Mark V tone, tuning for SED wing =C=

[bandit2013]

I have had the SED wing =C= for a few months now. I have lost track when I got them (in March perhaps). I play through the amp twice daily (I live close to work so I fire up the amp at lunch time for 40 minutes) and after work I may be at it for 2 to 4 hours. I am logging some hours on them for sure. They sound great but, sometimes I get tired of the tone. I have rolled the preamp tubes many times only to find out that what I had set up sounded better than the changes I made. This time I decided to remove the common denominator, the PI tube. I have tried many tubes there but was favoring the Sovtek LPS tube. More recently I returned back to the Mesa 12ax7a in all positions except V7. Sounded excellent with a few exceptions, a bit over the top on the high frequencies. 6L6GC tubes are notorious for brittleness on the top end. I was almost considering changing the power tubes to EL34 format but with a quad of JJ6CA7 just to see if I can tame the high end without sacrificing the low end.

After many experimental rolls, I found a great combination to tame the highs and preserve character that I desire in all channels. I do like CH1 but with the head unit and sealed 412 it will always lack that dry natural tone I can get from the Mark IV in clean through the C90. Here is the mix up now: Rectifier tube still original, Power tubes: GT6L6R-2 (SED =C= NOS versions from mid 80's)
V1 EH12ax7
V2 Ruby HG12ax7
V3 Mesa 12ax7a
V4 Mesa 12ax7a
V5 Mesa 12ax7a
V6 EH12ax7
V7 TS12ax7

I did like TS in V1 but that enhanced all the channels, I wanted something not quite as dark. I have even tried the TS in all positions, this did sound good but was lacking something in the midrange. The Sovtek LPS is a great tube but was supplying all of the tones to the power tubes. Since I had one matched TS, I gave it a go in V7 in hope to get a bit of attenuation on the upper freq. I should have tried this some time ago. The overall tone of the MKV is where I want it now.

 

[bandit2013]

For a while I was having Ice Pick issues through a EVM12L 412 cab. About that time I returned the stock 12AX7. Sounded good but top end was brighter than I desired. Not brittle but very sharp especially in the Extreme mode on CH3 (pentode bias and full power). It was sure to kill will the preset EQ selection. Part of this was the amp and speakers and the other was the acoustics of the room. Moving all of the amps and guitar stuff to an empty spare bed room cured the issue almost immediately.

Just for kicks, I did take out the SED's to try out EL34 tubes. Why not right? Out of the box the EL34's really rocked the house! Awesome tone, very tight bass and pristine cleans in all modes on CH3. Best of all at max power in pentode mode, I could not get the ice pick to reveal itself. However, CH2 and CH1 were not the same. That was a deal breaker for me. Clean in CH1 was better and so was Tweed voice. Had more ice pick top end in CH1. CH2 on the other hand, was lacking something unless you pushed the amp hard. The EL34 sounded great when driven to high volume but lacked in tone quality at lower volumes or reduced voltage such as Variac power mode. 45W was okay best in 90W mode, not much to say about the 10W except very thin. After I put the SED's back in (used the EL34 for about a week or so) I realized what I was missing. That put the WOW factor back in the 6L6 power tube. I am sure the EL34 were probably not in the best distortion range (too much head room so they may have been cold tubes - Late distortion).

When it comes to power tubes, SED wing=c= are at the top of the list for the Mark V.

 

[shimmilou]

In just about any amp, when comparing 6L6 and EL34, I always thought the 6L6 was best for clean, and the EL34 was best for distortion. I have never heard an amp with EL34s that had a clean sound that could compete with the clean sound of an amp that had 6L6.

Have you tried the GT 6L6 GE? I couldn't remember if you had tested them or not, didn't go back through your posts. I have recently compared the Winged C to the GT 6L6 GE in a Bassman head and the GT was much better, at least for my taste.

 

[swbo101]

I have never heard an amp with EL34s that had a clean sound that could compete with the clean sound of an amp that had 6L6.

+1

You will always sacrifice clean tone when going the EL34 route.

 

[R_ADKINS80]

I can sympathize with you on that one brother. I got =C= 6L6GC for my triple because everyone said were the be-all-end-all of power tubes. My thoughts? They actually charge that much for these? WHY???? I couldn't get a decent gain tone out of them at all. Cleans were good, but that's it. I sold them at a loss to my buddy. I much prefer New Sensor brands and Chinese offerings to them.

And yeah, I gave them about a month of daily playing to burn them in. They didn't get much better.

 

[bandit2013]

My first attempt to purchase the wing=c= from Doug's tubes, He had only matched pairs. Since I stated I needed them for Mesa Mark V, he said the one's he had would not work well for my application. However, he had a NOS quad of GT Premium GOLD series GT6L62-R which were relabeled SED/Svetlana's. These tubes have been performing exceptionally. The punch in the bass is declining a bit and the treble is starting to creep up, they still sound great. So far, they are the longest lasting power tube I have put into the Mark V. Originals red plated within 2 months. Tung Sol 7581 stripped and went flat in about the same amount of time. The only difference in my gear since I installed the SED's, I also replaced the V30's with EV's.

The EL34 actually had a nice clean chime to them in CH1. They appeared much brighter than the 6L6's I liked the tone from the SED's in CH1, as well as CH2. CH3 was the big difference. EL34 were okay. I guess the difference did not reveal itself until you really opened up on the master volume, or if in loop hard bypass, channel volume. If you crank the Mark V, the EL34 stood out with more definition (to some extent) when comparing the 6L6. However, I much prefer the character of the 6L6 over the EL34. Perhaps 6CA7 or KT77 would have been a better choice. I will have to get some and try them out. The SED's will not last forever, and finding an alternate at a lower cost would be great.