The Fender Super Bassman 300 thread

[LahLeylah95]

Thanks for the input guys! I believe it'll be my audio interface then.

I turned the DI dial all the way up like Goatrope said and the sensitivity from the audio interface all the way down; and from there adjust volume with the knob on the front of the amp.

I guess on stage the DI signal depends on the sensitivity of the mixer console of the sound engineer. I will check this out with our own P.A. system this evening.

 

[Ryan L.]

Thanks for the input guys! I believe it'll be my audio interface then.

I turned the DI dial all the way up like Goatrope said and the sensitivity from the audio interface all the way down; and from there adjust volume with the knob on the front of the amp.

I guess on stage the DI signal depends on the sensitivity of the mixer console of the sound engineer. I will check this out with our own P.A. system this evening.

Yep, in a live situation, setting the level on the DI is completely dependent on what the soundguy/board needs. Like I mentioned earlier, in my case, it ended up being around 5-6.

 

[LahLeylah95]

Yep, in a live situation, setting the level on the DI is completely dependent on what the soundguy/board needs. Like I mentioned earlier, in my case, it ended up being around 5-6.

And it's 7-8 on our own P.A. system. On the mixer console.. just before clipping into the red + a bit extra dialing back to make sure it won't distort on the loudest notes.

There is indeed no mid-scoop going on through a P.A. system, that'll be my audio interface causing it I guess.

It seems to be in working order now. Learned something new! Thanks a lot!

 

[Paul M]

Does the pilot light usually stay lit after the power is switched off? I noticed this for the first time today. Does it indicate a problem? It went off as soon as I unplugged the power cord.

 

[azwhofan]

Does the pilot light usually stay lit after the power is switched off? I noticed this for the first time today. Does it indicate a problem? It went off as soon as I unplugged the power cord.

It may indicate an issue if it stays lit for more than a second or two. Mine glows for less than a second before fading out completely. You should contact Fender customer support and see what they say.
FWIW, I cannot recall for the life of me what the issue would be … maybe something to do with capacitors not properly discharging???

 

[rodl2005]

SB300 and 115 Bassman for a function t'other day. Excellent as usual

 

[Paul M]

It may indicate an issue if it stays lit for more than a second or two. Mine glows for less than a second before fading out completely. You should contact Fender customer support and see what they say.
FWIW, I cannot recall for the life of me what the issue would be … maybe something to do with capacitors not properly discharging???

Thanks for the response. I just had a chance to test it now. It might interest other owners to know what happened.

It seems to be a mechanical issue in the power switch. The amp powered up as soon as I plugged it in, even before I switched it on. I flicked the power switch on and off. It didn’t actually turn off until I really pushed down on the switch.

Now I can’t make it act like that again. It’s like it never happened. I think maybe the switch was bumped hard at the gig but it looks ok. Everything seems ok now.

 

[azwhofan]

After several years (4 or 5?) of flawless operation with the SB300 a strange occurrence happened at my NYE gig. At one point late in our 2nd set, the amp started to not produce volume. It kinda faded in and out. Now, on my other tube amps, this is usually an indication of power tubes getting ready to kick the bucket . However, what was different about this gig is I did not put it in Standby mode after the first set so the amp didn't have a chance to cool down. Also the amp sits flush on top of my Fearless F112, i.e. there is no ventilation between the bottom of the head and the top of the cab. I'm thinking the lack of ventilation was the culprit as all LED's on the back of the head showed green. So I'm not 100% sure what is going on.

Here's a teaser shot of my rig from a corporate Christmas gig in December. Enjoy!

Your thoughts and opinions are welcome!

 

[Meghans Dad]

After several years (4 or 5?) of flawless operation with the SB300 a strange occurrence happened at my NYE gig. At one point late in our 2nd set, the amp started to not produce volume. It kinda faded in and out. Now, on my other tube amps, this is usually an indication of power tubes getting ready to kick the bucket . However, what was different about this gig is I did not put it in Standby mode after the first set so the amp didn't have a chance to cool down. Also the amp sits flush on top of my Fearless F112, i.e. there is no ventilation between the bottom of the head and the top of the cab. I'm thinking the lack of ventilation was the culprit as all LED's on the back of the head showed green. So I'm not 100% sure what is going on.

