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Messages - gunnar

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Reel to Reel Tape Machines / Re: Teac 3340s - Teac a3340s
« on: February 26, 2017, 04:34:01 AM »
Small note:
A similar phenomena occurs for those who happen to buy the "native american" version (117V) of the A-3340S for export to a 50Hz country. One could assume it would suffice with something like a 220 to 110V transformer but the problem will be mains frequency.
The capstan motor are synchronous in principle and runs in exact sync with the mains frequency, slower on 50 Hz. And even with a
step down transformer the deck will still be fed 50 Hz thus the machine will run too SLOW.

There exist versions of the 3340 that allow selecting mains voltages. Those also employ a dual-groove pulley on the capstan motor so that by allowing the rubber belt to go in the smaller groove this compensates for the slower running motor.

The single voltage version of the 3340 (most of the units on the north american market) were cost optimised in production so TEAC did away with the dual groove pulley, 50 Hz switch, voltage selector and used a transformer with less windings.

So converting such a 3340 for use in 50 Hz land requires both sourcing a dual groove pulley and changing the transformer (or use an external step down one).  Good to know for those outside the U.S tempted by these 4 channel icons on Ebay.
The 50/60 Hz switch is also a thing to study in a conversion. It switches in/out and extra capacitor to change an electrolyte capacitor used with a reel motor to have it work in harmony with the mains frequency and this needs to be rewired also in a 50 Hz conversion of the 117V version.

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