Super Reverb no punch

[Harvette01]

Ahh, right, it’s still on its original electrolytc cap ecaps
Unless proved good (for ESR and DC leakage on a dedicated tester - ie not a multimeter), they should be assumed to be worn out / life expired and replaced. All of them, a long time ago
The most critical is the bias supply cap; as that eventually fails, the output valves will run hotter and hotter, putting them and the valuable vintage transformers at risk of damage.
Note that the 50V rating there is seriously inadequate, I suggest a long life (>=10,000 hour) 105°C 100V type.

Other caps (eg film, ceramic) should only be replaced if proven bad.
Generally they don’t require checking unless there’s some sort of symptom / malfunction that can be somehow be related back to a particular cap.
An exception to that are the coupling caps feeding the output valve control grids. With vintage amps I’ve seen too many of those that are dodgy, I suggest it’s a very good idea to check those reasonably often, eg every year or three.
To check them (for DC leakage), lift the legs at the 220k junction eyelet, clip a meter set for DC mV (red to the free leg, black to chassis common), power the amp up and read the voltage on one then the other. Anything more than say 50mV indicates a problem, cap is best being replaced, uprated to a 630V type. In some abnormal scenarios, there can be over 500V on those 400V caps, eg the valve in V6 has heater failure, amp powered up with the valve in V6 removed.

All right! The original filter caps looked like new with no leakage. I changed them anyway. All I can say is "Wow!" The amp sounds like new. Serious bottom end with amazing punch. Sparkly high end with great reverb. Love it. Thanks for all the advice. Next up: The power cord is 3 line, but the plug is only 2, so I need to change it to a grounded plug.

 

[King Fan]

Good for you. You are now a poster child for why smart people don’t avoid e-cap replacement.

Note the 'leakage' we worry about is electronic, not physical. (Bulging/dripping caps are a different — and obvious — problem.) And note Wally's insight about filter caps weakening even before electronic leakage.

 

[D'tar]

Agreed!!! I find the puch returns with fresh reservoir and filter caps. The sparkle returns with bypass cap replacement which are all to often left in place. Just M .02 of course.

Enjoy a great amp!!!

 

[Wally]

Musical interlude….

 

[Harvette01]

The cap set I ordered came with all 25mfd caps, so I couldn't swap the second cathode bypass cap in the trem circuit for a 5mfd cap. I realize I now have WAY too much bass (even set between 2 and 3), so should I order a 5mfd to limit the bottom end? It really thumps on the low E, even on the bridge PU single coil.

 

[Wally]

That bypass cap on the trem circuit is not going to be a major influence on that low end. A smaller bypass cap on the input preamp gain stage…first triode in the signal chain…has influence on how much low end is created. So does the bass tone cap.
I test Bf/SF Fenders with volume and tones at 5. I know what to expect with those settings in a healthy and proper amp of this type, and there is not too much bass there for me. We all have our own ears, though. If the volume is BP above halfway, then 2-3 on the bass control might be ‘normal’ for me. What volume setting are you using?
What is the low end like with the bass control at 1? Could the bass tone pot be problematic? Is it original?

 

[Jasonpatrick]

The cap set I ordered came with all 25mfd caps, so I couldn't swap the second cathode bypass cap in the trem circuit for a 5mfd cap. I realize I now have WAY too much bass (even set between 2 and 3), so should I order a 5mfd to limit the bottom end? It really thumps on the low E, even on the bridge PU single coil.

So turn it to 1 or turn your mid and treble up more to compensate since you didn’t really have bass before. I had a twin that I set the bass to zero when at volume. It is a Super after all. They are known for this.

 

[Harvette01]

Everything except the new filter caps is original. I had plenty of bass before, just lacked punch. I now have great punch, just too much bottom end. If I turn my Super Reverb up to 5 and the bass to 5, it is really loud. I can tolerate up to 4, but it's pretty strong for stage volume (small to mid venue). Bass set between 2 and 3 seems to be the sweet spot. At 1, the bass just kind of disappears. Mids and treble past 6. I installed a push/pull master volume way back when. If I set both the input volume and master volume (in) at 5, it's pretty reasonable, with just a hint of breakup. Great distortion with the mv pulled out, but does tend to soften the bottom end punch. I will just learn to live with what I have. I do love it, just hoped I could have more control over the bottom end. I do appreciate all the advice.