I purchased this unit directly from the original owner and had it sent directly to AEA (Analogue Engineering Associates) Audio in November 2017 for their gold restoration, which included: hand cleaning; signal capacitor replacement/upgrade; power supply filter capacitor replacement/upgrade; inrush current limiter; replacement of filament supply selenium rectifier with silicon diode bridge; retention tube sockets; new power indicator pilot lamp #53; and installation of volume and tone control bypass using tape monitor switch. There was extra emphasis placed on getting the phono stage to sound just right.The preamp was then fully tested and results were documented in a detailed diagnostic report (will be provided to buyer) that includes the following sample comments from the folks at AEA: -- Frequency response is within specs, and especially flat from 20 Hz to 20KHz to within 0.8 dB -- Distortion is below specifications at maximum output voltage -- Individual resistors and capacitors were replaced/upgraded to allow the phono preamp to operate within 1 dB of specified RIAA equalization compliance. Both channels are well balanced with less than .5 dB across the entire frequency range -- This amplifier has extremely low noise and hum due to power supply upgrade. All noise components are more than 76 dB below 0 dB V, which is more than 84 dB below full output. Both channels have similar noise spectrum indicating matched gain and frequency response. 60 and 120 cycle noise components (hum) are noticeably absent. It comes with period correct Dynaco 12ax7 tubes and a GE rectifier that were tested by AEA audio. The volume and tone control bypass (via tape monitor switch) gives you the option to control volume through a source that has volume control. This option also bypasses the tone controls. I don't know how to rate a vintage piece. The physical condition of this preamp is pretty good. There are a couple scuffs on the top case; the front right lower corner has a very slight nick (not very noticeable); the top left front edge near volume control has a couple tiny nicks; the lettering around the on/off switch has worn away, but all other lettering is very nice. I am being very specific with details here. I tried to capture the imperfections in the pictures I provided. I am pretty picky with my gear and overall this piece presents nicely. So, there are a lot of Dynaco Pas preamps floating around on the various audio sites and Ebay at lower prices, some claim to be modded or restored. In many cases, the Dynaco 12ax7 tubes have long been removed (as they are valuable) and the restoration/modding at times can be suspect depending on who did the work. What I am offering here is a piece that was restored by a reputable company (please look up Analogue Engineering Associates) with full documentation including diagnostic testing results. It has the Dynaco 12ax7 tubes that have been tested by AEA. And, there was specific focus on getting the MM phono stage to sound just right. It is ready for many more years of service. My price includes paypal fees and shipping to the contiguous United States. This is a very nice piece. I turned 50 last year, felt nostalgic, and leaped into a vintage audio journey. This year, I am pulling back the reins and changing course a bit – thus the sale. I used this preamp with higher efficiency speakers (95 db) and it was nice an quiet -- no distracting noise or hum.
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