What would you change about a '59 Bassman build to make it more versatile?

I generally think this amp is rather versatile and perhaps suits my needs as-is.

BUT if you were going to build one up, what MIGHT you change about it?

I am using the Weber kit as the baseline.
Therefore Sig10s alnicos would be "stock".

Keep the copper Cap? Stiffen power supply?
Change the speakers?

Leave it alone?

~Thx All

Sacrilege. How could you? Just kidding.


I want to do one with a pentode with a morph control before the cathode follower. Then there is splitting the cathode resistor and capacitor on the inputs with different values.

Pardon me for asking a non-Tele, non-6-string question, but if I were to build a Bassman, I'd like it to be able to use my MM Stingray4, too! But it seems like it's not considered a bass amp at all these days...

Is there a reasonably simple way to make the circuit 'Single Coil/Bass Guitar' instead of the normal 'Normal/Bright'? inputs? My venue for the bass guitar is only 1,100 sq.ft., so I don't need the 'modern standard' 500-1000W bass amp, and kind of wonder what an all-tube bass amp might sound like...

I'm presently using a Mark Bass 121, which is SS 500W, and has a Vintage Loudspeaker Emulator knob which is supposed to make it sound like a tube amp! (I don't think it does...)

charisjapan

I built one once and went with a 2X12 cab. The ultimate tweed Twin IMO. I like the tube recto as opposed to the copper cap.

One thing that made the bassman a great guitar amp and a so-so bass amp was the open back cabinet. The bassman is (also) a fine bass amp with the right speaker cabinet.

If you need 500 watts of bass (some guys do), you won't get that kind of sonic boom with a bassman, obviously.

One thing that made the bassman a great guitar amp and a so-so bass amp was the open back cabinet. The bassman is (also) a fine bass amp with the right speaker cabinet.

If you need 500 watts of bass (some guys do), you won't get that kind of sonic boom with a bassman, obviously.

I was thinking that the open back cab was one of the problems... So the circuitry doesn't need much tweaking?

I personally have never had the Mark Bass much past 10 o'clock! Definitely DON'T need 500W. It's a great sounding bass amp, but I can never get it even close to the sweet spot. :sad:

But since playing a guitar though a 5E3 is so beautiful, I'm interested in how a bass guitar would sound. Maybe I'll try and see what the Deluxe sounds like with the M-B closed back cabinet. :?: :!: :idea:

charisjapan

I would think it would be great if it had a reverb section added and a tremelo. Those can be added as outboard effects, but I think it would be cool built in. Plus, set up right, like a Princeton, it ought to give you a bit of overdrive boost.

I'd just give it some reverb, that's all.
And yes, I know what Danny Gatton said.

char,

As music got louder, the sheer power of the bassman (in its day it was powerful), plus the tone controls and the open back cab with four ten inch speakers made the bassman naturally appealing to guitar players.

While good for guitar, the open back cab does not permit deep bass response.

I use my bassman head with an 80's era plywood, felt-covered, fiberglass-lined ported cab (BFI is the brand). Two twelves. It is a great rig for bass or guitar.

Pleasant tone and loud, but not earth shattering for bass. Could be improved some with with 15 inch speakers. These days, you hear a lot of powerful bass - earth-shaking - in live rock music. The result of 500 watt SS heads like yours.

Let me know if I can sell you a 5F6A Chassis kit.

Add a switch for the tone stack to make it before or after the second gain stage. And another for tone stack bypass. And another to add cathode bypass cap on the second gain stage.

My favorite amp, and next future build project. Thoughts from my studies of the circuit:

1) bright and normal not much different. I would definitely differentiate them more.

2) The negative feedback is key coupled with the nonlinear response of the push/pull power section. I will however mod this desing to be able to switch different configurations of NFB.

3) The speaker voicing I think is important. So much so that i will probably build a head and thus leave it open to deal with different speaker cabs.

4) How "saggy" or "not saggy" you want the power supply chain to behave will effect some of the pick attack sensitivity. I chose to stiffen my 5e3 a bit and may do so with my bassman.

That said I am intrigued with the idea of having a "Marshall" channel and some "Marshall" switch(s). Kind of two amps in one. The JPM50 was so close in design it looks possible. I know this is sacrilege, and Leo maybe turning in his grave, but copying somebody is the greatest form of flattery. Another amp that is interesting is the Traynor YB-1, very close to the bassman but with some interesting nuances.

