agedhorse

2 hours ago, Beedster said:

If price is set by the dealer, are you suggesting a conspiracy among dealers in Europe who all agree to set the price at around £500 above the USA level?

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Mmmm, that's not really what I was asking though is it?

 

You asked if I was suggesting a conspiracy, that's EXACTLY the question I answered.  Was there a different question I missed???

12 hours ago, Beedster said:

If price is set by the dealer, are you suggesting a conspiracy among dealers in Europe who all agree to set the price at around £500 above the USA level?

No, that is not what I am suggesting. We do not dictate in any way the selling price of the product.

I certainly understand the challenge with pricing, that's something that is set by the dealer selling the product which we have no say in. 

There sure appears be a lot of negative comments and speculation here on this side of the pond about an amp that you guys have never even played. Not sure why, but here's a video from a player in Germany who spent some time and effort to create something that might help you understand this amp a bit more:

1 hour ago, Frank Blank said:

Heft is a subjective term, not something inherent in the equipment (fnar) otherwise there would be a heft pot on amps. Until someone comes up with a definitive answer backed up with physics it's subjective, like me saying my amp has floral notes and fruity undertones, this may be the case for me but be experienced totally differently by someone else.

This description has an element of truth to the broadly interpreted description of heft IMO.

When I try to translate the term heft into an amp design, I think it's in part a combination of texture and voicing combined with the particular tastes of the individual user. This is why some players will say (for the same amp) that it has "heft" while other players will say it doesn't. Everything needs to be taken in the context of the player's entire rig, speakers, instrument, pick-up system/set-up, playing style and the music style that the rig is being used with. It's much more complicated than a simple black and white description IMO.

Sorry, but I'm afraid I have some bad news for you here. The WD-40 is one of the substances that I have confirmed through lab testing will damage your pots and will also migrate over the surface of the high voltage PCB and can cause additional problems there. WD-40 has no business inside ANY amp, especially one with high voltages present.

Yes, I handle the factory authorized service for your amp here in the states, but by doing what you have to your amp, the cost will increase well beyond the simple flat rate charge that it would otherwise cost because I won't touch it without replacing all the pots and removing and properly cleaning the high voltage PCB of residue. Because of this, I think your otherwise economical to repair amp is probably going to cost more than you can get a good used one for once shipping is involved. 

Why won't I repair it without doing the additional work? Because the repair won't be stable enough for me to have confidence that there won't be additional problems cause by the WD-40 down the road. Sending the amp back for the additional repairs would be impractical, and I don't want there to be bad feelings that could have been otherwise prevented.

44 minutes ago, Al Krow said:

Very helpful thanks, although my experience is just of a very articulate and clear amp with a great tone! 

A question you may not be able to answer: - given that production of these (lovely!) amps ceased in May 2017, I'm a little intrigued that they continue to be available "for order" from certain UK retailers!

Is that just a case of Mesa slowly unloading surplus stock they have hidden away in their stores?

I see that the UK prices have of new amps, if anything, gone significantly higher than before production ceased (whilst the used market for Mesa gear seems to be languishing) - which could be explained by scarcity, although on the other hand 'end of line' gear is more usually discounted.

I suspect the reason is that a few old stock amps that may have been ordered before the end of production may still be in warehouses, I seriously doubt that it more than a VERY small number. For overseas orders, there can be a significant time lag between the time a product is ordered (we typically build to order), the time all of the items on a shipment are ready to ship, the time for shipping, clearing customs, any additional in country safety testing and certifications, delivery to the distributor, then to the dealers can take 6 months or more depending on the country and how many different products are on the shipment. They have not been available from the factory in over a year.

Hope this helps with the confusion.

3 hours ago, Al Krow said:

Thanks very much for that. So I think for my simple head it's correct to think of the M6 as being a single 12Ax7 valve preamp + AB class poweramp (and certainly not a D class power amp).

When you say "aggressive nature" of the Carbines (which is of course very much in keeping with its machine gun branding!) what are you particularly referring to?

