| Author | Message | ||
     Steve Kennedy |
Go here for the whole story: Guitar Amplifier Blueprinting... GT Secrets The bottom line: The USA GT-6CA7 ... still a rumor out there, but here are some of the real ones in a 750 volt B+ amp, a Music Man after running some tests. These are not just a big bottle EL-34 as other folks are selling as 6CA7 tubes today. These are the real deal, off the original tooling as used by GE. These also have an active beam forming element, a critical item missing in the "6CA7" / EL-34 big bottle "conversions" sold today by some other vendors. With any luck, these will be shown at NAMM. You may even see an NVM (new vintage manufacture) 12AX7!  | ||
| Steve Kennedy |
Here is additional information about these tubes from the Guitar Amplifier Blueprinting site: NOTE: NVM stands for New Vintage Manufacture Tests against Sylvania NOS 6CA7, Philips 6CA7, and original 6CA7 showed the NVM 6CA7 to have curves most close to the GE and Sylvania in triode mode. In Pentode mode, the average tube had a slightly faster rise time than NOS GE original. Due to the higher vacuum of a 6CA7 over a soft vacuum EL34, these tubes should have a much longer life in guitar amp usage than an EL34. In life tests so far, at least a 40% increase could be easily expected. These tubes may have a very strong appeal to players wanting more clean headroom in Marshall style amplifiers and may be sonically preferred over the 6550 where folks use these. Listening tests are in progress. Tests in the Musicman 750 plate volt amp are in progress.  Tubes in triode mode test as expected, in pentode mode they show the characteristics of an active beam forming element. This is NOT the case on today's new so called 6CA7 tubes by other vendors. These "new" copy 6CA7 tubes are nothing more than the companies EL-34 in a big bottle without the active beam forming element, and generally show performance inferior to the same companies EL34. These NVM GE 6CA7 tubes have a very different bias than any other EL34, including the E34LS. The E34LS generally needs an additional 1.5 to 2 volts of increased bias over and EL34. These will require even higher bias voltage. Bias info should be included in tube packaging as is currently done with the GT designed E34LS tube. These NVM GT GE6CA7 tubes are even stronger than the current GT E34LS. In something like a 100 watt Marshall, I would not be surprised to see an average amp with a good power transformer bench 170 watts.  | ||
| Paul |
I got for Christmas Aspen Pittman's Deluxe Revised Edition of The Tube Amp Book (a very nice book!), and in it he talks about the GT6CA7GE built at his San Fernando CA factory. It mentions a first release as early as Summer 2003. Obviously they maybe a bit behind schedule, but I just can't wait until they get that one out the door. | ||
| Steve Kennedy |
I got that book as well, but I haven't had the time to read through it yet! I like the large format much better than the little handbook size. | ||
| Paul |
Yes. Great Book. And the CD is a nice touch, even though the GUI is not consistent across chapters. A little bit tired though of him and G. Weber snobbing the MM's the way they do. 'Good if you want clean', I'll disagree. They have have a very *precise* concept of what an amp should sound like, and if it doesn't meet their exact criteria for a nice sounding amp, it just isn't an amp. I find that this duo has absolutely no nuance in their taste. If it isn't BF or Tweed, it's bearly worth mentioning. Well I have BF/SF/Tweed/MM and about a dozen more vintage amps in my collection, and with the right guitars (need to match guitar-amp, very important), they all sound different and sweet.I enjoy reading their books, but I get annoyed with their narrow palette. It's like reading about an artist promoting cubism, and denying any recognition to impressionism, surrealism, and stating that italian renaissance is merely OK, if you really like that style. Good book though. Paul | ||
| Steve Kennedy |
I enjoy their books too, but over a long exposure time their "bias" becomes more evident, like a mild aftertaste with an otherwise fine wine! Steve | ||
| Bo Metz (mrdownchild) Username: mrdownchild Registered: 06-2008 |
I don't care for Gerald Weber. I purchased on of the early 2410 models. Matter of fact, my amp was number 245 in the very first run. It was a dog. The damn thing kept blowing fuses and was very tempermental. I eventually had to send it back to Weber. He claims to have repaired the amp, but on it arrival, I noticed a new serial number. I was now number 259 in the original run. It was a piece of crap too. I sold it while the stock was still high, and moved on. If would bash MM amps in my presence, I'd respond by pointing out the fact that Eric Clapton used Music Man amps for six years. How long has EC used Kendrick amps? The long and short of it is this: Gerald Weber is a con man. He has been more concerned with building an image that puts him in the league with people like Leo Fender, Ken Fischer, Howard Dumble, George Alessandro, Dr. Z,....etc. He should be more concerned with building a quality amp. |