Here's a teaser shot of my rig from a corporate Christmas gig in December. Enjoy!

View attachment 3652230

Your thoughts and opinions are welcome!

I highly doubt the floor of the cab has much effect on cooling: the fan pretty much handles that as long as the back is clear. Have you checked the pre-amp tubes? Fortunately swapping those out is a lot cheaper than the 6550!

 

[azwhofan]

I highly doubt the floor of the cab has much effect on cooling: the fan pretty much handles that as long as the back is clear. Have you checked the pre-amp tubes? Fortunately swapping those out is a lot cheaper than the 6550!

Haven't had a chance to take off the back and take a closer look at the innards yet.

I have noticed tho that the bottom of the shell is always a lot hotter than the top after a gig. Anyone else have similar experience?

 

[G-Dog]

After several years (4 or 5?) of flawless operation with the SB300 a strange occurrence happened at my NYE gig. At one point late in our 2nd set, the amp started to not produce volume. It kinda faded in and out. Now, on my other tube amps, this is usually an indication of power tubes getting ready to kick the bucket . However, what was different about this gig is I did not put it in Standby mode after the first set so the amp didn't have a chance to cool down. Also the amp sits flush on top of my Fearless F112, i.e. there is no ventilation between the bottom of the head and the top of the cab. I'm thinking the lack of ventilation was the culprit as all LED's on the back of the head showed green. So I'm not 100% sure what is going on.

Here's a teaser shot of my rig from a corporate Christmas gig in December. Enjoy!

View attachment 3652230

Your thoughts and opinions are welcome!

Hmmm, not anything I have first-hand experience with, but my thought is that the Auto Bias problem, admittedly more rare to the SB300 than the 100T, may be a suspect? See Fender's explanation of the Auto Bias v.2 Update, linked on the Bassman Club Wiki page (linked in my signature).

If bought new between 4 & 5 years old, it should still be under warranty! So, an Authorized Fender Service Center is your best bet.

Hope this helps.
.

 

[Down_Low]

It definitely may not be your problem, but when this happened to me a while back, it ended up being the speaker cable. A new cable and I haven’t had the problem again.

 

[flatwound62p]

Just had some fun fixing mine up.

I had my bias circuit replaced a bit over a year ago plus a new 12AT7 and a full set of matched EHX output tubes, all done by an A1 tech and it was running fantastic.

A few weeks ago I noticed the amp was a bit microphonic. If I played a short muted low C I got a ghost note following it, almost like an echo. When I leaned on the amp to see over the back I got a bit of noise, tapping on the wooden outside of the amp could be heard through the amp. Also saw orange lights for 2A and 3A on the bias indicator.

Cash is short and no spare $ for a trip to tech, just about to start a run of shows

So I pulled the back cover and did a chopstick test, tapping all the power tubes in turn. 2A and 3A are fine but 1A is badly microphonic

Last year the tech gave me all the original GT output tubes when I picked the amp up and said at least half of them were still okay. So I pulled 3A and tried all six GTs one at a time. Nup, still showing orange on both 3A and 2A. Did the same with the 2A slot and nothing changed.

Knowing 1A was microphonic I tried a GT in that slot. Bam! Green lights all the way, took only a few seconds to bias up and the microphonics plus the ghost note are gone. Amp sounds absolutely killer again

I still reckon this is the best sounding bass amp ever made. IMO.

Sharing in case somebody else strikes a similar problem.

 

[rodl2005]

Just had some fun fixing mine up.

I had my bias circuit replaced a bit over a year ago plus a new 12AT7 and a full set of matched EHX output tubes, all done by an A1 tech and it was running fantastic.

A few weeks ago I noticed the amp was a bit microphonic. If I played a short muted low C I got a ghost note following it, almost like an echo. When I leaned on the amp to see over the back I got a bit of noise, tapping on the wooden outside of the amp could be heard through the amp. Also saw orange lights for 2A and 3A on the bias indicator.
View attachment 3664352

Cash is short and no spare $ for a trip to tech, just about to start a run of shows

So I pulled the back cover and did a chopstick test, tapping all the power tubes in turn. 2A and 3A are fine but 1A is badly microphonic

Last year the tech gave me all the original GT output tubes when I picked the amp up and said at least half of them were still okay. So I pulled 3A and tried all six GTs one at a time. Nup, still showing orange on both 3A and 2A. Did the same with the 2A slot and nothing changed.

