Mark series amps lead tone comparisons criticism: can we really?

[FedWar]

I currently have three IIC+, mark IV rev A , 1978 mark I , loop modded mark IIB , quad + 295.
I've had and sold: mark III red stripe, mark IV rev b, JP2C, triaxis, studio preamp etc...

I have an amp and cab switcher, so I did numerous A/B comparison with the head I've mentioned.

Long story short: the IIC+ is the most coveted mark amp because of its 3D feel in the room, and how it responds so well to your guitar.

Followed by mark IV rev A and IIB loop modded. the 1978 mark I is fantastic for vintage tones since it is still retains the same 3D magic.

This is not a matter of GEQ, or settings.

 

[tbonesullivan]

I currently have three IIC+, mark IV rev A , 1978 mark I , loop modded mark IIB , quad + 295.
I've had and sold: mark III red stripe, mark IV rev b, JP2C, triaxis, studio preamp etc...

I have an amp and cab switcher, so I did numerous A/B comparison with the head I've mentioned.

Long story short: the IIC+ is the most coveted mark amp because of its 3D feel in the room, and how it responds so well to your guitar.

Followed by mark IV rev A and IIB loop modded. the 1978 mark I is fantastic for vintage tones since it is still retains the same 3D magic.

This is not a matter of GEQ, or settings.

Do you think part of that is due to the transformers used, or due to having the fully adjustable volume 1 control, which isn't present on the JP2C?

I will say that on my Mark V, the Mark I mode on Channel 2 is the one I feel is the most "responsive" and really able to make me feel connected to everything. The only other time I have experienced this is when I got to try an original JTM45, at "stage" volume. It was like I was part of the amp.

 

[Nandrewjackson]

I wonder if a variac could help ? Lol

 

[rarebitusa]

I currently have three IIC+, mark IV rev A , 1978 mark I , loop modded mark IIB , quad + 295.
I've had and sold: mark III red stripe, mark IV rev b, JP2C, triaxis, studio preamp etc...

I have an amp and cab switcher, so I did numerous A/B comparison with the head I've mentioned.

Long story short: the IIC+ is the most coveted mark amp because of its 3D feel in the room, and how it responds so well to your guitar.

Followed by mark IV rev A and IIB loop modded. the 1978 mark I is fantastic for vintage tones since it is still retains the same 3D magic.

This is not a matter of GEQ, or settings.

Yea the IIC+ certainly has something special, over the years I've tried to put my finger on it but maybe it is the 3D effect that sets it apart. I feel the III has many of the same attributes just a bit different gain voicing depending on the stripe.

I do find the GEQ just opens up the tonal options and shapes voicings but agree it's not the reason for it's mojo.

 

[Henz]

Hello everyone,

this post is to give you my comment on Mark amps lead tone comparisons and to hear the same from you.

I recently acquired a Mark V 90W head. In the past I tried a Mark V:35 combo, a JP2C, a red stripe Mark III combo and I also had a Triaxis for some years.

I have both read and watched a lot of Mark series amps comparisons and, owning one now, I feel the urge to share the following thoughts.

When comparing lead channel tones, you can often read descriptions like “nothing beats a Mark IIc+” or “the Mark III tone is the best” or “the Mark IV was the best”. And you can actually watch/hear some comparisons where you can indeed spot some differences (not always a “better” or “worse” difference, by the way).

Now, we all know that the graphic eq in the channel 3/lead tone of Mark amps is the real tone-shaper, because of its very late position in the preamp circuit. We also all know how touchy those sliders are, with a little movement going a long way in changing the final tone. I fine-tuned a lead tone that I love, using it, and if you’re reading this and own a Mark amp, you probably did as well, and took pictures/note of the “magic setting” for your setup.
But whenever I move the graphic eq sliders to try something different, I will never get the EXACT tone back, when I put the sliders in the previously dialed position. Although the new tone is still in the ballpark (probably ear adaptation plays a role as well), because of this I am actually scared to move them for whatever reason, and scared when I see my 3-years-son getting by it…
Now, if I cannot really dial my amp back exactly, after moving those powerful eq controls, can we really trust comparison videos or, even worse, written comparisons of experiences with different Mark amps but in different configurations (head + cab vs. combo), different eq sliders resistance tolerances, different speakers, different places, different times, maybe different guitars? Do you always hear your tone the same from one day to another? I don’t! Sometimes it’s gorgeous, sometimes it’s just ok, sometimes it’s so so. Our mood, and maybe room humidity/temperature and AC voltage variations in our houses probably play a role, too!

