Dumbleland Special 150w ser#009 Schematic

[Max]

Here is the schematic of what we believe to be Dumbleland Special 150w ser#009 …

This schematic shows used UL taps.

… all of these circuits used were imported from other amplifiers from the Dumble line, like … the Steel String Singer.

… the SSS: Some have … Sunn/Dynaco Iron. … I haven't seen one that actually uses the UL taps … http://ampgarage.com/forum/viewtopic.php?p=56158#p56158

Best regards,

Max

[jfs322]

.

[Max]

So this is the current state of information regarding the UL taps shown in the proposal for a "Dumbleland Special 150W ser#009 Schematic":

Up to now not a single specimen of Alexander Dumble's 150W guitar amplifiers with the Sunn/Dynaco OT of DLS150W#009 is known, the UL taps of which are actually connected as shown in this proposal for a "Dumbleland Special 150W ser#009 Schematic".

Best regards,

Max

[pompeiisneaks]

I've continued to see the back and forth, and it has remained a bit less confrontational, but I do want to say that my personal opinion is that I feel Tony's point makes the most sense to me.

Max, If you are just naysaying what someone has said, but don't provide valid facts/data to back it up, I don't see what we gain from the feedback. We know theoretically what 'might' be wrong, but have no answers as to 'why' or 'what is right' so we can't change what we have and realistically, the feedback was pointless.

Not saying you can't/shouldn't provide your input, but what does it gain anyone to hear NO but no way to learn/gain the YES information? There are way too many people in the world that deal in negativity, but won't focus on forward progression or positivity.

Max, how can you help us make these designs better in a concrete, discrete, insightful way? If you can't, then what do we gain?

I hope you can understand that sentiment?

Please feel free to continue providing your input in however you feel it necessary, but realize that at a certain point, it will start being ignored because you're only creating uncertainty with no real possibility of resolution.

It's really your choice on how you want to be known/remembered here. I know I see Tony as a massive benefit to the members with his depth of knowledge that he always openly and freely shares.

I feel strongly that sharing information openly is the best way to improve anything. Teamwork beats isolationism every time.

I don't know your contributions as well, because I've only been here a few years and haven't really had time to go back and read all the thousands of hours of reading material here in the forums, but so far all I've seen seems to be along the lines of:

"you're wrong, but I'll only leave really vague references around for you to guess of one of several thousand options that might be right, but I also won't confirm if you are right if you are, only if you're wrong"

Which ends up being some kind of odd game I definitely would never play. Not sure if others want to.

My 2 cents/pennies/centimes/pfennigs and basically probably only important/interesting to me, but I did want to give my feedback that is 100% opinion based....

sorry for the derail.

~Phil

[talbany]

Again..So members are not confused..Here was my reasoning for going Ultra-linear in ser#009 Schematic

1. The Sunn Transformer had taps
2. @ 550V IMO the screens needed to be regulated somehow,to preserve and protect the life of the screens in 6550"s
3. He ran ultra linear in his Winterland #003..(w/Dynaco iron)
This told me that Dumble ran the load lines and was aware that he needed some form of regulation on the screens to get that much power out of a quad of 6550's at those higher plate voltages, while preserving the screens and did it by going U.L..For me it made perfect sense
4.The Winterland was the forerunner to the Dumbleland
This is why Aaron and myself used the taps on the Sunn O.T in the schematic

Will check back ASAP

Thanks!
Tony

[martin manning]

This makes sense to me. At those voltages 6550's will need to run in UL or be provided with a fixed screen supply that is around 2/3 of the anode voltage, as in e.g. Ampeg SVT, which has an extra secondary on the power transformer for that purpose (which also provides the negative voltage for the CF drivers). Without that, there would have to be another power transformer somewhere. The same output transformer could be used either way. Below are some nice photos of a Sunn 1200S chassis and transformers from https://music-electronics-forum.com/for ... post603699 I don't think HAD was above lifting the whole power section from an existing design along with the transformer set.

[Max]

... 3. He ran ultra linear in his Winterland #003 ...This told me that Dumble ran the load lines and was aware that he needed some form of regulation on the screens to get that much power out of a quad of 6550's at those higher voltages. For me it makes perfect sense ...

Couldn't it be - at least from Alexander Dumble's perspective - that in a guitar amplifier with - as it says here in the opening post - an "output power rated @ 137 watts" - a different wiring of the output transformer may make sense than with a bass amplifier rated @ 220 watts?:

“ … The amps had the name Winterland on the front of them. They were the #3 and #4 of the amps he has built. I used #3 on a live album with Buffy Sainte-Marie. Each amp had 4 KT88 tubes with a rated output of 220 watts into 8 ohms. … Michael Husser“ Source: https://ampgarage.com/forum/viewtopic.p ... 61#p139661

“Dynaco A-451
2200ohm input Impedance
240 Watts output 6550 / KT88
4/8/16 ohm sec
5-7/8" x 4-3/4" x 6" tall”
Source: https://ampgarage.com/forum/viewtopic.p ... 50#p163950

And couldn't this difference (bass amp 220W vs. guitar amp 137W) perhaps explain why Brandon reported here:

… the SSS: Some have … Sunn/Dynaco Iron. … I haven't seen one that actually uses the UL taps … http://ampgarage.com/forum/viewtopic.php?p=56158#p56158

?

