Hiwatt amps are more mid-scooped than Fender blackface?

[Echoplexi]

Ha!
It was made in 1982 at the Biacrown factory .
Hand wired on turretboard w/ full size pots as I don't think
they had PCBs for this circuit in this later era.

it's like the first amp shown in this link

MHuss Hiwatt Amplifier Pages - Detail Views

Oh, wow- interesting!

 

[Bluesful]

I have a HIWATT CP103 circuit amp en route

I've gotta do it:

 

[John Quinn]

Couldn’t fit everything in the pic collage, center points are listed below it in my text. 300hz DR103, 500hz AB763. Here is original:

I don't recall hearing a Hiwatt with that kind of scoop.

 

[Wyzard]

Whatever the scope may be saying, in practical terms it's not really generating useful information. If ever there was an amp that you'd have to measure from pedal input to speaker output, in order to make any sense of its performance envelope, it's a Hiwatt.

I'll go with what's stated above: this is best done by ear.

 

[Dead Astronaut]

Id say there are other aspects of the Hiwatt design that help, like the unique cathode-driven phase inverter and EL34s, massive OT and Fanes... if anything, the tonestack cut helps trim the fat that might be overwhelming in the overall sum of parts.

The tonestack calc doesn’t take those other aspects into it, just the EQ curve itself... ultimate output curve can be very different

Excellent points – the tone stack's output isn't what comes out of your speakers, and sometimes the two might not even be particularly similar (e.g., a Boogie Mark with a pre-gain cascade tone stack).

A Hiwatt's mids will kick you square in the chest – I don't know enough about the filtering/power amp to say, but that dip around 300 Hz might even contribute to the gut punch you get between (at a guess) 600-2500 Hz, because the lows are so uncluttered. No boom or flub to dampen the impact, and dear god, "impact" is the word. I've only been in the room with a Hiwatt a couple times and have never had a chance to play one, but they sound like they should require a forklift operator's license.

You may have seen this already, but talking of Hiwatts and Colorsounds, here are Mick and Dan with their DR103. The contrast between Dan's vibrating-off-the-chair enthusiasm and Mick's brutalized grimace will tell you all about Hiwatt mids.

(A tangent, but maybe of interest: to my surprise, the new Mesa Rectifier Badlander can move very assuredly in Hiwatt territory. Put it in Crunch mode with the mids high, the bass a bit rolled off, and the gain somewhere between noon and 3:00, and an open A chord will just reach out and smack you.)

 

[Dead Astronaut]

If ever there was an amp that you'd have to measure from pedal input to speaker output, in order to make any sense of its performance envelope, it's a Hiwatt.

You said it. Harry Joyce and David Reeves, with undying respect to Leo Fender, were not the types to change a resistor value because 2.2kΩ was cheaper by the bucket than 1.6kΩ.

 

[Echoplexi]

I usually run my DR504 on a Suhr Reactive Load, and reamped through a STA100, so I can push it into overdrive at reasonable levels. I play it into a 70s 412 with purples.

Occasionally, I get the idea to remind myself what it’s like to play it off the leash. Yesterday I did, and remembered how intimidatingly powerful these are. Mine is “only” a 50 watt, but I basically have to throw in the towel around 10:00 on the MV before structural damage to my house occurs. It’s absolutely glorious sounding though.

These are special amps. There is no tonal compromise- stellar cleans that turn into stellar overdrive, not picky about pedals, doesn’t cave in if you push it hard, built extremely well, etc. You just need to find a way to harness the power in a way that pleases your ear but doesn’t kill the sound.

 

[teemuk]

...that dip around 300 Hz might even contribute to the gut punch you get between (at a guess) 600-2500 Hz, because the lows are so uncluttered. No boom or flub to dampen the impact...

Think for a while those 47 nF cathode bypass caps. Have you ever seen this in typical amp circuits? (Even "bright" Marshalls don't employ smaller values than about 680 nF). A gain stage with such cathode bypass is effectively basically akin to a treble booster, and some Hiwatts have two of them in cascade. Definitely no "flub".

 

[JPH118]

Think for a while those 47 nF cathode bypass caps. Have you ever seen this in typical amp circuits? (Even "bright" Marshalls don't employ smaller values than about 680 nF). A gain stage with such cathode bypass is effectively basically akin to a treble booster, and some Hiwatts have two of them in cascade. Definitely no "flub".

I always associated that with the high-end sheen that I’ve heard from Hiwatts, and it also might play into the unique presence control which is tapped from the plate of the same stage. It’s absurdly high, beyond most guitar speaker cutoffs.

 

[Dead Astronaut]

Think for a while those 47 nF cathode bypass caps. Have you ever seen this in typical amp circuits? (Even "bright" Marshalls don't employ smaller values than about 680 nF). A gain stage with such cathode bypass is effectively basically akin to a treble booster, and some Hiwatts have two of them in cascade. Definitely no "flub".