So, after I finally got my Mark V, and having a lot of fun with the channel 3, I am very very skeptical I can miss anything from a real IIC+ or III or IV that a millimeter movement of the graphic eq sliders can’t achieve!

Just my two cents, of course!

Giulio

I completely understand. I thought that I was the only one who experiences these inconsistencies. Drives me absolutely crazy. I get an awesome tone one night, don't want to power down, knowing that it won't be there next day. Yep, sure enough, right on cue.

 

[bandit2013]

If it dramatically changes that much, it could be something with the amp. I would hope it would be tubes as they can be replaced. If it is voltage from the wall outlet, the next question would be does it seem to occur at a specific time of day? If there is that much drift in the voltage level, it may be related to how much the utility is loaded due to excessive usage. The infrastructure is in need of upgrading especially in areas that have seen a recent boom in development.

It could be a number of things really. May not be the amp or anything else.

 

[bandit2013]

Ok, Fine, if you want to call me a troll go ahead. I did not single anyone out as a troll, so sorry if you felt targeted.

Variac or adjustable transformers will still transfer line voltage fluctuations. They are helpful in keeping the higher voltages at bay but will just mimic the changes in the input voltage as they are just another form of transformer. Dropping the voltage to a lower value, basically much the same thing that variac power does as it is already built into the amp.

A regulated power supply will do the job, that takes the line voltage, converts it to DC then approximates a sinusoidal voltage at a well regulated frequency. May need to add in some filtering unless that power supply was an expensive one or specifically design for Audio equipment. The industrial types that I am familiar with typically run from $3000 up to $30,000 if not more. However, I have seen some for guitar equipment at a more reasonable price.

https://furmanpower.com/products/p-2400-ar?_pos=2&_psq=p-24000&_ss=e&_v=1.0

 

[Henz]

Ok, Fine, if you want to call me a troll go ahead. I did not single anyone out as a troll, so sorry if you felt targeted.

Variac or adjustable transformers will still transfer line voltage fluctuations. They are helpful in keeping the higher voltages at bay but will just mimic the changes in the input voltage as they are just another form of transformer. Dropping the voltage to a lower value, basically much the same thing that variac power does as it is already built into the amp.

A regulated power supply will do the job, that takes the line voltage, converts it to DC then approximates a sinusoidal voltage at a well regulated frequency. May need to add in some filtering unless that power supply was an expensive one or specifically design for Audio equipment. The industrial types that I am familiar with typically run from $3000 up to $30,000 if not more. However, I have seen some for guitar equipment at a more reasonable price.

https://furmanpower.com/products/p-2400-ar?_pos=2&_psq=p-24000&_ss=e&_v=1.0

Dang! A bit pricey for me but I need something like that. Maybe some day. I currently use a Furman Pro Factor R. It supposed to keep amperage in store for things plus filtering. I think its just all hype what I have. I A, B it with a very low end Furman. I can't hear any difference. To do it right, I think one has to take your advice on the higher end products.

 

[bandit2013]

Dang! A bit pricey for me but I need something like that. Maybe some day. I currently use a Furman Pro Factor R. It supposed to keep amperage in store for things plus filtering. I think its just all hype what I have. I A, B it with a very low end Furman. I can't hear any difference. To do it right, I think one has to take your advice on the higher end products.