Best regards,

Max

[talbany]

Triad R25-A is advertised
400-0-400 =564V (no load) 5V rectifier tap and 6.3V C.T filament tap
https://www.waynekirkwood.com/images/pd ... 3-1974.pdf

Hammond uses an OC3 regulator tube to regulate and drop 100V that feeds the screens of the 6550's (and feeds the 12AU) on their Leslie amps.
(BTW.We built an amp called "The Regulator" using an OC3)

Hammond.jpeg

147-amp.jpeg

Thanks for the shots Martin..Very cool
Tony

[Max]

Triad R25-A is advertised ... 6.3V C.T filament tap ...

To be exact: 6.3V 3A and 6.3V C.T. 7A filament taps: https://www.waynekirkwood.com/images/pd ... 3-1974.pdf (page 16)

BTW:
May I ask how you explain this report from Brandon?:

… the SSS: Some have … Sunn/Dynaco Iron. … I haven't seen one that actually uses the UL taps … http://ampgarage.com/forum/viewtopic.php?p=56158#p56158

Or do you think that there is no need for an explanation?

Best regards,

Max

[Aaron]

Hi Max,

To me, Brandon is saying that he hasn’t seen a SSS with UL taps.

Aaron

[talbany]

the SSS: Some have … Sunn/Dynaco Iron. … I haven't seen one that actually uses the UL taps

He cut and pasted these 2 separate quotes together to make it look like the ones with Dynaco/Sunn iron might not be U.L .(Cast Doubt)
The way I read it?. The SSS's Brandon has been in did not have the taps, But that there were SSS amps that he knew of that had Dynaco/Ampeg/Sunn transformers, which is not really new news. If you take them seperate it makes sense.

Fwiw, I haven't seen one that actually uses the UL taps, I did hear of one that used Music Man Iron, so the plates were like 688v, and screens at 344v, but not via extra OT taps.

Depends on the SSS Some have twin Iron, some have Ampeg Iron, Some have Sunn/Dynaco Iron.

Later he said this

The ones I have seen are around 500 on the plates, high 490's on the screens

490 vs 550
https://ampgarage.com/forum/viewtopic.p ... s&start=45

Tony

[Max]

Whether the sentence

“I haven't seen one that actually uses the UL taps” (Brandon)

in terms of content is synonymous with the sentence

“I haven't seen one that has UL taps” (Aaron, talbany),

IMO everyone here can form her/his own opinion and then draw her/his own conclusions from this, how likely she/he thinks it is that the Dumbleland Special 150W #009 actually has the UL connections shown in the schematic poposed here.

BTW: “Why Doubt Is Essential to Science”: https://www.scientificamerican.com/arti ... o-science/

Best regards,

Max

[talbany]

“Why Doubt Is Essential to Science”

Max
Think about it like this?
Why did Dumble run his screen supply off the voltage doubler in his Music Man amps? So the screens would be running at 1/2 of the plate voltage..Why did he do this? To keep from damaging the output tubes!
it's the same "science'" as to why he would run U.L (or a seperate regulated screen supply), with his 6550's..everyone does this (at these high plate voltages) Ampeg/Marshall/Hammond/Dumble.
I am not against doubting science but before you do? know something about the science you are doubting
You didn't even know the Winterland was U.L..So spare me with your silly links!
Tony

Up to now not a single specimen of Alexander Dumble's 150W guitar amplifiers with the Sunn/Dynaco OT of DLS150W#009 is known, the UL taps of which are actually connected as shown in this proposal for a "Dumbleland Special 150W ser#009 Schematic".

[Max]

... You didn't even know the Winterland was U.L. ...

Up to now not a single specimen of Alexander Dumble's 150Wguitar amplifiers with the Sunn/Dynaco OT of DLS150W#009 is known, the UL taps of which are actually connected as shown in this proposal for a "Dumbleland Special 150W ser#009 Schematic".

So when writing your post, you probably only briefly missed the fact that the Winterland #003 is not a guitar amplifier, but a bass amplifier. And that led to the incorrect assumption that I did not know that the UL-taps of the A451 in Winterland #003 are connected.

But it happens of course to all of us that every now and then we read something too inattentively and then misunderstand. And IMO, that's not a big deal either, because misunderstandings can be cleared up together, like for example now in this post. So nothing for bad.

Best regards,

Max

[talbany]

So when writing your post, you probably only briefly missed the fact that the Winterland #003 is not a guitar amplifier, but a bass amplifier. And that led to the incorrect assumption that I did not know that the UL-taps of the A451 in Winterland #003 are connected.

Guitar/Bass/Keys/P.A doesn't matter?? it's the Voltages or how you would put it? "Science"
Now you know.
Tony