Angelo- sounds like almost too good a deal... I hope they are real TFN's-
A well known tube among audiophiles and guitarists, some people regard the Telefunken ECC83 as the ultimate pre-amp tube. It is used more commonly by audiophiles. The Telefunken is considered a wide-band 'neutral' or 'clear' tube. It does not really impart any color to the sound. Therefore, if you have an overly warm stereo or guitar amp, you may want to consider this tube. There are two main types of Telefunkens: smooth plates and ribbed plates. The smooth plates are usually more desirable and expensive for audiophiles, probably because people consider this type to be more 'neutral'. Telefunkens are not used in guitar amps as much as other ECC83 types. I have found that the smooth plate Telefunken lacks personality in a guitar amp and does not really overdrive well. The ribbed plates are a little better in this regard. However, there is a good place to put a Telefunken smooth plate in a guitar amp... in the phase-inverter slot (usually the last slot closest to the power amp tubes.) I have found that this can add some 'clarity' and '3-D' effect to your overall sound. Genuine Telefunkens always have an etched diamond shape on the bottom of the tube between the pins, so you must always look out for this. Telefunkens are also commonly faked, even with the diamond bottom. Usually these fake Telefunkens will have perfect labeling that is 'baked-on' and will not rub off with a cloth. This is a dead-giveaway that you are dealing with a fake. The labels on real Telefunkens are always fragile and will easily rub off. Look out for Telefunkens with other labels: Fisher, Gap-R Computor and others. These are genuine Telefunkens and can usually be had at special prices. There are also highly regarded 'Lab Quality' Medial Telefunkens that were produced for Leeds & Northrup Grummond. These will usually have red tips, say 'Selected' somewhere on the tube, and are sought after by audiophiles who will pay insane prices for these tubes.
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