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    New GM40 owner! +questions

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    JonnyNonsense

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    New GM40 owner! +questions

    Post by JonnyNonsense on Mon Jun 19, 2017 6:46 am

    Hi all,

    Just got my GM40 a couple of days ago, and I love it. Every channel sounds great, the amp looks cool as fuck, and the technology integrated into this thing is just unbelievable. I have already done some recording with the Red Box out, and I can't believe how convincing it sounds.

    Also very impressed with the tone shaping capabilities of the EQ controls. They really change the sounds nicely, and even with the more 'extreme' EQ settings, the tones are still very usable. And the boost switch! It makes the whole thing even more versatile, and I love the boosted sounds of the lead +ultra channels.

    Has anyone here experimented with changing the tubes in their GM40? Any recommendations?

    Also, what speakers is everyone running their GM through?

    thanks, JN
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    Ravensha

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    Re: New GM40 owner! +questions

    Post by Ravensha on Mon Jun 19, 2017 10:15 am

    I just received mine on Saturday.
    Still working through dialing things in.

    I am running a 2x12 Mesa cab with V30's.
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    JonnyNonsense

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    Re: New GM40 owner! +questions

    Post by JonnyNonsense on Mon Jun 19, 2017 10:25 am

    How does it sound through the Mesa?

    Was considering getting a Mesa 2x12 for my GM40 myself, as I like the Mesa low end, but not sure how well matched the GM40 is to V30s.
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    bordonbert

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    Re: New GM40 owner! +questions

    Post by bordonbert on Mon Jun 19, 2017 11:08 am

    It isn't exactly the same but start with threads in the GM36 forum on speaker choices and the usefulness of valve rolling, it has been done to death with a lot of common sense thrown in there.

    There are threads in the GM40D forum which discuss it too.  For my money and the money of most of the H&K old guard, valve choices make a minimal difference despite what everyone thinks.  Try reading what I wrote here, GM36 Speaker Cab Advice, to the same question.  My view is that of an engineer with a lifetime in the electronics industry so I can generally prove what I claim, and any questioning of "common wisdom" I may do is based on the lack of proof for most of it.  The GM36 is a different beast in some ways to the GM40D but the valve comments are universal and the speaker advice seems to run pretty much parallel between the two.
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    JonnyNonsense

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    Re: New GM40 owner! +questions

    Post by JonnyNonsense on Mon Jun 19, 2017 11:24 am

    Great, I'll check it out. Sorry if I'm bring up worn-out topics!
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    Ravensha

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    Re: New GM40 owner! +questions

    Post by Ravensha on Mon Jun 19, 2017 12:07 pm

    I also have a 4x12 Mesa half-back, I've played the amp through both.
    Specifically, I am using the 2x12 because my goal in getting the GMD40 was to reduce my live rig in size and weight - but still have a great sounding tube amp.

    Monday at work ... just wanting to get back home to play!
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    bordonbert

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    Re: New GM40 owner! +questions

    Post by bordonbert on Tue Jun 20, 2017 7:05 am

    No problem JN, it is always going to be a hot topic when new owners arrive here but it is useful to have a scout around for things which are so universal to us all.  There really is a wealth of experience and info out there in the threads if you take a bit of time to scan through it.  There is a HUGE valve swapping thread out in the GM36 forum and that info is pretty much universal.  Tube Swapping Thread  Have a look for later posts (from 122) on that page (5) by VoodooJeff who is really worth listening to as he is a full time pro using dual H&K amps in his work.  As a pro he has access to Wathen valves which are $130ish EACH!  Interesting reading as long as you have an open mind and don't want to hear your golden ears aree actually platinum. Wink

    I'm like you Ravensha.  I went to a 4x12" after trying my GMK36 out as a mini-stack with two 1x12" cabs and the amp stacked vertically.  (That alignment is much better for even dispersion.)  Very cool look but with Vintage 30s in there originally the sound was way, way too strident and toppy for me with a peculiar nasal quality which wasn't just a nice middley sound.  Even swapping them for G12M Greenbacks wasn't ultimately enough to get it to where I wanted it to be though it did smooth it out a fair bit.  The 4x12" sound is much more robust and solid with a lot of the extreme top end tamed.

