The Fender Super Bassman 300 thread

[DTRN]

Thanks for enabling me. I was hoping you would talk me out of it. What was I thinking! So...thought you should know I will be expecting the SB300 along with the neo410 waiting on my porch Monday. Actually it won't be waiting...I will. I'm certain I will be happy. Hard as I try I just can't get past "there's something missing" with SS. Kind of like the difference between CD's and vinyl.

Addendum: I have received my SB300 and neo 410 cab. All I can say is WOW! I can't believe I waited so long to acquire one. After I set things up I left the Rumble 500 set up as well to A & B the two. I played one note on the SB300, put my bass down and packed up the Rumble (which I will be keeping). One note is all it took to realize the HUGE difference. I couldn't be more pleased. Thanks for the encouragement. I know pics are in order here. When I get time next week I'll figure out how to do so.

 

[LetItGrowTone]

HUGE difference

My big tube amp isn't a SB300, and my Class D isn't a Rumble 500, but I know how you feel.

 

[rodl2005]

Addendum: I have received my SB300 and neo 410 cab. All I can say is WOW! I can't believe I waited so long to acquire one. After I set things up I left the Rumble 500 set up as well to A & B the two. I played one note on the SB300, put my bass down and packed up the Rumble (which I will be keeping). One note is all it took to realize the HUGE difference. I couldn't be more pleased. Thanks for the encouragement. I know pics are in order here. When I get time next week I'll figure out how to do so.

Exactly! Glad you can hear the difference, and, like I did.. . One note!
Congrats!

 

[the slug]

I am having a lot of hiss in my SB300 after it has been on for more than 15 minutes or so should I be looking at more preamp tubes or power tubes? Any help appreciated

 

[rodl2005]

I am having a lot of hiss in my SB300 after it has been on for more than 15 minutes or so should I be looking at more preamp tubes or power tubes? Any help appreciated

Is the hiss coming outta both channels?


Try the pencil test on the tubes.
While amp is on...
Lightly tap each one a few times.... there shouldn't be any noise coming outta the speaker.
This should isolate any microphonic tubes.
It's always good to have a cuppla spare pre amp tubes...

 

[the slug]

it is both channels that's why I was thinking power tubes. I'll do the chopstick test tomorrow thanks

 

[rodl2005]

it is both channels that's why I was thinking power tubes. I'll do the chopstick test tomorrow thanks

Then try swapping the pre amp tubes around and see if the problem 'moves' or changes. (Or swapping then with other, known good ones).
Let us know how you go

 

[flatwound62p]

Can you run a line out from the amp to a mixer or computer or something?
If you can listen through headphones you can pick the signal off from a few different points in the signal chain and see where the hiss starts. Try tuner output, DI clean, DI post and effects loop out. Should get you closer to where the problem is.
The block diagram in the manual tells you where all the outputs are positioned in relation to the preamp tube.

 

[the slug]

the problem is intermittent. I tried tapping all the tubes. none appear to be microphonic the amp has never had any tubes replaced, so I'm just gonna re-tube the whole thing and see if that fixes things. if not, I'll know it's not the tubes.

 

[iammr2]

the problem is intermittent. I tried tapping all the tubes. none appear to be microphonic the amp has never had any tubes replaced, so I'm just gonna re-tube the whole thing and see if that fixes things. if not, I'll know it's not the tubes.

That's a pretty expensive "shot in the dark". Why not just take it to a tech?

 

[the slug]

That's a pretty expensive "shot in the dark". Why not just take it to a tech?[/QUOTE
little easier said than done. I developed end stage heart failure a few months ago so I really cant carry the head to my car. I decided I would just tinker since I'm kinda stuck at home anyway.

 

[rodl2005]

Take care @the slug
Keep the old tubes then!

 

[flatwound62p]

Sure you can't try what I suggested? If you can narrow it down to being in the preamp you'll save a bunch of $$$. 12ax* toobs are relatively inexpensive compared to power tubes.
Also, more likely than not your bias lights would give an indication of something gone bad in the power section.
Don't mean to nag, just trying to save you some bucks

 

[iammr2]

I'm sorry to hear about your situation, @the slug.

 

[the slug]

appreciate the input. tubes are already on the way. I'm gonna start with preamp tubes once I get this figured out, I will probably be selling the amp. due to medical conditions the amp will probably never leave my house. while I love this amp, it's a little much for a practice amp.

 

[byacey]

I am having a lot of hiss in my SB300 after it has been on for more than 15 minutes or so should I be looking at more preamp tubes or power tubes? Any help appreciated

I'd be looking for bad solder joints or intermittent components in the tone filter network.

 

[born2lift]

Just bought a blonde & oxblood SB300 and matching 610 Neo on Marketplace. Decided to order a set of KT88s along with the preamp tubes from EuroTubes. I know somewhere in this thread someone contacted a tech from Fender and was told that they don’t recommend using KT88s because they are larger in diameter and will be very close to each other. I called EuroTubes today and they said that they have many customers that use the KT88s in their SB300s with no issues.

EuroTubes sells re-tube kits for the SB300 with KT88s or 6550s so I figure the TK88s will work.

I had an Ampeg SVT CL years ago that I put KT88s in and I loved to tone.

 

[Thundar]

View attachment 3952762 Just bought a blonde & oxblood SB300 and matching 610 Neo on Marketplace. Decided to order a set of KT88s along with the preamp tubes from EuroTubes. I know somewhere in this thread someone contacted a tech from Fender and was told that they don’t recommend using KT88s because they are larger in diameter and will be very close to each other. I called EuroTubes today and they said that they have many customers that use the KT88s in their SB300s with no issues.

EuroTubes sells re-tube kits for the SB300 with KT88s or 6550s so I figure the TK88s will work.

I had an Ampeg SVT CL years ago that I put KT88s in and I loved to tone.

A-HA! I wondered if someone on TB bought this head and cab! I saw it too, and man if it hadnt been 18 hours away from me...LOL
Very kewl!

 

[rodl2005]

View attachment 3952762 Just bought a blonde & oxblood SB300 and matching 610 Neo on Marketplace. Decided to order a set of KT88s along with the preamp tubes from EuroTubes. I know somewhere in this thread someone contacted a tech from Fender and was told that they don’t recommend using KT88s because they are larger in diameter and will be very close to each other. I called EuroTubes today and they said that they have many customers that use the KT88s in their SB300s with no issues.

EuroTubes sells re-tube kits for the SB300 with KT88s or 6550s so I figure the TK88s will work.

I had an Ampeg SVT CL years ago that I put KT88s in and I loved to tone.

Let us know how you go with the power tube retubing , and the KT88s.
Be interested to know, mine is still on its original power tubes, I don't run it hard nor often, from 2012. Still sounds great, so, until it don't, or there's an issue.... They're staying in it.
I'll be using the SB300 thru my NV215 Berg cab this Sunday at an outdoor gig

 

[azwhofan]

Let us know how you go with the power tube retubing , and the KT88s.
Be interested to know, mine is still on its original power tubes, I don't run it hard nor often, from 2012. Still sounds great, so, until it don't, or there's an issue.... They're staying in it.

Ditto for moi as well. My tubes date from 2013 and I'm very interested to see how KT88's fit. Pics would be greatly appreciated. And remember to wear gloves when you swap the power tubes, you don't want fingerprints on them!!