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View Full Version : Question about vintage power cable/psu for old amp



philv
26-01-2018, 20:13
I am looking at a 70s amp.

Tnere are 2 versions.

One with a fixed cable
With 210w written on the back of the amp.

The other with removable/kettle lead cable
With 300w written on the back of the amp.

The seller mentioned something about it having a cold device connection.
I didn’t understand.

Both versions are 25 wpc.

Has one got a bigger/better psu?

Thanks for any explanation.

philv
26-01-2018, 20:44
The version i am looking at says

110/120/220/240 v ~ 50 hz 300 w

Pharos
26-01-2018, 23:31
I would be concerned about running a 210V spec'd amp at the current standard of 230V.

Also a 300W power supply seems very high for a 2 X 25W per channel amp, even if it is class A with a maximum theoretical efficiency of about 45%.

Primalsea
27-01-2018, 08:26
Its 210 Watts, not 210 Volts.... No need for concern.

The figure that related to how much power the amp draws from the mains supply is usually a nominal figure that can be based on the possible maximum, or the average or whatever the manufacturer felt like at the time. It will be hard to say if one amp has a different PSU unless you look inside and compare the transformers and PSU capacitors.

snowman_al
27-01-2018, 08:57
Just to answer the 'cold' device connection question.
There are 2 types of IEC plug / socket. The 'hot' type, for kettles etc, has a ridge / notch in it and uses high temperature plastic and wiring.
The 'cold' type, for PCs, screens, hifi etc., has a solid body so it cannot be plugged into the 'hot' type and melt. (You can of course fit a 'hot' plug into either socket.)

Personally I go by the saying, the fewer connections the better! And as Paul has already mentioned wattage ratings on hifi are a law to themselves depending on what ever test the manufacturers used that time.

Pharos
27-01-2018, 09:45
Yes, sorry for error - tiredness.

philv
27-01-2018, 11:31
Thanks or the replies.

Is having a 300w power supply better than a 210w power supply?

Is that the reason it is 'cold' cabled?

It's a mid 70's marantz amp.

walpurgis
27-01-2018, 11:36
Surely it would heve been designed to function properly with whatever spec power supply it has? I can't see what relevance the cable may have.