    The problem with a 4x12" is that they inherently suffer from terrible beaming and there is nothing that can be done about this, it's a feature of having multiple sources spread across a much wider distance in both directions.  (Please DON'T anyone suggest I use Beamblockers! Evil or Very Mad  I have posted before on how ridiculous they are in the light of the Physics and results of high level engineering tests and you don't want another diatribe from me on a mathematical technical matter.)  I have been tempted for a while to try it with a G12M loaded 2x12" cab to see what difference if any that makes but I don't have the right cab to hand.

    Even though you are using V30s yourself, you are using 2x12" and 4x12" both by Mesa.  What difference do you find there is in sound between the two cabs Ravensha?
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    Syn666

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    Re: New GM40 owner! +questions

    Post by Syn666 on Tue Jun 20, 2017 7:54 am

    I'm using a Line6 DT 112, equipped with a Custom Celestion that I'm guessing is based around the Celestion K100, and I have no piercing highs at all.
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    bordonbert

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    Re: New GM40 owner! +questions

    Post by bordonbert on Tue Jun 20, 2017 8:45 am

    If that's a DT25 cab Syn, Sweetwater says it has a Custom Voiced G12H-90 in it. I can't get a clear view on the DT50 but it looks as though it may be the same. If that's true then I guess it would have a family resemblance to the G12Ms. I have 4 original 1960s G12H-25s and they are beautiful sounding if a little underpowered nowadays. They are similar to my modern G12Ms in basic character.
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    Ravensha

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    Re: New GM40 owner! +questions

    Post by Ravensha on Tue Jun 20, 2017 9:17 am

    bordonbert, I haven't spent time doing an A/B test between the cabs.
    Out of the box I ran the GMD40 through the 4x12 because it was the most accessible speaker cab.
    Since my goal here was to pair down my live rig, I have been using the GMD40 with the 2x12 cab (which is vertical), and working on dialing in the channels - since this is what I will be using.

    That being said, I have considered/wondered about having two separate but stacked 1x12 cabs.
    But before I dive into experimenting with that, I will need to first figure out what I will be doing with the MIDI switching situation first.
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    Phryght

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    Re: New GM40 owner! +questions

    Post by Phryght on Tue Jun 20, 2017 9:21 am

    Welcome to the club!

    I use a Mesa 2x12 as well as a DV Mark 1x12, when I want a really compact rig....


    JonnyNonsense wrote:Hi all,

    Just got my GM40 a couple of days ago, and I love it. Every channel sounds great, the amp looks cool as fuck, and the technology integrated into this thing is just unbelievable. I have already done some recording with the Red Box out, and I can't believe how convincing it sounds.

    Also very impressed with the tone shaping capabilities of the EQ controls. They really change the sounds nicely, and even with the more 'extreme' EQ settings, the tones are still very usable. And the boost switch! It makes the whole thing even more versatile, and I love the boosted sounds of the lead +ultra channels.

    Has anyone here experimented with changing the tubes in their GM40? Any recommendations?

    Also, what speakers is everyone running their GM through?

    thanks, JN

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    billgwx

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    Re: New GM40 owner! +questions

    Post by billgwx on Wed Jun 21, 2017 2:10 pm

    There must be a way to mitigate beaming of a guitar head thru a 4x10 cab no? I was able to do it for a 1x12 cab using open cell polyurethane foam cut to spec as described in a well-reasoned "sound dispersion" thread over at The Gear Page site. I don't recall if the technique works for a 2x12 or 4x10 cab...
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    bordonbert

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    Re: New GM40 owner! +questions

    Post by bordonbert on Thu Jun 22, 2017 7:21 am

    You had to ask didn't you? Very Happy

    There is no way whatsoever to remove or prevent it!  Beaming occurs because your cabinet is made up of multiple sound sources all sending out their own version of the signal.  In the case of a multiple driver cabinet it is easiest to consider each speaker as a signal source to grasp the principle.  That is an oversimplification for the moment but it serves to demonstrate what causes beaming.