Is the new WD-800 similar sounding?

Yes, more or less correct.

The aggressive nature of the carbine series (and carried forward in a different texture with the Prodigy/Strategy) is in part the voicing (mid forward, brash, with a bit of a bright edge to it) and in part the tightness, in keeping with the image of the guitar amps that were popular (Recto series) as the focus at the time they were designed are more towards the harder, heavier styles of music. The distortion generated when overdriven fit well with that kind of music.

The WD-800 is closer to the Walkabout than the Carbines, the Walkabout is more laid back, especially that later ones, in the high end, a bit understated, with a rounder, looser low end. There's a bit of politeness present in the Walkabout that set it apart from many of the previous Mesa heads. The WD-800 is similar to the Walkabout in that it's a little more polite than the carbines, but it's a little brighter than the WA, and where the WA had a wooliness and a looseness that could be difficult to work with in a gigging situation and had significant limitations with regard to power (which could not be scaled up), the WD-800 addressed this with a lot more power, a little tighter (though some of this is selectable through the damping feature), greater articulation and forwardness. 

Hope this helps.

2 hours ago, thodrik said:

Agedhorse will know more than me, I am pretty sure that the Trans-class Mesas (the M3, M6 and M9) have a single tube in the Pre amp section and the power amp is entirely MOSFET based. This is opposed to the 'Simul-state' Mesa's like the original Walkabout and M-Pulse Line which I believe used valves along with MOSFETS as part of the power section. The Simul-states like the Wakabout were designed to behave similar to an all valve amp. I think that the voicing of the Carbine series was designed to be a lot cleaner with lots of articulation with a more immediate response. This means that the M6 will have huge amounts of clean headroom and you won't lose any definition while you turn up the Master volume.  
 

Trans-Class is simply the way the solid state class AB output stage is driven and how the global feedback is configured as compared with say the Walkabout, which is similar totally different.at the same time. The aggressive nature of the Carbines is as much the preamp's native voicing and how the gain stages interact as it is power amp based.

1 hour ago, Al Krow said:

Speaking of legacy amps, I managed to get myself a Gator GRB-2U rack bag for my M6 (for around £40 from G4M). Hoping it will sufficiently protective and let me "get away" with not getting one of the heavier plastic cases. Am looking forward to using the M6 with the band for the first time...  

Don't drop it in either the bag or the plastic case. It's heavy enough to rip the folded aluminum rails right off the rack.

10 hours ago, wateroftyne said:

Yeah.. I paid top-whack for me brand-new 600 back in the day (they just didn't exist on the used market), and while it was beautifully built and featured, and LOUD, when I realised it didn't have 'it', I had to sell it and lost a fortune. I always regretted that.

Incidentally, the other amp along these lines that I did love was the Genz Benz GBE600 (which I assume Agedhorse had input into). That was just as nice, but for various reasons I had to let it go.

Correct, the GBE-600 was one of my projects.

For those of you complaining about legacy products being discontinued, and especially where these products are available on the used market for a fraction of the original cost, go out and buy your favorite legacy amp right now at "bargain prices". I don't see how this is a negative in any way?

To clarify, there's quite a difference in feature sets between the D-800 and the D-800+, there are players who prefer the D-800 for the simpler user interface and smaller size and have no interest in the plus model. There are also users who find the added feature set of the plus model essential, especially the sweep highpass filter and 2 bands of seeep eq. Both models, while voiced between the Walkabout and the Carbine, are closer to the Carbine side of things. 

The WD-800 is based on the tube (valve) preamp of the Walkabout, has the original eq section along with the passive mid and modified tonestack voicing and power amp damping control that comes directly from what many players liked from the original Walkabout. This model is by necessity larger than the other two models, but is rack mountable whereas the others are not (without using a rack shelf).

Different players have different wants/needs, that's why we don't all play the same amp. If these amps don't work for you, then make a choice that's better suited for your needs. 

