First impressions on the GMD40

Yep. I was setting up over the top of the amp, and plugged into FX return and Line Out, when it should have been FX Send and FX Return.

Really dialed a high gain patch using the Ultra on full power mode. The amp really does high gain well, and to me, for these settings, a compressor really helps getting crushing sounds.

Messed around a bit with clean and lead channels and the effects on the POD HD, and I really getting very pleasing result. Will still have to explore the Crunch channel, though...

Well, since I have to buy a 5-pin MIDI cable in order to use the POD HD 500 for channel switching on the amp, and 4CM for effects, I've been noodling with the amp alone.

So far, I've come up with awesome Clean, Lead and Ultra patches, both with and without effects. The Crunch channel has been the hardest to get sounds that I like, will have to delve a little deeper in it.

The amp is really responsive to pick attack, and it's EQ is voiced to interact with both Presence and Resonance controls. I've yet to try the new sounds in rehearsal, since I've been just using presets I copied on a bank, and my bandmates are really stunned by what it can do, so I've warned them there's more to come...

I'm now set on having two boards to go with the amp: One with the POD HD 500 for more diverse sounds, and a smaller on with a tuner, a volume pedal, the FSM MkIII and a wah. The 4CM takes a little more to set up, and I've still to workout the MIDI part of it, but its sounds combined with the GMD40 seems to have a more professional feel to it. The smaller board is awesome for rehearsals and home use, since is lightning-fast to set up, and yet have awesome sounds at my feet.

Didn't try it yet with Fredo's app, since from what I've seen on this forum there are still some bugs, but I'm getting used to program the amp with both my ears and a little knob fiddling, so I'm mainly interested on the app for saving presets, although a visual help to programming sounds would be really welcome.

I'm really, really amazed by this little amp- congrats to H&K for having the vision to develop such an awesome amp.

Hi Syn666

I echo what you are saying for the most part. I previously relied on my Mesa LSS for providing a solid and stunning clean sound then I would call on a variety of different pedals (mainly dirt) for each sound I needed.

I use a Boss ES-8 switcher which is rapidly becoming an expensive midi switcher for the GM40.

I find that, as I play covers mostly, that I set up say a number of presets for each track and call up by Programme Change (PC) command each preset.

I have started however to add in some CC commands (by the ES-8's assign feature) which allows me to stay on the one GM40 preset and select boost, switch on/ off reverb, global mute. I haven't delved too much deeper than that.

I am still struggling a bit, so much that I am struggling to articulate it clearly with the use of a second amplifier. I use this (which is a Princeton reverb 68) via the ES-8s second output channel.  My main gripe is that when I put the GM40 into standby the second amp remains active. This is normal behavior apparently. I will try and work out my issues and raise a separate post eventually. I am sure its not a fault there are just a few things to consider, FX loop in/ out and whether my Eventide H9 (in the loop) via the es-8 is set to Wet/ Dry or stereo mode.

Back to the amp and pedals; I think that I will eventually move on to my boutique pedals and replace with a second H9, keeping one for VERBS and one for Delays.

I'll chime in after almost 2 months of use. I love the amp's added versatility over the GM36, but am disappointed in the amp's voicing as compared to the GM36. The GM36 was able to cut through the mix in my band much more easily. With the GM40 I'm getting lost, even when cranking the mids all the way up and lowering the bass a little. After playing with the Duncan Tone Stack Calculator, my educated guess is that the GM40 really does have a much more Fender-ish tone stack, and that I'm going to have to roll off both the bass and treble quite a bit? Advice welcome!

Not really knowing the GM40D at all, what added versatility is it that you like Bill?  I hadn't really cottoned onto anything which was really ground breakingly different.

As to the tone controls, I can tell you that the H&K approach is a little more involved than just a plain old tonestack.  It has one that you would recognise but it is wrapped with other channel dependent features which tailor its action a lot.  The Duncan Tone Stack Calculator is a really good tool to learn about the general way a tonestack works but it's only applicable to absolute bog standard setups, not like the GM36.  As soon as something goes away from the Duncan schematic it can change the response drastically.  If you really want to get into doing this effectively I would have a look at Spice simulation.  It's free, (LTSpice), it's nowhere near as difficult as it is made out to be, and it models exactly any circuitry you want it to, so the tonestack and its surrounding parts can easily be accomodated.

I played mine live with the band in rehearsal for the first time.

The transition from the mesa LSS to the gm40 has not necessarily been as smooth as I would have liked.

We play a variety of styles and covers from Steely Dan to Dr Feelgood, David Bowie, Prince and Radiohead we currently call on a set list of about 30 tracks, and as the only guitarist in the three piece band I have to be able to call on a wide array of tones.

I reckon my band will have to be patient until we run through each track and I find the right levels etc.  I did notice that the GM40 was particularly sensitive to the guitar I am using. What sounded great on my Gibson Lucille sounded weak and a bit hi-fi on my Strat (even with JJ tubes installed).

Playing at house volumes is really no comparison with the performance levels it has to be said, so setting the amp up in the house and I spent many many hours tweaking, needed further work when playing live.

Ahead of our next session I think I am going to have to book time in the studio myself with my guitar and the gm40 and set up properly.

I did hook in the Red Box to the PA, which gave a further depth to the tones, but I think we are quite an undisciplined group and natural enthusiasm (and lack of experience) saw our volume levels rise as the session went on. Should the Red Box be set to LINE or MIC in this instance?

My original idea was to sell on the mesa LSS but I think I am going to try and keep both before making any final decision.

