Retube Time.....Soldano SLO-100

[mikey]

The spec info on these are all over the place. It seems they are considered 25-26 watts. Whatever the case, they are very durable and easily handle higher plate voltages. Keep em below 70% for peace of mind, set to taste, and they should run a long time!

 

[Rick Lee]

Alright, I put it at 28mA. Every time I come back to check drift, it's gone down .5mA. It's been burning in for a good two hours now.

 

[Jdub]

I've tried them all, 6L6 and variants including KT66. Best to my ears were the Sovtek wafer bottom 5881s. Not tried 34s which would require modding. But there's a reason Mike puts those wafer bottoms in. Cheap, reliable and they sound great. Bias around 28ma and you're set. Pre tubes, I've played with lots of combos and the Chinese 8th gen sounded best, with a Jan AT7 in the pi spot. Had my last SLO last year, that's my experience.

I agree here on power tubes. After 20 years and several SLOs with KT66, tungsols, jj's etc etc. The tubes Mike selects are as good or better than anything else al things considered. Tone reliability, cost etc.

I do remember having some JJs once in of them that were great. Big and a little dark , but they sounding great cranked, particularly for heavy stuff. That SLO had the depth mod too. I was on AIC/Pantera/slayer influenced mode at that time at it rocked. The bias was set higher, I wanna say it was at 37ma IIRC but this was10 or more years ago.


All said it done , use Mike tubes bias to taste.

 

[azzzy]

Sorry for resurrecting a thread... Has anyone tried EL-37's in an SLO? They are allegedly rated at 400V but since 5881's don't blow up in an SLO... wondering if anyone dared to stick vintage Mullard EL-37's in there.

 

[CrazyNutz]

Sorry for resurrecting a thread... Has anyone tried EL-37's in an SLO? They are allegedly rated at 400V but since 5881's don't blow up in an SLO... wondering if anyone dared to stick vintage Mullard EL-37's in there.

The Sovtek 5881's can handle well over 500v, this is why Mike used them, not all 5881's can do this.

Putting some rare Mullard EL-37's in a SLO would be risky. I personally would not risk 1k worth of vintage tubes.

 

[Luca79]

The 7027A is another variant of 6L6GC.

 

[Racerxrated]

The wafer 5881s are the best tube for the SLO. I've had 3 of them, and I've tried my stash of Sylvania 6L6s to see if they were better and the 5881s are still the winner to my ears.

 

[CrazyNutz]

The wafer 5881s are the best tube for the SLO. I've had 3 of them, and I've tried my stash of Sylvania 6L6s to see if they were better and the 5881s are still the winner to my ears.

I agree, nice balance with a nice mid. I tried 6l6gc's, it got scoopy, and too bottom heavy. Also tried kt66's, kt77's, still wen't back to 5881 wafer bottoms.

Now el34 are nice, really need to change the screens to 1k, and adjust the bias range.

 

[azzzy]

The Sovtek 5881's can handle well over 500v, this is why Mike used them, not all 5881's can do this.

Putting some rare Mullard EL-37's in a SLO would be risky. I personally would not risk 1k worth of vintage tubes.

Well, vintage tubes are usually MUCH more durable than the current production tubes. Just because EL-37's are rated at 400V (although in some sources at 800V - that in itself is confusing) doesn't necessarily mean they couldn't take 500V. Although my question was not a hypothetical. I was asking if anyone ACTUALLY tried EL-37's in an SLO. Or any other guitar amp for that matter. I have a few (maybe 10 or 12) and being a huge fan of Mullard tubes I am eager to see if anyone has any REAL experience with the British Mullard EL-37's.

 

[steve_k]

My 2 cents....and that's what its worth....

Don't hack up your SLO to run 34's. Bias supply runs at -48v or 6L6.

Anything other than Sovtek 5881's will take the plate voltage down from 505 to somewhere in the 470-480 V range. The high current draw from 30W and 35W tubes all do it. Run the 5881's around 28mA bias and retain the proper operating PV.

Been around the block with all of them, and keep coming back to the 5881 to retain the punch and clarity.

 

[blackba]

I found this thread interesting on the coin base 5881/6L6WGB. http://www.tdpri.com/threads/sovtek-588 ... tt.639935/

The 5881/6L6WGB seem to be replaced with the standard base 5881WXT
https://www.tubedepot.com/products/sovt ... acuum-tube
https://www.tubesandmore.com/products/58816l6wgc-sovtek

I am looking for some backups for my Soldano HR-25. Not sure how different the 5881WXT is from the 5881/6L6WGC coil base.

Not sure if these are Sovtek, but they are a great price. https://nesstone.com/product/mesa-boogi ... ower-tube/

 

[Nigel]

There's no difference in new production wafer base and claw base.

The difference is in the vintage rebranded sovtek 5881 and original logo 6P3S-E.

AFAIK Black Logo Sovtek is ('99 vintage pictured) is way past military quality. The one on the right has the rebrand silver, and has the military quality.

The other two pix are of real military branding, one reflects Sept. '83 and the other a '73 vintage. Apparently early 80's and prior has "the tone," tig vs tab-in-slot plate construction being a tell. Getters are different too.

Seriously guys, buy a set and have your mind blown. It's as big a difference as real Mullard EL-34/12AX7 vs. the ones Mike Matthews sells today: Mullard-In-Name-Only, not in tone.

 

[blackba]

There's no difference in new production wafer base and claw base.

The difference is in the vintage rebranded sovtek 5881 and original logo 6P3S-E.

AFAIK Black Logo Sovtek is ('99 vintage pictured) is way past military quality. The one on the right has the rebrand silver, and has the military quality.

The other two pix are of real military branding, one reflects Sept. '83 and the other a '73 vintage. Apparently early 80's and prior has "the tone," tig vs tab-in-slot plate construction being a tell. Getters are different too.

Seriously guys, buy a set and have your mind blown. It's as big a difference as real Mullard EL-34/12AX7 vs. the ones Mike Matthews sells today: Mullard-In-Name-Only, not in tone.

So where would you recommend getting a set from. I only need a matched pair?

 

[Nigel]

http://www.cryoset.com/catalog/product_ ... cd49b9fa87

He tests them if you don't feel comfortable ordering NOS from across the pond.

Might even get better highs/etc. due to the cryo process. Call him, he's really personable. Otherwise, just hit eBay. Tubes are everywhere!