SWR Super Redhead Owners - Best Preamp Tube

Downsizing while upweighting. I had a SRH for a few years; I got tired of the heavy, awkward schlep pretty quickly. Lots of full size rigs that weight less and easier to move around, unless it is being parked somewhere and staying put.

As to what tube, I never messed around with tube rolling on it so, no help there.

Hope this helps.

 

NOS Mullard ECC83.

bottom line, like as not you will hear little difference between tubes so just use what the amp came with.

 

To expand on BassmanPaul's comment, the reason you're unlikely to hear a difference among preamp tubes is that SWR did not use the tube in the gain circuit so you can't overdrive it. It probably contributes "something" to the tone but there is a derogatory term for hybrid amps that don't use the tube for gain: a "marketing tube." YMMV.

 

From the various reports I have read, tube rolling makes very little difference in this amp or any other SWR amp. But I will provide some comments related to various new production tubes I have rolled in various amps.

In my experience, the JJ ECC83S is a warm sounding tube in many circuits. I actually hate them in every bass amp I have tried them in, but I like a tight clean tone with extended highs and deep, punchy lows. The JJ ECC83S doesn't have much low end or much high end, and in some circuits they are grainy sounding and break up extremely easily. They are inexpensive and pretty common in guitar amps. Maybe you could borrow one from a friend's amp to see if it changes the sound of your Redhead. If the sound is unchanged, their is probably little point in trying other tubes.

I personally like the JJ ECC803S quite a bit in many of my bass amps. This is a long plate tube. The ECC803S has a wider frequency response than the ECC83S and seems to have what I describe as a little harmonic shimmer on the upper mids. They sound tight and aggressive without being overly bright or clanky and are a bit lean on the bass.

If you want warm, I would avoid the Tung Sol 12AX7. This is one of the highest rated new production tubes, but it tends to be bright and punchy with very strong upper mids, which are great if you like a lot of clank and fret rattle. The Tung Sol is one of the highest gain tubes you can buy, but it doesn't compress or distort easily in my experience. Chinese 12AX7As are somewhat similar to the Tung Sols.

 

I downsized some 20+ years ago from an all-tube Traynor amp w/ a 6X10 cab to my beloved SRH, went through a difficult transition to find “my sound” again and have tried a few tubes to no real effect.

The SWR may be cleaner and more well-defined than you’ve become used to, and the preamp has its quirks. Always set your input to nearly clipping to get the most out of the tube preamp (and now I use an always-on Sansamp BDDI before the input into the amp for the ‘warmth’ or ‘dirt’ or whatever that I had become used to - all knobs set at noon except for the blend which you can play with). And a lot of SWR cab users roll back the tweeter some.

That Aural Enhancer circuit is a resonance filter and not primarily a tone shaper, like electronically changing the size of a box on an acoustic guitar - resister/capacitor/inductor in a tunable circuit. It will give you a pretty good scoop around 200hz though, which you can fix with the EQ. I have become hooked on what it does to my sound. Wide open makes the amp sound huge, but you may need to roll back the bass a bit (pull the bass knob out for the 30hz setting) as there is no HPF.

I hope this helps – it was quite a learning curve for me… and I really like that amp.