I have only seen them used on rack mounted setups. A few members make use of such as I have seen them on their rig posts. I can see needed one of those power regulators for use with gigs and shows and that sort of thing. There are other regulators from Furman. I did not realize I picked one that was on the high end. The regulators will cost more than the conditioner types. Also depends on the Amps of service it can provide. The 15A version is lower in cost than the 2400.

https://furmanpower.com/products/p-1800-ar

I just use a Furman Power strip that eliminates line transients. PST-8. Nothing Special. It will not regulate voltage levels so whatever shift may occur in the line voltage, the amp will see that too. Power strip is just a sacrificial lamb to take the hit during any power surges, spikes or other damaging transients that can happen. Rather blow out a power strip than the gear connected to it.

If the amps change is that dramatic from one day to the next. If you have any other amps that do the same thing, I would assume it is power related which would require some sort of fix to regulate and condition the line voltage source for the amps. If it is just related to the Mark V90 in general, that would sort of point at something most people tend to forget, the Rectifier tube. Considering I have a MWDR and Roadster, never had issue with the Rectifier tubes with those. I do not recall if I ever changed them either. Mark V90 on the other hand, I have gone through a few. How can this affect things? it is in the circuit at all times, the silicon diodes run in parallel to that one rectifier tube. They wear out just like any power tube and need replacement.

If you are in a pinch, you can remove the rectifier tube if you only use 90W or if 45W keep the two toggle switches on the back panel for CH1 and CH2 set to diodes. Do not use the 10W power mode. Not sure what would happen if you removed the rectifier and then used the tube tracking on CH1 and 2 in 45W mode or decided to change to 10W power. I personally would not run the amp without the Rectifier tube installed.

I do not recall when I had issues if it was causing tone shifts though, Most of the time it would just short out and blow the fuse. Typically shift in tone or character from one day to the next, I would lean on that being the age of the tubes. If it still occurs after replacing with new tubes it would possibly indicate some other issue is happening, it could be leaking power caps (leaking meaning they are not storing energy like they used too). Caps age over time too, but only happens when you run the amp as it is the thermal change on the cap that results in its degradation. If they are leaking fluids (electrolyte), that is a different problem, could be related to overheating and failure of the pressure relief seal. Not sure if the Mark V90 has been plagued with bad caps or what their lifespan is relative to other amps made the same year. Some of the discussion above seems to be indicating tubes reaching their EOL as they can do some interesting things before they red-plate or fail to operate properly. This includes the rectifier tube, that can affect the DC power of the amp, resulting in lower output of the power supply which in turn will alter the tonal characteristics of the amp in general.

I get it, had that experience before, (tone shift or character one day is different than the next time I powered it up). It was mostly tube related than anything else. Not saying I disagree with line voltage issues, humidity, barometric pressure or any other influences that could result in change in an amps performance from one day to the next. Perhaps one could dig into relative humidity as playing a key role in change of tone or performance. There is more merit to that and I will explain next.

 

[mkVplayer]

https://reverb.com/item/4146822-fur...ator-for-rack-mount-system-m8xar-proaudiostar

ART used to make one that was considerably less $ but it’s now a “legacy product”

 

[bandit2013]

For those who do not understand relative humidity thinking it cannot affect the tone of an amplifier. It can. I doubt the air density in the environment if indoors is that dramatic but sure it can affect how sound travels in the air and humidity can play a part on that to some extent. However, there are other aspects due to humidity one cannot ignore.

Just for S&G's I assume that most have guitars made of wood. Either painted in solid colors, clear coat over fine decorative woods, in many different types of compounds from nitro to polyurethane. Some guitars may just be raw wood or have a light covering of tung oil finish. Wood is one of those hygroscopic materials that can and will be affected by relative humidity. On damp days you may notice a slight change in the guitar's resonance, it may sound dull or bland. In very dry days it resonates quite well and sounds really good. If you live in humid areas, probably a good idea to put your axe away in its case, add a desiccant pouch into the accessory cavity in the case and close it up when done playing for the day. Sure, things may have come a long way with some technologies like carbon fiber reinforced necks and different coatings. That is fine for the wood and stability of the main materials. However, what about the electronics of the instrument? not all control pots are sealed. They can and will be subject to humidity just like everything else. Not all resistive elements are created equal, those too can have hygroscopic properties. If they absorb moisture from the air, do not expect its resistive element to remain the same as it was under dryer conditions. OK, this is just the instrument, so what about the amp?

