...that I've somehow missed? Dave Hunter, who (from a cursory Google search) I've been led to believe is some kind of tube amp guru, says that the DR103 sports an "active EQ." I know that the tone of this post is probably going to come off like I'm being some kind of smart-ass, or something, but I genuinely want to make sure there isn't some awesome DR103 variant out there somewhere that I've somehow overlooked.
His [Dave Reeves] tone stage read Treble, Bass, and Middle just like Marshall’s, but behind the panel lurked an active 12AX7-driven network in which each of the three knobs had a major impact on the frequency band it governed.
ESSENTIAL INGREDIENTS
> Four EL34 output tubes generating around 100 watts RMS
> Fixed-biased output stage
> Four ECC83 (12AX7) preamp tubes
> Active EQ stage
> Solid-state rectification
> No-holds-barred construction and component quality
Just guessing here: maybe he's trying to say the tone dials on Hiwatts have a greater range of sweep compared to many other amps of the day (which is true in my experience anyway compared to say Marshalls). For the record I am not trying to be a wise-ass and I'm also not a Hiwatt guru or anything else for that matter, just not sure.
DR103 does not have an active EQ. However, The Sound City amps that preceded it DID, and it did not sound very good. Maybe he is getting his amps mixed up? IIRC the Hiwatt EQ is very similar to Fender designs (100K slop resistor, TMB Tone Stack). I can see how someone could "think" it was active, as It does have a very pronounced sweep in tonality across the knobs.
"It's like what Lenin said... you look for the person who will benefit, and, uh, uh..."
Agreed regarding the Sound City 120. I had one back in the 70's. It had active tone controls, (6) EL34's, and the tone sucked. I think this might have been the amp that prompted the derogatory moniker "Sound Shitty".
I ended up putting a modified Marshall circuit in it. It rocked quite hard after that but was too loud. Later I fitted a MV out of necessity.
And the Sound City Plus / MkIV series tone controls were only ‘active’ in the very broadest sense, eg they didn’t use nfb. Due to that I regard them as a passive type but folks cleverer than me have disagreed so there you go.
What all agree on is that they aren’t in any way an improvement on a regular tone stack, so can therefore be regarded as a waste of several ECC83 sections. https://el34world.com/charts/Schematics ... 50plus.pdf
Some Hiwatts (including the dr103) have a presence control arrangement that can cut and boost, so maybe that, along with the tweaks to the regular tone stack, got Dave Hunter into a muddle? https://el34world.com/charts/Schematics ... _dr103.pdf