Dumbleland Overdrive Special!!!

[rccolgan]

Just got a new scanner and a magazine in the mail

[rccolgan]

Google translate. https://photos.app.goo.gl/RXuC1SiKnVH24kcF6

Anyone guess what the 4x12 opening dimensions would be?

[talbany]

Thanks Ryan!..Very Cool! I might have a theory as to what might be a Dumbleland although a part of that requires a look at the output transformer? ..
I mean come on!.. turn the dang flash on
BTW..The version I posted was Google translated..or so I was told
Tony

[rootz]

The picture reveals enough I think. Compare the back of the one in the magazine to the Dumbleland Spacial I added. The left bolt connecting the OT to the chassis is visible. They seem to be in the same place, exactly between the two rightmost power tubes and in line with the impedance selector. Also the right bolt/nut through the end bells is visible. To me that looks to be in the same place. Also the impedance switch goed from 4 to 16 Ohms, like you'd see on the Dumbleland.

So in short, there are some indications they might use the same OT's. This of course is all educated guessing.

[Bombacaototal]

Great detective work. That plus the comment on the magazine that the PT side is so heavy that it tilts the headshell, and one should be careful when trying to carry it might be another evidence

[talbany]

The picture reveals enough I think. Compare the back of the one in the magazine to the Dumbleland Spacial I added. The left bolt connecting the OT to the chassis is visible. They seem to be in the same place, exactly between the two rightmost power tubes and in line with the impedance selector. Also the right bolt/nut through the end bells is visible. To me that looks to be in the same place. Also the impedance switch goed from 4 to 16 Ohms, like you'd see on the Dumbleland.

So in short, there are some indications they might use the same OT's. This of course is all educated guessing.

Thanks Rootz
Yes it wouldn't be that big a surprise to see he used the same X-Former set as this was his Iron of choice for whatever iteration of hie 150 watt amps..Here we see the same transformers in 121 ODS w/ Dumbleland style PI and quite possibly's SRV's Blackface SSS same PI..(This was the Sunn 1200S output transformer)
Tony

Sunn_1200S2.jpg

image.jpg

121_009.jpg

IMG_0140.jpeg

[Guy77]

Looks like that Sunn amp was using vintage Tung Sol 6550 tubes but Dumble seems to prfer the GE style 6550A tubes.
At least that's what I think they are in the second and third photo (black amp)? Then someone must have re tubed the last amp (orange one) with Groove Tubes.
What's interesting is that the GE 6550 tube actually has specs that are closer to a KT88 . It puts out 42 watts like a KT88 and can take higher screen voltages than the newer production 6550s like the JJs for example.


Guy

[talbany]

Looks like that Sunn amp was using vintage Tung Sol 6550 tubes but Dumble seems to prfer the GE style 6550A tubes.
At least that's what I think they are in the second and third photo (black amp)? Then someone must have re tubed the last amp (orange one) with Groove Tubes.
What's interesting is that the GE 6550 tube actually has specs that are closer to a KT88 . It puts out 42 watts like a KT88 and can take higher screen voltages than the newer production 6550s like the JJs for example.


Guy

Class AB1 450V the Triad's in 009 and 0121 B+ provided around 550V..
discussed and debated here..https://ampgarage.com/forum/viewtopic.p ... 60#p427060

Screen Shot 2021-04-21 at 11.55.21 AM.png

[Max]

... the same X-Former set as this was his Iron of choice for whatever iteration of his 150 watt amps. ...

In this generality ("whatever iteration"), this is obviously not the case. To name just a few examples:

The Dumbleland "DL-150VG" (pictures in this thread) has other transformers.
Alexander Dumble's official data sheet for the SSS 150W specifies an output impedance of 4 ohms or 8 ohms, i.e. not an output impedance of 16 ohms.
Eric Johnson's SSS 150W did not have such transformers, as far as I can remember.
There's at least one Dumbleland Special 150W that doesn't have such an output transformer.

[talbany]

... the same X-Former set as this was his Iron of choice for whatever iteration of his 150 watt amps. ...

In this generality ("whatever iteration"), this is obviously not the case. To name just a few examples:

The Dumbleland "DL-150VG" (pictures in this thread) has other transformers.
Alexander Dumble's official data sheet for the SSS 150W specifies an output impedance of 4 ohms or 8 ohms, i.e. not an output impedance of 16 ohms.
Eric Johnson's SSS 150W did not have such transformers, as far as I can remember.
There's at least one Dumbleland Special 150W that doesn't have such an output transformer.

As far as we know? Dumble used either Twin or Music Man Iron (S.A) in his 100w SSS's, Ampeg Iron and Sunn/Dynaco Iron in 150W (Iterations) ..Although the spec sheets might show the 4 or 8 ohm option doesn't necessarily prove the type of transformer? being as he simply no need for the 16 ohm tap?.
This makes sense given he used several different types of transformers on the same model SSS 150W being either Sunn or Ampeg

The Dumbleland Models, however were spec'd at 4-8-16 .(other than the one you mention) Would seem to imply the use of the Sunn OPT given the Ampeg SVT were only 4 and 2 ohms AFAIK and had no 16 Ohm tap..Unless there is a transformer he used we do not know about??..
Unfortunately Bill Morgans site does no longer list the sheets for either SSS or Dumbleland Models

There's at least one Dumbleland Special 150W that doesn't have such an output transformer.