How many control pots are on it? They are not sealed pots either, some may be flux-tight (keeps out some moisture and dust) but they are not hermetically sealed controls. Now we add in the 5 sliders for the GEQ. Do they have a carbon element, cermet or are they conductive plastic? Carbon composition resistive elements are susceptible to moisture. may not be a hygroscopic material like wood but the resistance will change due to the presence of moisture. Cermet materials are superior as they are not affected by moisture exposure. they are a ceramic with infused metals. They are more expensive than carbon composition types. Conductive plastics, depends on construction of the resistive element. Some may use carbon and others have some sort of infused metals. In short, some potentiometers can be affected by humidity. To what extent? hard to say. Sure, when you are running the amp, things get warm or even hot enough to evaporate any moisture that may have settled on the parts when cold. Just so you know, when the amp is shut down, things cool off and will reach equilibrium with the room air. If those surfaces are at a temperature below the dew point of the air mass in the room, you will have condensation on those surfaces.

OK, that may make some sense. However, it does not explain why the JP2C and Mark VII do not seem to be affected as the Mark V90 was in the same room at the time I was comparing them. Sure, some things did seem a bit different than say the day before. Should I have left the amp to warm up longer before pushing the electrons? One also has to consider that the pots and sliders do not have dry elements, they are lubricated with some sort of grease. Does humidity affect electronics, it can but doubt it is a major issue unless the everything is well saturated with condensation. Perhaps it is probable but not always the case.

Ambiant temperatures would probably affect the amp from the start, Depending on how cold things are at time of power up, it may take a bit longer for the tubes to reach their operating temperatures to maintain electron emissions. Then there is the vacuum integrity of the tube to consider. So how do they wear out? When the plate surfaces get hot, they can outgas any trapped compounds, that shiny getter flash is there for a reason, to absorb any gases formed from the hot plates to maintain the vacuum of the tube. They can only absorb so much before that reactive barium becomes an oxide and sluffs off like snow inside the tube. That is just the nature of tubes. Then there is the nickel materials of the cathode to consider, is it plated nickel or is that a nickel tube? Depends on how cheap manufacturing has made them. The heaters can also weaken over time, their thermal efficiency will degrade and if the vacuum is not maintained, they will not heat up to proper temperatures. Sure, what makes the tube amp sound so good can also has its disadvantages when those components begin to reach their end of useful life.

So, all of this blah, blah, blah, does not provide a set answer to the question as there is no single simple answer to give.

I can see the point. The GEQ circuit can be an issue at times. Once you set it and then change to try something else, it can be tricky to get it to the same exact position that gave you the sound you liked the day before. Probably why I sold the Mark III, not an easy amp to dial in and if you bumped the controls, it would take a long time to find that sound again. What made the Mark IV a better amp, separation of the lead channel. What made the Mark V even better, complete separation of the three channels. That feature is also there with the JP2C and the Mark VII, even the MWDR, Roadster, Triple Crown.

 

[bandit2013]

What I wanted to say originally before this thread went on the deep end.

The basic mark lead circuit has remained very much the same since the IIC+ came out. Some variations on that circuit may have combined the two triode gain stages into one tube location and then the design shifted back to separating the two triode gain stages to separate tubes. Not much has changed in its characteristics over the years. Some amps may have a brighter tone, some are darker toned. That may be a factor of the power amp section when comparing the differences between the DRG (Simul-Class) to the HRG, SRG and KRG (Class AB). Not sure if they had a KRG that combined simul-class and 100W of class AB at the same time. The power section does have an impact on tone and gain characteristics. I went from the Mark III, to the Mark IVB, then to a Mark V90, then to the JP2C and now the Mark VII.
I still have the Mark V90 and JP2C. I did have a few issues with the V90 so I retired it for now and will deal with it later on when I feel up to digging into the issue. I would like to get it to perform to its standards. May be easier to dump it and get another one.

