HXDA vs. 25th w/ mod?

Boogie

Zombie Two, DFZ
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Can anyone give my a first-hand comparison between the production HX/DA and a 25th Anniversary with the HX/DA mods installed? Other than the master volume on the HXDA and the detent-ed attenuator approach on the anni, aren't they supposed to be identical? I'm just trying to cover all of my bases with the options available out there. Isn't the 'HX' mode the same as the stock anni?

Thanks!
 
I think Hans was planning to have a 25th modded. Maybe he can shed some light on this?
 
I think Hans was planning to have a 25th modded. Maybe he can shed some light on this?

Sure thing. Amp leaves for PRS tomorrow. When it gets back, I'll let you know what I think.

My understanding is that it's just a 25th Anniversary circuit that can be modified on the fly with the HX and/or DA switches.
 
Mine was done about 4 months ago,.,at the suggestion of Brian Meader. It's much more versatile and the tone better for me personally in the DA setting. YMMV though....
 
Mine was done about 4 months ago,.,at the suggestion of Brian Meader. It's much more versatile and the tone better for me personally in the DA setting. YMMV though....

Are your switches 2-way? As I understand it, the base 25th is changed slightly by the mod leaving the HX and DA modes.

I'm considering picking up a used modded 25th instead of a new HXDA and want to make sure I understand the differences, if any. Thanks guys! cool:
 
Any update, Hans? Enquiring minds want to know.
Working my way through it now, Boogie Man. I got the amp back just before vacation. The upgrade was super clean. I will try to have a solid report with photos by next Sunday.
 
nudge-nudge. ;) You don't have to go into an in-depth review. What are your initial impressions? How much of a difference do you notice between the stock anniversary tone versus the mod?
 
Sorry for the delay fellas. I just needed the house to myself for a few hours so I could really crack it open. I spent some quality time with the amp today and have some initial thoughts. For this tone report, there were no pedals in the signal path and I was playing though The Raven; a modified 305 running a Deep Dish 2 humbucking pickup in the bridge position and a pair of 305 single-coils with the PTC "Hot Rod Mod" in the middle and neck positions.

The Story
I sent my amp back to Mr. Doug Sewell (one of the nicest guys on the planet, by the way) because a capacitor had become mechanically disconnected (probably during shipping) and the amp was not getting filtered on the screens/phase inverter. Turns out the ground wire to those caps had come off. This was the source of some ghost notes (not good) along with some really fantastic overtones (very good). It was an odd trade off and I was a little worried to "fix" the amp and risk losing those overtones. Doug made the repair under warranty and then installed the HX/DA switches per my request. I told Doug that I loved the stock tone of the 25th Anniversary amp so he adjusted the HX/DA switches a bit from the production models so that in the HX positions I would still have my original, pristine, 25[SUP]th[/SUP] Anniversary tone. The only variance in the HX mode on my amp (from a production HX/DA) is that mine retains .022 uF coupling caps in the phase inverter where a production HXDA is .1 uF. Don't ask me how that translates to tone - I have no idea. The DA positions, however, take the amp into production component values for that setting.

General Comments about the Amp
If you've never played a 25th or HX/DA, its hard to grasp just how versatile they really are. The Treble and Bass gain knobs have a dramatic impact on tone but not necessarily the volume. There is a master volume that does a good job of keeping the tone consistent across the spectrum but I confess - the lowest setting is anemic compared to the next one up - which is a little too loud for home use (but I do it anyway). The full power mode is best reserved for stadiums. In the 9-o-clock position of both knobs, this thing is really clean, full, and tight. I can get some funky/spanky cleans on the neck single-coil and it sounds fantastic. Crank the Treble knob to 12 o'clock (with bass still at 9) and I have decidedly rock-oriented tone. By the time I hit 3 o'clock with the treble gain knob (and bass still at 9), this amp transforms into a #$%^&* flame-thrower.

