Binson Echorec II Servicing
by Phil Taylor
What do you do over Christmas, when you start getting a little bored? Rebuild a Binson Echorec! It's something I'd been promising myself I would do when I get a spare moment and the day after boxing day is usually when I start getting a little stir crazy for some intellectual stimulation. It took me a couple of weeks to service and overhaul. You might question if it is worth all the time and effort, when there are plenty of little boutique stompboxes that claim to emulate tape echo? My answer is a resounding, "Absolutely!". There's nothing that comes even remotely close to the complex and involving mixture of delay, reverb, phasing and tube distortion these devices produce. Musically inspiring mix between the sounds heard in Dr Who's Tardis in the early 60s and Alex Lifeson's solo in La Villa Strangiato. The Binson Echorec creates complex, cascading echos as the repeats swirl and degrade to produce a rich, lush wall of sound. Read on to find out more about the care and feeding of this fabulous delay machines . . .
Disassembly
These are not the easiest to work on being more difficult and complicated to take apart than Watkins Copicat Tape echo units or vintage guitar amps, I've worked on previously. If you are not confident, qualified and experienced, I seriously recommed you get your Binson serviced by a professional. These vintage machines are beautiful and collectable deserve to be treated with respect. That said, this is not rocket science, so if you are good with a soldering iron and have some experience of working on tube gear, this page may help provide some guidance.
The Binson has to be fully diassembled to gain access to the circuit board for inspection and replacement of components and wiring. The bottom and back panels are removed first, which is straightforward. From here on things get a little more scary. I removed the knobs and the little self-tap cross-head screws so that could take off the illuminated plastic frontpanel. The memory system (magenetic drum, head and idler wheel on the mounting plate) was removed by unsoldering the wires connecting the heads and then undoing the four securing nuts on each corner of the mounting plate. Be careful with this - it's expensive to replace and is not a renewable resource. I removed the remainder of the self-tap screws on the top panel and side panels. Unsolder the two wires connecting the motor and slide out the top panel. Now we are in.
Inspection, Cleanup and Rewiring
Looking inside this old echo unit I was relieved to see that a majority of old wiring had been replaced, leaving just a few difficult to get H.T. and heater wires to be replaced. It is essential to undertake this undesirable job as the original Echorec wiring is of very poor quality. I'm not sure why it is so bad on a high-end product like this, as other gear from that era, such as '60's fender amps did not exhibit this problem. The Binson wire insulation breaks-down and "sweats" oozing a sticky resin that attacks copper and any other metal parts including the chassis and component leads causing unsightly damage and making a real mess of the internals. Just touching one of those fragile wires with your tweezers and insulation drops off and wires break. The copper oxidizes turning green or black turning to dust and gradually the insulation disintergrates, crumbimg into fragements. The only solution is to completely remove this old wiring and replace it. I highly recommend PTFE wire where possible. It's virtually immune to corrosion, tolerates much higher tempaertures than PVC and has good aging properties.
On Resistors and Capacitors
Installing Jack Sockets
The final task was to remove the Italian "Geloso" sockets. I've never been enthusiatic about DIN style sockets. My dislike stems from having to solder the German 5-pin DIN sockets found on hi-gi gear from the 70's. It was always a challange to understand the wiring and even more challenging to solder all the wires in such a small space. The Echorec Gelaso sockets are larger, however even though I had the correct leads they were electrically unreliable causing intermittent breaks and spurious noises. Here I explain how I modify the Binson for 1/4" jack sockets. The mod is completely reversible with no cutting of metalwork required.
How to Adjust all those Trimpots
Still working through this. I've found the trimmer that controls the "Swell" i.e. the number of repeats. If you click on the trimpot picture you'll see an enlargement showing all the trimpots. The one on the bottom row far right is the "Swell" trimpot. This is an important trimmer as it controls self-oscillation. There are also dedicated trimpots for playback levels for all four fixed playback heads. Just for interest, the Watkins Copicat has three playback heads and the Echoplex just one head that can be physically moved to achieve different delay times.
The Memory System
Coming soon . . .