The GEQ circuit was just as temperamental as the Mark IVB, Mark V90, JP2C and the Mark VII. Perhaps when that amp was new it did not seem to be that much of an issue. It did become problematic over time. Either the faders were noisy or it had what seemed like dead spots but that may be more or less due to wear of use, I sold it after 24 years of use. I can find some of that same characteristic in the JP2C between the two GEQs. The Mark VII are much newer so I have yet to get to that state. I am bad with my gear as I do not cover it up all the time. By the time the amps cool down, I forget to put the covers on them. Not sure if that would make much of a difference.

If you are having issue with the GEQ not behaving the way you want it too, try a digital GEQ in the FX loop. Since you can bypass the GEQ with the footswitch, having one in the loop can also provide a wider range of tones. Source Audio has a digital one (EQ2), and the Boss EQ-200. The boss unit has sliders but they are used to set the digital parameters that can be stored, much like the Source Audio unit. I have the Boss EQ-200. It works great. However, it does not have the same frequencies as that of the GEQ on the mark amps. The Boss has ±15 dB boost/cut where as the Source Audio is ±12 boost/cut which is closer to the Mesa boogie 5 band GEQ pedal with the ±12dB boost/cut. I do like having the ability to store the settings digitally for recall as that is a huge bonus. No need to mess with the sliders unless you want to do so. The boss unit is compatible with instrument level up to +7dBu. The Source Audio is +8dBu max, the minimum was not specified.

 

[user 83127]

What I wanted to say originally before this thread went on the deep end.

The basic mark lead circuit has remained very much the same since the IIC+ came out. Some variations on that circuit may have combined the two triode gain stages into one tube location and then the design shifted back to separating the two triode gain stages to separate tubes. Not much has changed in its characteristics over the years. Some amps may have a brighter tone, some are darker toned. That may be a factor of the power amp section when comparing the differences between the DRG (Simul-Class) to the HRG, SRG and KRG (Class AB). Not sure if they had a KRG that combined simul-class and 100W of class AB at the same time. The power section does have an impact on tone and gain characteristics. I went from the Mark III, to the Mark IVB, then to a Mark V90, then to the JP2C and now the Mark VII.
I still have the Mark V90 and JP2C. I did have a few issues with the V90 so I retired it for now and will deal with it later on when I feel up to digging into the issue. I would like to get it to perform to its standards. May be easier to dump it and get another one.

The GEQ circuit was just as temperamental as the Mark IVB, Mark V90, JP2C and the Mark VII. Perhaps when that amp was new it did not seem to be that much of an issue. It did become problematic over time. Either the faders were noisy or it had what seemed like dead spots but that may be more or less due to wear of use, I sold it after 24 years of use. I can find some of that same characteristic in the JP2C between the two GEQs. The Mark VII are much newer so I have yet to get to that state. I am bad with my gear as I do not cover it up all the time. By the time the amps cool down, I forget to put the covers on them. Not sure if that would make much of a difference.

If you are having issue with the GEQ not behaving the way you want it too, try a digital GEQ in the FX loop. Since you can bypass the GEQ with the footswitch, having one in the loop can also provide a wider range of tones. Source Audio has a digital one (EQ2), and the Boss EQ-200. The boss unit has sliders but they are used to set the digital parameters that can be stored, much like the Source Audio unit. I have the Boss EQ-200. It works great. However, it does not have the same frequencies as that of the GEQ on the mark amps. The Boss has ±15 dB boost/cut where as the Source Audio is ±12 boost/cut which is closer to the Mesa boogie 5 band GEQ pedal with the ±12dB boost/cut. I do like having the ability to store the settings digitally for recall as that is a huge bonus. No need to mess with the sliders unless you want to do so. The boss unit is compatible with instrument level up to +7dBu. The Source Audio is +8dBu max, the minimum was not specified.

