Guitar Gear Forum

Last week I was emailing with the B.A.D. support (Soldanos parent company) with some questions about bias etc and the rep suggested me to try 7581A tubes, which according to them raises the plate voltages and brings the amp closer to 45w. So I bought a set of Tung Sol 7581As to try it out.

I got them a few days ago but only had the time to try them today. First, I measured the plate voltage with the stock 5881s and got 420v. Then I measured it again with the 7581A set and the plate voltage is now 463v with the tubes biased at 37mA per the spec sheet that came with them. So they were right about that part.

But how does it sound? Holy shit, it's a major improvement!! The headroom is much bigger and the amp has considerably more volume. I was using the amp at around 4 to get stage volume before, now I can barely go past 3 before it's too loud.

Tone wise, the 7581As have slightly less midrange and a tighter low end, which I assume comes from the extra headroom.

So anyway, highly recommend these tubes for the SLO30!!!

ha cool! I already forgot about these, but cool to see the results.

Hell yeah! Truly getting it in to the 50 watt range.

I'm kinda kicking myself for not just getting the 30, but glad to hear it's working well for you!

Very cool of them to make the suggestion. The issue that I had with the SLO30 was in how muddy the overdrive channel was for my uses. I don't know what the higher plate voltage does for the tone, but cleaning up some of those cloudy low mids could have done the trick for me.

eyeball987 wrote: ↑Wed Jun 05, 2024 7:13 pm Very cool of them to make the suggestion. The issue that I had with the SLO30 was in how muddy the overdrive channel was for my uses. I don't know what the higher plate voltage does for the tone, but cleaning up some of those cloudy low mids could have done the trick for me.

Were you running it maxed out? I didn't have a chance to max it out volume wise but at the loud volume I tried it I got the same results as my SLO100. Basically the opposite of muddy.

Vladimir Putin wrote: ↑Wed Jun 05, 2024 7:19 pm Were you running it maxed out? I didn't have a chance to max it out volume wise but at the loud volume I tried it I got the same results as my SLO100. Basically the opposite of muddy.

I used it by itself, and with a PS2. Using the PS2 I was able to put the master in every position but still had the same results. Maybe the one that I picked up had an issue? IDK.

Interesting, never even heard of a 7581A

Interesting. The one I tried felt and sounded identical to my SLO100. I got it at least to band volume and it held together no issue.

eyeball987 wrote: ↑Wed Jun 05, 2024 7:23 pm

Vladimir Putin wrote: ↑Wed Jun 05, 2024 7:19 pm Were you running it maxed out? I didn't have a chance to max it out volume wise but at the loud volume I tried it I got the same results as my SLO100. Basically the opposite of muddy.

I used it by itself, and with a PS2. Using the PS2 I was able to put the master in every position but still had the same results. Maybe the one that I picked up had an issue? IDK.

Follow up questions...Have you played the SLO100? How did you feel about that?

Personally, I like the SLO a lot, but coming from playing tight metal amps with a relatively clear and compressed low end, the SLO does NOT have this, by comparison. Compared to say a Recto, yes, tighter and clearer, but compared to a Mark or EVH, no, it is loose and muddy. I could not use a SLO as my main amp without a boost.

ninjaraf wrote: ↑Wed Jun 05, 2024 7:46 pm Follow up questions...Have you played the SLO100? How did you feel about that?

Personally, I like the SLO a lot, but coming from playing tight metal amps with a relatively clear and compressed low end, the SLO does NOT have this, by comparison. Compared to say a Recto, yes, tighter and clearer, but compared to a Mark or EVH, no, it is loose and muddy. I could not use a SLO as my main amp without a boost.

I did play a SLO100 years ago, but it wasn't mine. Not enough experience to really have an opinion but I do remember loving it. For me, I tend to boost just about everything and prefer a bit more of a vintage flavor of high gain. I really liked the 6505+ that I had over a 5150, and have sold two 50W 5153's because I found them to be too modern for me. Oddly enough, the Synergy SLO module has been my main tone for a year or so now.