Tivoli Audio Model One
Written by Bryce Ringwood   

The Model One

The Model One
Good looks and acceptable sound quality coupled with ease of use make it popular.

You might be asking "what's this doing here?" - and quite justifiably, since my cut-off date for repair age is 1980 and these were introduced in 1999. This, however, is my own radio, so I had to fix it, to maintain credibility with the rest of the family. (See later - it failedfrown)

The Tivoli Audio Model One has a small loudspeaker (or "Drive Unit") with an enormous magnet. The wooden case is designed as a proper speaker enclosure and the drive unit is driven by what appears to be a car-radio audio amplifier chip. There are, however numerous other "complications" (as watchmakers might call them) on the audio/power supply board. The result is good quality audio reproduction, although my set now has a slight hiss which could be annoying on quiet passages. It would seem that this problem is not uncommon.

The slow motion tuning drive is a nice feature on this analog-tuned radio. The tuner sensitivity is allegedly very good. I say allegedly, since FM signal strengths are quite high in my area. (The Fremodyne will pick up stations without an aerial, so it would be surprising if the "Model One had" any difficulties.) I'm not sure what a "MESFET"* is, but apparently its the thing that contributes to the Model One's sensitivity. The FM tuner is contained inside a sealed tinfoil compartment.

Controls have been limited to the bare minimum, so this is a simple to use radio. Tuning indication is via a yellow LED. The brighter it is, the more tuned in you are.

All this comes at a price, and although mine was a present, expect to pay more then R1200-00. I have to say that several valve radio models (Grundig 5088, for example) sound superior to my ear, but this is something that you would have to judge for yourself. I also prefer the "magic eye" to a LED. Some "boom boxes" equipped with heavy magnet drive units are also very good  but either of these options is much larger than the Model One.

 

Inside the model one

 

General view of the inside of the set. Note the 3" drive unit.
Later models have cable ties rather than elastic bands to hold the wiring in place.

 

The "complications" unfortunately mean that there is more to go wrong. Tivoli Audio stolidly refuse to give out any circuit diagrams or service information, because they fear their circuitry will be copied. Well, of course, that's a risible policy, because there are armies of good designers that could (and do) produce equally good products. There are many other companies who behave like Tivoli Audio, which is one reason why I don't do sets after 1980.

After 5 years use the set developed an intermittent fault - rather like a faulty volume control. In this case there was nothing wrong at all with the volume control. Pressing the audio board with my finger removed the problem, but, of course gave no indication of what was really wrong.

The board contains predominantly surface mount components, so I decided to adopt the brute force approach of re-soldering everything in the vicinity of where I'd put my finger. This included  the leads to the surface mount chips.  This is the method adopted by my board-level computer repair expert. Nevertheless, I removed and tested the electrolytics - just in case.

This procedure got the set working again with background hiss, but for how long, I can't say. This type of repair is never very satisfying, but sometimes is the only way.

Audio Board of the Model One

 

The offending Audio board. Note the surface mount construction.
Board material is SRBP, not fibreglass. Resoldering sometimes cures a problem, for a while.

Update: The hiss was annoying, so I replaced one of the ICs (TL084) whereupon the original fault manifested. I might get it repaired by Tivoli Audio or I might use the parts for something else and spend the money I would have spent on the repair on another radio. Obviously, Tivoli Audio have spare boards, whereas I would have to trace the circuit diagram, determine the true fault, and correct it.  The parts are held on to the board with glue, so that unlike the Grundig, you run the chance of ruining the board, ruining the component or both if you try to fix the problem.

*MEtal Semiconductor Field Effect Transistor. I don't have any part numbers for you to experiment on.

 

 

 
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