RA100, Have you tried other power tubes? if so what ?

I am unsure how long the RA100 was on the market. Probably not that long since I can still find new Electa Dyne models here or there.

Just curious if you have ventured into different power tubes. The basic stuff like 6CA7, KT77, or other flavor of EL34 (B, L or just the plan old standard one). If you have, care to share your opinions? My short term plan is to get the RA100 head first. I already have 412 cab I can used until I build up another one. Would like to hear it with the speakers I have first before committing to the cab. I am sure I will eventually find out for myself on the tube options. Hopefully when I get the amp, the original tubes will last longer than 2 months. So far I am pleased with the JJ version of the 6CA7 in the Mark V. I spend more time using the Crunch voice of CH2 than any other channel. So I have a feel that the RA100 would be up my alley.

I guess everyone is happy with the stock EL34's.

Since I bought my RA100 second hand, the tubes were well used. I tried a few of what I had in my inventory.
KT77, no bad although they sounded better in the Mark V. I have tried TAD6L6GC-STR and that sounded thin. I did get some new tubes to pop in shortly after I got the RA100. Figured while I was spending money to get the SED =C=EL34 before they become too expensive or scarce. In comparison to the EH EL34, Mesa EL34, and the KT77, the SED =C= EL34 are amazing. Definitely a huge difference in character. I tried them in the Mark V first and they sounded similar to the EH EL34 that I got nearly last year. Not sure the 6CA7 would be a wise choice for this amp due to the extended low range. Clean channel is dark enough. However the Hi/Lo channel could use dome darkening since it is overly bright. That was an easy fix, swap in two Mullard reissue into V1 and V2. Still has a bright tone but not as brittle as the Mesa 12AX7A. V3 is always active and the signal passes though this tube regardless of the effect loop use. NOS 12AT7 may be an alternative to the current production 12AT7. I was having issue with the noisy reverb which was easy to jump to conclusions about where the noise was coming from. Noise was fixed with a change in V3. NOS RFT 12AT7 did the trick. I also tried JAN/Phillips 12AT7 but liked the RFT better due to difference in tone. As for V4 and V5, I could not find tubes that sounded better than the Mesa 12AX7A. I am using the same in the reverb V6 but the Preferred series 7025 was an improvement especially in noise reduction. This RA100 rocks. The Mullard tubes really opened up the Hi/Lo channel considerably. Lo is not as bright, not brittle. I can use my strat bridge pup without needing cotton wadding in my ears. The Hi setting, now we are talking Mark V extreme territory set to pentode, or possibly Mark IV mode in the V with the switch set to triode on the power tube drive.

My primary use for this amp is the single coil guitars. Humbuckers sound awesome too. My next thing to add will be a Mesa flux drive with EQ. I can wait for a while. Considering how good the amp sounds without it not sure I need an eq but I will get one anyways. Thing about the Mark series amps with EQ, they do not sound all that great without it especially with the overdrive channels, that is my opinion anyway which may not hold up for others that like there amps without the EQ turned on.

Thank you for this report. I have an RA-100 that I like a lot. All stock tubes for now, but will probably change them out down the road. I've recently been getting some added noise from the amp on the HI channel. A fairly big jump is amp hiss & hum. The gain is about 2 o'clock, and dead silent on the clean, and LO channels, but when I switch to HI it gets noisy. More than I would expect. I tried switching out V1 & V2, but didn't try V3. Honestly, I haven't had the best of luck with Mesa tubes. I'd like to take it to a tech and have it fitted with a whole new set of tubes to really bring out its best qualities, and hopefully quiet the HI channel a bit.

If you can afford the SED = C= EL34 they are incredible. Only issue I have with the tubes I got is that they can be noisy (plate and grid rattle when low frequencies are dominant but is only noticeable at low volume, had the same issue with the Mesa EL34 and EH EL34).

