCA-80Q incorporates special circuitry which enables Dynaquad™ 4-dimensional playback for increased realism from a four speaker system without any additional electronics. Alternatively it may be used as a conventional two channel stereo amplifier with provision for optional connection of a second pair of speakers in a remote location.
The SCA-80Q has been designed to be used under normal conditions without special safety precautions, just as if it were a high grade tube amplifier. There are no circuit breakers, speaker fuses, or other resettable devices to impede the use of the SCA-80Q under any reasonable conditions of use or abuse. This is achieved by using novel circuits (on which patents are pending) which automatically and instantly protect the amplifier.

The components in the SCA-80Q are of the highest quality to protect against failure, both now and for many years in the future. The transistors have been selected for minimum noise and distortion in sustained use. All parts are used conservatively with close tolerances to assure proper operation, and all four etched circuit modules in the kit have been pretested under actual use conditions to ensure that every unit, after assembly, will meet the specifications normally associated with laboratory prototypes.
The specifications of the SCA-80Q speak for themselves. The distortion at low levels is comparable to that of the finest tube designs, while the high power distortion remains inaudible. Specifications do not reveal all the facets of sound quality, however. In use with varying program material, the SCA-80Q justifies its design efforts to have qualities of ease and naturalness always sought and rarely achieved in solid state designs. There is no extra brightness or stridency which is unfortunately sometimes attributed to high fidelity sound, but rather there is an impression of limitless range and effortless handling of the highest power peaks.

Specifications:
Rated Power Output:

30 watts continuous average power per channel into 8 ohms, 20-20,000 Hz at less than 0.5% total harmonic distortion. Distortion decreases at lower power levels.
Power at Clipping, Single Channel, 1000 Hz, less than 1% distortion:

50 watts @ 8 ohms, 36 watts @ 4 ohms, 26 watts @ 16 ohms.
Intermodulation Distortion:

Less than 0.5% at any power level up to 40 watts rms per channel into 8 ohms with any combination of test frequencies. Distortion reduces at lower power levels.
Half-Power Bandwidth:

20 watts per channel at less than 0.5% total harmonic distortion from 8 Hz to 50 KHz into 8 ohms.
Frequency Response:
Phono: ± 1 dB of RIAA curve @ 1 watt into 8 ohms.
High level: ±0.5 dB, 15 Hz to 50 KHz @ 1 watt into 8 ohms.
Hum and Noise:
Phono: More than 60 dB below 40 watts output.
High level: More than 80 dB below 40 watts output.
Input Sensitivity: 100,000 ohm load; 1.3 volts for 40 watts into 8 ohms.
Impedances:
Magnetic Phono: 47,000 ohms.
High Level: 100,000 ohm.
Tape Output:
From Phono inputs, 10,000 ohms minimum load.
From High Level inputs, same as source.
Headphone Output: 8 ohms or greater.
Phono Input Overload: 80 mV @ 1000 Hz.
Tone Controls:
± 12 dB @ 50 Hz;
± 12 dB @ 10 KHz.
Separation: 65 dB by IHF standards.
Semiconductor Complement: 20 transistors; 10 diodes.
Size: 13-1/2" wide by 12" deep by 4-1/4" high.
Shipping Weight: 18 lbs.
Maximum Power Consumption:

35 watts quiescent; 250 watts maximum; 50/60 Hz, 100, 120, 220, or 240 VAC.

DYNAKIT Pas-3

DYNAKIT Pas 2

Dynakit Preamplifier PAS-2 is a versatile, two channel preamplifier control unit, which permits either monophonic or stereophonic reproduction from any modern program source with any type of modern amplifier. This preamp is a self-powered unit which contains all the necessary amplification, equalization, and control facilities for playing phonograph records, tape, radio, microphone, or other such sources either stereophonically, or monophonically. The Circuit of the Dynakit is unique, and is a subject of patent applications. All stages are enclosed in feedback loops and are adjusted for an absolute minimum of distortion and noise. Signals going through this instrument, proving that its characteristics are ideal, since the goal of any high fidelity equipment is amplification and reproduction of the original signal without change.

The preamplifier essentially has five parts. The power supply is one part and is common to both channels. This power supply contains a full-wave rectifier and a power transformer. A separate rectifying system is used to provide direct current to heat the filaments of the tubes. This is one of the reasons why there is practically no hum in the Dynakit.
The remaining four sections have several functions. There are equalizer-amplifier stages: high-gain circuits designed to bring up the level of such devices as magnetic phonograph cartridges and at the same time to impose the proper playback characteristic on the frequency response. There is one of these stages for left and another for the right stereophonic channels. THe remaining two sections consist of the two amplifying-tone control stages, one for left and one for right channel. High level signals such as those from a radio tuner are fed through these stages, and the functions of volume control, tone control, and similar control functions are accomplished at these points in the circuit.

Specifications:
Inputs: 3 stereo low level: RIAA phono, NAB tape head (7-1/2"), "Special" (optional second phono, microphone, etc.). 4 stereo high level: FM-AM, FM-Multiplex, Spare, Tape.
Outputs: Tape output. Audio output.
Controls: Selector, Volume, Balance, Blend, Individual Treble and Bass for each channel, Tape Monitor, Loudness, Scratch Filter, Power.
Tone Control Range: ±14 dB at 20,000 cycles; ±20 dB at 20 cycles.
Distortion: Less than 0.05% intermodulation at 2 volts (sufficient output to drive any amplifier). Distortion does not increase at low settings of volume control. Harmonic distortion below the measurement capabilities of regular commercial grade test equipment.
Response: ±.5 dB 10 cps to 40 kc. Response not affected by position of volume control.
Transient Performance: Passes square waves without ringing and with minimum deformation from 20 cps to 20,000 cps. No overshoot or bounce on pulse type signals. Instantaneous recovery from overload.
Hum and Noise: 2 microvolt equivalent noise input on RIAA. 74 dB below level of 10 millivolt signal.

Gain: 60 dB at 1000 cps on RIAA;

60 dB on Tape Head input.

20 dB on Radio and other high level inputs.
Impedances:
Output impedance 1,000 ohms. Terminating impedance 100,000 ohms or higher. Low level input impedance 50,000 ohms; high level input impedance 250,000 ohms.

Tubes: 4 12AX7 (ECC-83); 1 12X4; 1 selenium stack.