    When you are "on the beam" positioned at equal distances from these points, all of the signals arrive at your ears at the same time.  You are getting the full range of frequencies more or less as they are leaving your drivers.  When you move off the beam the path distances from each speaker begin to differ.  That then means that the signals from the points further away take longer to arrive at your ear and are therefore out of phase with the closer signals when they do.  This means the multitude of signals begin to cancel each other when your ear adds them which lowers the level.  This cancellation effect is frequency dependent because the wavelength of the signals gets smaller as their frequency rises.  So it produces a "comb" type filter with the effect most noticeable at the highest frequencies and virtually no cancellation for frequencies where the wavelength is much longer than the difference in path length.  Hence you get a drop off of frequency bands at the top end at some points off the beam.  If this gets extreme it is even possible that at some frequencies the signals come back into phase a whole wavelength later and they add together again which is the cause of the comb effect.

    As I said, the problem is simplest to understand if you consider a multiple driver cabinet with a number of speakers set apart on a flat baffle as they would have to be.  It is however also the case even in a single driver cabinet as any speaker driver acts as a set of multiple points on its cone each one acting as an omni-directional point source.  The idea that cones send most of their high frequency from the centre aimed straight forwards is a MYTH!  It is absolutely the wrong thing to assume to start your argument for anything in this field.  People believe it to be so simply because of this beaming cancellation effect which means that maximum high frequency is naturally heard on the centre line.  That is due to cancellation of the real multiple signal paths not because the speaker is sending out more from its centre.  Every point on the cone acts as a full frequency point source vibrating across the whole frequency spectrum.  That is why tweeters are tiny!  There are less point sources on their cone/dome and a lot less spacing between those points in relation to the signal wavelength.

    The spacing of the drivers in a 2x10", 4x10", 2x12" or 4x12" or in fact any multiple driver setup makes this effect absolutely unavoidable in at least one plane.  It doesn't matter how you try to "scatter" the signals (as in the useless Beamblockers which even introduce other bad effects like signal bouncing back into the speaker and then forward again off the cone to be even more out of phase than ever), or how you angle them (as in specialist cabinets with split baffles angled inwards or outwards).  That delay due to different path lengths cannot be removed, hence beaming can never be totally removed.  I should say that those other systems may sound better to your own ears, that is a subjective thing.  But it is due to the other random factors that they change and the fact that your setup may have other problems which they may reduce.  They can do absolutely nothing to circumvent the Physics of beaming and it is immoral to claim that they can when all of this is incredibly simple to demonstrate in a laboratory and has been done with the results being made public!

    The only system I have ever seen that actually works is Jay Mitchell's "Mitchell rings" and this only works for single drivers.  Just as Mitchell predicted and openly stated would happen, these produce other effects like a slight drop in high frequency level overall but that can be balanced with tone controls.  They are set up as the opposite to the commercial Beamblockers.  It is a setup where a flat open cell foam "doughnut" across the entire front of the driver is used to remove the high frequency content from the outer area and only allow it to escape through the centre hole.  Low and middle frequencies which have longer wavelengths and do not show the same degree of beaming pass straight through the foam.  They are very easy to make and fit but the correct material in the correct thickness with the correct sized centre hole is essential.

    Jay Mitchell seems to have come up with this idea as he was disgusted with the way some commercial people were cashing in on people's ignorance.  He is not a popular character in some areas of the audio world, he takes no prisoners in any argument about the Physics of sound, but he is a very highly respected audio engineering expert who has published academic papers on aspects of audio reproduction. He made nothing out of the idea, he runs a very successful audio design consultancy with profits elsewhere, and happily gave the explanation and plans to the public along with his high tech anechoic chamber measurements of the rings and competing systems to prove his point.  Very few people even bother to look into it even when it is pointed out to them, (like this Wink, as their "Guitar Gurus", many of whom have no real engineering background, simply poohpooh him and insist that the myths are still true.  They just prefer to swallow the bullshit the sellers of other systems feed them and blank the evidence which proves that those other systems do not live up to their claims!

