tivoli: Henry Kloss Model One Crackly Audio

Dear Colleagues,

My "Model One" developed a fault resembling a "dirty pot". The fault was traced to the audio/power supply board. I checked the electrolytics - all OK. and finally resorted to poking the component side of the board with my finger to see if the problem was a dry joint. Eventually, I narrowed the problem down to one area and decided that the best strategy would be to resolder everything in the area of the "TL084" chip (purpose unknown). This was done using a fine tip and 22 swg solder, and the set then worked correctly.

This not really the way I like to "repair" things, but often is the only way when dealing with surface mount components. I believe Tivoli Audio have a policy of not releasing their circuit diagrams, for fear a competitor may copy them. 

Maybe other members could comment on their experienes with "Modern" radios.

- Bryce 

PS I had to repair this to maintain credibility with the family :)

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It's a common op-amp. Probably a preamp. As to why such a simple radio with presumably an IC power audio amp might need it is a mystery.

I wonder is the set RoHS and using lead free solder, which is hugely more prone to dry joints unless there is very strenuous high quality manufacturing control and processing. Any touch of track with bare finger or contamination degrades the subsequent flow soldering much more than 60:40 solder.

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Hi

There are a number of these on the audio board. Part of the power supply regulator? Part of the signal strength indicator? - without a circuit diagram - who knows.

As for lead-free solder, I can only agree. It also chews away my soldering iron bits and tips, and the flux fumes choke me. But, as they say, that's progress.

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Use 60/40 for all "vintage" gear. It's still made as certain product categories are exempt from RoHS lead ban.

For "Lead free" use proper SMD solder with silver and other metals alloy Tin Lead free, not cheap pure tin.

Use separate irons and bits for Lead Free & 60/40.

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It's got various active filters to attempt to make a 3" speaker sound better. Possibly also buffers for the line level I/O jacks.

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