ITEM & DESCRIPTION:Dynaco PAS-2X & PAS-3X Stereo Preamplifier Instructions for Assembly & Operation.Questions about my items for sale are always welcomed.

Here we have a DYNACO PAT-4 Stereo Preamplifier Assembly & Operation Manual ORIGINAL I have more than one of these and they are all originals. Because manuals are subject to copying, no returns are accepted. Thank you for looking

THIS WAS OBTAINED FROM A LOS ANGELES SOUND TECHNICIAN. SERIAL NUMBER IS 328. NOT A TON OF THESE WERE MADE. THIS QUALITY PIECE OF EQUIPMENT IS GUARANTEED TO OPERATE FLAWLESSLY. Manufacturer's Specifications: Phono Preamplifier Section Input Impedance: 47 kilohms. Input Capacitance: Selectable at 30, 130, or 360 pF. Gain: 35 dB. RIAA Accuracy: ±0.1 dB from 30 Hz to 15 kHz. Input Level: 2 mV. Channel Separation: 65 dB at 1 kHz. THD at 2.0-V Output: At 20 Hz, 0.05 percent; at 1 kHz, 0.01 percent; at 20 kHz, 0.015 percent. Input Stage Acceptance Level, 1 kHz (See Text): 1200 mV rms. Input Stage Acceptance Level, RIAA Pre-emphasized 500-Hz Square Wave and 1-uS Rise Time: 3700 mV p-p. Input Sine Wave Overload Level: 140 mV at 1 kHz. S/N (New IHF): 72 dB. Maximum Output Level: 7 V rms at 1 kHz and 20 kHz. Line Amplifier Section Rated Output: 2.0 V rms. Gain: 20 dB. Frequency Response: 20 Hz to 20 kHz, ±0.05 dB; 0.5 Hz to 80 kHz, ±3.0 dB. S/N: 87 dB, A weighted. THD, 20 Hz to 20 kHz: 0.012 percent maximum. IM Distortion: 0.012 percent maximum. Maximum Output Level: 9 V rms. Treble Control Range: +9 to-12 dB at 15 kHz. Bass Control Range: ±12 dB at 20 Hz. Subsonic Filter: -3 dB at 18 Hz,-20 dB at 5 Hz. General Specifications Power Requirements: 120 V, 50/60 Hz, 9 W. Dimensions: Rack panel version, 19 in. (475 mm) W x 31 in. (87.5 mm) H x 12 in. (300 mm) D; silver panel version, 18 in. (450 mm) W. Weight: 13 lbs. (5.91 kg). The preamplifier in question is called the RG Dimension 3, or D-3 for short. Its front panel controls are intelligently laid out and their number suggests that the unit is mid-way be tween the so-called straight-wire-with-gain approach and the no-holds-barred philosophy of preamplifier-control unit design. The selector switch at the left has Phono 2, Phono 1, Tuner, and AUX positions. Note that even this arrangement has been carefully thought out, in that the two most often used program sources, Phono 1 and Tuner, are assigned to adjacent switch positions on the selector, avoiding the need to switch through unused positions in most cases. Illuminated LEDs indicate which program source is in use, including a pair of LEDs associated with the four nearby rectangular push buttons that control two tape monitoring and two-way dubbing functions. A mode switch, with settings for mono, stereo, reverse, left-only or right-only comes next, followed by bass and treble tone controls, the balance control and a large master volume control. The three push buttons to the right of the volume control are for activating a subsonic filter, bypassing tone controls, and applying power to the unit. Actually, calling the last button a power switch is a bit of a misnomer. The circuitry of the RG D-3 remains on continuously so long as its line cord is plugged into a power receptacle. RG Dynamics elected this approach to maintain circuit stability and to reduce noise. Power consumption is less than six watts when the power switch is off. Flanking the line fuseholder on the rear panel of the D-3 are a total of five a.c. convenience outlets, two unswitched and three switched. Clearly delineated jack clusters which follow include a double pair of main outputs, in-and-out jacks for any sort of external add-on processor (expander, noise reduction unit, etc.) with an associated slide switch that provides access to this loop or bypasses it with jumper action, Tape-1 and Tape-2 in-and-out jacks, and the AUX, Tuner, Phono-1 and Phono-2 input jacks. Below each pair of phono jacks is a three-position slide switch enabling the user to load the phono cartridge with either 30, 130, or 360 pF of parallel capacitance (over and above the capacitance that will normally be contributed by the phono cartridge audio cables). In the well-written owner's manual supplied with the RG D-3, there is a list of 28 turntable manufacturers, 15 makers of separate tonearms, and 19 manufacturers of popular phono cartridges, along with recommended capacitance values for the cartridges and known wiring capacitances for the tonearms or complete turntable systems. A block diagram of the RG D-3 is shown in Fig. 1. According to the company, the unit's