Tweaking the Silverface Musicmaster Bass Amp

[taylornutt]

75 - 76 sounds right.

Some thought and observations:

The speaker baffle has been modified - looks like a baffle was installed inside the original baffle? What's behind the new add-in? I can see the original speaker hole peaking out in one of the shots. I wonder if the original baffle is blocking the speaker? The speaker as it is sits lower in the cabinet than in a stock configuration.

The tubes shouldn't be too loose - on the FDP there is a whole thread on cleaning and tensioning tube holders. Your tubes might be fine and tight enough - a little contact cleaner on the pins and some in and out might be all it needs.

The tone knob on MMB is pretty much useless - I leave mine at 3.5 or so as do I think most people that use these amps for guitar.

Finally, I didn't find my 12 watt MMB twice as loud as a 6 watt Champ - so yours might be just as loud as it was ever meant to be.

Cool amp.

I played the amp for about 5 minutes before my kids started bugging me to take a bike ride.

I noticed the speaker baffle was altered, but not sure why. I plan to get some contact cleaner and clean the connects to the tubes. It sounds better in the house than it did in the garage. I will try to do a quick demo soon with my flipvideo camera. I agree with your insight about the tone knob...once it gets past 3ish it engages and I can't tell much difference between 4 and 10. I wonder if there is a mod to help with that? Pedals really make this amp come alive. Every pedal I tried sounded delicious. The Bugera V5 sounds louder, but it also has a gain control which the MMB doesn't. Without the gain, the Bugera V5 is very quiet. Kicking on my MBM Saltbreaker/booster or MBM Fuzzface was downright nasty and I loved it. I also liked my EHX Wiggler on the Leslie Speaker setting. I need to get 2 nuts because the chassis is being held in by two screws at the moment.

I will probably do a side by side with the Bugera V5 soon and decide which one I am keeping and which one I am selling.

yeah, whenever you're ready to sell that, let me know.

And yes HotRod, I will let you know if I am selling the MMB. (or you can send me your Jag-stang )

[taylornutt]

I got some replacement nuts so now the chassis can't move around. I could be wrong, but I am starting to believe these tubes could be originals. The speakers are Fender Specials and so are the tubes. Unless the previous owners put the same tubes back into it. I plan to drop the chassis soon and take some gut shots. How can you tell if the pots need cleaning? and if so, how do you clean them? No matter what I plan on replacing the tubes before making any final judgment on the amp. I think the tubes are shot because every demo of this amp I have seen, the amp really starts to breakup at higher volumes and this one doesn't do that. Eventually this amp or my Bugera V5 will get sold, but I want to hear this amp at full strength first.

[Sidney Vicious]

The pots are likely fine - looking at them will tell you nothing - but if when you turn them you hear a scratchy sound through the speaker it may be because the pot contacts are dirty. A little squirt of deoxit or such contact cleaner is all it needs.

If you think the tubes are bad, I would just grab some known-to-work tubes and replace those in the amp and see what happens. The 6v6's don't have to match. And if its a tube issue you will know right away that's what it was.

[taylornutt]

After struggling with my tele the last 2 nights, I grabbed my Jagmaster with Jazzmaster pups (8400-neck, 9400- bridge) and plugged in the MMB. Sounded killer and it was much louder. I plugged my AVRI Jag and it sound good too. I am starting to wonder if I really need new tubes. The first 2 times I played it, I couldn't hear much difference when the volume was at 5 or 10, but now I am hearing the break up at the higher volumes Maybe this amp just needs to get used a bit after sitting up for a while. I will definitely get some contact cleaner and maybe I can wait on the new tubes for a while.

[taylornutt]

I did a quick shootout between my Bugera V5 and the MMB Amp. Not even close really. The MMB is definitely staying around. I will put the Bugera on Classifieds tonight. I love the headphone jack, the adjustable power, and the reverb, but tone-wise it isn't even a contest. I love the two different inputs on the MMB and how the 2nd input is grittier than the first input. I think I might get a simple A/B box and run cables into each one to switch back and forth and try both together. I love this amp! (Sorry HotRod!)