Bassman 5b6

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M Fowler
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Bassman 5b6

Post by M Fowler »

Reference this thread: http://ampgarage.com/forum/viewtopic.ph ... highlight=

Results of testing two pedal steel guitars yesterday, it was a pleasure to meet Rodger and listen to his playing.

http://bb.steelguitarforum.com/viewtopic.php?t=237617
Yesterday I had the pleasure of meeting Mark Fowler (fowleramps@yahoo.com) at his workshop in Moorhead, MN and take a look at the 5b6 cage amp pictured in the link in Tim's post above. I've followed the enthusiastic response to the "Little Walter" but hadn't heard one. Mark has been building amps mostly for guitarists in the Trainwreck, Dumble and classic Marshall, Vox and Fender styles and had a roomful when I arrived. He built the 5b6 as a lark a few years ago and was surprised to hear in the last few weeks that pedal steel players might like it.

I brought along a Clinesmith and a Cater U12 with an Alumatone along with a 15" Black Widow Neo to test with the amp. I have to say that to my ears, the enthusiasm for this circuit is deserved. The tone is round and musical, with articulate highs and lows, with no dropouts in between. There is this sort of 3d effect from the octal tubes; a gentile natural reverb and single notes blossom with an almost symphonic full spectrum ambience. The Don Helms high 6th chords nailed the original sound and Hughey-land was the best I've heard from my guitars. The low B6 chord combinations were detailed, not veiled and single note and chordal runs onto the higher strings and registers maintained a tonal quality and evenness that surprised me.

Of course with a roomful of Dumble, Vox, Marshall and Trainwreck clones, I couldn't resist trying them all, wearing out my ears in the process, but I have to admit none of them sounded as good to me as the 5b6. Overdriven, the distortion was creamy and musical.

Mark is adding an effects loop and a line level, post power stage output to the build to increase the versatility of the amp. Mark is easy to work with and happily tweaks his builds to suit the preferences and needs of his customers.

rodger
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Colossal
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Re: Bassman 5b6

Post by Colossal »

Great job Mark! 8)
Matt D
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Re: Bassman 5b6

Post by Matt D »

Glad to see your success over on the SGF! My iron for the 5b6 showed up a couple days ago. Excited to start this build and see what all the fuss is about. Do you guys think an effects loop is really necessary in this circuit? If so, passive or buffered? I'm going to build it in a 16x8x3 chassis I have lying around so I have plenty of room to add stuff.
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M Fowler
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Re: Bassman 5b6

Post by M Fowler »

Thanks Dave and Matt,

I run all my pedals through the input jack with no problems at all including Boss reverb and Boss Digital Delay DD3.

But the preamp out and line out jack is a good idea for recording or slaving to powerful amp setup.

Mark
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ToneMerc
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Re: Bassman 5b6

Post by ToneMerc »

Great job as usual Mark. I got around to ordering my iron today and I am hoping my chassis should show up any day so That I can start cutting some holes.

Mike
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M Fowler
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Re: Bassman 5b6

Post by M Fowler »

Thanks Mike,

It's going to be fun around here soon with your new 5b6 amp builds coming together guys.

Any thoughts on head cab, cage or combo for your builds?

Mark
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JazzGuitarGimp
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Re: Bassman 5b6

Post by JazzGuitarGimp »

Hi Guys,

This thread made me curious, so I did some poking around on google for the 5B6 schematic. I see the 5B6 used a pair of 6V6's, and I also noticed a schematic for the 5B6-A, which uses a pair of 6L6's. Am I correct in thinking you are building the 6V6 variant?

Thanks,
Lou
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M Fowler
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Re: Bassman 5b6

Post by M Fowler »

Lou I built the 6L6 version.
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M Fowler
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Re: Bassman 5b6

Post by M Fowler »

Added line out off OT secondary no level pot.

Added simple effects loop.

Everything works well so only thing left to do is add mini toggle switch next to input to change 2nd input jack switchable from 2m or 4m or 10m. (grid leak).
Last edited by M Fowler on Wed Jan 09, 2013 9:13 pm, edited 1 time in total.
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ToneMerc
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Re: Bassman 5b6

Post by ToneMerc »

M Fowler wrote:Thanks Mike,

It's going to be fun around here soon with your new 5b6 amp builds coming together guys.