The guitar I'm playing obviously has a notable impact on tone but there are some general comments I feel safe making:
1) This is a fantastic amp for clean tones with a sing-coil pup. It is warm, punchy, and chimes quite nicely
2) If you're after hard-rocking crunch with a fat/tight bottom end, this amp will get you there too
3) It's pretty easy to find an amp setting that allows me to get both 1 & 2 (above) by using the volume knob, tone knob, and pickups selector on my guitar

Stock 25th Anniversary vs. the HX/DA Mod
Since I have the king of clean (a '64 Twin Reverb), I don't spend much time playing with the clean settings on this amp. If you're curious about the differences between HX and DA in clean mode, I couldn't tell you. Not yet anyway. I also didn't experiment with different combinations of switches. I'll get to it eventually but this tone report is focused on the dirty side of things. What I want from this amp is a hard-rocker that I can clean up with the volume knob (Think "Monkey Business" from Skid Row). And... I don't want to have to use pedals to get there. The HX mode does this without ever breaking a sweat. In fact, I turned on Monkey Business after typing that comment (listening to it now) and it sounds very much like this amp in HX mode. It offers searing lead tones with saturated tube shimmer for days. It is not muddy in any way and it serves up plenty of woof on the low end - which probably has a lot to do with the sealed 2 X 12 cab I'm using.

The DA setting, however, is notably more complex with less brightness. It's warmer, fuller, with more "air" in the tone. It's nuanced (but not delicate) with a wider range of emotions - not quite as "balls out" when compared to the HW. When I switch all three toggles from HX to DA, it's like I turned down the presence knob and added back in a whole new range of overtones. The DA setting is quite saturated so I tended to use it for soloing on backing tracks where the HX mode was more fun playing chunky rhythm parts. I'll be curious how changing guitars impacts that last comment. I'd like to spend some time trading out guitars to get a feel for the DA setting so I can be more specific but if I was in a classic rock band, this is probably the mode I would use. But an AC/DC, Van Halen, or even Skid Row cover band? HX mode. No question about it. If the DA setting is like a fine red wine that is best appreciated by educated pallets, the HX is a flaming shot of tequila from the navel of a stripper named Dominica.

The Verdict
My favorite guitar tone comes from an EF86/EL84 amp like an old Vox AC15, Bad Cat TremCat 30, or Matchless C-30 or Cobra. If that's the tone you're after, this is not your amp. But if you are looking for something that gives you Plexi, Marshall Super Bass, and JCM800 tone in a single (and probably more reliable) package, the HX/DA is a slam dunk.
 
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Great report, Hans! Here's where my stock HX/DA differs:

The master volume on the stock model (as opposed to the modded 25th) is a continuous attenuator, not a stepped attenuator as you have. Thus I can dial "in between" the steps on your master volume, and find a good volume level for home use, recording, or other settings.

Sidebar notes:

I think when you play other guitars with the amp, you'll find this amp very revealing of the differences between pickups. Some amps are better at this than others, and the HX/DA is one of the best. In fact, I think it's on the level of a Two-Rock in being able to respond differently to different pickups and guitars. But the point is, you should have a lot of fun trying out your many guitars, and working with the pickups and the volume and tone controls.

The differences between the pickup sounds on my 3 guitars is truly night and day with the amp, you can really hear how they affect the tone. I've also found that the amp reveals the sound of the woods of the guitar very well. It makes picking the right guitar for a particular job extremely easy. There is no "Gee, I wonder what I should use to get this tone." You *know* what to pick up once you get an idea of the amp's response to each guitar.

Also, if you haven't tried this already, all the switches don't have to be HX or DA at the same time. I get various tones by switching the different ones in or out, and there is a lot of coolness to be had doing that.

For example, I can get some of the warmth and complexity of the DA setting by switching the first switch on the left to DA, and leaving the rest in HX. This gives me a "best of both worlds" setting that I like a lot with the SC58. Warm, with a little more grit than DA.

