Bassman 10 build.....Better late than never!

[Blindog]

Hello everyone. Been lurking here for a while trying to figure out what to do with my '74 Bassman 10. From what I've seen, the layout BobW posted looks like a great fit for my iron. I gather from the other threads that that is what he did to his Bassman. Am I correct? This would be second mod project, the first being an old Bogen CHB35A mod. I realize this is amuch greater feat! I guess I'm looking for a nudge in the right direction. Does anyone have a source for an eyelet board for that layout?
I saw Funkalicous Groove had some boards , but I'm not clear what they were for. Any help you can give this noobie would be great!

[Icetech]

Blind, im not 100% familar with the bassman 10, but i have one done in a older bassman, i did normsters ODS with reverb in it... just used the standard bassman power filter setup, with differetn dropping resistors.. and a generic board from turretboards.com

[Bob-I]

A few things on the Bassman 10.

1) You'll need to drill out for more controls. A Dumble needs gain, T M B, drive, OD level, master and presence. The BM10 only had V T B on one channel, V TMB on the other if I remember right.

2) You'll need to gut it, fabricate 3 boards and wire everything up.

That said it should make a decent transplant. It has the right number of tube sockets, 3 9 pins and 2 8 pins, plus it has decent iron.

Check out Normster's bassman transplant layout in the files section.

[Blindog]

A few things on the Bassman 10.

1) You'll need to drill out for more controls. A Dumble needs gain, T M B, drive, OD level, master and presence. The BM10 only had V T B on one channel, V TMB on the other if I remember right

Went to the "The Lab" to check the the old Fender out. Got V T B on 1 channel and V T M B on channel 2. Then there is Master Volume. Should be OK

The only thing I might change is the OT. I've heard people say it's undersized on this model. Any reccomendations?

BTW, thanks for the input. I need all the help I can get!

[Bob-I]

The only thing I might change is the OT. I've heard people say it's undersized on this model. Any reccomendations?

BTW, thanks for the input. I need all the help I can get!

I like the Bassman replacements from Mojotone.com

[BobW]

I'd suggest trying the stock transformers first. The stock AB165 PT and OT sound great in my amp. The OT seems to have more iron than the BF, but I could be wrong. Blinddog, you may also want to check out my faceplate arrangement (located below the board layout) in the FILES section, under the Layouts post, about 8 or so posts down. hth

[Blindog]

The stock AB165 PT and OT sound great in my amp

Well, I think that's the problem. My amp is not an AB165 circuit. I'll definitaly try it out, it may be fine. Someone on another forum thought they were a bit wimpy. Thanks for the info on the faceplate location! I was just going to ask where I might find one. The Bassman 10 is kind of a strange Bassman config (master volume, 4x10 sealed back combo, Studio channel, Normal channel) Based on the speaker codes, mine is 1974, so its pre ultralinear OT. I think I may keep it in the combo format when I'm done Dumbling. Probably change the speakers (32 Ohm wired for 8 Ohm load).

[Luthierwnc]

That amp ought to work fine. I think I'd leave the stock OT in there until you are sure it won't work. The acid test is if you can bend a low G up to an A and keep it clean. Speakers will have a lot to do with that.

As mentioned before, you will need to gut it and punch some extra holes. You may also find that the holes aren't where you want them. A new piece of 1/16" aluminum can cover a lot of hacking.

If I can leave with one extra note, pay a lot of attention to the grounding. A steel chassis will be touchier than the aluminum units a lot of us use. I recommend running a central buss wire behind the pots. Either isolate the pots from the chassis (hard) or don't ground the pot cases (easier). I would also isolate the jacks.

Skip

[Bob-I]

The stock AB165 PT and OT sound great in my amp

Well, I think that's the problem. My amp is not an AB165 circuit. I'll definitaly try it out, it may be fine. Someone on another forum thought they were a bit wimpy. Thanks for the info on the faceplate location! I was just going to ask where I might find one. The Bassman 10 is kind of a strange Bassman config (master volume, 4x10 sealed back combo, Studio channel, Normal channel) Based on the speaker codes, mine is 1974, so its pre ultralinear OT. I think I may keep it in the combo format when I'm done Dumbling. Probably change the speakers (32 Ohm wired for 8 Ohm load).

You'll have to scrap the boards in that amp but the chassis and xformers will most likely be just fine. I'd start with Norm's great layout for a Bassman, drill whatever holes you need and fabricate boards. Ultralinear is not what Dumble used although one of my amps is UL and sounds great.

I agree that you should replace the speakers. A pair of Eminence Red White and Blues, 16 ohms on parallel would do the trick but there's other choices too. Make a new baffle and put 12's in.

I've often thought that this would be a great platform for a Dumble. Good luck.

[DiademRoyale]

Having modded more than a few Bassman's in the past, the "Ten" was never a favorite because of the small OT. It is different iron than any other Bassman used. Any of the better replacements are fine- the original will almost definitely come up lacking in the tone department. W*b*r has several different versions available at pretty good prices. Also, check out Tubes and More.com. both companies sell American made iron.and it is good quality......... MDW

[Blindog]

Here is a pic of the OT: http://i51.photobucket.com/albums/f359/ ... n10001.jpg

Chassis: http://i51.photobucket.com/albums/f359/ ... n10003.jpg

Cab:
http://i51.photobucket.com/albums/f359/ ... n10005.jpg
http://i51.photobucket.com/albums/f359/ ... n10004.jpg
http://i51.photobucket.com/albums/f359/ ... n10006.jpg

Based on DiademRoyale's comments and others, I'll probably swap it out. I'll still try it, maybe save some $$$. Got a new baby coming next week and my amp fund is drying up! Luckily I've got next to nothing invested in this donor. I won't say how much as not to cause undue jealousy! Guess I'll put my foot in pool and start gutting!

[Blindog]

double post

[Blindog]

I thought I would post some pics of the Bassman 10 conversion I've been working on. Let me say, I couldn't have gotten this far without the help of the Great and Powerful heisthl He has been a huge help (and inspiration), not to mention the boards and panels he made for me. You rock Henry. If anyone sees any glaring errors or things to do differently, I'm all ears. I have to wire up the PI, and then the pots and ground bus. This is my first real build attempt. I'm really curious as to how this 4x10 is gonna sound. I'ts hard not to rush and get it done.

Regards,

Mark

[ic-racer]

Looks great. Is that a new back plate graphic? Did you use the backing board for your new preamp board?

[Blindog]

Thanks! The front and rear panels were made by heisthl. They are thick photopaper peel and stick. The circuit board is mounted on standoffs, so no need for the old backing board.