1966 Geloso 3215 Tube Amp

It may be due to Flanders irrevocable ties to the Holy See or just because of the numerous musical Italian immigrants, but there are a lot of Italian Geloso amps for sale in the low countries.

Giovanni (John) Geloso (1901 – 1969) was an Argentinian immigrant who established one of the most important electronics factories in pre and postwar Italy.  More information on the Geloso company can be found here.

This is a 17W 1967 Geloso G3215:

img_5308An 1967 handwired, all tube 17W amp running a set of tubes very familiar to the guitar player and hence affordable!  ECC83 or 12AX7 for the preamp, EL84 power tubes and a EZ81 rectifier. In fact, this is the exact tube complement of an earlier incarnation of the Vox AC15.

Filaments of the preamp tubes are run off negative DC, which assures absolutely noiseless operation. And there is the extra filter coil often omitted in guitar amps.

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This amp still had all the original Geloso branded tubes:

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The amp was sold to me in working condition. In the context of tube technology, this often means, the tubes glow up.  So it was in this case, tubes glowed, but no sound.  Things only changed when I changed the mains power switch from 240V to 220V – then this little Italian beast came to live.  It is loud, noiseless and has an absolutely acceptable guitar tone.  I decided to install an input jack and keep the amp stock for now.  The big yellow capacitors are not Geloso, but Sprague, date coded 1966, 26th week.

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Input jacks are shielded from the rest of the circuit.  The wiring is to a very high standard as are the components, who are holding up perfectly, even after half a century.

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An additional advantage of these Geloso amps is that they allow you to drive any speaker from 1.5 ohms up to a 1000 ohms.

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For now, I installed speaker jack in such a way that you can switch the ends to different poles on the output transformer.

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Cleaned up, input jack and chicken heads installed:

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