    And Stevie Ray Vaughan knew nothing about the physics of this when he draped his towel over his cabinet.  It doesn't prevent beaming, it simply drops the level of the frequencies he didn't like in his signal.  Path length is the key.  The speed of sound is constant for all of the signals coming from your cabinet into the same environment.  You can't change that.
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    billgwx

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    Re: New GM40 owner! +questions

    Post by billgwx on Thu Jun 22, 2017 12:16 pm

    Yes, Jay Mitchell's ring is exactly what I'm talking about and using in a 1x12 cab. I want what I hear on stage to match what listeners out front hear as much as possible...
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    bordonbert

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    Re: New GM40 owner! +questions

    Post by bordonbert on Thu Jun 22, 2017 12:38 pm

    Yes, you've definitely settled on the best case. And once you know, (or others who come across this thread Wink ), the theory or at least understand what it is based on you then know it can't work for multiple driver cabinets, or at least in one or more planes. There is a case which says that, with the Mitchell rings in place, a 2x12" cab with the drivers arranged vertically would be pretty good to go as the beaming would only occur in the vertical plane and dispersion is improved in the horizontal plane as a different issue too. In the horizontal plane they would react much as though they were a single speaker. It can't help the 4x12" case at all though as they would suffer from beaming in both planes.
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    Graham G

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    Re: New GM40 owner! +questions

    Post by Graham G on Thu Jun 22, 2017 1:09 pm

    Just my 2 penneth,but from what i've heard coming from the GM36(which is very little)& what i've heard from the V30 in my R30C,i wouldn't even think about using V30's with a GM36,i have a feeling this would also apply to a GM40,i suspect it would rip your ears off,even old deaf ones like mine. Laughing
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    JonnyNonsense

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    Re: New GM40 owner! +questions

    Post by JonnyNonsense on Thu Jun 22, 2017 1:25 pm

    But...the Hughes & Kettner cabs have vintage 30s in them. I find it hard to believe they are building amps that aren't voiced for their cabs, or vice versa.

    There is someone selling a mesa 2x12 in my area, maybe I'll check it out. That also has vintage 30s though..
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    Graham G

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    V30's

    Post by Graham G on Thu Jun 22, 2017 2:56 pm

    JonnyNonsense wrote:But...the Hughes & Kettner cabs have vintage 30s in them. I find it hard to believe they are building amps that aren't voiced for their cabs, or vice versa.

    There is someone selling a mesa 2x12 in my area, maybe I'll check it out. That also has vintage 30s though..

    Hey,don't worry about my opinions(they're only worth what i said in my post)plus i'm old & deaf Smile ,so when you plug in you will almost certainly disagree,just adding to the conversation.
    I can't stand listening to the V30 in my Amp.but i use an extension cab with it with a different speaker,that makes it all work well.
    This is just an aside,i would never be surprised what manufacturers of Audio do.
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    bordonbert

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    Re: New GM40 owner! +questions

    Post by bordonbert on Fri Jun 23, 2017 3:34 am

    The H&K V30s are specially voiced for them. I have no idea how different that would make them sound. And of course you should remember that they have produced an amp and speakers which fit a chosen design remit. Firstly they are Germans, secondly they want to hit a large market. It's designed to do high gain/metal types really well and sod the rest. For my money it does.

    And you should also remember, there are other people here who swear that the GM36/V30 sound is exactly what they want. The amp is always criticised by people like me in the context of the music I want to play through it. For me, that is classic late '60s/'70s/early '80s rock. My criticism of the shrill character is always because I want to dial in a smoother stronger sounding overdrive and distortion and I feel the amp can't do it, certainly not partnered with any V30s I've heard. I openly praise it for being a monster machine for higher gain types of rock. The H&K designers have spent a lot of time with their complex voicing arrangements to make it fit that bill, there must be people other than those Germans ( Wink ) who want to create the sound of The Hoff.

