Q- HRM/nonHRM

[Pete]

Can anyone please clear something up for me?

Some points being discussed in recent threads here has brought up a fundamental question (to me anyway) regarding the two basic models of ODS referred to as HRM and NON HRM.

My observation of info & pics etc. (limited to the typical sources on the net) leads me to a view that all authentic original (not clone) examples would be defined as:

Non HRM = (amps like #0124) LNF, 100K plate/1.5K cathode, Fender or similar transformers, 6L6s, i.e. the goal being a modified Fender like sound.

HRM = no LNF, larger val plates/cathodes, post OD tone stack, Marshall or similar transformers, EL34s, i.e. the goal being a modified Marshall like sound.

The question is, is this an accurate way to view the two models? In other words, do any real ODS models exist with combinations of features?

[dogears]

Yes....

Dumble made about a dozen Music Man trannied amps, such as the tan Ultrasound one. EL34 tubes. Skyline tonestack but with 100K plates.

There are a bunch of early 80s amps that had the higher plate loads with 6L6 tubes and either Skyline or older tonestack.

There are some oddball amps that have crazy plate and cathode values and even strange tonestacks....

There are HRM amps with 6L6 tubes and LNFB!

There are HRM amps with Marshall style power amps and non traditional clean tonestack.

There are HRM amps with traditional power amp and tonestack but with either Fender or Marshall iron.....

Basically he could and did mix and match........... I have pictoral proof of all of this btw.

[chris_sanford]

Yes....

Dumble made about a dozen Music Man trannied amps, such as the tan Ultrasound one. EL34 tubes. Skyline tonestack but with 100K plates.

There are a bunch of early 80s amps that had the higher plate loads with 6L6 tubes and either Skyline or older tonestack.

There are some oddball amps that have crazy plate and cathode values and even strange tonestacks....

There are HRM amps with 6L6 tubes and LNFB!

There are HRM amps with Marshall style power amps and non traditional clean tonestack.

There are HRM amps with traditional power amp and tonestack but with either Fender or Marshall iron.....

Basically he could and did mix and match........... I have pictoral proof of all of this btw.

What he said! Adding to this list are the 100k plate/large value cathode resistor amps that don't have Music Man iron (usually Fender instead), and are built on the three piece chassis w/wood sides (similar to the MM iron amps).

Or how about the 150 watt ODS that uses what looks to be Sun/Dynaco iron, 4x 6550 tubes, and features reverb AND trem?

And Scott didn't even get into the early 'silverface' ODS amps, or the Overdrive Reverb Specials (some of which have been updated with HRM).

Who knows what else might be out there!



chris

[Pete]

Thanks for the responses guys. Interesting info I've never really heard much discussion of it.