Dumbleland Special Schematic

[pompeiisneaks]

Sure thing... please create it, and I'll sticky it.

~Phil

[talbany]

Sure thing... please create it, and I'll sticky it.

~Phil

Will do
Thanks!

Tony

[dreric]

Hi Guys,

I've been following this thread and appreciate all the effort put into figuring out the Dumbleland.

And.................I wondering what everyone thinks about the idea of building a Dumbleland or any of the amps with a cathode follower and mating in with a lower wattage, say 2 - 6V6 power tubes.

I've built 2 SSS amps one with 4-6l6 and the other 2-6550, while I love them , I don't really need another 100 watt monster.

Hope everyone is healthy.

Eric

[Bombacaototal]

I would like to thank Aaron and JFS322 for their contributions to the effort

, I thought my contribution helped but nevermind

[talbany]

Hi Guys,

I've been following this thread and appreciate all the effort put into figuring out the Dumbleland.

And.................I wondering what everyone thinks about the idea of building a Dumbleland or any of the amps with a cathode follower and mating in with a lower wattage, say 2 - 6V6 power tubes.

I've built 2 SSS amps one with 4-6l6 and the other 2-6550, while I love them , I don't really need another 100 watt monster.

Hope everyone is healthy.

Eric

Hello Eric

I would think it would depend on how you plan to use it? If say this were simply a living room practice amp I imagine you could use this 12AU/BH7 driver w/ a 2X6V version of the Dumbleland PI/Driver for a clean punchy little practice amp..If for some reason you plan to use along side a drummer or at higher volumes at some point you may find your saturating the smaller output transformer with something as small as say a Deluxe size core compressing the low end. If you wanted to get somewhere in the middle I would think a pair of 6L's w/Bassman iron would cover all of those bases. Even with the Bassman set up you could get that in a rather compact chassis 4 preamp tubes..Depends on what you want to do with it. This is the only thing that comes to mind..Anyone else.

Tony

[talbany]

I would like to thank Aaron and JFS322 for their contributions to the effort

, I thought my contribution helped but nevermind

OOPS Sorry forgot thanks for the reminder.

edit:

I would like to thank Aaron and JFS322 and Bombacaototal

https://ampgarage.com/forum/viewtopic.p ... 51#p426651

Tony

[Bombacaototal]

Hi Guys,

I've been following this thread and appreciate all the effort put into figuring out the Dumbleland.

And.................I wondering what everyone thinks about the idea of building a Dumbleland or any of the amps with a cathode follower and mating in with a lower wattage, say 2 - 6V6 power tubes.

I've built 2 SSS amps one with 4-6l6 and the other 2-6550, while I love them , I don't really need another 100 watt monster.

Hope everyone is healthy.

Eric

It all comes down to the pre amp you will use and how you build up gain hitting the PI. My 2x6V6 25W is way louder than my 4x6L6 100W SSS4 clone, because the latter is really a very low gain amp..so as a rule of thumb, low gain pre plus high wattage power and high gain pre and low wattage power will work, if we are talking about modern day stage volumes. A Wonderland for example which is even lower gain than the SSS4, really needs 100W or more.

Practice amp like Tony mentioned is a different approach..

...and thanks Tony

[mojotom]

I would rather build a Dumbleland with 2x6L or 2x6550 power section rather than 6V6’s. Seems useless to build the 2 tubes PI mate to such power section for that amp imho.

Been there (ODSR and Mini Major) and glad I switch to 6L at least.

[talbany]

I would rather build a Dumbleland with 2x6L or 2x6550 power section rather than 6V6’s. Seems useless to build the 2 tubes PI mate to such power section for that amp imho.

Been there (ODSR and Mini Major) and glad I switch to 6L at least.

I agree! Best thing to do would be to get an old seasoned output transformer off a Bassman 70 w/ultra linear taps.
That's kind of a big part of the sound from those amps! That and the PI/Driver
Tony

[mojotom]

I would rather build a Dumbleland with 2x6L or 2x6550 power section rather than 6V6’s. Seems useless to build the 2 tubes PI mate to such power section for that amp imho.

Been there (ODSR and Mini Major) and glad I switch to 6L at least.

I agree! Best thing to do would be to get an old seasoned output transformer off a Bassman 70 w/ultra linear taps.
That's kind of a big part of the sound from those amps! That and the PI/Driver
Tony

Yes and I think I have one somewhere but for a 4 tubes output section.