15 hours ago, wateroftyne said:

Hello Mr. Horse, and thank you for contributing.

To be fair to the previous poster, you might want to have a quiet word with your marketing department who don’t exactly hold back on the WA comparison:

You spoke, we listened. In direct response to player feedback and the longstanding demand for a more powerful version of our WalkAbout™ Bass Head, we’re proud to unveil the latest in the Subway® Bass Amp Line, the WD-800™ Head. This Head combines the warm, soulful sounding magic of the WalkAbout tube preamp section with the musical Class D Output Power used in our Subway Line (D-800™ and D-800+™), to create the ultimate lightweight hybrid.

I think that statement accurately represents the amp, and doesn't represent it as an identical yet larger Walkabout. It's very much related to the Walkabout, models many of the elements that players liked and asked for, but also intentionally avoids some of the things that were not liked (including the always present wooliness that got in the way of some clean players and the difficult to control (especially with some under-damped ported speakers) low end response that could quickly become too much of a good thing. The new model is a little bit brighter, closer to the earlier versions. Since this model had a close to 15 year lifecycle, there are some minor differences as the design evolved.

It's very much based on the original Walkabout (including much of the basic preamp circuitry), and since there were players who did not care for the Walkabout, I would expect the same for the new amp as well. Respectfully, that's why I suggest that conclusions don't get drawn based on guessing rather than actually spending some time playing it. If it's not your tone, that's fine too... there are plenty of fine options out there for bass players these days.

On 04/01/2019 at 10:54, Blues Marvel said:

Call me skeptical on this new amp.

So I kind of got off a Class D train here are some of my cons on the new WD amp

If you do the research and go back and look there are countless statements by the engineer that design this amp on the internet where he says they can never design and amp to sound like the Walkabout series it can't be done so now he wants us to believe he did it?

 

The WD Maybe a good I am but I'm sure it's not a walkabout in any shape or form then the other argument is the old Walkabout isn't loud enough and I've used mine and countless situations with two twelves at 4 on and it's freaking plenty loud for any imaginable situation unless you're playing arena games so I call BS on that one

Then there's the whole rated wattage of this amp notice they claim it's 800w but look at the THD it's at 10% Distortion which in my opinion is unusually high for a high-end piece of gear at 1% this is probably a 500 watt amp and that's just a guesstimation

 now here's the next question when is this amp going to be Obsolete and they're going to come out with a new improved version? This seems to be the goal of the day make these little small light way inexpensive to build products and a couple years down the road make them obsolete so everybody wants the new version I am off of that train

 

Since you are quoting me, and quoting me incorrectly, let me clarify what I have said and how the WD-800 came about.

I have said that it is not possible to design a higher powered Walkabout that sounds exactly the same as the original Walkabout because of the was the power amplifier works. The very benefit of it's dynamics is also the very thing that prevents scaling that design up to a higher powered yest otherwise identical Walkabout.

On Talkbass, a number of dedicated Walkabout devotees created a thread about where they would wish the Walkabout might evolve to IF there was a follow-up model, knowing that it wouldn't (couldn't) be identical. Players listed their likes and also their dislikes of the existing amp and what they would like to see changed or added to maybe make it better for players gigging out. Some specific changes that were asked for included a (much) quieter fan, aux input, headphone output, more power, a sweepable high pass filter, no pull-switch type controls and smoother operation of all controls. Of course they wanted to keep the tone and feel as close as possible.

The resulting amp is the result of a collaborative effort based on this player input which resulted in an amp that's quite close in tone and feel (but not identical) to the original WA but also includes enhancements that allow it to go to places that were simply impossible due to the significant limitations of the original model. If somebody really wants an original, there's nothing stopping them because they are readily available used. If the original Walkabout is loud enough for you, great, but you don't represent other player's needs anymore that they represent yours.

