new SLO with KT66

[splatter]

I'm not feeling the KT66, bottom end feels mushy and undefined. I'm not sure if I should go with kt88 or 6l6.
I play mostly hair metal type stuff.
Thoughts?

 

[rstites]

I'd just go with the 6L6. It's what the amp was designed for and it'll get the type of tones you want just fine with that.

 

[Six Stringer]

I'm in 100% agreement with rstites.

 

[lespaul6]

I never heard of any pro's who used the SLO in the past, switching power tube types... ever

 

[harddriver]

I thought the amp was designed around the 5881, I think the Sovtek, I'm sure some SLO guys will come in here to clarify the 5881 type that's best. You might like the 6l6 better as it has a tighter low end and a bit less mids emphasis, think the EVH amp with 6l6 versus EL34. I think the 5881 also has a slightly softer low end response but I'm sure that's what Soldano designed it around for some reason.

 

[stratjacket]

I thought the amp was designed around the 5881, I think the Sovtek, I'm sure some SLO guys will come in here to clarify the 5881 type that's best. You might like the 6l6 better as it has a tighter low end and a bit less mids emphasis, think the EVH amp with 6l6 versus EL34. I think the 5881 also has a slightly softer low end response but I'm sure that's what Soldano designed it around for some reason.

Yes that’s correct, mine came with a set of Sovtek 5881/6L6WGC as eyeballed in the amp.

 

[psychodave]

I thought the amp was designed around the 5881, I think the Sovtek, I'm sure some SLO guys will come in here to clarify the 5881 type that's best. You might like the 6l6 better as it has a tighter low end and a bit less mids emphasis, think the EVH amp with 6l6 versus EL34. I think the 5881 also has a slightly softer low end response but I'm sure that's what Soldano designed it around for some reason.

Yes that’s correct, mine came with a set of Sovtek 5881/6L6WGC as eyeballed in the amp.

You both summed it up.

For the OP, try some 6L6’s and see if you like it. I know it’s going to cost you $$, but unless you try them you’ll ever know.

If I owned a SLO it would be loaded with Sylvania 7581a’s. My 5150 absolutely crushed with them. I’m sure the SLO would be insane.

 

[CornNutz]

I tried GL kt66 in one of the SLO Clones I built. Promptly packed them up, and sent them back. I tried GL kt77, and it slayed, however they dont last very long for the money so cannot recommend.

Went back to 5881, and it just sounds best.

 

[panhead]

wont make a bit of difference unles you turn it past 5 or run it like Haynes pre 9 oclock master 3 oclock

 

[CornNutz]

wont make a bit of difference unles you turn it past 5 or run it like Haynes pre 9 oclock master 3 oclock

Different power tubes have different characteristics even before you really push them.

 

[cardinal]

Mine had 5881. I wouldn't call it a tight amp. The bass/low end is a bit brown and soft IMHO. It's a cool amp with a bright, cutting high end, which I guess is why people remark on its clarity etc., but the low end isn't really defined or fast IMHO.

 

[panhead]

wont make a bit of difference unles you turn it past 5 or run it like Haynes pre 9 oclock master 3 oclock

Different power tubes have different characteristics even before you really push them.

not really if it was a 6l6 amp I doubt you could tell by hearing it if it was 6l6 5881 or kt 66`s, besides that an slo is all preamp unless you get the volume up. Then it sounds a lot like a superlead/ marshall

 

[godgrinder]

If I owned a SLO it would be loaded with Sylvania 7581a’s. My 5150 absolutely crushed with them. I’m sure the SLO would be insane.

I have Tung Sol 7581A's in one of my SLOs, bigger lows and brighter than 5881's yet less fizz. Can totally vouch for them.

 

[rstites]

I thought the amp was designed around the 5881, I think the Sovtek, I'm sure some SLO guys will come in here to clarify the 5881 type that's best. You might like the 6l6 better as it has a tighter low end and a bit less mids emphasis, think the EVH amp with 6l6 versus EL34. I think the 5881 also has a slightly softer low end response but I'm sure that's what Soldano designed it around for some reason.

The SLO was designed around the 6L6GC, as far as I know. I run old Philips 6L6GC in mine. I think the 5881 were later made standard as they're more readily available, more rugged, and much less expensive than good NOS 6L6GC's. Regardless, I still like the 6L6GC's in mine.

 

[CornNutz]

wont make a bit of difference unles you turn it past 5 or run it like Haynes pre 9 oclock master 3 oclock

Different power tubes have different characteristics even before you really push them.

not really if it was a 6l6 amp I doubt you could tell by hearing it if it was 6l6 5881 or kt 66`s, besides that an slo is all preamp unless you get the volume up. Then it sounds a lot like a superlead/ marshall

I can hear the difference. And yes SLO is all pre-amp when it comes to gain, which is basically all modern amps. However SLO is not all pre-amp when it comes to overall tone. Power tubes still have tonal characteristics, they are not transparent. kt66's sound similar to 6l6's, but those sovek 5881's are more mid focused, probably because they don't have the low end of a 6l6GC.

Anyhow I've build about four SLO clones, and experimented with power tubes extensively, and in a band mix. KT66 did not cut through (mids wer way gone), and felt mushy. The 5881's, GL kt77's, and JJ e34l all worked better.

I've past my SLO phase, moved on to other builds.

 

[the4thlast1]

Tad 6l6 or Sovtek WXT+ are both tight on the low-end. the Tads also have great clarity , might work really well in the SLO..... SLOs have mushy bass in general , Im sure some guys will say not but on the lead channel it can get pretty mushy in the bass. Keep the gain down and throw a tube scream in front that will help too.

 

[Mr. Willy]

I didn’t like 6L6’s in my SLO at all. Felt like it neutered the amp and took a lot of its aggression away.

 

[Racerxrated]

I thought the amp was designed around the 5881, I think the Sovtek, I'm sure some SLO guys will come in here to clarify the 5881 type that's best. You might like the 6l6 better as it has a tighter low end and a bit less mids emphasis, think the EVH amp with 6l6 versus EL34. I think the 5881 also has a slightly softer low end response but I'm sure that's what Soldano designed it around for some reason.

The SLO was designed around the 6L6GC, as far as I know. I run old Philips 6L6GC in mine. I think the 5881 were later made standard as they're more readily available, more rugged, and much less expensive than good NOS 6L6GC's. Regardless, I still like the 6L6GC's in mine.

I've had a good stash of Mesa STR 415s for a few yrs now, since I've owned my first 2C+. I've tried those in 2 of the 3 SLOs I've owned, plus a quad of KT66s and without a doubt, the best tubes for that amp are the wafer bottom 5881s. Just no contest. KT66 were just too mid heavy even with the mids dropped, and the Mesa 415s(Sylvania 6L6GC, the gold standard for 6L6) were just OK sounding which was disappointing to say the least since it makes the 2C+ sound incredible. Far and away the cheap simple Sovtek Wafer bottom 5881s were the obvious choice after tube swaps. My Mesa 415s are all very strong with my tube tester and withstand the huge voltage my Coliseum puts out, so there's no question of the health of those tubes.
Wafer 5881s for the win, and don't look back. Mike Soldano knows a thing or two about his amps, and they were his choice for years.

 

[panhead]

Crazy thing about the SLO is Mike says that it has more in common with a Fender twin than a marshall, go figure?

 

[aftec]

SLOs have mushy bass in general? A couple of things would pop into my mind about SLOs but mushy in bass is not. If it feels mushy or loose, there is way too much bass dilated in or the depth is too high. Using drop Z is not a real option either, the time it was designed, sub octave B chiuging was not even invented.