    If V30s do it for you then great stuff, you've got your perfect sound in an easy to implement package. The only mistake is to assume that their gear must be the best match for itself or accept someone else's advice without questioning and listening objectively. Your needs may just not be the same as theirs. At the end of the day the only way to make a sensible informed decision is to try out any combination you are interested in before you part with any cash and don't be frightened to say "that's not what I hear" to absolutely anyone. Not doing that is how musical myths are born!
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    Phryght

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    Re: New GM40 owner! +questions

    Post by Phryght on Fri Jun 23, 2017 2:50 pm

    My advice concerning V30's.... listen to your rig in a band mix. While they can sound quite harsh by themselves, they really cut through in a live setting.
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    JonnyNonsense

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    Re: New GM40 owner! +questions

    Post by JonnyNonsense on Sun Jun 25, 2017 9:24 am

    Phryght wrote:My advice concerning V30's.... listen to your rig in a band mix. While they can sound quite harsh by themselves, they really cut through in a live setting.

    To be honest, that's what attracted me to H&K amps in the first place. I play a lot of gigs and every time I see a band using H&K's, their guitars just sound great in the mix. They really stand out from other amps live.

    @Bordenbert - I totally get what you're saying about different needs. I do want to be able to use a range of sounds, even though I lean towards high gain stuff. I have seen an ex-display H&K cab going cheap near me, so I might buy it, and if I don't like the sound maybe I'll swap one of the speakers. TBH I am quite happy to have a mid-heavy sound, as long as it's not overly trebly.
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    Graham G

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    Re: New GM40 owner! +questions

    Post by Graham G on Sun Jun 25, 2017 1:37 pm

    Phryght wrote:My advice concerning V30's.... listen to your rig in a band mix. While they can sound quite harsh by themselves, they really cut through in a live setting.

    I didn't know there was any other way of using gear Laughing
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    JonnyNonsense

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    Re: New GM40 owner! +questions

    Post by JonnyNonsense on Sun Jun 25, 2017 2:01 pm

    Phryght wrote:Welcome to the club!

    I use a Mesa 2x12 as well as a DV Mark 1x12, when I want a really compact rig....


    How does your GM sound through the Mesa? Do you know how this sound compares to the GM through an H&K cab?

    I basically have the choice between a Mesa 2x12 and a H&K 2x12 that are on sale. Mesa cabinets are supposed to be some of the best there is, but the H&Ks are probably ideally voiced for the GM. Would it be worth me spending an extra 300 to spring for the Mesa?

    Unfortunately I can't try the GM through the H&K cab in person, as the store is rather far away.
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    JonnyNonsense

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    Re: New GM40 owner! +questions

    Post by JonnyNonsense on Tue Jun 27, 2017 2:55 pm

    Update: I tried the GM40 through a Mesa cab today (with V30s).

    Holy shit you guys weren't lying! It sounded awful. Shrill and trebly is an understatement. Even with the treble and presence all the way down, it sounded very bright. And the other controls didn't seem to affect the tone much. Weird.

    Shame because I also have a Mesa head, and I know it sounds amazing with the Mesa cabs, so it would have been nice to have a cab that suited both my heads. Going to stick with my Marshall 4x12 for now and check out some more 2x12s. Definitely not going to get the H&K cab without trying one first.

    There's a used Peavey EVH III 2x2 on sale in my area, maybe I'll try that out.
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    Graham G

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    Re: New GM40 owner! +questions

    Post by Graham G on Tue Jun 27, 2017 5:58 pm

    JonnyNonsense wrote:Update: I tried the GM40 through a Mesa cab today (with V30s).

    Holy shit you guys weren't lying! It sounded awful. Shrill and trebly is an understatement. Even with the treble and presence all the way down, it sounded very bright. And the other controls didn't seem to affect the tone much. Weird.

    Shame because I also have a Mesa head, and I know it sounds amazing with the Mesa cabs, so it would have been nice to have a cab that suited both my heads. Going to stick with my Marshall 4x12 for now and check out some more 2x12s. Definitely not going to get the H&K cab without trying one first.

    There's a used Peavey EVH III 2x2 on sale in my area, maybe I'll try that out.

    I'm not trying to promote a different brand,but the cab that i've heard that sounds consistently excellent,even coupled with a couple of amps that i've never heard a good sound out of is the Orange Jim Root 2 x 12",it really sounds good,that would be the first cab i would plug a GM into.
    once again my opinions worth what i was paid for it.

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