Any thoughts on head cab, cage or combo for your builds?

Mark
I'm using the 12.5 * 8.0 * 2.5 outer lip chassis from Watts. Taylor doesn't
know it yet, but he's making me a small box tweed or brown rough tolex head cabinet :lol:

6L6 version, not really chasing the steel guys, just something different for reg guitar with a few minor changes and a couple of additions.

TM
Last edited by ToneMerc on Wed Jan 09, 2013 9:29 pm, edited 1 time in total.
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M Fowler
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Re: Bassman 5b6

Post by M Fowler »

I like the brown ruff tolex myself good choice.

Taylor you need to get to building buddy.

I'm starting on another one this one is in Ken Watt's 12.5x8x2.5 inner lips chassis and I'll use MC bassman iron.

I need to talk to Milkman about his vendor for a nice brown faceplate.
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ToneMerc
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Re: Bassman 5b6

Post by ToneMerc »

M Fowler wrote:I like the brown ruff tolex myself good choice.

Taylor you need to get to building buddy.

I'm starting on another one this one is in Ken Watt's 12.5x8x2.5 inner lips chassis and I'll use MC bassman iron.

I need to talk to Milkman about his vendor for a nice brown faceplate.
I debated about which lip type and figured I would just try the outer. I was on the fence about a custom PT and the low power tweed Twin OT from Mojo. Then just decided for this version, it seemed like the MCI 35W Valco set would be about perfect.

I had meant to contact Milkman's guy as well.

This should be fun as I have never used octal preamp tubes before.

TM
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JazzGuitarGimp
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Re: Bassman 5b6

Post by JazzGuitarGimp »

Thanks guys.

I was thinking the 6V6 version might be a bit underpowered for steel guitar, but I suppose that depends on what the player is looking for.

My 5E3 clone was serving me nicely (strat style guitar) in my classic rock band when we were two guitars, bass & drums. When we added the keyboard player, all bets were off for the 5E3. In the interim, I am using an early 90's custom shop Tonemaster head with a single, half-open EVM12L cab until I can build something a bit more potent that the 19 watts I'm getting from the Deluxe. Even with two of the 6L6's removed from the tone master, it is way too much.

Would one of you be willing to spend a minute and describe the sound of the bias-vary term in the 5B6 vs. say, a blackface reverb amp? I am not sure I've ever heard the bias-vary varietal.

Many thanks,
Lou
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ToneMerc
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Re: Bassman 5b6

Post by ToneMerc »

JazzGuitarGimp wrote:Thanks guys.


Would one of you be willing to spend a minute and describe the sound of the bias-vary term in the 5B6 vs. say, a blackface reverb amp? I am not sure I've ever heard the bias-vary varietal.

Many thanks,
Lou
Lou, the 5B6 does not have a trem circuit. You might want to start another thread about the brown verses black term circuits though.

TM
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rp
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Re: Bassman 5b6

Post by rp »

OK, now I've got one of these planned out - great. We really need a sub forum for support in DIY amp withdrawal, with a 12 step sticky - 1) when I get the urge to solder I will go out and play with the dog instead. 2) instead of buying capacitors I will buy tomato plants...

But till then, question for Mark:
M Fowler wrote:only thing left to do is add mini toggle switch next to input to change 2nd input jack switchable from 2m or 4m or 10m. (grid leak).
Do you have a different schematic? Not using a 6SC7 maybe? The one I got off Hoffman shows a cathode bias V1, though with no stopper and a 2m for the load. As it's a shared cathode both inputs will have to be one bias type or the other.

Out of curiosity have you tried a standard 68K/1M set-up and prefered the no stopper/2M set up? I set up my 5C8 so that V1a/b is stock grid-leak, V2 has V2a as 33K/1M and V2b as no stopper/1M. I can very clearly hear the diff in V2, I like both.

I was thinking of building with only one input jack and a switch allowing me to parallel the grids of V1. Have you tried that out?
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Last edited by rp on Sun Jan 27, 2013 4:21 pm, edited 1 time in total.
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