Advent Model 300 FM Receiver

The Advent Model 300 receiver is an example of exquisite industrial design! I see Dieter Rams' influence in the input selector switch and knobs, as used in the Braun CSV60 tube integrated amplifier from the early 60s while the rotary vernier tuning dial echoes FM tuners by H. H. Scott.

In the early 80s, I used to see and hear this receiver at mom and pop bookstores and record shops in NYC tuned to WNCN or WQXR driving New England-type speakers - Advent, AR, EPI, KLH and etc. The combination sounded very pleasant to my ears. If I had not found a good deal on a NAD 3020, I may have built a hifi system around this receiver instead.

In my quest to relive my youth, both this and the NAD 3020 were in my shortlist of audio components I'd like to hear again. Just as it happened in the past, the 3020 showed up first. With enough persistence, I eventually found a Model 300 advertised on Facebook marketplace available for pick up in South Philly. The seller was forthright about a hissing issue on one channel so we agreed on a fair price. 

Since I was in his neck of the woods, I invited my buddy Joe Roberts to join me and Tish for a bite. Here we are enjoying an after dinner brew!

The lower trace reveals the hiss on one channel, which is also reflected in the digital voltmeter readings. Troubleshooting and fixing the noise issue was a challenge since I don't have much experience nor knowledge about solid state equipment. That said, I ordered a rebuild parts kit from eBay. 

Advent Model 300 Schematic

I started by recapping the signal path (marked in green) but that didn't solve the problem. The fizzling noise went away after I replaced the two transistors marked in red. To avoid future issues, I replaced all the similar spec'd transistors check marked in pencil. I decided to quit while I was ahead instead of pushing my luck and doing a complete rebuild. Besides, I was impatient to hear it make music! 😉  

With the noise gone, I inspected/tested the remaining original caps looking for leaky/bulging or out of spec units. After that, I did a couple more bench tests just to make sure the amp was working up to spec. As pictured above, using a 1 kHz sine wave input, at the onset of clipping the output = 11.79 Vrms into 8Ω or 17.4 watts with both channels driven. It easily met its 15 watt per channel factory rating! That may look measly in this day and age, but during that era it was plenty enough to drive paper coned 8" acoustic suspension speakers with a typical sensitivity in the vicinity of 88dB/W/M like the AR18.

After finding a new home for my pair of Snell JIIIs, I no longer have New England-born speakers. So I connected the Advent 300 to a pair of period correct Fulton FMI 80s (to be featured soon) via Belden 9497 speaker cables, which to my ears provide a better synergistic match with solid state amplifiers rather than with my flea powered SE-DHT amps.

It's time for the most fun part - listening to music! 

Although not quite as sensitive nor as quiet as my Yamaha T-2 or NAD 4300, the FM tuner section is capable enough to pull in my favorite FM stations - WPRB, WRTI and WXPN - connected to my garage attic-mounted Winegard HD-6010 antenna.

Tokyo Sound ST900 + Shure M44-7

A nice feature of the Model 300 shared with the 3020 + a few other receivers and integrated amps from that era is the flexibility of being able to disconnect the (tuner)/preamp section from the power amp. Used as a preamp, I found the Tomlinson Holman designed phono section most enjoyable when fed by American magnetic cartridges with conical stylus - Pickering XV15, Shure M44-7, M3D and V15-IIIG.

Stax UA3NL + Shure V15-IIIG (generic VN3G stylus from Voice of Music)

Truth be told, I prefer the more spirited presentation of the NAD 3020 phono stage. Perhaps the Holman phono section is more accurate but in my mind's ears live music is about tone colors and dynamic nuances.

Through the kindness and generosity of a very good friend and fellow audio traveler, I finally was able to pair up my mid-50s RCA 501S1 12" Bi-Axial drivers and mounted them in 3 cf ported Altec Coronado cabinets. Let's see how the Advent Model 300 fares driving them. The digital source is my trusty six month old SMSL PL100 CD player used as a transport + nosTDA1541tube DAC. 

Even if I'm partial to the NAD 3020, I fully understand how the Advent Model 300 receiver appeal to those who value sonic refinement and finesse. It sounds as dignified and elegant as it looks!