Dumbleland Overdrive Special!!!

[Bombacaototal]

... 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

Max, out if curiosity, do you know what the VG stands for?

[talbany]

. 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 ...

I would agree with this comment you made here as to try and compare the "Pentode" amp (As Howard called it) to any other Dumble amp..It is a one of a kind..

Has anyone else here noticed that the amps that have Dumbleland written on them don't seem to have a Presence control? (Accent switch) Do we know why that is??.

BTW.. In the description of the here https://www.gbase.com/gear/dumble-the-p ... -crocodile reads?

Sold- Here are a couple of photos of a very unique and impossibly rare Dumble that was called “The Pentode Amp” and we have heard it also named “The Velvet Glove”. 150 watts with 6550 power tubes, reverb, tremolo, and rare silver-foil crocodile type covering. We hated to let this one go.

The "Velvet Glove" was actually the nickname SRV gave to Jacksons Dumbleland Special he used on Texas flood.
https://ampgarage.com/forum/viewtopic.p ... 74#p277874
Tony

[Max]

Max, out if curiosity, do you know what the VG stands for?

Unfortunately, no.

... the amps that have Dumbleland written on them don't seem to have a Presence control? (Accent switch) ...

All Dumble amps I've seen so far on pictures with the word "Dumbleland" or its abbreviation written on their front or rear side have either a "Presence" control (black chassis) or an "Accent" or "Mid Accent" switch (silver and gold colored chassis).

[talbany]

Max, out if curiosity, do you know what the VG stands for?

Unfortunately, no.

... the amps that have Dumbleland written on them don't seem to have a Presence control? (Accent switch) ...

All Dumble amps that I have seen pictures of with the word "Dumbleland" or its abbreviation written on their front or rear side have either a "Presence" control (black chassis) or an "Accent" or "Mid Accent" switch (silver and gold colored chassis).

Yes I mentioned the accent switch..What I was referring to were all the 150W Dumblelands that you reference below w/ 4/8/16 (Not the Alligator) that do not have an accent switch but has the later "Presence Control" feature..As these have a different function in circuit than the switch. A picture would be helpful
https://ampgarage.com/forum/viewtopic.p ... 04#p145004

. All 150W Dumblelands I am familiar with or heard of - those for guitar and those for bass guitar - are switchable for 4/8/16 ohm (one exception: the pentode DL has a 4/8 ohm OT).

[Max]

The reasons why A. Dumble initially equipped the vast majority of his amplifiers with an "Accent" or "Mid Accent" switch, and only later (late seventies/early eighties) switched to equipping them with a "Presence" control (be it as a modification or from the beginning) are not known to me.

[talbany]

The reasons why A. Dumble initially equipped the vast majority of his amplifiers with an "Accent" or "Mid Accent" switch, and only later switched to equipping them with a "Presence" control (be it as a modification or from the beginning) are not known to me.

OK..Thats not what I asked but thanks anyway?
BTW..According to Electron who at one time had the Alligator at some point states? output is Sunn amp me thinks.

That is the amp. Silver alligator.

The PI tube is a 12Ax7a. PI values are as in an ODS, Prescence knob is 5k though, prescence cap is 3.3uF.

Iron: MM Power transformer (MusicMan). The CF after the PI needs a large negative voltage (bias) around -150V. Look at TUT for details on this circuit.

Look at the block diagramm of the 150W ODS in the Groove Tubes book to see the PowerSupply.

Output Iron from Sunn amp me thinks.

One Fender style choke, a small 6.3V transformer to supplement the MM PT heater voltage.

NO relays in the amp. FS is for Tremolo (plain vanilla Fender style Tremolo).

Grid resistor is 220k.

See ya,

Electron

https://ampgarage.com/forum/viewtopic.php?p=3651#p3651

Tony

[Max]

As far as I can remember, A. Dumble built the Dumbleland "DL-150VG" in the mid-eighties, at a time when - for whatever reason - the vast majority of his amplifiers were already equipped with a "Presence" control.

A. Dumble built the "Dumbleland" Overdrive Special # 006 discussed in this thread at a time when - for whatever reason - he was still equipping the vast majority of his amplifiers with an "Accent" or "Mid Accent" switch.

In my personal opinion it is therefore not particularly surprising that the Dumbleland DL-150VG has a "Presence" control and the Dumbleland Overdive Special has an "Accent" switch.

[Max]

@talbany:

Your question was:

Has anyone else here noticed that the amps ... [Max: 150W with 4/8/16 OT] .... that have Dumbleland written on them don't seem to have a Presence control? ... Do we know why that is??.

