Dumble mods for Fender Bassman 50????

[Baddog01]

I figure I could mod the bass channel to have a little more dirt than the normal channel then I would adjust the mixing resistor to get both channels to be at the same volume level. This is all just fun and games on my end as I don't play in a band . My older brother played guitar and I jam with him from time to time .
I was thinking of adding the Deep Switch and maybe a " soul control" . I have a little time tonight so I think i'll head to the dungeon and start some mods. The nice thing is I have a major highway in my back yard so I can just take my amps on the back deck and test them out. The cars don't seem to mind. Of course ill have to wait until tomorrow morning to try the mods out.
Thanks for all of your help Mark.

[Mark]

Start with adding the deep switch to the bass channel, that will be interesting. I wouldn't get too wound up with a soul control. I assume this a variable pot on the feedback loop. Having no feedback on low wattage amps can be cool as there is a bit more gain on tap and they sound livelier. At louder volumes the bass starts to sound a bit flappy and not very tight.

[Baddog01]

Thes soul control is already installed so ill try it out tomorrow and see if i like it. I guess i dont have a 10ka pot to do the deep bass mod so i'll have to wait on that mod until i can order some parts. I guess i can always use more parts.

Keith

[Mark]

Keith you don't need a 10K mid pot, have a look at this 3rd gen Dumble circuit and see how it is implemented.
https://tubeamparchive.com/download/file.php?id=14344

[Baddog01]

It shall be done:)
What do you think of the "accent " switch? Have you ever tried it?

Thanks Mark

[Mark]

The accent switch has the presence either hard on or hard off. I don't think it is a big issue. The Jazz/Rock switch changes things a lot, but there is a loss of level associated with this mod.

I was initially against using the jazz position, but a lot of people who used the amp I built got very SRV like tones from it in the jazz position, so I stand corrected about the Jazz/Rock switch.

[Baddog01]

The deep switch is very cool. I love it . It does seem to give a little boost to the signal.

[Mark]

Glad you liked the deep switch, I think it is quite underrated.

I'd use the Skyliner channel for the amps other channel, the Bluesmaster is okay, though I find the megaboost a bit over the top and I like the way the Skyliner pre-amp sounds.

https://tubeamparchive.com/download/file.php?id=14703

https://tubeamparchive.com/download/file.php?id=16846

Bluesmaster

https://tubeamparchive.com/files/bm_dcl ... 71_552.pdf

https://tubeamparchive.com/download/file.php?id=15545

[Baddog01]

Mark, i might just have to build another amp:)

[Mark]

Yeah it gets like that, probably Ceriatone and Mojo kits are the good options, I have always found Nik very helpful and accommodating. Have a look at what is about first, Postage is a factor too.

[Baddog01]

My home made 18watt plexi is a Ceriatone design. I used a Hammond L100 series organ chassis and iron for the build . Sounds really good

I had the Bassman outside yesterday afternoon and I had a chance to openip the Bass Channel . The amp really sings now when it cranked . The deep switch is really warm and full. The Soul Control almost make the amp a little hard sounding when cranked. I like a smooth overdrive .

All an all a great project . I still have to install the bright switch on the back of the amp and I'm almost considering adding the deep mod to the normal channel .

Keith

[Mark]

Keith if you have a spot for a mid pot try the Skyliner with Jazz/Rock switch. The only thing you need to check is your treble pot do you have one of those 2-35 taper treble pots?

If not then talk to Ted Weber.com about their 30% taper pots. I personally like the feel of the 30% taper of the treble pot with the 10 to 15% taper of the bass and middle pots. According to the Bluesmaster schematic the pot number is 021857, I'd still measure the treble pot either way, (set the treble to 50% and you should 30% [roughly 75K] of the total resistance across the wiper and one of the legs.)

[Baddog01]

Mark,

The Weber camp is where I started building amps. I learned what I know about amp building from them in fact I build my first fender champ with there help. I used to talk to Ted all the time till he passed away.

I was looking at the Skyliner and noticed it has a relay . I'm guessing this a some sort of channel switching or am I wrong here? I'm not families with the use of relays in amps . I used to do heating and cooling for a few yours and ran into relays in furnaces so I know how they work. Would I be able to implement the Skyliner preamp without the relay?

Thanks
Keith

[Mark]

Hi Keith, I've made a few changes to the drawing to help you get your head around the changes. As you can see there isn't any relays in these changes, I've ditched the mid boost too. The treble cap is 330pF.

Does this help?

Keep your stock PI and when the pre-amp is completed you can try a few different PI stages and see what you like.

[martin manning]

The relay in the Skyliner tone stack is for the pre-amp boost (PAB), which is a kind of tone stack lift. If you are not wanting to use the Rock/Jazz feature just hard-wire it in Rock mode. If you do want the R/J switch, you can use an on-off-on (3 position) toggle and get PAB on the middle "off" position.