Finally, HX doesn't have to be set to flamethrower to get some very sweet overdrive; the gain controls are very responsive and there are a lot of very gritty-but-not-wild-man lower and medium gain settings to be had. I usually set my amp controls to produce a good crunch at 2/3 of HX gain, and a touch of DA gain, when the guitar volume is around 6-7.

Lower the guitar volume, and it's clean, raise the guitar volume, and the amp goes from a nice overdrive to higher gain territory depending on guitar volume.

In general, though, I think you have a good handle on what the amp does! Great job! It's pretty easy to dial in exactly what you want with it, isn't it?

Oh yeah, one more thing: Because the amp responds very well to nuanced playing, I'm finding new ways to approach picking and its singing tone is making me play more melodic parts, as opposed to "licks." That's an improvement in my playing, so the amp is really helping me make better playing choices.

I just love this thing. I played it all afternoon, and afterward, had a bite with a fellow studio owner, and all I wanted to do was talk about the darn amp. I probably bored him to the point where he decided to go ahead and schedule that hip replacement he needs, as a more enjoyable thing to do than listen to me.
 
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Here's where my stock HX/DA differs:

The master volume on the stock model (as opposed to the modded 25th) is a continuous attenuator, not a stepped attenuator as you have. Thus I can dial "in between" the steps on your master volume, and find a good volume level for home use, recording, or other settings.
I should have had that upgrade done - assuming it's an option.
 
Excellent review, Hans! You don't know how close I came to buying a 25th Anniversary and immediately send it in for these mods. Thhhhiiiiissss close. ;) Between your and Les' reviews there's no reason why every '60s/'70s/'80s rock player should not at least demo one of these for a few days. Inspiring!

Have either of you guys owned/played/demo'ed other Plexi-ish clones from makes like Fargen (Mini Plex) or 65 Amps (Empire)? While these examples are designed to be low volume solutions, is there any comparison?

]-[ @ n $ 0 |v| a T ! ©;46786 said:
I should have had that upgrade done - assuming it's an option.

That was one of the things that I found challenging during the demo. The HX/DA attenuator is a solid improvement, even if the lower settings were unusable to me.

Any chance you could claim this head to be your carry-on baggage the next time you come to BF Egypt? ;) Markie doesn't have one of these.
 
Have either of you guys owned/played/demo'ed other Plexi-ish clones from makes like Fargen (Mini Plex) or 65 Amps (Empire)

One of my friends brought a Fargen into my studio and we played it for awhile. Another studio-owner friend has a 65 Amps Empire. I've only heard it at his place, and didn't play through it.

I don't think of these amps as Plexi clones for several reasons, not the least of which is that they were really designed to be able to capture several eras of Marshall tones. And you can hear the difference in the transformers and tube compliments.

Both of these are very fine amps. They're also different from the HX/DA, as one would expect. I found that the Empire sounds more modern, crunchy and a bit less "warm" and liquid than the HXDA. More toward JCM 800 tones, with a brighter emphasis and what I call a little drier tone, and of course, a 22 watt 6V6 amp is going to have a slightly different character from a 50 watt EL34 amp in terms of headroom and overall tone. The transformer alone will make a difference.

The Fargen was also a lower-power amp that blended a few different Marshall eras. I don't remember the tube compliment. If memory serves, it too was a little more of a JCM kinda sound than pure plexi.

I have nothing bad to say about either of these amps, they're really nice instruments. But they're different enough from the HX/DA and what it does that it's easy to hear there's a difference in the tone and the overall approach to the amps.

Call it buttery syrup (HXDA) vs spicy dipping sauce (Fargen and 65). Or as my old roommate from Georgia might say, grits and gravy vs grits. All are great. It's a pick a flavor kind of thing.
 
