KT 77's in a Helios?

[gbsmusic]

Going to give them a try. Any good or bad with them? Thanks.

 

[SavageRiffer]

Going to give them a try. Any good or bad with them? Thanks.

I have. Try 6CA7s first. KT77's were good, but I loved the difference 6CA7s made. They felt nicer when I'd open up the volume on my Helios 50. They give a nice width and level of harmonic detail. The Helios is very midrange oriented. KT77s seemed to kind of make the lower mids more prominent and a little harder sounding. There were some things in the tone that opened up, but I think 6CA7s were very cool. Where they really made the difference was on the low input. At lower volumes, the low input was kind of anemic with EL34s. 6CA7s made boosts/overdrives even better through the low input. I didn't notice much difference in headroom except almost negligibly with the Variac on.

The differences are barely noticeable at lower volume, but to really appreciate what the big bottles can do, you need it at least loud enough for a light drummer. The Helios can hardly be improved upon with stock tubes. It has an incredible feel and breakup. It seemed like KT77s felt tighter and 6CA7s were slightly bouncier. Both tubes are a bit stiffer, but if you use Variac mode (on the 50, the 100w would be 30w JTM mode) it gets even punchier.

You can hear slightly more low end with 6CA7s, KT77s seem maybe a hair more low end, but the 6CA7s give it an almost 6L6 quality. Anyway, it's not so much a big deal, but I suppose it's kind of like the big bottles let a wider range of frequencies through. I doubt that has any technical merit to it but that's the way I perceive it.

When you strike a power chord and let it ring, 6CA7s let the growl kind of linger. I'm not talking about sustain just kind of the way the harmonics swirl around. I don't know if that makes much sense but I think you'd see what I'm talking about if you try it. Bottom line is both 6CA7 and KT77 have a bit more low end, feel a little stiffer, and kind of less compacted midrange than EL34.

If you give either a try, let me know what you think.

 

[fusedbrain]

I did the EL34/6CA7/KT77 experiment with my 50watt Helios about 2 weeks ago. The 6CA7's stayed in.
I agree 100% with everything SavageRiffer said ^^^

 

[9ball]

i used KT77's in a marshall i had for awhile. they sounded good. i still have a couple sets actually. some jj's and a set of gold lions

 

[gbsmusic]

Cool, thanks for the info!

 

[born_hard]

Going to give them a try. Any good or bad with them? Thanks.

I have. Try 6CA7s first. KT77's were good, but I loved the difference 6CA7s made. They felt nicer when I'd open up the volume on my Helios 50. They give a nice width and level of harmonic detail. The Helios is very midrange oriented. KT77s seemed to kind of make the lower mids more prominent and a little harder sounding. There were some things in the tone that opened up, but I think 6CA7s were very cool. Where they really made the difference was on the low input. At lower volumes, the low input was kind of anemic with EL34s. 6CA7s made boosts/overdrives even better through the low input. I didn't notice much difference in headroom except almost negligibly with the Variac on.

The differences are barely noticeable at lower volume, but to really appreciate what the big bottles can do, you need it at least loud enough for a light drummer. The Helios can hardly be improved upon with stock tubes. It has an incredible feel and breakup. It seemed like KT77s felt tighter and 6CA7s were slightly bouncier. Both tubes are a bit stiffer, but if you use Variac mode (on the 50, the 100w would be 30w JTM mode) it gets even punchier.

You can hear slightly more low end with 6CA7s, KT77s seem maybe a hair more low end, but the 6CA7s give it an almost 6L6 quality. Anyway, it's not so much a big deal, but I suppose it's kind of like the big bottles let a wider range of frequencies through. I doubt that has any technical merit to it but that's the way I perceive it.

When you strike a power chord and let it ring, 6CA7s let the growl kind of linger. I'm not talking about sustain just kind of the way the harmonics swirl around. I don't know if that makes much sense but I think you'd see what I'm talking about if you try it. Bottom line is both 6CA7 and KT77 have a bit more low end, feel a little stiffer, and kind of less compacted midrange than EL34.

If you give either a try, let me know what you think.

I just bought a modded jcm 800 ( Jose Mod) and would like to try 6ca7 tubes. Which brand did you use? And did you notice that the 6ca7 work well at lower volumes? Cause as we know the 6550 are really clear without saturation until you turn the volume up. And i still want some breakup in the mids at lower volumes.

 

[SavageRiffer]

Going to give them a try. Any good or bad with them? Thanks.

I have. Try 6CA7s first. KT77's were good, but I loved the difference 6CA7s made. They felt nicer when I'd open up the volume on my Helios 50. They give a nice width and level of harmonic detail. The Helios is very midrange oriented. KT77s seemed to kind of make the lower mids more prominent and a little harder sounding. There were some things in the tone that opened up, but I think 6CA7s were very cool. Where they really made the difference was on the low input. At lower volumes, the low input was kind of anemic with EL34s. 6CA7s made boosts/overdrives even better through the low input. I didn't notice much difference in headroom except almost negligibly with the Variac on.

The differences are barely noticeable at lower volume, but to really appreciate what the big bottles can do, you need it at least loud enough for a light drummer. The Helios can hardly be improved upon with stock tubes. It has an incredible feel and breakup. It seemed like KT77s felt tighter and 6CA7s were slightly bouncier. Both tubes are a bit stiffer, but if you use Variac mode (on the 50, the 100w would be 30w JTM mode) it gets even punchier.

You can hear slightly more low end with 6CA7s, KT77s seem maybe a hair more low end, but the 6CA7s give it an almost 6L6 quality. Anyway, it's not so much a big deal, but I suppose it's kind of like the big bottles let a wider range of frequencies through. I doubt that has any technical merit to it but that's the way I perceive it.

When you strike a power chord and let it ring, 6CA7s let the growl kind of linger. I'm not talking about sustain just kind of the way the harmonics swirl around. I don't know if that makes much sense but I think you'd see what I'm talking about if you try it. Bottom line is both 6CA7 and KT77 have a bit more low end, feel a little stiffer, and kind of less compacted midrange than EL34.

If you give either a try, let me know what you think.

I just bought a modded jcm 800 ( Jose Mod) and would like to try 6ca7 tubes. Which brand did you use? And did you notice that the 6ca7 work well at lower volumes? Cause as we know the 6550 are really clear without saturation until you turn the volume up. And i still want some breakup in the mids at lower volumes.

I've tried EHX which I think were pretty good. Whenever you switch from EL34 to bigger bottle tubes like 6CA7 and KT77, you're going to get more headroom and less saturation at lower volumes. What makes up for it is how well the preamp and power amp respond to your playing dynamics. Some amps need the gain set higher to get a liquid feel, other amps seem to do it with half the gain. I think 6CA7s give a real nice power amp response. 6550's are a bit harder and don't quite give it up that easily. They can sometimes be a bit harsher in the high end. 6CA7s can sometimes be a bit warm, so they work well in brighter amps. Think of 6CA7s as kind of 6L6. I think you'd have a bit of JCM900 qualities if you swapped for 6CA7s.