M
myles
New member
Below is an email I received from my friend Bruce Egnater. Bruce is attempting to produce a great EL34 based amp and over at least a year if not more we have worked together to try to get a reliable amp. Bruce's amps sound great and are reliable but no matter how talented a designer might be and how carefully he builds his amps the issue of poor current production tubes surfaces a lot of the time.
In the case of some folks like Bogner and Rivera the use of real winged C Svetlanas is recommended. Bruce was looking for other options rather than have one single source for tubes. I thought that putting some of our dialogue here may be of interest to others.
_______________________
Hello Myles,
Sorry to bother you again. Svetlana is being very difficult to deal with. Any other decent EL34 you can recommend? I know that is an oxymoron (decent and EL34) but I need to find an alternate that will be....potentially reliable.
Thanks!!
Bruce Egnater
EHMP LLC
3833 West 12 Mile Road
Berkley, MI 48072
Tel (248) 541-9100
Fax(248) 541-9102
http://www.egnater.com
NEW EMAIL ADDRESS
bruce@egnater.com
Bruce,
I really have no other options other than NOS. The winged C Svet is the only tube that will work with any degree of reliability over 450 B+. If screen voltages are over 400 most all the others also fail.
There are also mechanical issues. The EL34 is somewhat of a lightly constructed tube and the current offerings are pretty fragile. Maybe they work in a studio or bedroom but when it comes to road travel they are pretty fragile.
Back in the heyday of Marshall even with great EL34s they still put 6550s in USA bound amps as the travel had a lot of amp arrive DOA due to tube failure and the light construction of the EL34 even back then. Things have gotten even worse.
The JJ is a nice strong tube that may be an option you can try but they are an aggressive tube in tone and have something of a hard edge. Hard rockers that use a lot of pedals and do not rely on the output section for smooth distortion like these but they do not have the creamy overdrive that a nice Siemens or Mullard will have. But, they are a strong tube physically.
The EL34 Mullard reissue from New Sensor shows the same sort of results, curves and performance of the older Electro Harmonix EL34. Soft vacuum, light construction, and the shortest life and lowest overall output of any current EL34. Using RCA/GE/Mullard test specs of 265 plate, 250 screen and -13.5 bias the test spec is for 100mA of plate current for an EL34. Most of these have a hard time breaking 75-80. Those that do make it to 90 or more have very short life and run very hot even when biased a bit cool. You can apply all of these findings to the current Electro Harmonix tube as well as this Mullard reissue.
The Groove Tubes EL34M xf2 double getter reissue of the Mullard is a Chinese tube and is wildly inconsistent. If a set is properly matched one day you may find one of the tubes in a duet or quad has drifted out of range from the other(s) in less than ten hours.
ALL of the tubes called 6CA7 fall into two categories. One category is a tube with nothing more than an EL34 with a different label. The other category are EL34 offerings that are assembled in a big bottle. None of these has the performance or reliability of an original GE 6CA7. The GT (Groove Tubes) attempt at making this tube failed drastically. Anything over 250 plate and screen volts will show over a 90% failure rate in less than an hour.
The Sino Chinese tubes are unreliable and low in output. The Shuguang is much the same although Ruby Tubes has a tube built in China for them as an exclusive offering from them called the EL34BSTR that was one of the great EL34 tubes and if still available may be a contender. Tom McNeil at Ruby Tubes keeps tight reign on the Chinese factory and production and seems to be the only person capable of getting the folks over in China to follow direction and have good quality control, or it may be the testing at Ruby Tubes / Magic Parts just takes a lot of tubes and through their testing procedures yields great consistent results. You might want to give a call to Magic Parts and Tom McNeil as he may have some good thoughts and he is also a great fellow and easy to work with.
I hope this helped ....
Myles
In the case of some folks like Bogner and Rivera the use of real winged C Svetlanas is recommended. Bruce was looking for other options rather than have one single source for tubes. I thought that putting some of our dialogue here may be of interest to others.
_______________________
Hello Myles,
Sorry to bother you again. Svetlana is being very difficult to deal with. Any other decent EL34 you can recommend? I know that is an oxymoron (decent and EL34) but I need to find an alternate that will be....potentially reliable.
Thanks!!
Bruce Egnater
EHMP LLC
3833 West 12 Mile Road
Berkley, MI 48072
Tel (248) 541-9100
Fax(248) 541-9102
http://www.egnater.com
NEW EMAIL ADDRESS
bruce@egnater.com
Bruce,
I really have no other options other than NOS. The winged C Svet is the only tube that will work with any degree of reliability over 450 B+. If screen voltages are over 400 most all the others also fail.
There are also mechanical issues. The EL34 is somewhat of a lightly constructed tube and the current offerings are pretty fragile. Maybe they work in a studio or bedroom but when it comes to road travel they are pretty fragile.
Back in the heyday of Marshall even with great EL34s they still put 6550s in USA bound amps as the travel had a lot of amp arrive DOA due to tube failure and the light construction of the EL34 even back then. Things have gotten even worse.
The JJ is a nice strong tube that may be an option you can try but they are an aggressive tube in tone and have something of a hard edge. Hard rockers that use a lot of pedals and do not rely on the output section for smooth distortion like these but they do not have the creamy overdrive that a nice Siemens or Mullard will have. But, they are a strong tube physically.
The EL34 Mullard reissue from New Sensor shows the same sort of results, curves and performance of the older Electro Harmonix EL34. Soft vacuum, light construction, and the shortest life and lowest overall output of any current EL34. Using RCA/GE/Mullard test specs of 265 plate, 250 screen and -13.5 bias the test spec is for 100mA of plate current for an EL34. Most of these have a hard time breaking 75-80. Those that do make it to 90 or more have very short life and run very hot even when biased a bit cool. You can apply all of these findings to the current Electro Harmonix tube as well as this Mullard reissue.
The Groove Tubes EL34M xf2 double getter reissue of the Mullard is a Chinese tube and is wildly inconsistent. If a set is properly matched one day you may find one of the tubes in a duet or quad has drifted out of range from the other(s) in less than ten hours.
ALL of the tubes called 6CA7 fall into two categories. One category is a tube with nothing more than an EL34 with a different label. The other category are EL34 offerings that are assembled in a big bottle. None of these has the performance or reliability of an original GE 6CA7. The GT (Groove Tubes) attempt at making this tube failed drastically. Anything over 250 plate and screen volts will show over a 90% failure rate in less than an hour.
The Sino Chinese tubes are unreliable and low in output. The Shuguang is much the same although Ruby Tubes has a tube built in China for them as an exclusive offering from them called the EL34BSTR that was one of the great EL34 tubes and if still available may be a contender. Tom McNeil at Ruby Tubes keeps tight reign on the Chinese factory and production and seems to be the only person capable of getting the folks over in China to follow direction and have good quality control, or it may be the testing at Ruby Tubes / Magic Parts just takes a lot of tubes and through their testing procedures yields great consistent results. You might want to give a call to Magic Parts and Tom McNeil as he may have some good thoughts and he is also a great fellow and easy to work with.
I hope this helped ....
Myles