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If memory serves, the Fargen Mini Plex is more of an 18 watt EL84 design, I played one at the LA Amp Show a couple of years ago and really liked it. IMHO it's more comparable to the 65Amps London and Reinhardt 18 than anything. I dont own an Empire but I do own a London and an HX/DA and find them to be very complimentary amps, but they're also very different sounding. The London has a clarity and top end articulation & bite that the HX/DA doesn't, the HX/DA has a depth and fullness to its sound that the London doesn't. I put that down mostly to the power sections between the amps, although there are a lot of other differences as well.
 
Oh yeah, one more thing: Because the amp responds very well to nuanced playing, I'm finding new ways to approach picking and its singing tone is making me play more melodic parts, as opposed to "licks." That's an improvement in my playing, so the amp is really helping me make better playing choices.

That's a really insightful of putting it, Les. I tend to think of these kind of amps as surgical tools that do exactly what you want them to do as opposed to a blunt "pebbles and bam-bam" kind of instruments (Mesa Recto, for example. Great amp, but not exactly known for subtlety). The HX/DA can allow for a lot more subtlety and nuance, but at the cost of possibly highlighting warts, clunkers and mistakes. I've had to really work on my chording, for example - I used to kind of hack my way through difficult changes, muting hard to reach notes instead of playing the clearly. These amps don't let me get away with that.
 
That's a really insightful of putting it, Les. I tend to think of these kind of amps as surgical tools that do exactly what you want them to do as opposed to a blunt "pebbles and bam-bam" kind of instruments (Mesa Recto, for example. Great amp, but not exactly known for subtlety). The HX/DA can allow for a lot more subtlety and nuance, but at the cost of possibly highlighting warts, clunkers and mistakes. I've had to really work on my chording, for example - I used to kind of hack my way through difficult changes, muting hard to reach notes instead of playing the clearly. These amps don't let me get away with that.

I agree, a great amp like these makes you want to play more precisely.

Though I gotta say, my Mark V seemed to want a lot of accuracy as well, especially in its Tweed mode, and I dug the Mark V, even though I feel more connected to the HXDA.
 
I feel the same way about the Recording Amp...so I am assuming this holds for the 25th Anniversary Platform based amps...its interesting because A/B circuitry I have personally viewed (to my hands and ears at any rate) as more forgiving than Class A amplifiers.

Interesting you should mention that. An amp designer of note once told me that other than single-ended (one power tube) class A designs, there are no true Class A guitar amplifiers. I don't remember why, I'm sure someone can elucidate. Might have been Bruce Egnater that told me this, but it was a while back, so it's too difficult to recall whether it was him or not. I know a few of the guys who're making amps pretty well.

In any event, Two-Rocks are very very revealing, fast amps, with very quick transient response, and they're often regarded as more revealing of errors, and they're Class AB, and I agree that certain modes on the Rectos are very revealing. I had a Tremoverb, essentially a recto, and it was capable of a lot of nuance if you didn't crank the gain too high, which you probably know I don't.

I got sick of mud and buzzsaws on my recordings. I keep the gain pretty darn low or moderate. If I want a big sound, I use layers.

I just don't like the extremely high gain stuff at all. Unless I'm forced to play it by a client with a purchase order in hand. ;) Haha! I'm a ho!
 
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...there are no true Class A guitar amplifiers...

...Two-Rocks...often regarded as more revealing of errors, and they're Class AB, and I agree that certain modes on the Rectos are very revealing. I had a Tremoverb, essentially a recto, and it was capable of a lot of nuance if you didn't crank the gain too high, which you probably know I don't.

It's funny but I felt the same way for quite a while, especially about my Boogie. And after trolling the Grailtone forums for years, I'm convinced that there are very few Boogie owners that keep the preamp gain as low as I do. Ended up going to strictly the class A mode (probably not true class A mode) and keeping the master between 5 and 10. It was a completely different animal that revealed nuances of my picking style and helped solidify something unique to me (and sounded freakin' amazing with P90s!). I honestly believe that some of the best inspiration comes when you throw all convention out the window.
 
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