My answer (in a nutshell):

I don't know "why that is". But I don't find it particularly surprising either, because the 150W Dumblelands with 4/8/16 output transformers, of which you can find pictures on the Internet, all come from a time when the vast majority of all the Dumble amplifiers did not yet have a "Presence" control.

[Bombacaototal]

Tony, the Alligator has both OT and PT from musicman based on the details of the tech who has been inside the amp. I reference the part numbers on my schematic of this amp

[professormudd]

... 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

Max, out if curiosity, do you know what the VG stands for?

My guess would be Velvet Glove.

[talbany]

Tony, the Alligator has both OT and PT from musicman based on the details of the tech who has been inside the amp. I reference the part numbers on my schematic of this amp

Yup!
Ser# says 6-150 likely came off the HD-150 4/8 ohms..This pretty much solidifies the fact that apart from the 150W 4X6550 rating the Pentode amp really has not much else in common with the earlier Dumbleland (w/Accent switch)..Different preamp/different power amp-PI different transformers..Apples and Oranges...Next

Looks like a Music man from here

SSS Top View.pdf

m23518938202_2.jpg

SSS Partslist Power Amp.pdf

Tony

[Max]

... the same X-Former set as this ... [Max: e.g. DL-150W #009] ... was his Iron of choice for whatever iteration of his 150 watt amps. Here we see the same transformers in 121 ODS ... [Max: with a "Presence" control and a 7025/7025 inverter/driver combination] ... w/ Dumbleland style PI and quite possibly's SRV's Blackface SSS ... [Max: with a "Presence" control] ... same PI..(This was the Sunn 1200S output transformer) ...

... Dumble used either ... Ampeg Iron and Sunn/Dynaco Iron in 150W (Iterations) ...

Tony, the Alligator ... [Max: Dumbleland 150W DL-150VG] ... has both OT and PT from musicman

Yup!

@talbany:

In order to avoid misunderstandings:

Could you perhaps explain again which of the 150W iterations, in your current opinion, are equipped with the transformer set, which is known, for example, from the Dumbleland Special 150W #009?
Or to put it another way: In your current opinion, is there any common denominator that applies to all 150W watt Dumble amps in which this transformer set was installed?

Picture of Dumbleland Special 150W #009:

dumble_dumbleland_2.jpg

[talbany]

If we take two of the purist examples of a Dumbleland Special 150W we have for analysis we get.
Jackson's Dumbleland Special (The one SRV used on Texas Flood)

dl002.jpg

The Merle Hagard Ser#009 Dumbleland

IMG_0140.jpeg

Both have 4/8/16 ohm sec and both appear to be Sunn/Dynaco 4X6550 as well as the BH7/12AU AC coupled driver section..(same as the odessey)
All 3 are tubes up and have the accent switch (No Presence)

So if we are to now compare the Dumbleleand Overdrive Special with these two specimens we get the same features?.A.C driver w/4/8/16 OPT.

Screenshot 2021-09-05 at 20.06.15 (2).png

Given that Dumble spec'd a 4/8/16 ohm for the Dumbleland Special this obviously limited his options for transformers, Dynaco being the only one I know of with 16 ohm tap...AFAIK
The other interesting thing to note is the Sunn/Dynaco 1200 OPT has Ultra linear taps and the rest do not..AFAIK

Like I said in my previous post..the pentode is a one off and given the amp was a Musicman 700v makes sense to pair it with a Music man output for correct primary impedance matching..
Here is a list of transformers Dumble has been known to use..I threw the Roadmaster in as an extra
Dynaco/Sunn...4/8/16
Ampeg SVT......2/4 ohms
Music Man...4/8 ohms
Fender 4 or 8 ohms
Peavey (Roadmaster)?? 150w...2/4 ohms

IMO!..given the limited amount of documented Dumbleland Specials available we go with what we have and when we start to compare what others perceive as Dumbleland like specs or sound qualities in other amps like the SSS only confuses and clouds the comparison further



Tony

[Bombacaototal]

Hi Tony, you are forgetting about two of Christopher Cross Dumbleland amps which use SVT OT and PT. I think the answer is as simple as , dumbleland was bottom mounted and SSS was top mounted, everything else is bespoke and different, depending on what Mr. d was after.

[talbany]

Hi Tony, you are forgetting about two of Christopher Cross Dumbleland amps which use SVT OT and PT. I think the answer is as simple as , dumbleland was bottom mounted and SSS was top mounted, everything else is bespoke and different, depending on what Mr. d was after.

Thanks
In the previous post i was addressing Max's question referring mainly to the 150w Models
Since the Dumbleland 300 uses primarily an SVT output transformer and is 2/4 ohms is kind of a no brainer..it does however share the same AC driver as the 150W versions and does have Dumbleland on the chassis so good point!
BTW..As far as the chassis thing goes? I'll add it...