Scott 344C Receiver
Refurb 1-2022
This project is a trip down memory lane for me. My first piece of real audio gear was a Scott 344C receiver, back in 1968, when it listed for $400 (about $3,200 in 2021 dollars!). Not sure how I was able to afford that as a teenager, but I did buy it at a discount house: Carston Studios in Brookfield, CT (still in business as Carston Stereo/Video in nearby Danbury). I recently found a well-used by working unit for a good price, and this webpage details my refurb process.
This receiver wasn't very powerful by todays standards, just 30 watts RMS per channel (that's 90 watts "music power" for marketing purposes, see below), but it had an excellent FM tuner. The well regarded Scott 312D tuner was basically built into the 344C.
With this receiver, FM ("free music") was my primary source, and my formative years were spent listening to WNEW FM in New York. Lots of great historical info on WNEW FM here: https://www.nyradioarchive.com/wnewfm.html
The following ad from Soul & Jazz magazine, Sept 1975, shows the WNEW DJs as of that date:
Below: This full page ad for the 344C ran in the January 1968 issue of AUDIO magazine. Note the $399.99 list price.
Shown below is the full 1968 lineup of Scott receivers. FM only models included the 342B (18 watts/channel RMS), my 344C (30 watts), and 348B (40 watts). Adding AM are the 382b (18 watts), 384 (30 watts), and top of the line 388B (40 watts).
Below: Full specs for the 1968 line of Scott receivers and other products.
The 344C as received:
Front view of my new unit as purchased, not looking bad at all, no significant dents or marks. The inside was quite dirty, but thats what Q-tips are for.
I'm certain that this is not the 344C that I owned 50-ish years ago, as it was destroyed in a lightening strike on my parent's home.
One operational note: the bass and treble controls as well as the volume are concentric controls where the back portion of the knob controls the left channel and the front the right. They two are clutched together so moving either moves both - its take a conscious effort to uncouple their movement, e.g. to adjust balance. Hence no separate balance control.
Rear panel of the receiver. Power transformer on the left, speaker outputs in the center, and output transistors (under black covers) and RCA inputs/outputs on the right.
Internals, top view, front is at the bottom in this photo. Clockwise from upper left: multiplex PCB, power supply PCB in the center rear, IF amp PCB (blue), RF front end, tone control PCB at front center, and preamp PCB on the left. Power transformer is at the right rear. At the front (bottom in this photo) you can see the white lamp assembly for the dial and the tuning wheel to the right. The main power supply capacitor is the silver can to the right of center.
Bottom view. Clockwise from the upper left: Power transformer, with the IF amp PCB below it, power supply PCB in the center, multiplex PCB, preamp PCB (lower right), tone control PCB (large green one), and RF amp in the metal box at the left.
My Refurb:
A full set of documentation on this unit is available at a number of places on the web (GIYF), and includes schematics, board layouts and testing instructions, originally priced from Scott at $1.00. This was back in the day when audio gear was designed to be maintained locally and the design wasn't kept more secret than the nuclear launch codes. If you need the documentation and can't find it, email me for a PDF copy.
My refurb process was fairly simple:
All electrolytic caps were replaced, as they are now over 50 years old. All of the new power supply caps were 105 degree rated for long life, and Elna Silmic II caps were used in most of the RF and audio circuits. The main power supply cap (spec'ed by Scott at 1,000 uf/75V) was replaced with a Nichicon GU: 1,800 uf/100V, photo below. Except the main power supply capacitor, all caps were kept at their original design values.
One note: Since these are older, single sided PCBs, the work of removing the original caps was much quicker and easier that newer gear with plated thru holes.
The AC fuse holder and power cord were both cracked, so both were replaced with new for safety reasons.
Clean, clean, clean. 50+ years of accumulated dust and grime coated the top surfaces. Primarily cleaned with 99% isopropyl alcohol.
I replaced the 5 incandescent light bulbs with LED bulbs, so they likely will never have to be replaced again and the LEDs eliminate some heat from the unit.
Reset bias and balance, per the Scott documentation.
Since I plan to use the unit for FM, I haven't replaced the crappy RCA jacks on the rear panel. I'll likely make up some new assemblies and replace them at some point, but for now, that basic refurb is complete.
Photos below show more details of the receiver, post refurb.
First the power supply was re-capped, shown here. It provides regulated 12VDC and 33VDC. Main filter cap was chassis mounted, shown below.
This shows the bottom end of the original twist-lock filter cap on the bottom right, now over a half century old. I clamp-mounted the new Nichicon filter cap nearby, but left the original in place. This supply provides 60VDC to the amp.
Next I tested all power supply voltages and confirmed all was good before moving on.
The preamp PCB was re-capped next, shown here. There were only a dozen or so plug-in connectors on the board, so I removed it from the unit for this work, making it much quicker and easier. 9 new Elna Silmic II caps here.
Here's that PCB reinstalled in the receiver.
The Tone Control-Drive PCB was re-capped next. I left this one in place for the re-work, as it was easier to access than the preamp PCB. A total of 16 new Silmic caps here.
One helpful technique: I flipped (left to right) the PCB layout diagram from the Scott documentation and printed it out, allowing easy identification of component from the bottom of the PCB.
The Mulltiplex board is shown here, some of these caps were replaced by the previous owner, but all 5 electrolytics are now new.
Not shown here, but the RF Front End, IF Amp PCB, and Inter-station Noise Muting PCB each had one electrolytic cap that was replaced.
New fuseholder and AC power cord.
View from the top after my refurb. Looks virtually identical to the "before" photo unless you get close up.
The angled clips in the white housing at the bottom in this photo are the lamp mounts, now holding LED lamps.
And the view from the bottom.
The finished receiver in operation:
Below: The receiver tuned to WFUV at 90.7 in New York. That public radio station is where a number of the original WNEW-FM DJs shown above ended up over the years, including Vin Scelsa, Pete Fornatale and Dennis Elsas (who still has the afternoon show on weekdays at FUV).
