Ever since this amp came out, there are many that complain the TC50 lacks any low end. Sure, it is a different amp when comparing to a Mark V90 (which many have migrated from). Ok, to start with, it is 50W, but to get that power it appear you need the EL34 tubes. As I have stated before in this forum, the STR447 do improve with use and that harshness will fade. However, is this the ear getting used to the change in tone? No, it does mellow out a bit but will retain its brilliance and character that I began to favor with the TC50. Not as robust and beefy as the TC100, I do have to dial back on the bass with that one. TC50, on the other hand is well balanced. Since I have been on a kick of trying out the STR445 (JJ 6L6GC) tubes which are the stock glass bottles used in the Mark VII, why not see if the amps compare with the same tubes on board. Bottom line is: They do not compare. End of story. Oh well, it was worth a try. Mind you that the sonic character on the hi gain channel is there, nothing with the Mark VII will match the lo gain channel, and the clean sort of floats in the area between clean and fat on the Mark VII. Aside from the tone and grind characteristic sort of coming close, the main issue is the output level or loudness. I felt like the was something wrong with the amp with the 6L6GC tubes, this also held true with the STR440, STR441, and STR443. I have not tried the STR448 and if I did it was not rememberable. I am sort of getting the impression that when setting the bias to 6L6 tubes, It sounds like the amp is running in triode mode due to the dramatic loss of output power. I doubt that is what is happening. It could be due to the small power and output transformers. There is even a power drop with the TC100 but not as dramatic as it is with the TC50. It is not power sag as that would have been evident. It could be the difference in the tube impedance more than anything.
Comparing the TC50 with the STR445 6L6 tubes to the Mark VII at the 45W setting just did not cut it. Even the 25W power mode on the Mark VII was a bit more without having to adjust the channel volumes. I generally keep them at around 9am on the Mark VII.
I shut it down, waited for the power tubes to cool so I can swap the SRT447 EL34 tubes back in.
Back to operating wonder, the TC50 can be loud with the EL34, no issue keeping up with the Mark VII at 45W or 90W. I did not need to push the global output volume all the way up and had to back off a bit on the channel settings.
Design change for the TC50, remove the bias switch so it is EL34 only (6V6 uses the EL34 setting as well) or change the transformers so they can support the 6L6 and provide at least 45W. The Badlander does not seem to suffer this fate. I do not have the BAD50 so I cannot relate that fact but the BAD100 does not have any dramatic power loss when changing to the 6L6GC tubes.
Fret not, I sort of like the TC50 with the STR447 tubes. It sounds good. Never felt that the amp lacked any bass, there is plenty there. It is not a Dual Rectifier or a Mark amp where most dial out all of the bass and some midrange to compensate for higher gain settings. Would that mean the other amps have too much low end? To be honest, after I stuffed the original glass back into the TC50 I continued to play with the two amps. I feel the bass response is comparable in some ways, just not as deep as the Mark VII with the STR445 tubes. Not that I feel like doing it, I have not tried the Mark VII with the EL34 tubes yet. Sometimes it helps with perspective if you put the shoe on the other foot.
That was an interesting experiment, the STR447 EL34 are more fun. Then again, the 6V6 for that half power and louder than the 6L6 in this amp is also good if you are after a more vintage vibe.
Comparing the TC50 with the STR445 6L6 tubes to the Mark VII at the 45W setting just did not cut it. Even the 25W power mode on the Mark VII was a bit more without having to adjust the channel volumes. I generally keep them at around 9am on the Mark VII.
I shut it down, waited for the power tubes to cool so I can swap the SRT447 EL34 tubes back in.
Back to operating wonder, the TC50 can be loud with the EL34, no issue keeping up with the Mark VII at 45W or 90W. I did not need to push the global output volume all the way up and had to back off a bit on the channel settings.
Design change for the TC50, remove the bias switch so it is EL34 only (6V6 uses the EL34 setting as well) or change the transformers so they can support the 6L6 and provide at least 45W. The Badlander does not seem to suffer this fate. I do not have the BAD50 so I cannot relate that fact but the BAD100 does not have any dramatic power loss when changing to the 6L6GC tubes.
Fret not, I sort of like the TC50 with the STR447 tubes. It sounds good. Never felt that the amp lacked any bass, there is plenty there. It is not a Dual Rectifier or a Mark amp where most dial out all of the bass and some midrange to compensate for higher gain settings. Would that mean the other amps have too much low end? To be honest, after I stuffed the original glass back into the TC50 I continued to play with the two amps. I feel the bass response is comparable in some ways, just not as deep as the Mark VII with the STR445 tubes. Not that I feel like doing it, I have not tried the Mark VII with the EL34 tubes yet. Sometimes it helps with perspective if you put the shoe on the other foot.
That was an interesting experiment, the STR447 EL34 are more fun. Then again, the 6V6 for that half power and louder than the 6L6 in this amp is also good if you are after a more vintage vibe.
