Fender Bassman 100 - New Amp Day!

moishelichtfuss · #1 05-06-2011, 07:26 AM

So...a friendly trucked just pulled up and brought me this:

Since I already went the modern, lightweight and still great sounding route (Micro-VR), I thought I'd try a heavy old guy for a change. I read that the cab isn't really that popular, but it came with the amp...and looks fine.

However, a couple of questions arise:

1. Are there any precautions one should take before turning this thing up to 11? (so far everything sounds nice...the big tubes are labelled 'Ultron' the other ones i haven't checked yet)

2. When opening the cab I noticed that someone had felt-markered the speakers. On three of them it says '4 ohms' on the other one '8 ohms'. That's just what it said. I haven't checked yet, if it's really the case. If so, does that pose any problems? The cab is 4 ohms.

Everything powers up nicely and sounds really good. But I will only be able to really tell, once I've hauled the guy over to the rehearsal space and turned it up.

BassmanPaul · #2 05-06-2011, 09:30 AM

If you have a digital multimeter disconnect one connection from each driver (one driver at a time) and measure the resistance of each. They should all measure the same.

Dave44 · #3 05-06-2011, 09:52 AM

It's a real beauty you have there congrats. You will however, find it will not have enough head room for a live set but it should work at a rehearsal. Though I guess that depends on the volume of the drummer. Never the less it's a keeper in my books I find the vintage Fender Amps sound so cool with a J-Bass. I have a 60 watt 1972 Fender BassmanTen (my first ever amp and she still rides shotgun with me once in a while) and my J-Bass never sounded better.

Basshappi · #4 05-06-2011, 10:11 AM

Congrats!
I love the Bassman 100, played one for years and want one again.

DiabolicLow B · #5 05-06-2011, 10:19 AM

Never played the 100 but I had a Fender Bassman 50 for a long time, like posted above they sound great at lower volumes but tend to fart out rather quickly when turned up to gig levels, you might want to consider a mic for your cab depending on your needs.

moishelichtfuss · #6 05-06-2011, 10:21 AM

Quote:

Originally Posted by BassmanPaul

If you have a digital multimeter disconnect one connection from each driver (one driver at a time) and measure the resistance of each. They should all measure the same.

Thanks. What if they don't?

moishelichtfuss · #7 05-06-2011, 10:46 AM

Quote:

Originally Posted by Dave44

It's a real beauty you have there congrats. You will however, find it will not have enough head room for a live set but it should work at a rehearsal. Though I guess that depends on the volume of the drummer. Never the less it's a keeper in my books I find the vintage Fender Amps sound so cool with a J-Bass. I have a 60 watt 1972 Fender BassmanTen (my first ever amp and she still rides shotgun with me once in a while) and my J-Bass never sounded better.

Well, so far i managed rehearsals and gigs with an Ampeg Micro-VR (an SS amp) with one 212 cab (at 150W) and recently added another 412 to it (so now it's running at 200W) because we got a second guitar player and got a little louder on the whole. So I'm not really sure how this is gonna change the situation. Is it gonna be weaker, the same, a little louder? I'll find out. The Micro is pretty close to its limits, though. But I guess, because of the DI and the greater portability I'll still probably take the Micro along for gigs more often.

The Bassman was just too neat. I had to get it.

I mainly play a P-Bass (the J is my home-bass).

kaiser_sosea · #8 05-06-2011, 10:59 AM

Love the Bassman 100's from way back. My first real bass amp but unfortunately and foolishly I sold it a couple years ago. If you ever get in a situation where you feel there isn't enough volume try running a more efficient cab. I never had any issues with mine not being loud enough.

BassmanPaul · #9 05-06-2011, 11:05 AM

Quote:

Originally Posted by moishelichtfuss

Thanks. What if they don't?

Then you have a problem.

The DC resistance of each driver will be a tad lower than its actual impedance so ~ 6Ω will be an 8Ω driver, ~3Ω indicates 4Ω.

Mixing impedances will cause some drivers to have to work harder than others potentially putting them at risk. Certainly messing up the impedance of the system as a whole.

moishelichtfuss · #10 05-06-2011, 11:10 AM

Thanks a lot again! I'll check it out.

moishelichtfuss · #11 05-06-2011, 11:11 AM

Quote:

Originally Posted by kaiser_sosea

Love the Bassman 100's from way back. My first real bass amp but unfortunately and foolishly I sold it a couple years ago. If you ever get in a situation where you feel there isn't enough volume try running a more efficient cab. I never had any issues with mine not being loud enough.

