Max Wrote: Just to avoid misunderstandings:
The chassis of "ODS 006X OD50WX" is called a "3rd generation ODS chassis" in this thread:
https://ampgarage.com/forum/viewtopic.php?f=5&t=20316. And the topic of this thread with the title "Dumble ODS Generation Information by Max" are the chassis of the original ODS amps without reverb, tremolo, 150W power amps etc. And because of this no picture in this thread with the title "Dumble ODS Generation Information by Max" shows the chassis of an ODS with reverb and/or tremolo etc.
No misunderstandings...I fully understand what you are saying, however, the reality is that the Overdrive Reverb in question was built in 1978 (not long before the ODS #006X was produced). Even though one amp has reverb and the other does not, and the reverb amp has a measurable larger chassis compared to the non-reverb ODS chassis, the general Bill of Material of circuit components between the two are remarkably similar...which isn't surprising in the least. The circuit board material, the plate resistors, cathode resistors, the coupling caps, the electrolytics, the FET, the trimmer pots, the extensive use of Piher carbon film resistors where metal film resistors are generally not found in most any Dumble amp...etc.
My point is very simple...the ODR #008X was built a year prior to the #ODS 006X. Yet the serial number postdates the ODS by a large sequential amount. So what does this really mean? Great question. Many surely will draw obvious conclusions such as HAD had various chassis made in batches and he serialized them perhaps in batches too...perhaps some of them were laying around un-serialized and he serialized them with the next number in his master range when he got ready to turn it into an amp? Just speculation but it seems very plausible to me.
Anyway, the ODR #008X is more akin to a 2nd generation circuit and it has the ODR chassis with the slide switch rectangular thru-holes. This style ODR chassis is thought to have been used in the earliest versions of the ODR. Contrast this well-known ODR #0060 which is sequentially lower serial number than the ODR #008X which has the round thru holes for the mini toggles. It is, of course, well known that ODR #0060 was modified by HAD over a period of years so it is impossible to assess what it started life as and when exactly it was originally built. It is very safe to say that the last incarnation of #60 as it exists today was finished sometime around 1982 or 1983. I'm not really certain what one would call the ODR #0060 in terms of Dumble lineage? It has "Medium Plate" resistors on V1 A/B and a Skyline-esque tonestack. The V1A/B Plate resistors are a curiosity in themselves being rather obscure silicone-oil filled carbon film, ceramic bodied, hermetically sealed specimens. These parts alone do not fit into any "generation" of Dumble product...their values and brand/construction are unique to this single amp. My point is there are too many anomalies (such as this example) to be able to neatly categorize or classify Dumble products into a tidy amp taxonomy
The reality is that ODR #008X was built in 1978...and is numerically in the 80's number range. ODS #006X was likely built in 1979, later in time yet has a serial number sequentially lower by a substantial number for comparison sake. We know that Dumble did not have a separate serial numbering range for the ODR's versus the ODS's. In the Santa Cruz era when both these amps were built, he was a 1-man operation with the occasional assistance from his then buddy Jack Smith. He really wasn't in a position to build large volumes of amplifiers...not that he ever wanted to. Plenty of evidence that his production output in this period was quite low. The only plausible explanation for the serial numbers not aligning with the date of production is that some of the chassis' had to have been pre-serialized and others were not. None of this really matters...but it makes sense given the one-man-show nature of these amps. No mass production...just a one man churning out what he could when he could. Little did he know the world would become fascinated with his creations and discussing them in such detail all these decades later.
Max Wrote: Just to avoid misunderstandings: Up to now I've never seen a "Tandy" branded coax in an original 1st, 2nd, and 3rd generation ODS chassis.
In regard to "COLUMBIA FLEXFOAM 1389": Indeed (as posted here since 2010):
https://ampgarage.com/forum/download/fi ... &mode=view
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No misunderstanding on this topic as well. I was not really making a reference to RG-59 in Dumble amps in general, nothing relating to 1st, 2nd or 3rd generation ODS's specifically...what I was trying to point out is that the type of RG-59 used in various Dumbles (of multiple vintages) is not always the Tandy brand/make of cable. I simply explained that some of his amps used a Columbia brand RG-59 (That's what the catalog snippet I linked into the post was all about). And yes, the center conductor was most definitely a copper-clad steel which is pretty typically used in RG-59. He obviously liked the insulator material and the low capacitance/ft. specification. Or maybe he just acquired some on the cheap? Nobody but he knows...but he definitely used this particular Columbia RG-59 cable in some of his amps.
Best Regards,
GPD
OMFG I got the 75's in the amps confused with the one's I have 81's How embarrassing and 