circuitry is a new topology (for which patents are pending); the design goal was to handle the most difficult peak signals of wideband phono cartridges without introducing peak distortion or TIM. One of the techniques used in the design is passive high-frequency de-emphasis between the two stages of wideband linear amplification. The manufacturer indicated that this minimizes any peak handling problems in the second preamp stage and in all subsequent stages. Although sine wave overload quoted for the preamp is fairly typical (140 mV at 1 kHz), peak over load claimed is up to 30 dB better than with typical preamp circuits. Measurements Fig. 1--Left-channel circuitry of the RG D-3; right- channel circuitry is identical except where noted. Fig. 2--Test signal used by RG Dynamics is an RIAA compensated 500-Hz square wave. Fig. 3--Fed with test signal of fig. 2, conventional preamp exhibits overshoot spikes at output. Fig. 4--Phono preamp of D-3 unit exhibits no over shoot spikes when test signal of Fig. 2 is applied. Fig. 5--Dual sweep spectrum analyzer display showing the most significant harmonic distortion component as 90 dB below the fundamental 1-kHz reference signal. Fig. 6--Range of tone controls in the RG Dynamics D-3 preamp. In the course of developing this circuitry, RG Dynamics came up with a special test signal which we have duplicated and shown in Fig. 2. This test signal is nothing more than a 500-Hz square wave, RIAA pre-emphasized, and band limited to 60 kHz, for the-3 dB roll-off point. Rise time is approximately 1 NS. With no overload or time-domain problems, a phono preamplifier having RIAA playback equalization should be able to reproduce this signal at its output as a near perfect square wave. In our tests, we adjusted the amplitude of the signal for slightly more than 3.5 V peak-to-peak. Feeding this signal to what we had regarded as our standard lab reference phono preamplifier, we were shocked to discover an output which contained very large overshoot spikes, as shown in Fig. 3. Feeding the same signal through the RG Dynamics D-3 preamp, we obtained an output signal as shown in Fig. 4, with no evidence of any overshoot. Measuring conventional THD of the phono-preamp section proved to be a bit difficult, since 'scope observations clearly showed that we were reading more noise than THD on our meter-reading distortion analyzer. For the record, the reading was just under 0.01 percent at 1 kHz. By employing the combination of the Sound Technology 1700 distortion analyzer and our Tektronix spectrum analyzer, however, we were able to read actual distortion components which were in fact much lower. As can be seen in Fig. 5, a reference 1-kHz signal is positioned at mid-screen. Using the distortion-output terminal of the Sound Technology instrument, we were able to change the sensitivity of the readings on the spectrum analyzer by 70 dB so that while the two distortion components observed during the second sweep of the analyzer appear to be 20 and 25 dB lower than the reference signal, they are, in fact, 90 and 95 dB lower. (Each vertical division of the display is, worth 10 dB, to which must be added the 70-dB difference in sensitivity between the reference and distortion sweeps of the analyzer). The actual total harmonic distortion, then, consisting primarily of third-order and fifth-order harmonic components, works out to an infinitesimally low 0.00363 percent! THD measurements taken via the high-level (line) inputs of the preamp, for a rated output of 2.0 V, were 0.0065 per cent at 1 kHz, 0.0083 percent at 20 Hz, and 0.012 percent at 20 kHz. SMPTE-IM distortion measured 0.0075 percent. Phono input sensitivity, referred to 0.5-V output and with the master volume control fully open, measured 1.1 mV, while for the high-level inputs it was 64 mV for 0.5-V output. Sine wave phono overload measured 145 mV, or just a bit better than the 140 mV claimed. RIAA equalization was so accurate that we cannot assign a plus-and-minus tolerance to this response characteristic. As for the high-level input, frequency response was flat to within 1 dB from 4.5 Hz to 105 kHz, and within 3 dB from 0.5 Hz to 200 kHz. Signal-to-noise ratio for either set of phono inputs was 75 dB, A weighted, referred to 5-mV input and 0.5-V output. For the high-level inputs, the S/N ratio measured 81.5 dB, again referred to 0.5-V output with 0.5-V input. At minimum volume settings, the hum and noise was 87 dB below the 0.5-V output level reference. CONTACT ME BEFORE PURCHASING SHOULD YOU HAVE ANY QUESTIONS.