You are equivocating....and I have been stating that I DID have the same issues and the same suppositions....what is so hard to understand that I put a Variac in the line THREE years ago( maybe two)...and my problems have all gone away as far as inconsistency.... I AM SICK OF BEING TOLD I AM STIUPID ON HERE>>>I AM NOT>>>AND MY RESULTS ARE REAL>>> and frankly no skin off my back that you dont listen...but the fact is if you REGULATE LINE VOLTAGE AT THE WALL>>>TO A STABLE NUMBER YOU WILL LOSE ALL THE INCONSISTENCY! I know a Variac is TONS OF MONEY>>>I MEAN>>>I think I paid 45 for mine!!!! (I turned on my rig today and this AM had a reading of 114...on a variac that is adjusted daily to 119 at power on and 117 when the standby switch is off (yes you will drop two voltage points taking it off standby..) AND...the line filtering you speak of isnt necessary until you add effects with the V...they have a gimmick in the amp to filter noise...and I have found that a Keeley Compressor plus has a noise filter in it...it took away all the garbage just putting that in my setup!!!(noise from the cables and effects loop). ALL i have done here is TRY an tell people how to get rid of inconsistency in their amp and what I GOT was told I FLUNKED HIGH SCHOOL MATH>>>WHEN IT DOESNT ENTER INTO THE SUBJECTIVE EXPERIENCE>>>ONLY THE EXPLANATIONS EVEN GOT THERE AND MAN>>>THE **** YOU GUYS CALL SCIENCE?!?!?!!?..HUMIDITY AFFECTS YOUR EAR HOLES>>>PATHETIC!!!! (I said what humidity affects and the fact you took it the place you did WAS SO IMMATURE....HUMIDITY EFFECTS THE GUITARS WOOD>>THE WAY YOU HEAR>>>THE **** YOU WRITE APPEARENTLY, BECAUSE ONLY WATER ON THE BRAIN COULD EXPLAIN THE CONCLUSION THAT THE POWER FLUCTUATION ISNT THE ISSUE THE WATER IN THE AIR IS!!!!!!!! AND IF THAT IS TROLLING THEN TEACHERS OF THE WORLD UNITE ANFD TROLL THESE PEOPLE INTO SOME SEMBLANCE OF INTELLIGENCE!!!!

 

[bandit2013]

Not sure why you are so bent out of shape.

I will support your use of a Variac. If one has line voltage that runs on the high side, say 125VAC rms or higher, using a variac to drop that voltage to a more suitable range to keep it around 120VAC or a bit lower is a good thing to do. Based on other comments on voltage drift, meaning the wall voltage is shifting or dropping to a low value and then rises to a high level, that is not easily corrected with a variac. The amps's power supply is just a simple step up transformer with diode rectification dumping into large capacitors. There is no voltage regulation on that high voltage power supply. However, for the 24Vdc and 12Vdc circuits do have some voltage regulators used to keep them stable since the switch gear inside operates better with stable power that does not fluctuate.

Chill out dude. Nobody is calling you names or what you are claiming in your latest post or any of your posts.

If you want to experience line transients, come over and plug in at my house. Without the filtering I will hear pops every time the central AC unit kicks on. If the dishwasher was running, I would get the inverter noise from that through the amp. No effects used. I fixed that issue when the old dishwasher crapped out and replaced it with a new one. At least the electrical noise from that no longer poisons the line voltage. However, some people may have issue with line noise that may be from the community they live in and may not be directly related to the appliances in their own homes. Some old equipment may have been permitted and were not fully governed under FCC rules. Now they are which is mandatory. Line noise or poising is a major thing. I am in the industry and am aware of the requirements to meet FCC regulations regarding unintentional emissions/radiation of electrical noise. Filters become a need once you decide to do any recording. This issue affected all of my amps, more so with the Triple Crown amps than others. I even have one room I cannot run any guitar amps unless I like that noise, filter did not work much as power line to the air handler is below that room. I live in a rancher and the HVAC equipment is in the crawl space below the home.