[Max]

Perhaps - for example in the sense of the advice of jfs322 - some even more(?) experimental approach would also be fun? E.g.: Dumbleland preamp (perhaps PCB and in a separat 19“ chassis similar in look to a Dumblelator or 19” ODS preamp?) combined with an Odyssey 100W power amp with the usual Odyssey 100W Fender iron (as long as pictures of the DL-interior aren't available the suspected UL-circuit is just a speculation anyway). Based on my personal experience the resulting difference in stage volume between e.g. an ODS preamp > Odyssey 100W combination vs. e.g. an ODS 50W head (Bassman iron) isn’t as great as their 50W vs. 100W designations may suggest. And if someone should like adding some delay he could perhaps combine such a configuration with a Dumblelator and a separat spring reverb ( some personal DIY solution, or e.g. a Soldano Surf Box etc.) and/or some analog/digital delay. And if you add a separat ODS preamp (PCB 19”?) maybe you could have fun by switching between the DL preamp and the ODS preamp with some high quality switching system. AFAIR e.g. Kevin Dukes used two Odyssey 100W power amps in his stereo rack system (later Odyssey chassis = ODS chassis upside down = 19").

All the best,

Max

[dreric]

Wed Apr 14, 2021 12:46 am
Hi Guys,

I've been following this thread and appreciate all the effort put into figuring out the Dumbleland.

And.................I wondering what everyone thinks about the idea of building a Dumbleland or any of the amps with a cathode follower and mating in with a lower wattage, say 2 - 6V6 power tubes.

I've built 2 SSS amps one with 4-6l6 and the other 2-6550, while I love them , I don't really need another 100 watt monster.

Hope everyone is healthy.

Eric

Hello Eric

I would think it would depend on how you plan to use it? If say this were simply a living room practice amp I imagine you could use this 12AU/BH7 driver w/ a 2X6V version of the Dumbleland PI/Driver for a clean punchy little practice amp..If for some reason you plan to use along side a drummer or at higher volumes at some point you may find your saturating the smaller output transformer with something as small as say a Deluxe size core compressing the low end. If you wanted to get somewhere in the middle I would think a pair of 6L's w/Bassman iron would cover all of those bases. Even with the Bassman set up you could get that in a rather compact chassis 4 preamp tubes..Depends on what you want to do with it. This is the only thing that comes to mind..Anyone else.


Well it looks like we'll try this out, just scored a 70's Bassman 70 OT with the ultra linear taps!
ERic

[dreric]

Forgive me for my limited amp designing skills and subsequent stupid questions but since I got a Bassman 70 OT and PT I may sa well try a Dumbleland adventure.

But....................... I'm wondering if it would be possible and if it's worth trying to make a two channel amp.

Channel one: Some version of a Dumble preamp (124, 60, Bluesmaster etc) which feeds into the the second channel, Thinking OD + clean

Channel two: the Dumbleland, Thinking all clean

Eric

[talbany]

as long as pictures of the DL-interior aren't available the suspected UL-circuit is just a speculation anyway).

This is not a "speculation" but an operating characteristic of the 6550's load line. Dumble was always cognizant of his screen supply voltages in Music Man amps his Winterland and now the Dumbleland..In the case of 6550 and with 550V on the plates is too high so the screen voltage needs to be regulated by the UL taps
As Martin Discusses here

f you pick 550V for plate voltage, and then a load line that stays within plate dissipation limits, say 4 or 5k, the knee in the 0V Vg1 curve looks well positioned at 300V Vg2. If you run the screen voltage up to 550, the whole family of grid curves moves up and to the right, and the load line will cross far below the 0V Vg1 knee. That means a loss in headroom and the screen current will begin to shoot up long before Vg1 is driven to zero.

https://ampgarage.com/forum/viewtopic.p ... 03#p291303
We can take this a step further with 121 (Todd Sharp Amp) Uses the same "transformers" as Dumbleland S.#009

4X6550The power amp is similar to a 150 W Dumbleland (same transformers),

Why use the same transformers? Because you need the taps.
It would also not make much sense to attach a transformer with U.L taps on 2 different amps /w same power tubes unless you plan on using them
https://thesubjectmatter.com/dumblearch ... efault.htm

I also want to stress this point as well! a guitar amplifier that utilizes Ultra-linear taps and runs the screens lower will alter the sound and overall feel of the amplifier too. So this (along with the AC driver) would be a rather large part of the overall character and sonic signature of an amp with these kinds of features. Here is David Hafler discusses the performance characteristics of ultra linear operation
https://www.aikenamps.com/images/Documents/UL.pdf

So I will Paypal anyone $100.00 (sends me pictures of #009) and proves to me that he did not use the taps on that 606-Schumacher Any Takers??
Tony

[Max]

Wouldn't it be possible just by trial and error to see if someone likes the sound and feel of an UL-OT equipped amp better when its UL-taps are used or when they are not used and/or when the amp in question is equipped with an UL-OT or when it is equipped with a standard OT without UL-Taps?

All the best,

Max