bandmaster mods...

[daniel]

...I installed a heyboer bassman OT in my bandmaster last night. I'm pretty happy with the result though it was a little more subtle than I expected. Practise with the band tonight should give a better idea. I decided to make the change since the other guitar player in my band is playing a 67 circuit plexi and I have to compete. I am digging the extra beef the tranny provides. I've modded the tone stack a bunch too. All the vibrato circuitry is removed, .022 bass and middle caps, 25k mid pot, 56k slope resistor, and a .047 coupling cap on vibrato channel. Normal channel is stock. These changes have given it a great overdrive sound that is pretty beefy w/many similarities to a marshal but a little creamier. I think my next step is going to be to convert the vibrato channel to a jtm45/tweed bassman cathode follower preamp. I can then have the stock Bf channel or the tweed channel for different sounds. Is any one else running the blackface amps this way? My bandmaster is '68 by the way, so i'm not to stressed about modding it as all the changes are reversable.

[gldtp99]

i put the Heyboer 4/8/16 Bassman OT in my '65 Bandmaster mostly because it came with a 2 ohm Super Reverb OT and other butchery--- it gives the option of using many different cabs to suit different occasions--- i agree that the difference between my other stock '65 Bandmaster isn't extremely drastic but it has more bottom and is more versitile---- it's cool that you're tinkering with the Vib channel to make it more "Marshall-ly"--- you could try running less NFB in stages to see if you like it---- if your bandmates Plexi is a 100 watter, it's going to walk all over a 40 watt Bandmaster no matter what you do---- EL34's are rated for less plate dissapation than 6L6's but it takes less input Voltage to drive them to similar levels, so they <Crank> vs. 6L6---- a Fender Showman (85 watts) head might stand a chance vs. a 100 watt Marshall---- i've built up a series of heads on Bogen and Gibson Atlas chassis that roughly follows the progression from Tweed Bassman to JCM 800 to see for myself how the circut/tube changes really effect the tone-- and also to learn more without going bankrupt by buying kits for each model---- the last two i've done are a 35 watt EL34x2 cathode biased Superlead w/parallel V1 triodes (like jumpered input 4-holer) and a 50 watt 6L6x2 hotrodded JCM 800/Gibson Atlas---- but tonite i'll probably play my '68 Fender Dual Showman w/Heyboer 4/8/16 OT with an old Rat pedal because i'll be playing with my old Atomic-SPL drummer---- good luck on the Bandmaster mods..............gldtp99

[daniel]

My bandmaster actually holds up really well along side the plexi which is surprising since I'm only using a 2x12 as well. He's got ppimv on his since we usually have to tame our amps a bit to please the sound guys which helps.

[bob barcus]

I had John McIntyer in Nov 1993 mod a 65 Bassman.It still looked stock,but Gain,Gain,and more Gain EL-34.It was good w/ Hbuck,but single Pups voiced a little bet more on mine. I think you can find the mod in GP may 1994.I would crank it to 8 all day,and only ever blew a screen grid R. Also my 63 Bandmaster has 2 extra tube sockets,if yours does too,what about 4 6V6's or 4 El-34

[Flames1950]

I had John McIntyer in Nov 1993 mod a 65 Bassman.It still looked stock,but Gain,Gain,and more Gain EL-34.It was good w/ Hbuck,but single Pups voiced a little bet more on mine. I think you can find the mod in GP may 1994.I would crank it to 8 all day,and only ever blew a screen grid R. Also my 63 Bandmaster has 2 extra tube sockets,if yours does too,what about 4 6V6's or 4 El-34

I did that mod to a Bassman that I sold just a couple of months ago, except I designed a turret board for it........gain, gain and more gain is putting it mildly, it had so much that it sounded like a fuzz to me when you really racked it out. But the guy I sold it to seems to love it, so what the hell.......

I have the McIntyre mod in PDF if anyone really needs it.

[daniel]

Hey Andy, I put the mod in the bandmaster tonight but it was a huge oscillating mess. I ended up putting everything back the way I had it cause I leave on tour in two weeks and need my amp in tip top shape.

[novosibir]

I have the McIntyre mod in PDF if anyone really needs it.

I'd be curious to see that "ultra-gain" mod

Would be glad, if you send it to my email address, which is open in my profile.

TIA, Larry

[macula56]

hey Flames, is that the same as the one on blueguitar?

[NY Chief]

I had John McIntyer in Nov 1993 mod a 65 Bassman.It still looked stock,but Gain,Gain,and more Gain EL-34.It was good w/ Hbuck,but single Pups voiced a little bet more on mine. I think you can find the mod in GP may 1994.I would crank it to 8 all day,and only ever blew a screen grid R. Also my 63 Bandmaster has 2 extra tube sockets,if yours does too,what about 4 6V6's or 4 El-34

I did that mod to a Bassman that I sold just a couple of months ago, except I designed a turret board for it........gain, gain and more gain is putting it mildly, it had so much that it sounded like a fuzz to me when you really racked it out. But the guy I sold it to seems to love it, so what the hell.......

I have the McIntyre mod in PDF if anyone really needs it.

I'd like to see that Andy!

[Flames1950]

E-mail sent, Chief.......

hey Flames, is that the same as the one on blueguitar?

I don't know, could be....I don't remember where I downloaded it from.

[daniel]

So I think I have finally reached the conclusion of tweaking the amp to suite my tastes. I changed the phase inverter to the blonde/tweed version and popped a 12ax7 in and then copied the prescense circuit from the 6g6 blonde bandmaster(100k neg feedback resistor, 25k pot etc.). This did wonders for the amp. If anyone feels their blackface amp is too clean for their tastes changing the driver circuit yields excellent results. Next, I changed the driver tube input cap to a .001. This change was subtle but did improve things. I also added a ppimv and it sounds just as good with the master on 6 and up, but it does get a little buzzy lower than that. This amp is now much more to my liking. The only other change I am going to make is removing the insulation from the cab except for the back panel to liven the cab up a bit. Thanks to Andy, Dan and everyone else here who is willing to help those with limited experience such as myself.