Your experience is not at all uncommon George, many of us found exactly the same thing as you.  There is a vast difference between the tone of in-house levels and rehearsal/gigging levels, even using the Power Soak.  I assume you are doing all of your environmental level adjustments with only the Master Volume?  Altering Gain or Volume to suit a bigger space wouldn't be the way to go at all.

As Yoda might say, "Steep the learning curve is on this one!", and he'd be absolutely right.  You will take a few sessions at high levels before you find your best sounds.  And you will have to get used to the idea that you will need a set of patches for high level use and maybe a second set for home use and the two will end up being different.  It's no good at all tweaking your patches at home then transferring the same settings and adjustments to your live set.  You should see a live patch as perhaps starting from a home one but then being tweaked from there only due to live level observations.

You could use Fredo's app here to make sure you have this all backed up - - - - but you have a GM40 of course!  It is a disaster to lose the only set of patches you have for the whole of your set.  (I know that one from early on in my GM36 use, before the app was in place).

On the subject of valves....  (Here he goes again!   )  You say "...even with JJs installed."  I would stress here, (and it may upset you though I would hope not), valves do not make anywhere near as much difference as people make out they do.  Circuitry is even designed to minimise the effects of the valves in it, (that's what negative feedback is).  This has been discussed a lot on this site with people ranging from engineering types like myself to professional musicians like VoodooJeff giving their opinion.  If you can get past the industry hype and really do some critical comparisons of extraordinarily high quality valves as for example VoodooJeff has the opportunity to do, or if you have the situation to actually do some practical engineering measurements and tests on gear, you will find that any difference is - "slight, at best".  People spend months if not years searching for the perfect valve for them, and the difference a plain decent quality valve like a JJ makes over another decent quality valve like an Electro Harmonix in sound terms is very small.  And the classic old Mullards are not too much better.  This can be shown to be the case on the bench with high quality test equipment.

The level differences that test equipment can detect are thousands of times smaller than anything your ears can.  If you can't measure it you can't hear it, if you can genuinely hear it you can measure it!  Mojo is at best engineering that the person with the Mojo hand does not understand yet, or at worst a total myth given the situation.  There is very little that we do not understand now about the causes of how a guitar amp sounds and that info isn't in the heads of your average guitar tech who still works from the same industry myths handed down for the last 50 years, (nor is it all in mine but I at least do have a background where I understand the issues and a lot of experience which parallels this one).

And before anyone gets on their high horse and upset I do not mean that all techs are thick!!!!  The good ones are highly skilled and knowledgeable individuals in a particular role, to know the models they will encounter and to understand how they go wrong and how they best complement each other.  They have no need to understand how and why they were designed in a particular way.  Some go on to take in that aspect of course, but in my own experience too few have a modest view of their limitations in that area.  That is why in other areas of electronics the engineer designs and the technician maintains, building is a grey area between them and they respect each others areas of expertise.  (Only it doesn't seem to work like that in the music industry. )

To lay this one to bed for a while, if you haven't already read this, have a look at VoodooJeff's comments regarding his using a set of hyper galactic dark matter infused string theory implementing valves he had the opportunity to get his hands on.  GM36 Valve Swap Discussion: Start at post No.122 and read on from there for a while what Jeff says about his Wathens, (individually priced $1684 per set, knockdown bundle bargain price $1179).

I am with you re the Valves, the biggest difference I made was swap out my speaker on my TM112 from the Vintage 30 to the Celestion Gold.

At the end of the session when the guys where clearing up I opened the amp up (volume wise) and played a number of presets, the sound was very impressive.

I just need to work at the levels and make sure that I have optimized the presets for each track we play and as you've stated at the volumes expected of that preset.

By and large I still am hugely impressed by the amp, it does offer some improvements in functionality to the Mesa LSS (if not the immediate clarity of tone), but then again I don't have to haul about a two tonne weight with me...

Well, on my accounts the bank I programmed at home with 4 different presets sounded wonderfully at rehearsal, and we play at high volume... Still had to tweak a bit of EQ and gain, the same going for FX levels, but I was indeed surprised.

I finally decided on the small board for rehearsals and small gigs: a Stagg UPC-688 pedalboard (had one before, a bit flimsy but I'm careful with all my gear), the CAE MC404 wah on the left, the FSM MkIII on the center top, the Korg Pitchblack Poly tuner on the center bottom, and a Fender FVP-1 voume pedal on the right. Chain will be Guitar-->Volume Pedal--(Tuner Out) Korg Pitchblack-->CAE MC404 wah-->Amp input. The FSM MkIII will be used just for preset selection.

Have to agree with BordonBert, the have does have a steep learning curve, especially for one used to Marshall and Carvin valve amps and Line6 modellers. To find out how gain and volume controls interact with both EQ and power amp controls (Presence and Resonance) is a chore, but I'm getting awesome results.

As some of you may know, I have issues with my WMI-1 (whereby in standalone mode the wifi signal it distributes is showing a performance enhancement is required, talked to H&K who advise a replacement).

Anyhoo, with this winging its way to Germany for replacement, I am forced into using the amp without the presets.

I have to say this in itself is a revelation, I was lazily trying to make each of the presets fit my various guitars with varying degrees of success.

I would recommend to anyone, in order to get to know how this amplifier works with your own guitar(s), play with the basic amp settings yourself.

I am getting stunning results with all my guitars now, from my Fenders (Jag, Tele, Strat) to all my gibsons (SG, Lucille and LP).

I think I was suffering from tone blindness (didn't want to say deafness there)... So, up front spend time with the amp before getting lost in the 90 or so presets.