Fender bassman Ten mods

[Slobrain]

Man, I finally found one of those Fender bassman Ten amps with the enclosed 4x10 cab built in.

I wanted to ask if any one has changed speakers in this amp to give it the big Marshall 4x12 oomph?

It sounds pretty good with rated 50 watts and its still got the RCA black plate power tubes in it too.

Thanks

SLObrain

[stokes]

You'd be hard pressed to get 4X12"s in that cab.Some beneficial mods to that amp would include,new tubes.I know those Black plates are very desirable,but that amp was discontinued in '82,they likely are past their prime.Also changing that bias "balance" pot to a true bias adjustment,maybe even a full blackface mod.And definately new filter caps,and while your at it upgrading that first filter to a 100uf,this will really tighten up that bottom,especially when the amp is cranked.If you arent happy with the speakers in it I would suggest contacting Ted at Weber speakers.He makes some great speakers and if you explain what you want to achieve he will point you to the right choice.

[Slobrain]

Hey Stokes,
Thanks for the reply.
Actually the other night I decided to just mod the hell out of the amp.
I did the bias conversion, put some sylvania STR 6l6s in it and changed the output section to a Marshall non master style output.

Also redid both channels to vintage fender and the amp sound way better now.
I couldn't believe the odd changes Fender did to this amp design
.
The speakers and e-caps are going to be replaced too.

I'm putting in a couple of the 220/500vdc caps for the mains to REALLY tighten up the low end So I'll get around 110 UF in filtering. the rest of the caps will be the same uf.

The speakers I'm getting are some cheapy Electro Harmonix 10s that are supposed to be similar to celesions but I'll bet I will wind up putting in some of those new celestion vintage 10s that Avatar sells. Those are suppose to be some really good sounding celestions.

I never got into amps with 10 inch speakers, I always like the big sound of the celestion 12" speakers but I seen this amp in a pawn and decided what the heck, I need a new project to work on. I really needed this after losing my Dad to cancer a few months ago. I've been so down that I hadn't want to even play guitar since then

Heck, Maybe I'll build in a SLO-50 into this amp to see how it sounds...

SLO.....

[stokes]

Condolances on losing your dad,Slo.While you are at it I would suggest changing the screen cap to 40 or 50uf along with the main.You want that screen supply to keep up with the plate.Dont mess with the value of the preamp caps tho,could severely alter the tone.I would put fresh ones in the whole rail,after 10 years they begin to deteriorate, and by upgrading the main and screen you will want the ones down the rail in the preamp to keep up.10"speakers are awesome,especially when you use multiples.Much better than 12"s I have come to find. I have a pair of those new Celestion Vintage 10"s in a 50watt amp I built they are great.Also I wouldnt use any of those Jap xichon or the like brand caps.I like the F&T's for the 220uf/300v's and Sprague for everything else.Those Taiwanese caps really suck.You got a nice amp there, a good platform to experiment with,good luck with it.

[Satamax]

Hi everybody!

Slowbrain, i don't know how you feel about fender amps, but a very cheap trick i have had in mind for awhile, is to feed the V2B of the bassman 10 (or any bassman ) into V1A. i've done this on sound cities, but both chanels share everything but V1 That gain mod on a fender could have been done by Boogie at the very early start it's realy "in the spirit of" Boogie at the begining.

Bye.

Max.

[Rick Erickson]

Man, I finally found one of those Fender bassman Ten amps with the enclosed 4x10 cab built in.

You say that like it's a good thing... <LOL>
Sorry to hear about your father, I hope fixing/modding this amp up can help with the healing process, and one thing these amps are good for is modifying. As I've mentioned before, the OT in the Bassman 50 4-10 was usually a very wimpy, tiny little thing. A good replacement OT can help improve the bass response & headroom in these amps. The original speakers were never very good either as I recall. The Celestion 60W "Vintage 10" would probably be a good replacement choice. The great thing about a project like this is that you can remake the amp as many times as you like and try different circuits. If I was creating a clone type amp I would probably lean towards a "D.M.B.L.E." type circuit. I like the smooth sublte distortion from those amps, and the clean is as bf Fender as it gets.

RE

[Slobrain]

Hey Fellas,
Yes Rick, as funny as it may seem I really wanted a bassman ten. LOL

Reason was that it has that fully enclosed cab for the 4-10 speakers with the amphead built in so its easy to throw it into a car.