I've never looked closely at a Hiwatt schematic, but gawt dam, a 47nF bypass cap would certainly do that. You're right, that's sort of like a built-in Dallas Rangemaster, and no wonder!

 

[Humble Texan Fan]

Has to be a sum of many factors though. For instance we don't think of Voxes as Fender like but a typical Vox tonestack has even a deeper/ steeper dip than the Fender one, albeit shifted a little higher.

 

[ProfRhino]

Has to be a sum of many factors though. For instance we don't think of Voxes as Fender like but a typical Vox tonestack has even a deeper/ steeper dip than the Fender one, albeit shifted a little higher.

sure, but the tone stack is a minor influence, compared to the radically different circuits downstream.
ymmv,
Rhino

 

[JPH118]

Has to be a sum of many factors though. For instance we don't think of Voxes as Fender like but a typical Vox tonestack has even a deeper/ steeper dip than the Fender one, albeit shifted a little higher.

sure, but the tone stack is a minor influence, compared to the radically different circuits downstream.
ymmv,
Rhino

Not only downstream, but it doesn’t account for what’s feeding into it from upstream, either... an AC30 TB would have a very small coupling cap, 500pf or so, to emphasize the highs and roll off a LOT of bottom before signal hits the EQ... Fender presents a mostly flat signal to its tonestack in AB763 models... and like we mentioned earlier, jumpered channels on a DR103 would really push lows and low-mids to the forefront of the spectrum heading into the stack. The different tonestacks will produce much different results based on the given input.

Also, any signal compression post-EQ will limit those dynamics as well, so a -13dB cut might be half that or less after the next gain stage or an output stage pushed hard.

 

[HotBluePlates]

... I saw one graph ... that showed the Hiwatt being even more mid-scooped, but ...

You'll have to listen to recordings of each amp. Even then, there are numerous pitfalls.

Something like a graph showing the final EQ curve of the amp/speakers is also fraught with pitfalls. Even glossing over some of those, it's a very tall order. Very few folks will have the environment & proper setup to measure the amps & generate trustworthy frequency-response curves for the amps/speakers.

 

[Rumors of War]

Interesting. I definitely do not perceive my Hiwatt as mid scooped in the slightest. Although, I can’t say I ever EQ’d it to be that way.

Me either. I was actually shocked at the tonestack graph. Although 300-400 hz is where mud tends to hang out, so maybe that explains the stellar clarity of Hiwatt. I perceive the tone as more even and balanced than both Fender and Marshall.

 

[Tone_Terrific]

Guitar amps are voiced here, there, and elsewhere.
The tone stack, per se, is just part of a balancing act.
Looking at its chart only shows how much variation is available and does not create or define define a flat freq response.
Very YMMV.

 

[HotBluePlates]

... I perceive the tone as more even and balanced than both Fender and Marshall.

The naked guitar pickup is not "even and balanced" but is very midrange-heavy.

Probably no one has a home stereo with a 1/4" jack anymore (my folks' old Marantz dual cassette deck had 1/4" inputs for recording to cassette). Plug your lone guitar into a commercial stereo, and it's mostly bland midrange mud.​

Amplifiers whose circuits are "even and balanced" (like a tweed Deluxe or Champ) deliver a resulting sound that seems mid-heavy (speakers might offset that some).

Amplifiers eventually received mid-scooped tone circuits (in the late-50s to mid-60s) to counteract the pickup's midrange; these tend to sound "even and balanced."



And then add the effect of the other preamp tone-shaping, and speaker, and any pedals... Lots of elements to the sonic-stew.

 

[Tone_Terrific]

Probably no one has a home stereo with a 1/4" jack anymore (my folks' old Marantz dual cassette deck had 1/4" inputs for recording to cassette). Plug your lone guitar into a commercial stereo, and it's mostly bland midrange mud.

Lots of folks have PA and recording gear.
Similar result. EQ is the magic leveller.
And if it were all and only an EQ section, any amp could be turned into any sound.
It's not that easy, BUT you can sure get them close enough to work in a band, if you have to, just mod, add, or adjust eq.

 

[Emiel]

My DR103 clone started life as a CP103 (The Who model) ... one of the most mid scooped amps I've heard. It's a glorious one-trick crunch monster but when you run it clean it sounds very much like a 100W AC30 treble boost circuit (similar tonestack)... very bright and very tight. Rather unpleasant with anything but a P90 equipped guitar. I had it eventually modded into a regular DR103 which is all together a much more usuable amp. The tone controls on the DR are very very effective, especially the mid control. The bright/brilliant channel is pretty bright but with jumped channels it's absolutely fantastic.

 

[Wyzard]

Lots of folks have PA and recording gear.

I like my Hiwatt PA amps too