Fender Bassman 300 Pro...help?

Bassmec · #2 03-21-2011, 08:06 AM

Its broken take it to the menders, it should not sound weak or thin in any way shape or form.

Nsmccarty91 · #3 03-21-2011, 08:10 AM

delete

BROKEN OHMS · #4 03-21-2011, 11:30 AM

They're ridiculously LOUD. You shouldn't be able to turn it up past 3. As far as the deep tone you're looking for...that's definitely in there too. Take it to someone who can fix it. Maybe just needs new tubes?

Mr. Foxen · #5 03-21-2011, 11:57 AM

Could try swapping some preamp tubes, that is doable yourself.

**f64** · #6 03-21-2011, 08:21 PM

First thing I'd do is check the speaker load. This could be contributing.
Here's the manual: http://support.fender.com/manuals/ba...ead_manual.pdf
To test it:
Run channel 1 flat only.
EQ mid position or off.
Everything for channel 2 should be off.
Low & High set at 5.
Comp off.
If you still get no results here there are a few other things to check. Each set of power tubes is fused. Plug everything in and rotate the head so you can see the back clearly. On standby there is a red light next to each fuse between every set of tubes. When you switch off standby do the lights turn green? If not you've got a power tube issue. Pre-amp tubes could be the culprit also but before I'd go rotating them I'd head to a tech.
You got a great price on the head. Spending a few bucks to have it looked at might be in order.
I got mine unbadged, tolex gone with a Fender 810 Pro included in the same shape for $600 total. I know I got a steal. I checked the s/n’s three times to make sure it wasn’t hot. I could afford to send the head to a tech at that price. I re-tolexed each, regrilled both of them and because Fender wouldn't sell their nameplates landed up buying broken, newer Rumble 15's just for the logo's.
Hope you get to the bottom of the issue. They are probably the best tube head out there today.

rodl2005 · #7 03-21-2011, 09:06 PM

great amp & as said above- HUGELY LOUD. It'd EASILY blow up my old SVT410HLF (500w rating RMS) if I'd've wanted it too. Goes IMMENSLY low & 'Dubby deep' too, :-

so DEFINATELY something wrong there. Probly just a new set of power tubes (By the 'sound' of it).
But you sure can TRY changing pre amp tubes-even try swapping the same ones(AX7's) around IIRC there's a 'AT7' in there too.

jastacey · #8 03-21-2011, 11:13 PM

First thing I'd check is the Bias, it's explained in the owners manual, you'l need a multi- meter ... if you can't get a reading of 80mvDC or better/higher, the output tubes are weak, make sure all the (3) fuse lights are green when the amp is switched out of stand-by ... make sure you let the amp warm-up for at least a half an hour, when you check/set the bias ..... on the up side, a set of new output tubes Sovtek 6550 is not that expensive and that's what came stock with the amp, if you do change the output tubes, change the inverter tube 12AXY (V3) and the driver tube 12AT7 (V4), as a side note the 12AT7 that is in there sounds the best, I tried others but I went back to the stock tube, as it sounded/performed the best, the 2 preamp tubes in the front are for channel 1 (V1) & 2 (V2) they are O.K. sounding as is, but V1 does respond nicely to tube rolling ..... are you using channel 1? ... channel 2 is very middy sounding and it is the dirty channel, and it really has no body, it is used to blend it into the clean (1) channel to get some gritt .... so before even going to the power tubes, set the preamp to channel one, there's a small toggle switch that does this, make sure the Mid-Notch switch is out, on the graphic EQ switch is out, switch out the compressors, set your bass to about 7-8, treble to taste ( I keep mine at 7 ) and make sure the 6db switch, which is located by the input, is switched off, make sure the speaker impedance is set to 4 ohms ( I'm assuming your cabinet is 4 ohms ), with these settings, you should get really full/loud sound from your bass, enough to crack sheetrock, break glass windows, rattle all the china in the kitchen, get evicted from you current residance ..... I'm assuming you checked your input cables, speaker cable, and hooked into the main speaker jack ... what is the bass your using? if active, did you check your battery?