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Post by hdahs143 on Feb 20, 2009 13:36:37 GMT -7
Myles, or anyone who knows:
To my understanding, this unit applies a set plate, and bias voltage to a tube, and then current draw and transconductance measurements are taken. So if one set of EL34's for example have a PC# of 20, and another set have a PC# of 23, does this mean that the set rated at 20 draws less current, and is a cooler running tube? And does this mean cleaner? This info will help in selecting a good rating for my Matchless Clubman. The amp sounds great, but went through the stock set of JJ's in about 6 months. Just put a set of Ruby EL34BSTR's in. Will see how they do.
Also, if you know, what does CE Dist/Antique Electronic Supply use to match their tubes? The second # on their label's for EL34's for example is 4.8 to 5.2, which doesn't sound like a traditional TC rating.
Thanks! Harold
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Post by myles on Feb 23, 2009 15:03:34 GMT -7
Myles, or anyone who knows: To my understanding, this unit applies a set plate, and bias voltage to a tube, and then current draw and transconductance measurements are taken. So if one set of EL34's for example have a PC# of 20, and another set have a PC# of 23, does this mean that the set rated at 20 draws less current, and is a cooler running tube? And does this mean cleaner? This info will help in selecting a good rating for my Matchless Clubman. The amp sounds great, but went through the stock set of JJ's in about 6 months. Just put a set of Ruby EL34BSTR's in. Will see how they do. Also, if you know, what does CE Dist/Antique Electronic Supply use to match their tubes? The second # on their label's for EL34's for example is 4.8 to 5.2, which doesn't sound like a traditional TC rating. Thanks! Harold Harold, Tha Maxi-Matcher is a great device. Yes ... 20mA would run cooler than 23mA but keep in mind that 20% difference is an industrial match and 10% is a very good audio match for hifi and guitar amps. Higher plate current tubes will stay cleaner longer and are stronger than lower plate current tubes BUT .... stay within the spec range as once outside of the range it means there is something wrong with the tube if it is a new tube and was not put together properly. This goes for plate current that is too high or two low. The Maxi-Matcher has a scale of an acceptable range for each tube printed right on the unit. In your case this is a nice match. That 4.8 and 5.2 number is transconductance and the actual values would be 4800 and 5200 respectively. Generally plate current is used to match tubes rather than transconductance.
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Post by hdahs143 on Feb 23, 2009 15:10:54 GMT -7
Thanks Myles! Tried the Rubys over the weekend. Pretty good sounding tube. A little less bottom than the JJ's but more mids. The most shocking thing was how alive the amp was again, and LOUD. I had to reduce my previous volume settings just a tad . The Clubman may be hard on tubes, but it is an amazing amp!
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