I knew the circuit was gonna be different from the old Fenders but the preamp circuit was horrible....

After building the SLO amps a few years back and other amps I was sorta burned out, then my Dad was diagnosed with cancer early in 2006 and I just dropped every thing to help him.

I swear that when you see a family member die from cancer it really makes everything else in life seem unimportant.

I'm trying to get myself back to a norm but its still not easy, maybe this can get my spirits back to playing guitar again.

Yep Rick, that OT is a wimpy lil thing. LOL looks more like a OT from a vibrolux or a bandmaster.

That thought on a Flumble clone may be the ticket since I havent built one of those, but getting the right schem to build from is gonna be a chore since there is a few different ones floating around.


Thanks again guys for the suggestions. I'll have fun with this one, a mini Marshall or Flumble or something else......

SLO

[55Tweed]

I have a Fender Bassman Ten. I would like to mod it to make it as "blusey" as possible. Can anyone help with the best modifications to turn it into a tone monster similar to my 1955 Tweed Deluxe? Thank you 55Tweed

[TheElectricMoron]

No trick to that at all fixing that baby up.

I've done three of them now and one of the 70watt UL'ers. And have two more sitting here waiting. Stock they are were not exciting for me, sorta like everything was done in a strange/not good way, but that is just sooooo easy to make right. You might notice that the PT has 5v leads for a tube rectifier, the early ones all do I think. And there is plenty of room in there to punch in a hole for another socket if you've a mind to and a GZ34 will fit easy.

As for the rest of the amp, I just depopulate the board and make it a tweed bassman - it'll all go in there if you spend some time thinking about it. OR you can just make it a BF Bassman with no trouble at all. And that gets rid of all the preamp, PI, bias, etc BS that CBS put in there. And you will love it.

Those closed/ported cabs are a little boomy tho. You can make that better by just plugging the ports. I cut discs w/ a hole saw and Elmer's them in. Yank the speakers and put some pad inside the cab too. Sometimes the orig speakers are OK but usually they are a bit harsh to me. One I put G10L35's in and that was WOW! Another I put some old CTS alnicos in and they were nearly as good. But, surprise surprise, a cheapo set of usually floppy blue Jensen repros out of a tweed Bassman repro were totally cool. I asked Ted Weber about that and he said that the closed cab supported the cones better than an open cab and made the difference.

Anyway - LOTS of potential in there to let go several good directions. Hard to go wrong. Have fun you'll be much happier.

Charlie

[Satamax]

I have a Fender Bassman Ten. I would like to mod it to make it as "blusey" as possible. Can anyone help with the best modifications to turn it into a tone monster similar to my 1955 Tweed Deluxe? Thank you 55Tweed

No trick to that at all fixing that baby up.

I've done three of them now and one of the 70watt UL'ers. And have two more sitting here waiting. Stock they are were not exciting for me, sorta like everything was done in a strange/not good way, but that is just sooooo easy to make right. You might notice that the PT has 5v leads for a tube rectifier, the early ones all do I think. And there is plenty of room in there to punch in a hole for another socket if you've a mind to and a GZ34 will fit easy.

As for the rest of the amp, I just depopulate the board and make it a tweed bassman - it'll all go in there if you spend some time thinking about it. OR you can just make it a BF Bassman with no trouble at all. And that gets rid of all the preamp, PI, bias, etc BS that CBS put in there. And you will love it.

Those closed/ported cabs are a little boomy tho. You can make that better by just plugging the ports. I cut discs w/ a hole saw and Elmer's them in. Yank the speakers and put some pad inside the cab too. Sometimes the orig speakers are OK but usually they are a bit harsh to me. One I put G10L35's in and that was WOW! Another I put some old CTS alnicos in and they were nearly as good. But, surprise surprise, a cheapo set of usually floppy blue Jensen repros out of a tweed Bassman repro were totally cool. I asked Ted Weber about that and he said that the closed cab supported the cones better than an open cab and made the difference.

Anyway - LOTS of potential in there to let go several good directions. Hard to go wrong. Have fun you'll be much happier.

Charlie

May be a cheap trick i would try first, disconect the bias, and make the amp cathode bias! Dead simple. And the electric moron is right about the GZ34. All you want is sag. Wich the two mods above would give you. After that. You may be can leave the circuit stock.

Even bluesier?

Ditch the long tail pair PI, and turn that into a gain stage and concertina PI. And put a 10K pot in the NFB loop to find the sweet spot.