Btw..Do you have any shots of this Dumbleland that has a different output transformer??

Eric Johnson's SSS 150W did not have such transformers, as far as I can remember.

BTW..According to Brandon it's either Ampeg or Sunn/Dynaco since he worked on that amp.
https://ampgarage.com/forum/viewtopic.p ... 161#p56161

Tony

[Max]

History of the Steel String Singer amplifier
...
SSS #5:
"Silver Face"
Owned by Santana, 2 other owners previously, and Commissioned and owned by Steven Bruton and Eric Johnson
The first of the 150w amps
Peavey Transformers
Skyliner Tone stack
2 tube Reverb
5 step filter positions on high and low filter, 1 bypass for each
Ftsw'able FET, PAB, and Reverb Off
Cathode follower driver tube.
...
https://ampgarage.com/forum/viewtopic.p ... 78#p397978

Dumbleland "DL-150VG":

dumble-the-pentoden-silver-foil-crocodi-x7tn8Ys.jpg

Transcript from Bill Morgans site:

DUMBLE Amplifiers

“Steel String Singer”

The “Steel String Singer” is designed to deliver the guitar sound necessary to fill stadiums and large halls. The power ability and tone circuitry work together to produce volume and tone of very exiting dimensions. The amplifier provides the player with a huge, clean sound that is enriched with a warm, singing quality.

SPECIFICATIONS
Power Output: 150 watts of true power
Dimensions: 12”H x 28.25”W x 10.5”D
Weight: 80 pounds (head only)
Power Requirements: 120VAC, 60Herz, & 540VA at full output
Output Impedance: 4 ohms and 8 ohms switchable
Input Impedance: NOR = 1M ohm, and FET = 3.3M ohms

TUBE COMPLEMENT
4 x 7025 high-mu twin triodes
1 x 5751 high-mu twin triode
4 x 6550A beam power tubes

CONTROLS AND EQ SWITCHES
Preamp Controls: volume, treble, middle, and bass
Preamp Switches: bright, deep, rock/jazz, hi step filter & low step filter
Reverb Controls: send, and return levels
Master Section: master volume, and presence

SIGNAL CONNECTIONS
Inputs: NOR, and FET
Access ports: preamp out and power amp input (2.5V, 500K ohms)
Outputs: main speaker, and extension speaker

POWER SWITCHES
A.C. mains on/off
A.C. mains grounding
Operate/standby

REMOTE SWITCHING
Preamp boost on/off
Reverb on/off

[talbany]

SSS #5:
"Silver Face"
Owned by Santana, 2 other owners previously, and Commissioned and owned by Steven Bruton and Eric Johnson
The first of the 150w amps
Peavey Transformers
Skyliner Tone stack
2 tube Reverb
5 step filter positions on high and low filter, 1 bypass for each
Ftsw'able FET, PAB, and Reverb Off
Cathode follower driver tube.

That info was originally posted here by Greg (boldaslove),
https://ampgarage.com/forum/viewtopic.p ... 98#p214298
So I cannot vouch for it's accuracy 100% and do not know where he gets his source?. Dumble has been known to use Peavey Iron from a Mace/Deuce 120 (4X6l6) in his Overdrive Specials.The Roadmaster? does have 4X6550's However, the Roadster output transformer is 2 or 4 ohms? It could be possible Greg was referring to the Power only??..I would be more inclined to believe Brandon since he was the one that actually had the amp in his shop.
https://peavey.com/manuals/80300050.pdf

Max I thought the Silver Alligator amp (Cooder amp) was the pentode amp w/ Music Man transformers? 700V (4/8 ohm) or is this a different amp you just posted here?
If not then,

This "silver alligator" is indeed a "one off" amp. Henry Kaiser once told me, that HAD called it the "pentode amp". It has nothing more to do with a SSS as any other Dumble amp. If you are after the sound of a SSS, you probably better take a different ...

https://ampgarage.com/forum/viewtopic.p ... 230#p55230

dumble-the-pentoden-silver-foil-crocodi-x7tn8Ys.jpg

Tony

[Roe]

Dumble has been known to use Peavey Iron from a Mace/Deuce 120 (4X6l6) in his Overdrive Specials.

Tony

Allegedly these transformers were also used in some 150w SSS according to some earlier posts here (370VAC secondary giving 500+ VDC with 2k3 Z)

[norburybrook]

Dumble has been known to use Peavey Iron from a Mace/Deuce 120 (4X6l6) in his Overdrive Specials.

Tony

Allegedly these transformers were also used in some 150w SSS according to some earlier posts here (370VAC secondary giving 500+ VDC with 2k3 Z)

that exactly what I have in my JM/Wonderland build and it has 510vDC on the 6L6 plates


M

[Max]

... Max I thought the Silver Alligator amp (Cooder amp) was the pentode amp ...

"Silver Alligator amp" and "Pentode Amp" are both nicknames for the 150W Dumbleland "DL-150VG" the back of which can be seen in this photo in my last post. This is the source for this picture of the back of the Dumbleland "DL-150VG": https://www.gbase.com/gear/dumble-the-p ... -crocodile