Bottlehead Forum

General Category => General Discussion => Topic started by: butchbass on October 11, 2013, 05:40:55 AM

Title: Tube nomenclature
Post by: butchbass on October 11, 2013, 05:40:55 AM

What would the difference in a 12AT7 and a 12AT7WA be? 

Title: Re: Tube nomenclature
Post by: Paul Birkeland on October 11, 2013, 05:48:45 AM

The "W" traditionally indicates some additional testing in accordance with military specifications.

The "A" indicates a controlled heater warmup characteristic.

Neither of these are appreciable differences. 

Title: Re: Tube nomenclature
Post by: Grainger49 on October 11, 2013, 09:50:04 AM

They are drop in replacements, the "WA" is possibly better sounding for Paul's reasons.

Title: Re: Tube nomenclature
Post by: butchbass on October 11, 2013, 03:53:27 PM

Thanks for the info. Music enjoyment is the best part of this hobby but the eduction also brings fulfillment.