I have been rolling the preamp again.
I changed V1 to a vintage Mesa tube 12ax7a which is quite similar to a Shuguang 12AX7-A but the getter is a halo and not the square mortar board. The Mullard reissue (long plate) is still in V2. That really brings out the low end and retains the highs enough. Lo channel is still bright but not as bright as it would be with a JJ tube (same as current Mesa).

As for V3, there are many affordable NOS tubes in the 12AT7 that may be lower in cost than current production. V3 will definitely alter tone. I found the RFT enhances the boldness, I have tried the JAN/Phillips 12AT7 which sounds a bit different. I had enough of the 12AT7 tubes to try in the Mark V, WOW that sounded great for the gain channels but the clean channel suffered from lower output so I did not keep them in the V. Believe it or not, it did not take away from the gain quality all that much.

The best so far for V4 and V5 are the vintage Mesa tubes (Chinese 12AX7A). I thought the Mesa (JJ) tubes sounded great but they seemed to be a bit dull (probably the ones I selected were not so good). As for the reverb, it is a toss up between Preferred Series 7025 or Mullard CV4004 (I settled on the CV4004).

I should get a few Shuguang tubes in the A and B versions. May source them from GT or TAD since they may have a better screening process.

Recently bought a Roadster for my evil doings, or actually just about anything. Love the amp with the Mesa tubes so I bought a complete set of new Mesa tubes for it. Now on to the topic. I have tried other tubes with the RA100. SED=c=6L6GC, GL KT77, SED =c= EL34, TAD6L6GC-STR, Svetlana 6L6GC, Tung Sol 7581. Out of all of this, the SED =C= EL34 were tops. That was until I thought why not give the stock tubes a shot from the Roadster. Mesa STR440 Yellow and marked #10. Wow, this amp can rock with attitude with proper 6L6 tube in it (no power soak). EL34 will perform better with the power soak due to dearly clipping compared to 6L6GC. With the Mesa 6L6GC loaded, it still has a classic rock sound but more modern. Definitely a Marshall killer tone, not as abundant as the Roadster, but still had me in awe. Clean channel also changed a bit, sounded more like a Fat clean on the Mark V with bold enabled, or the clean channel on the Roadster. However, boosting the gain up in the clean did not clip as much as it would with EL34's still sounded good though. I may keep the 6L6's in the amp for a while since I am actually enjoying the change. Besides, the 6L6 tubes do not vibrate or rattle like the EL34 which was driving me nuts, they may sound great but so far every EL34 I have had experience with over the years did this with the exception of the original EL34/6CA7 (RCA or Sylvaina?) tubes that came in my Mark III when I bought it 24 years ago, or the Mesa replacement tubes marked as STR440 also with the EL34/6CA7. I guess the Special Tube Request number gets reused after a few decades.

At it again, I did like the character of the 6L6 but was missing the tube saturation I was getting with power soak and the clean channel. 6L6 was not bad though, just had more headroom. Instead of popping the SED =c= EL34 back in, decided to try the EH EL34 that were in my stash of tubes. Why these? I checked all of the tubes including the Mesa EL34's (basically the same tube as the EH) only to find the EH tubes that I had on hand were quiet when tapped lightly. The SED's had a rattle that was annoying (sounded more like a broken light bulb with any vibration.) EH and Mesa branded EH tube both have crimped plates. SED and KT77 were both spot welded. Under close examination, there is some differences between the Mesa branded EL34 compared to the EH tube, that being the grid, screen and halo rods being copper in color, not the case with the EH branded tube. Perhaps I have taken the SED's to their useful life as I have found I needed to boost volume to have the same effect. I practically had to drop the masters considerably with the EH tubes, very much the say effect I notices when the SED's were new compared to the spent Mesa tubes that came in the used amp.

Looking at some alternatives to use. I prefer the EL34 character and tone over the 6L6. The EH EL34 appear to sound much louder but also develop a rattle at lower frequencies. When pushed the tend to sound harsh. SED = C= EL34 are awesome, not harsh in any way. The quad that I have are mechanically noisy, as is the case with most EL34 I have used. I am considering Tung Sol el34B and or Ruby el34bstr. Have not decided yet.