Which cab might be more efficient? These are some things I'm reall shamefully ignorant about.

Sunnmon · #12 05-06-2011, 11:30 AM

Very Cool Amp.
I love mine. I play it into my Sunn 200S JBL D-140 equipped cabinets and my SWR cabinets. All the cabinets I've got are very efficient. Consider them if you need more volume. And of course there's always my B-135.

Rock on BassBro.
Peace and Happiness to all.
sunnmon

moishelichtfuss · #13 05-07-2011, 02:47 AM

So...back to the cab question.

I don't have a potentiometer on me so i just took a look at the speakers first.

As already mentioned:

Someone labeled the speakers with felt marker. On 3 of 'em it says 4 ohm, on one it say 8. The first three are the usual blue label fender speakers on would expect in such a cab. The one labeled 8 ohm has an orange label on the back saying "Custom engineered for Fender...Utah Electronics"

It also have the feeling that this one is louder than the others.

So, just a general question (because i still don't understand the implications):

- Could using this cab harm the amp in any way?
- Could it only harm the speakers?
- Or is it just less than ideal to use it in this way?

Hawaii Islander · #14 05-07-2011, 03:02 AM

Congrats on your Bassman 100 rig! Looks sweet!
My first bass amp was a Fender Bassman 50 head and 1x15 cab. I used it for five years before selling it to a friend just before I joined the US Air Force. Wish I still had it. Enjoy!

Bassmec · #15 05-07-2011, 06:29 AM

Quote:

Originally Posted by moishelichtfuss

So...back to the cab question.

I don't have a potentiometer on me so i just took a look at the speakers first.

As already mentioned:

Someone labeled the speakers with felt marker. On 3 of 'em it says 4 ohm, on one it say 8. The first three are the usual blue label fender speakers on would expect in such a cab. The one labeled 8 ohm has an orange label on the back saying "Custom engineered for Fender...Utah Electronics"

It also have the feeling that this one is louder than the others.

So, just a general question (because i still don't understand the implications):

- Could using this cab harm the amp in any way?
- Could it only harm the speakers?
- Or is it just less than ideal to use it in this way?

You need to measure as bassmanpaul said, use a multi-meter
and test each speaker as paul described.
Twice the amplifier power will go to the 4 ohm speakers
so you should have one quiet speaker if the 8 ohm label is in fact correct.
The caulking between the angled baffles in my old cab broke up causing rattles and air leaks etc. so check you cab.
As someone else said the real best speaker/cab/s for combination with this amp are a pair of the old JBL D/K/E140 15". I would see if you can find an old sun 2x15 rather than a fender bassman 2X15 because the sunn cabinet design made a lot more of those old but very efficient 15" speakers.
You wont harm the amp using the cab, as its not going to be very different to the nominal overall impedance of 4 ohms.
Even if one speaker is actually 8 ohms.
If someone has rewired the fender pyramid cab, you must check that 2 speakers are wired in parallel and then the other two speakers are wired in parallel and then the 2 sets of parallel speakers are then wired in series.
Thus returning to a 4 ohm load for the cab.
What one poster talked about was old SWR cabs these are
sometimes equipped with the old EC-106O XL cast frame 10" driver.
These are very loud speakers by David Eden well worth finding cabs that use them as high efficiency is the trick here.

pgk · #16 05-07-2011, 09:31 AM

very cool amp. i'm a die hard fender bass amp guy too. there are some very simple mods to reduce farting (need a tech though) here: Blocking Distortion

afa cabs go very efficient is the way to go. i have a Kustom 2-15 loaded with a pair of original JBL D140's and while the tone is glorious it can't hold a candle, afa efficiency and deep low end goes, to my one mid sized (22 x 18 x 22) Bag End S15L-D. if had a pair of those cabs i'd knock walls down. don't believe the naysayers that say you don't have enough power, you just need the Right kind of cabs and you wil blow minds. bfm, bag end, schroeder, etc depending on what kind of voicing you're looking for. horn designs (bfm) are your most efficient by a wide margin. i've gigged with with a heavily modded bf "bassman" as my main amp for almost 25 years now, but it's still 65 watts at best. i laugh out loud when folks say a lo-po amp can't cut it in a gig situation, and i play in some pretty loud bands...