This is one amazing sounding preamp. It has been carefully serviced to ensure longevity and safety. All original Dynaco labeled Telefunken 12AX7 tubes are present, and really painting the sound of this to be just decadent. This preamp is everything that tube audio enthusiasts speak praise of. It’s midrange is extraordinary, and everything emanates with ease and roundness that only a high-quality piece of tube gear, with the right tubes can create. It is a very clean unit, with some minimal cosmetic flaws, including some minor lettering loss as you can see in the photos, as well as a scratch or ding on the face plate. Electronically, and functions 100%, with one minor quirk that has been a well-documented quirk of these PAS preamps. There is a slight imbalance in volume in the midway point of the volume control, but it is easily compensated,for by adjusting the balance control, which was as intended by Dynaco to keep things balanced throughout the listening range. You can connect two turntables to this preamp. The phono input will play as intended, and the “special” input has had the optional setting performed that will make it a phono input as well, so think of it as phono 1 and phono 2 A very involved service was performed as follows: First things first, the main filter cap has been completely rebuilt, re-stuffed with original values of high temperature electrolytics. Secondly, the filament power supply capacitors are were replaced with high temperature, long life electrolytics as well and the selenium rectifier was replaced with reliable diodes. Other standard services provided were testing each tube to ensure that it is strong and balanced, the controls were cleaned and lubricated, but the most important thing was fixing any previous errors in routing and wrapping wires to the re-create, the exact demands of the assembly manual. This is an important step to ensure quiet operation and minimal bleedthrough of sources.

Thank you for visiting! Please read the following instructions to ensure a good shopping experience for you! [ Description ] We are all original and authentic. We have several in stock for some items. In such cases, if the item we actually send you is an in-stock item, we will send you an item in the same condition as in the pictures shown. [ language of instruction manuals and menus ]. We mainly handle products for the Japanese market. Therefore, as a rule, we only offer instruction manuals and menus in Japanese. [Electronic Equipment] ?Japan Voltage: 100V Please check the voltage in your country before ordering. Buyers may need a transformer to use our goods. ?Plug type: A Please check the plug of each country. It may be necessary to replace the plug. [International buyers - please note ] Import duties, taxes, and charges are not included in the item price or shipping cost. These charges are the buyers responsibility. Please check with your countrys customs office to determine what these additional costs will be prior to bidding or buying. [ Shipping Method ]. Expedited shipping- EMS or FedEx or DHL Standard shipping- AIR MAIL or FedEx or DHL

CLASSIC PREAMPLIFER, WITH CUSTOM BUILT 220V POWER TRANSFORMER, CURCIO MOD ON THE PHONO STAGE AND ALL NEW CAPACITORS. FOR THE REST ORIGINAL AND IN VERY GOOD SHAPE, FACE PLATE IS PERFECT.

Dynaco DYNA PAS Stereo Tube Preamp Preamplifier &Audio Dimensions modified Dynac.it untested thats why Im selling in parts all 3 is dynaco

Dynaco DYNA PAS Stereo Tube Preamp Preamplifier &Audio Dimensions modified Dynac.it untested thats why Im selling in parts all 3 is dynaco