Knowing 1A was microphonic I tried a GT in that slot. Bam! Green lights all the way, took only a few seconds to bias up and the microphonics plus the ghost note are gone. Amp sounds absolutely killer again

I still reckon this is the best sounding bass amp ever made. IMO.

Sharing in case somebody else strikes a similar problem.

Excellent to hear, and thanks for posting!
A good way to check output, or pre amp tubes is to swap the signified 'bad' tube to another position, and see if the problem follows it.

Glad yours is A-OK now.
Agreed too. Best sounding amp, possibly ever!

 

[flatwound62p]

A good way to check output, or pre amp tubes is to swap the signified 'bad' tube to another position, and see if the problem follows it.

Honest answer is laziness. All my bad tubes were in the easy access back row and the good ones hiding further inside. I didn’t enjoy dealing with those spring loaded retainers at all

Next I think I’ll pull the front panel and try some V1 and V2 tube rolling. I’ve got about 20 odd used 12ax7, 12at7 and 12au7 to experiment with. Could be something good ... or not

 

[rodl2005]

Honest answer is laziness. All my bad tubes were in the easy access back row and the good ones hiding further inside. I didn’t enjoy dealing with those spring loaded retainers at all

Next I think I’ll pull the front panel and try some V1 and V2 tube rolling. I’ve got about 20 odd used 12ax7, 12at7 and 12au7 to experiment with. Could be something good ... or not

Can be interesting, for sure. I put Raytheon 5751's in mine

 

[flatwound62p]

Ended up back where I started with tube rolling. Tried a few 12AT7 in V1 but invariably lost the “oomph”. They have a gain factor of 60 vs gain factor of 100 that a 12AX7 has so obviously the gain is too low. Definitely going to grab a 5751 like Rod suggests and try that for the middle ground. Also tried a couple of 12AX7 and 7025 but couldn’t tell the difference between any of them.
And in V2 the 12AT7s gave a grainy cleanish sound vs the distortion sound produced by the stock 12AX7 which I liked. But it seemed to skew things toward more bottom end and reduced the top and high mid volume, so result was too muddy for my liking.
Overall I got nothing that I couldn’t get a better version of with stock tubes and some tweaking of input gain and/or tweaking the bias hotter or colder.
For context, I like a grainy cleanish sound with thump and to get that I prefer to use the attenuated input jack. For tube testing I tried both inputs. Not suggesting tube rolling your Super Bassman isn’t worthwhile for other folks, just not my ears.

 

[rodl2005]

Ended up back where I started with tube rolling. Tried a few 12AT7 in V1 but invariably lost the “oomph”. They have a gain factor of 60 vs gain factor of 100 that a 12AX7 has so obviously the gain is too low. Definitely going to grab a 5751 like Rod suggests and try that for the middle ground. Also tried a couple of 12AX7 and 7025 but couldn’t tell the difference between any of them.
And in V2 the 12AT7s gave a grainy cleanish sound vs the distortion sound produced by the stock 12AX7 which I liked. But it seemed to skew things toward more bottom end and reduced the top and high mid volume, so result was too muddy for my liking.
Overall I got nothing that I couldn’t get a better version of with stock tubes and some tweaking of input gain and/or tweaking the bias hotter or colder.
For context, I like a grainy cleanish sound with thump and to get that I prefer to use the attenuated input jack. For tube testing I tried both inputs. Not suggesting tube rolling your Super Bassman isn’t worthwhile for other folks, just not my ears.

Or with the tubes that you tried, perhaps. There is often much variation in tubes of the same kind, just from different brands.

There was certainly nothing wrong with the SB with the stock tubes, mine still sounds fantastic with the stock power tubes in it btw. I'm pretty sure the original GT tubes were in it for sound, and price. ....
About all I got from the different tubes in, iirc, v1 and v2, was a slightly smoother overdrive in both channels. Again, this is as far as I can remember, I did it back in 2013 or so

 

[Ronnie Thunders]

Little too quiet, can't be the affinity

 

[shwashwa]

oh my gosh. how long has this existed?? i only post this because i think this is what the fender bassman 800 should have been and there were some mock up pics earlier in the thread. does anyone know how it sounds?

700W Bass Half and Half