1978 Dumbleland Special #009 Chassis & Photos

[martin manning]

I hadn't looked that far, thanks for pointing that out. I saw an absence of connections to the 100R resistors and stopped there. Looking more closely (see red circles) it appears that there may be some under-board jumpers.

[martin manning]

Comparing to other second gen preamps it looks like there may be a couple of errors in the DL 011 schematic posted on the Captain Guitar Lounge site. See below. The bass control will not function properly without the 10k to ground.

[Max]

...Looking more closely (see red circles) it appears that there may be some under-board jumpers. ...

Thanks for pointing out those two solder joints. The absence of these two LNFB connections and the associated components on DL#011's V1 V2 board likely explains why there was room for the two 20µF TVA-1906 electrolytic capacitors—and why, consequently (?), the can-style electrolytic capacitor on the top of the chassis could be omitted in DL#011's case.

[dbharris]

I wonder if anyone has an opinion on the circuit differences (LNFB loops in particular) being different between DL 009 and DL011 being a result of: 1. Progression of the circuit design, 2. Circuitry being tailored for a specific player and their gear, and/or 3. Simply a guitar vs. a bass amp?

In other words are the LNFB loops being present or absent and the lack of reverb the unique parts of the DL line of amps vs. the SSS. Or is it the driver circuit and the cathode follower driven master volume?

I don't recall if at the time these DL amps were made the SSS was offered in 150W or if that came later only.

This is the type of info, that imo should be shared by the "Dumble Preservation Society" and it's frustrating that they continue to hold it under wraps when this poses no risk to protecting their purported IP.

-Dan

[martin manning]

You can read some history around the relationship between DL and SSS amps here: https://www.d-toneamps.com/dumble-steel ... inger.html There is a lot of other reading on that site about all things Dumble. Is it absolutely accurate? Maybe and maybe not. My guess is that the NFB loops were dropped from the DL post-009. As to the reasoning, perhaps HAD decided it was too clean?

[dbharris]

Thanks Martin. I don't think I've ever seen that site before.

[Max]

I wonder if anyone has an opinion on the circuit differences (LNFB loops in particular) being different between DL 009 and DL011 being a result of: 1. Progression of the circuit design, 2. Circuitry being tailored for a specific player and their gear, and/or 3. Simply a guitar vs. a bass amp? ...

The fact that there exist very different versions of the Dumbleland and Steel String Singer is, in my opinion, due to the fact that the comparatively small production numbers allowed more scope to incorporate the evolution of his own ideas and of the personal preferences of his customers into the creation of these relatively few unique amplifiers. Alexander Dumble also says something similar in the interview linked below:
"Once you got started, did a Dumble philosophy evolve?
I try to be flexible. ... The actual techniques I use to get the sound that I go after have evolved extensively. It's a growing process. That's the toughest thing about staying with one thing; you're always thinking of new ways to do it. Basically, I've kept the Overdrive the same, but the other models are open to flexibility."https://ampgarage.com/forum/viewtopic.p ... 52#p262952)

... I don't recall if at the time these DL amps were made the SSS was offered in 150W or if that came later only. ...

According to this interview linked above, Alexander Dumble began offering an amplifier called "Dumbleland" in 1966 and was still offering it at the time of this interview. The first price list I recall that includes an amplifier called "Dumbleland" is the one valid from May 15, 1978 (see below). Under the heading "Dumbleland Special Amplifiers," a "DS-150 Watt" model is listed for $1,410, and the same model with reverb for $1,760. That Alexander Dumble was still offering these amplifiers at the time of the interview linked above is evidenced by the price list valid from January 1, 1986 (see below), which lists three amplifiers under the name "Dumbleland": a "Dumbleland Bass 150 Watt," a "Dumbleland Special 150 Watt," and a "Dumbleland Special 300SL". A "Dumbleland amplifier" without a wattage rating is also listed in the 1990 price list, valid from April 15, 1990 (see below), with the highest price listed in that price list.
To my recollection, a "Steel String Singer" was first listed in the price list valid from May 15, 1978 (see below). Under the heading "Steel String Singer Amplifiers," the "SSS-100 Watt" model is offered - exclusively as a combo - with a 12" speaker for $2,490 and with a 15" speaker for $2,500. The 1986 price list valid from January 1, 1986 no longer includes a 100-watt SSS, but does list a "Steel String Singer 120 Watt" and a "Steel String Singer 150 Watt". The price list valid from April 15, 1990 (see below), lists only a "Steel String Singer amplifier" without a wattage rating.
The Dumble distributor's price list for Europe, effective May 1978 (see below), lists a "Dumbleland Bass Amplifier" as available in Europe from autumn 1978 and a "Steel String Singer Amplifier" as available in Europe from July 1978.

[martin manning]

Thanks, Max! Great info. I agree with you on the HAD philosophy of establishing a model aimed at some specific need, but not an exact circuit. Accordingly, all models were in a constant state of evolution as new player input and new circuit ideas to address it came in. Not unlike the team of Leo Fender (design) and Don Randall (marketing).