#FENDER MUSICMASTER BASS DRIVER#
#FENDER MUSICMASTER BASS SERIES#
#FENDER MUSICMASTER BASS FREE#

So why is there a resistor too? Compensating for a poor choice of transformer? Or perhaps just burning off some extra power to avoid saturating the transformer or burning the primary? Or some kind of protection for the transformer, or tuning resonance? Or is that just touch-up circuit-tweaking?

#FENDER MUSICMASTER BASS DRIVER#

Yes, 'Most of the current to the driver plate comes through the primary of that transformer' like it does on an normal output transformer primary. Obviously I need to actually get and play and listen before I start dreaming up mods! There's no way I would want a long high-gain shielded cable to a stomp box to switch, but it would be interesting to mount a teensie toggle in a big shielded jack body, to have a hi/lo switch for instant comparison.

#FENDER MUSICMASTER BASS SERIES#

Thanks so much for pointing out my misread of the input jack schematic, now that new paradigm is forever etched in my brain for future recognition! One of my early Alembic preamps had something sort of similar except jack #1 was straight in without any series resistor, like some Mesa amps, but still did a 50/50 mix if you used both for a stereo guitar like an ES-345 I don't know whether they used more contacts on the jack.my later Alembic didn't have that 'feature'.

#FENDER MUSICMASTER BASS FREE#

That is a free +16v already sitting there, and that is plenty for the job.ĮNZO thanks for your indulgence reading my over-enthusiastic dump and taking your time to reply, you've always been a guiding light. And rather than create a B+ divider, I'd simply connect the string to the power tube cathodes. To elevate the heaters, you need to rewire so neither side is grounded. But mainly, if you look at the schematic,you will see one side of the heater string is grounded. First, we are assuming you have some hum from that source, you may well not. This is not a high gain amp.Īs to making a B+ voltage divider for the heaters, several thoughts. If you have not yet taken possession of the amp, perhaps a good listen first before trying to modify the thing for hum/noise we do not yet know exists. If the first two B+ filter caps are good, I doubt a choke will make it any quieter. replacing it with a choke would raise that B+ to closer to the screen voltage. The 10k resistor in the B+ is there to drop the B+ by 40v for the preamp, as well as be part of the decoupling. I am not saying it is a bad idea ultimately, but do it for the right reasons. Just changing the one part because some othe circuit used it in similar position, is not a good reason.

047 elsewhere, but it was also in a different circuit. Remember, the amps are about circuits, not parts. The input cap blocks any DC riding on the input, but mainly serves to limit the low end response, which would suck power and probably overdrive the speaker.įor transformer manufacture codes, you tell us, look on the part. Most of the current to the driver plate comes through the primary of that transformer. Now stepping on the switch switches from high gain to low. But really, who plugs two instruments into one channel?Īn old trick is to plug the guitar into one jack, and then a simple shorting stomp switch into the other jack. yes, if you plug something into both, then each has a 68k in series and the resistors do their best to mix it. And a great deal of the rest of the amp world do as well. Fender has used this arrangement for decades on end. This is a basic 2/1 voltage divider, so using J2 cuts the signal input exactly in half, which is a 6db reduction. In other words, there are now two 68k in series from the input to ground and the tube gets the signal from the middle. The tube gets the signal from the junction of the two. From J2, the signal flows through the other resistor, but the remaining one is now grounded through J1. If you plug into J1, the two resistors are in parallel for 34k, and the signal flows through it. You already HAVE low and high gain input jacks, that is what the two resistors do. Try gathering your thoughts so it is easier to read. Wow, eleven posts in an hour and five minutes.

Fender musicmaster bass