I do not have water on my brain. When have I gone out of my way to post insults? Sure, I admit the Mark V90 is not my favorite amp. I have issues with it. That does not mean that others have the same problems. So why bash on an amp that was a disappointment to me if it is not a disappointment to others? I can easily slip down that road and rip on the Mark V90 why I hate it, why it is a waste of money. Why I have regrets ever buying it. I have played through other Mark V90's and they were ok, I could have replaced it with another one that was not an ice pick or power tube killer or one that burns out voice coils of the speakers you have plugged into the amp. No point in that. It is a lemon and I have delt with it and moved on.

Sure, humidity will affect how sound travels in the air, just as much as the air density (barometric pressure). When closer to sea level like the eastern side of NC, it is very flat, I would be surprised if my elevation is no more than 100ft above sea level. Where I used to live in PA, the mountains were at least 800ft above sea level, may have been more. Those who live in other areas may be much higher than that, like Denver Colorado. Talk about humidity, the east side of NC is mostly swamp land. It gets humid. Unlike coastal regions around the gulf, Houston Texas gets very humid, then we have the entire state of Florida. I deal with many contractors in those areas involving products for dehumidification especially related to fresh air ventilation. The tighter they make the homes for energy efficiency, the worse the indoor humidity gets due to occupancy and their activities. That requires the home or building structure to bring in fresh air from the outside, that will add to the indoor humidity and makes life unbearable. Combining fresh air ventilation with a dehumidifier unit is the solution but they do not want to spend the money on it. I want it cheap, cheap, cheap. Sure, hear you go, you can use an ERV (energy recovery ventilation unit) costs as much as a dehumidifier but does not remove as much moisture from the air.

If I was so brain dead as you claim, I would be in sales or perhaps the CEO of the company. I am an engineer who works on new products and provides solutions for customers so I am not that high in the organization, just your average pee-on mushroom in the dark room of despair. They sort of stuck me into being the ventilation guru at work but that is just limiting my skills. Yeah, I have water on the brain or I am brain dead as I am responding to you as you seemed a bit disturbed. From now on, I will just let it go. I don't really care. Still, there is no reason to get bent and throw out insults. It is not offending anyone. I do not see any posts that targeted a single individual except for yours.

 

[kingtone2017]

I am afraid this can be a rabbit hole with no end. I currently have a 50 caliber plus combo and a mark v 35 head and wide body 1x12.
Here are my thoughts.

1. If the 50 caliber plus (on lead channel) is on about 1-2 on master volume and the lead master is at 2-3 it is a snarling midrange harsh devil dog. There is almost nothing you can do to get it to settle down including eq use.

2. The mark v can be dialed to many different styles/sounds at any volume that sound good.

3. If I connect the 50 caliber plus to my UA OX and attenuate it, it can be an entirely different amp. Turn the master to about 4. EQ off. treble maybe 6-7, bass and mid 2-3. Input gain can be anywhere from 6-10. Then it is a pretty ripping sound but not nearly as harsh...lots of sustain.

4. The mark v also comes alive even more and really sounds great when you get the master up to 5.

5. If I plug either into my cab without the OX and put them on those types of settings they really sound stellar. Basically no harshness can be pretty easily achieved. For reference I use a scumback speaker in my cab that is a little darker because I am a mostly fusion player and like that sort of thing. The caliber has a front mounted speaker and small cab size and IME that means really harsh and midrange - treble heavy. After a few different speakers in the small cab I know that the tiny cab is probably not to my taste.

They are different amps with different tubes, etc but when they are quite loud they do start to work in a more similar, and pleasing fashion.