As far as the power rating, due to the way the preamp gain and driver stages are designed there is some distortion generated in the preamp proportional to gain/level that is almost the same as in the original Walkabout. At higher levels, that distortion is very much a part of what made the Walkabout popular and the WD-800 follows this signal path quite closely. The power amp itself (though it can not be accessed since the aux in and fx return are pre-driver stage) is capable of about 700 watts (RMS) at 0.1% distortion and about 750 watts (RMS) at 1% THD, though this is not how the amp is being used.

Why don't you reserve your comments until you get an opportunity to play one and spend some time exploring both its similarities and differences to the original WA?

The Focus and Contour cabinets are basically identical electro-acoustically, the cosmetics are different.

Should be close enough phase response-wise, but the voicing is somewhat different in the mids. Try it if you can to see if it works for you. Any extension cabinet you use with the Contour should be 8 ohms so you don't go below the minimum 4 ohm total impedance rating of the amp. The Contour cabinet part of the combo is 8 ohms.

Warranty policy from our website:

USA/Canada:  https://mesaboogie.zendesk.com/hc/en-us/article_attachments/216157588/US___Canada_Limited_Five-Year_Transferable_Warranty_for_Amplifiers_and_Cabinets.pdf

International:  https://mesaboogie.zendesk.com/hc/en-us/articles/218236347-Warranty-Information-Outside-of-the-USA-Canada

39 minutes ago, itu said:

OK, so if the amp has linear power, the situation is totally different than with switching powers? My understanding may be outdated, because SMPS has pretty much different behavior compared to linear, transformer-based supplys. I would say, that linear needs quite a lot of power to produce the claimed numbers - in RMS.

I have an old HiFi amp from the 80's that can push 2 x 110 W RMS continuous to 8 ohms (tested) and its maximum input power is 650 W. I understand losses and the power consumption of the other components, so the amount of input power makes sense. But if an amp says 1 kW and the input power is 200 W, I feel like I have fallen from the train. Sir, please, open up this a bit more; I do not have reasonable access to that standard, as it costs 300 € + VAT. Can this SMPS class-D amp push continuously 1 kW RMS to 8 ohms or not?

It's no different between a line frequency based supply and an SMPS (with a bit of a distinction for PFC based supplies).

It's all about total efficiency, the higher the efficiency the lower the input power that's needed to achieve rated power. 

Taking your hi-fi amp as an example, if it's rated at 110 watts/channel (RMS metrics), then it's going to be roughly 160 watts/channel at 4 ohms. The calculations would be as follows:

Total audio power at lowest rated impedance is 2 x 180 watts (total of 2 channels) = 320 watts. The NRTL agency testing power will be (320 x .125) = 40 watts total.  Say the efficiency is 35% for the amp and 75% for the power supply, the rated average power being drawn will be 40W/(35% x 75%) = 152 watts which is what the agency will be looking for as the "rated average input power".

There's another number that can be included, it was more often used on hi-fi and more commonly used a while ago, but that is "MAXIMUM" input power which is of little use unless you are operating the amplifier continuously with a sine wave signal (your speakers may not appreciate this).  Here, the calculations will be a little different in that instead of the 1/8-rated power specified by the safety regulations, you would use the total rated power at the lowest rated load impedance. Note that the efficiencies are typically higher in full rated power testing) In this case it would be ~320W/(45% x 85%) = 830 watts (this is higher than your given number, I suspect that my assumption of 4 ohm power is on the high side OR the amp is not rated for 4 ohm operation.

With class D, you can run the same calculation but substituting the average efficiency of about 90%, and with an SMPS the average efficiency is typically about 92%. Thus: 40W/(90% x 92%) = 48 watts rated average input power. 

There is not a "something from nothing" scenario here, it's all about how the regulations require that we state the input power, and in reality the 1/8-rated power is not too far off until we get into heavily overdriven or compressed tones where the crest factor (an expression of the ratio of peak to average content of the signal) decreases. IF the amp is designed specifically to support such operation, especially if it is advertised as such, the 1/8-power factor may be increased to more accurately reflect the expected operation of the amp. Note that different countries have slightly different requirements for testing and labeling (called "national differences", but this is by far the most common way it's done.