Oh and did I mention it MUST have a Master Volume. My family and neighbors never let me dime it that often!

Add a switch for the tone stack to make it before or after the second gain stage. And another for tone stack bypass. And another to add cathode bypass cap on the second gain stage.

Something like this?

http://i406.photobucket.com/albums/pp142/printer2_photo/guitar%20amp/5E3-Bassman-BlackfacePreamp.jpg

you could ignore the funny stuff with the switches around the volume controls. It rearranges them to be configured as a 5E3 Deluxe. The tone control switching is done with the three switches at the bottom. The circuit at the side is another option.

Sweet **** all! I love it just the way it is,Best amp I ever had.And I play all kinds of music from Blues to Country to Rock!!:razz:

char,

As music got louder, the sheer power of the bassman (in its day it was powerful), plus the tone controls and the open back cab with four ten inch speakers made the bassman naturally appealing to guitar players.

While good for guitar, the open back cab does not permit deep bass response.

I use my bassman head with an 80's era plywood, felt-covered, fiberglass-lined ported cab (BFI is the brand). Two twelves. It is a great rig for bass or guitar.

Pleasant tone and loud, but not earth shattering for bass. Could be improved some with with 15 inch speakers. These days, you hear a lot of powerful bass - earth-shaking - in live rock music. The result of 500 watt SS heads like yours.

Let me know if I can sell you a 5F6A Chassis kit.

Well, I didn't get the chance to connect the 5E3 to my bass cab, but I did hook it up to a closed back 'convertible' cab I made. It is one big box, divided into 2 closed sections; one is the volume of a Champ and has an 8" Jensen AlNiCo, the other the volume of a Tweed Deluxe but with a single 10" Celestion. Results are that a standard humbucker bass sounds reasonably good, but not that loud. 8" is too growly, 10" is kind of nice. With an active MM Stingray, the 8" is way too distorted, but the 10" is a very usable (and loud!) bass sound up to noon on the dial. After that, too much distortion for a pleasant blues bass.

So, I might just take you up and make a Bassman for bass!

Weird, but I was looking all over YouTube for a bass guitar playing through a Bassman amp... zilch! Poor Leo! (just kidding, the Bassman turned out OK! :wink:)

charisjapan

If you want to use it for bass I would consider the Bassman - Blackface switch (three pole toggle). It will help keep the preamp clean. I redrew it and cleaned up the schematic. The added master volume probably would not be necessary in your case.

http://i406.photobucket.com/albums/pp142/printer2_photo/guitar%20amp/Bassman-BlackfaceTonesimple.jpg

If you want to use it for bass I would consider the Bassman - Blackface switch (three pole toggle). It will help keep the preamp clean. I redrew it and cleaned up the schematic. The added master volume probably would not be necessary in your case.

Printer,

Thank you for the schematic. It might take me a bit to work out what it means, but I aim to try!

Just a thought, but could a 5E3 be "cleaned-up?" Honestly, the volume was not the problem, but the (great for a gee-tar) Tweed distortion and low-efficiency speaker. I would think a bit more clean, like to noon, and an efficient 12" speaker would be plenty for our little venue.

(but I still want to build a Bassman! :grin:)

charisjapan

Printer,

Thank you for the schematic. It might take me a bit to work out what it means, but I aim to try!

Just a thought, but could a 5E3 be "cleaned-up?" Honestly, the volume was not the problem, but the (great for a gee-tar) Tweed distortion and low-efficiency speaker. I would think a bit more clean, like to noon, and an efficient 12" speaker would be plenty for our little venue.

(but I still want to build a Bassman! :grin:)

charisjapan

The biggest thing you could do to a 5E3 to clean it up is to add NFB around the output and to run without the bypass capacitor on the second gain stage. Look how I did it on this SE amp. You will have to determine how big a NFB resistor to use depending on how much you want to clean it up. It also has the effect of extending the bass response, basically flattening up the amp's response inside the feedback loop.

http://i406.photobucket.com/albums/pp142/printer2_photo/guitar%20amp/6CW5Champ.jpg

In this amp I tried the tone control before and after the second stage but found it did not make enough of a difference for me to keep. Used the switch to switch out the other bypass capacitor on the input.

i went to choke input B+ power supply switched the tubes to 6V6s, changed the output trannie to one with 2, 4, 8 ohm outputs.