 

[robvoyles]

I Cant' speak about humidity on sound but it does play hell on my guitar necks!! but i will tell you what a doctor told me about hearing, it changes daily. Fluid in my ears were driving me crazy, but anyways she said the average person will hear differently from one day to the next based on many factors going on in your ears, brain, etc...But i can say having all of the mark III stripes, IIC+, Mark 5 they are all so close, there is no drastic tone, character difference between all of them. I can make my III's Sound pretty much the same as my IIC+ with a bit of EQ changes and it doesn't take much tweaking. using a variac my sweet spot is 86 volts. it just smooths them out and lowers the volume a bit. What will make a HUGE difference is speaker changes and tube changes. But comparing with the same tubes and speakers, they are all so close to one another. just my experience with my amps.

 

[DrKev]

But it doesn't change the FACT that humidity has an impact on the travel of soundwaves which in turn can affect what we hear coming out of an amp. Pick up a book some time

Physicist here. When someone says "this effect exists!", the question to ask is not only "is the effect real?" but also "under what conditions is the effect size large enough for us to care?"

Yes, humidity affects sound. High humidity air conducts sound better than lower humidity air, contrary to popular belief. i.e if you shout from a boat on the Atlantic ocean people will hear you further away than they would if you shouted in the Sahara desert. The size of that effect is frequency dependent; in the Sahara desert your voice would sound somewhat darker/muddier at distance compared to the same distance on the Atlantic. The size of that effect is also dependent on the distance the sound travels; the farther we go from the source the darker your voice will be. This is why thunder is rumbly from miles far away but a sharp crack up close.

So, let's use some actual data. Say I'm 100ft from a noise source and I measure levels of 1 kHz and 4 kHz signals at 90% RH, what would I measure at 20% RH? From 100 ft away, the 1 kHz signal will be down about 0.06 dB, i.e. virtually unchanged, and the 4 kHz signal to be down about 1.7 dB. But how often are you 100 ft from your amplifier? Through 10 ft of air we'd get 1/10th of that, i.e. about 0.17 dB difference at 4 kHz and it's not even measurable at 1 kHz. And this is kind of a worst case scenario; we rarely see such a drastic change in humidity. Clearly, we already don't care.

Also, (and relevant to the original thread topic) it is impossible to make precise comparisons from memory of sounds that are separated in time by more than a few seconds. This called "echoic memory". Even the time it takes to switch a cable from one amp to another is too long. Minute-to-minute, hour-to-hour, or day-to-day comparisons are useless for all but very large changes. Doesn't matter if we're talking about humidity or variacs, voltage, tube rolling. Also doesn't matter *who* because all human beings are subject to this.

This is why scientific audio tests involving humans judging tonal quality need pre-recorded, loudness-matched, blinded audio comparisons. Under those conditions, the best most experienced ears (probably not you or I) can hear MAYBE 1 dB difference in certain isolated frequencies. Re: humidity changes, we'd need more than 50ft of air between us and our amplifiers to hear that and only in the context of comparing pre-recorded A-B testing.

In other words...

We really don't need to care!

Yes, humidity affects sound propagation BUT the effect size is too small for any of us to perceive with out amplifiers on a day-to-day basis. Just forget about it and move on.

Pick up a book some time? Well, I did.

 

[bgh]

Physicist here. When someone says "this effect exists!", the question to ask is not only "is the effect real?" but also "under what conditions is the effect size large enough for us to care?"

...
Also, (and relevant to the original thread topic) it is impossible to make precise comparisons from memory of sounds that are separated in time by more than a few seconds. This called "echoic memory". Even the time it takes to switch a cable from one amp to another is too long. Minute-to-minute, hour-to-hour, or day-to-day comparisons are useless for all but very large changes. Doesn't matter if we're talking about humidity or variacs, voltage, tube rolling. Also doesn't matter *who* because all human beings are subject to this.
...

This is why when I am trying to dial in something new and I want to keep comparing settings, I record some licks onto a looper and then let the looper drive the setup. I found that when I played a lick, then stopped to change a setting (turn up treble, turn down gain, ... whatever), I would start playing again - and be unable to remember the first sound. Using the looper to drive it, I can change a setting back and forth (if need be) to catch any nuances.