Soldano SLO KT66's and Depth mod

[Marshall Freak]

I got an SLO a while back, and I think I'd like to try some KT66's in it. Either Gold Lions or Shuguang's. What do you bias it at? Like 6L6's or do they have a higher or lower wattage? What can I expect when I change them out?

I'm thinking I'd like to try putting a depth mod in it, and I've read it's pretty easy. Mine doesn't have the Line out, so I can use one of those holes to put it in. What's it take? Is it pretty involved or simple? Will it change the tone any? I had an SLO before with the depth, Haynes, and SRV mods, and didn't sound anywhere near as good as this one does IMHO, I'd rather not destroy that if modding it does that.

 

[Nigel Tufnel]

I would treat kt66's as 25w tubes when biasing but the shuguangs do seem to sound best when biased on the hotter side in my experience, I would just experiment to taste on that. Kt66's are a nice marriage of el34 and 6l6 tones imo, you get a nice full bottom, great mids and airy highs, plus they overdrive in a more pleasant manner than 6l6's. If you are really happy with the tone of the amp I wouldn't fool with the depth mod even though it is quite easy to implement. It only involves a pot, a cap and a bit of wire. If you want to be able to dial in more lo mid/bass response it's a good mod, I like experimenting with different values of pots and caps to get what I want. I will say that after a while the depth/resonance whatever you want to call it mod starts to wear on me tone wise, there is just something unnatural sounding about it but you can always turn the knob to zero.

 

[Marshall Freak]

I would treat kt66's as 25w tubes when biasing but the shuguangs do seem to sound best when biased on the hotter side in my experience, I would just experiment to taste on that. Kt66's are a nice marriage of el34 and 6l6 tones imo, you get a nice full bottom, great mids and airy highs, plus they overdrive in a more pleasant manner than 6l6's. If you are really happy with the tone of the amp I wouldn't fool with the depth mod even though it is quite easy to implement. It only involves a pot, a cap and a bit of wire. If you want to be able to dial in more lo mid/bass response it's a good mod, I like experimenting with different values of pots and caps to get what I want. I will say that after a while the depth/resonance whatever you want to call it mod starts to wear on me tone wise, there is just something unnatural sounding about it but you can always turn the knob to zero.

Thanks! If they're more EL34 sounding than 6L6's, I'm sure I'll like them.

I like the tone of the amp a lot, but at lower volumes (Master around 2-3) I've heard the depth mod really helps, so I thought it might be worth it.

 

[Nigel Tufnel]

Kt66's do have some more british flavor to them, certainly more el34-like in the mids. The depth mod is good for filling things out at lower volumes.

 

[Nigel Tufnel]

Oh and I might add that kt66 tubes are very full sounding on their own so you might try swapping a set into your amp before taking the soldering iron to it. If that doesn't fill things out enough then the depth mod would probably be a simple and rather non invasive solution.

 

[Capulin Overdrive]

the chinese will have a Marshally EL-34 crunch compared to 5881's.

the Gold Lions will be a more modern mean and pissed off tone than the chinese.

 

[Shark Diver]

Agreed. I love the Gold Lion KTs. I find the depth mod totally unnecessary, especially in a band setting.

 

[Nigel Tufnel]

the chinese will have a Marshally EL-34 crunch compared to 5881's.

the Gold Lions will be a more modern mean and pissed off tone than the chinese.

I haven't tried the Gold Lions yet, I've been meaning to get around to it. I like the Shuguangs pretty well, better than the HP Reflektor version although they were pretty good too. I'm lucky enough to have some of the GEC originals, man do I wish somebody could pull off a dead on reasonably priced clone, they're my favorite power tube of all time.

 

[Nigel Tufnel]

Agreed. I love the Gold Lion KTs. I find the depth mod totally unnecessary, especially in a band setting.

I've been hearing good things about the new Gold Lion version, and I agree about the depth mod with volume on your side. It's a fun at home thing for a while but like I said above it does wear on me after a bit.

 

[Marshall Freak]

Oh and I might add that kt66 tubes are very full sounding on their own so you might try swapping a set into your amp before taking the soldering iron to it. If that doesn't fill things out enough then the depth mod would probably be a simple and rather non invasive solution.

I'll start with the KT66's then, It's not lacking bass really, just wanted to fill it out a bit.

 

[Marshall Freak]

the chinese will have a Marshally EL-34 crunch compared to 5881's.

the Gold Lions will be a more modern mean and pissed off tone than the chinese.

Sounds like the Chinese tubes are what I want then, the band I'm going to use this amp in is more of a classic rock band.

 

[Marshall Freak]

Agreed. I love the Gold Lion KTs. I find the depth mod totally unnecessary, especially in a band setting.

I haven't played it with a band yet, but the rest of the band uses smaller 15-30 watt amps, so I might want the Depth mod to help fill things out, playing at the same levels they are. My other band plays more classic/hard rock, lots o Jackyl, ACDC, Buck Cherry, and I use a Quick Rod with that band. I'm going to take both and use the SLO this weekend, should be fun.

 

[Death by Uberschall]

The Depth mod is all of about $5 worth of quality parts, not the cheap stuff, so you can splurge.

When turned down/off, you will have the stock SLO sound. I put mine in the line out location, never used the line out anyway. As you crank the master volume, it become less effective, less noticeable. So it acts like the "loudness" function on a stereo system. You'll have the chassis out to bias the tubes, spend 15 minutes throwing it in there.

 

[Riddick]

This is what it looks like in my SLO

 

[Marshall Freak]

This is what it looks like in my SLO

Wow, that's it? Looks pretty labor intensive!!

 

[stratotone]

Charlie, I can take you a pic or two of mine if you can wait a day or so. I got instructions from Bill Sundt at Soldano on mine and put the pot where the second cab goes, or was it the line out? I can't remember, it was one of those. Anyways, it was a really easy mod and it seems to be 'out of the circuit' when you turn it off. Makes a nice difference at lower volumes and as you crank the amp you can turn it down.

Regarding KT66s, I have no idea. I retubed it with sovtek 5881s and it sounds great. Kinda nice to have an awesome amp like an SLO and can get good results feeding it cheapo tubes.

Pete

 

[Marshall Freak]

Charlie, I can take you a pic or two of mine if you can wait a day or so. I got instructions from Bill Sundt at Soldano on mine and put the pot where the second cab goes, or was it the line out? I can't remember, it was one of those. Anyways, it was a really easy mod and it seems to be 'out of the circuit' when you turn it off. Makes a nice difference at lower volumes and as you crank the amp you can turn it down.

Regarding KT66s, I have no idea. I retubed it with sovtek 5881s and it sounds great. Kinda nice to have an awesome amp like an SLO and can get good results feeding it cheapo tubes.

Pete

Pete, That would be awesome! No hurry, I'm still mesing with it. Mine doesn't have the Line out, just metal plugs in the holes so that's where I'll put it. Thanks!!