Hope this helps.

On 18/11/2018 at 00:01, Passinwind said:

In the US the unit's power consumption from the wall  figure is typically spec'ed at 1/8th duty cycle, although 1/4-1/3 is generally more realistic for rock or hard rock with some signal compression. You can easily confirm the relevance of this by recording some actual bass guitar playing and analyzing the crest factor.

Thanks Charlie!

On 19/11/2018 at 05:12, Count Bassy said:

With industial servo amplifiers (to drive motrors) you tend to get a specification such as  6 amps continuous, 18 amps absolute peak for 2 seconds, 10 amps for 10 seconds etc. and generally get some sort of graph showing current again how long it it will deliver it for. However it is all very complicated, for example if you've just used 18 amps for 2 seconds, how long before you can do it again? 

If after the first 18 amps for 2 seconds it goes back to zero then you might be able to repeat it after 4 seconds (i.e. the average over 6 seconds is the continuous rating of 6 amps).

If after the 18 amps for 2 seconds it drops back to 5 amps then you might have to wait 26 seconds before you could do it again.

It all comes down to "Duty Cycle", but it's all very complicated. With servo drives you tend to work out what you think it needs, add a bit for luck, and see how it goes. This is why a lot of industial motors and drives are over specified - i.e. it's cheaper to over spec it than to underspec it and have to replace it.

 

This is very much the same process that we use when designing amplifiers, developing the combination of load profile, driving signal and thermal conditions, integrating these factors over time. This was even more the case when designing linear amps when we had to worry (a lot) more about SOA (safe operating area). Class D amps are more forgiving in this area than linear amps due to cut-off/saturation operation.

On 19/11/2018 at 06:28, Chienmortbb said:

Peak of a sine wave is 1.414  x RMS and Peak to Peak is 2 x Peak.

 

 

While this is correct for voltage, it is NOT correct for power as you would be ignoring the squared factor in the power equation (P=V^^2/R)

On 10/12/2018 at 09:00, Chienmortbb said:

The only way to test and amp is into a resistive load and quote the continuous power (RMA amps x RMS voltage). That give s Average watts. Sadly some use RMS Watts. If you audition an amp or speaker it has to be against another amp/cab in the same room at the same time as our ears have no memory.  You may still get it wrong though as the room is a major component of your sound.

When RMS is used in describing power, all it means is that the voltage and current are based on RMS units, not that the power itself is in RMS units. It's a short-hand notation that's understood by most professionals in the industry and has been used for years.

On 17/11/2018 at 15:06, itu said:

One thing is this power taken from the mains. If the unit takes less than claimed, the unit should be able to produce this amount of extra power by itself. Got it? It should be able to create power from, yes, where from?

Does this serve us customers? I don't think so.

I think you are misunderstanding what the rated input power number means and why it's required of any amplifier that is sold in the EU, as it must be tested and certified to EN60065. This regulation specifies that the rated power input be based on a minimum of 1/8 rated audio power (in RMS units) at the lowest rated impedance. It can be higher than 1/8-duty cycle if the amp is specifically designed for this operation, and passes the tests accordingly (many do not, or the companies may choose not to test to extended duty cycle beyond the legally required 1/8-power which is 12.5%) Designers have no choice but to follow these regulations, they are regulations that the European countries have specified that we designers follow. If you don't like it, take it up with the authorities having jurisdiction in your region.

The reason for this extends all the way through the audio world, in pro audio for example, this number is used to assist in sizing branch and feeder mains circuits, environmental heating loads and such for installations where many amps may be installed. The same certification standard applies to bass amps.  This is a commonly misunderstood bit of information, if you wish to denigrate any manufacturer for using it you might want to understand more about what the number legally means first.

Once you understand what this number means on a product that carries an NRTL agency approval, you can then calculate backwards by using efficiency to discover the maximum rated power in RMS terms. 

I normally don't post here, but am available at TalkBass as many of you here already know.