Best Lightweight Head at 8 ohms

[KJung]

Ken, are you saying " nothing " about the GK and Carvin heads because of all the problems they have had initially, or have you actually tried both of these heads and dislike them for other reasons?

If the reliability isn't there, I have no interest even trying them. Been there, done that

 

[jnewmark]

I the reliability isn't there, I have no interest even trying them. Been there, done that

I drop in on the GK and Carvin threads once in awhile and it seems as if, at least Carvin, has addressed the initial problems, and nobody is complaining about the latest versions. The GK still seems to have some issues here and there, but have largely been addressed. What made you so sure that the TECAmp would'nt have problems? They are relatively new on the scene, no?

 

[agedhorse]

Please let me clarify some incorrect and misleading information that is being presented in this discussion. First of all, I am the engineer of record for the Shuttle and GBE products, so I am absolutely qualified to comment on the specifications and design intent of our products.

1. IMPO, the original testing methodology used for the "BGM" tests was so flawed as to produce worse than meaningless results. Line voltage must be held at 120 volts to produce the rated output, this is true (in general) of most amp products by most manufacturers. The problem with the tests is that the voltage drop is due to the current being drawn and the big (linear) amps that have no VI limiting will always draw more current and the output power will fall off by the SQUARE of the input power voltage drop. So, the bigger the amp, the greater the deviation (by exactly the square) between their measured power and the rated power at 120 volts. It was unfortunate that their technician did not appreciate the importance of the squared factor flaw in his test. Since the GBE-1200 was the largest amp tested, it showed the greatest deviation. I performed the testing on the same amp here at my R&D lab with proper equipment and found that it passed the power spec with no problems at all, and that IIRC the line voltage would have had to fall to roughly 109 volts to replicate their invalid data. There were also significant measurement errors that we discovered after the magazine was released that ANY engineer worth his salt would have seen as an impossible value, but the technician did not understand why the number didn't make sense. (extra credit... identify the flawed measurements). Also, you can not use purely distortion numbers for powet testing thresholds on musical instrument amplifiers because many of the functions inherent in tube amp stages and emulation processes generate harmonics. I wonder how an all tube amp would have faired in this test... probably not well because the base line distortion would quickly exceed the measurement cutoff threshold.

2. The power versus frequency test was so inaccurate and meaningless as to make me question what the tech was trying to quantify. The only thing this produced was a frequency response profile which matches the preamp's inherent voicing. The power amp delivers full rated power from 20Hz on up, and any (intentional) rolloff or boosts in the preamp would of course be reflected in the corresponding output levels of the power amp. This is how amps work, not rocket science. Additionally, the tech did not do this measurement with the LF extend filter engaged, which extends and alters the low frequency rolloff point down. This function (switch out) is useful for players who must tame challenging rooms or will be playing with compact cabinets and want to avoid overexcursion.

3. The limiting function was not engaged, and the tech did not understand one of the fundamental design features of the amp. ALL of my output limiters are multi-function in that they emulate how a tube power amp overloads from the gradual rolling into soft clipping and then a dB or two later (after about 3-6dB of input level) another transition as the power amp begins to actually clip. This is well described in the owner's manual but clearly not comprehended. This feature is something I have used in various forms for well over 20 years now. This function increases the area under the power curve (hence an increase in power) while controlling the addition of higher ordered harmonics. It requires a true RMS meter that looks at the real power, not based on an extrapolated sine wave conversion.

4. Regarding the way the Shuttle gain and volume controls work... the execution is exactly as we intended it to work and how most of our customers use it. The Shuttle 6.0 is not designed to do the heavy overdrive thing, the tube circuit gain is adequate to getthe tube flavor and mild grind from most pickups, and with higher output pickups it is certainly possible to get significant overdrive. If the heavy overdrive thing is what you want, use a booster (preamp) pedal with ~12dB of additional gain. The ShuttleMax has this additional gain built into the high gain switch function, so it's more appropriate (without a pedal) for getting the heavy overdrive thing going. The tapers for the controls is to allow a good feel and operating range with a wide variety of today's pickup levels.

5. The CLIP/LIMIT LED has 2 function, the first is to indicate that the player has crossed the threshold of the output tube emulation limiter and that there is roughly 6dB of compliance left before output stage clipping is approached. It is an INFORMATIONAL indicator so that you as a player know where you are operating the power amp before you run out of steam. IMO, it is an important and useful bit of information that if understood makes perfect and logical sense.

From my discussions with Tom and his new engineer, I understand that they too have determined that testing amps in a meaningful way is much more difficult than it seems on the surface and that they are in the process of reformulating thesting procedures and propocols. I have spent almost 30 years learning everything I possibly could about REAL WORLD amplifier performance and how each variable impacts the player and the tone. I also split my design projects between musical instrument amps and full-on pro audio products, so I have a pretty wide angle view of how things work. I ask that you all consider that sometimes reviews are not accurate for whatever reason, and testing errors and methodology affects every manufacturer differently depending on their particular design philosophy. By the way, it hurts me to see a competitor's product bashed in a review when it's basd on invalid or inaccurate testing methodology too. It's just not good for anybody, including you the consumer. Play as many products as you can and buy what works for YOU, even if it's not our product. That's ok, really

 

[pagiatis]

^That's a great and informative post.

 

[::::BASSIST::::]

You are in the minority here, but again, most have a clear favorite and they are both nice heads, and IMO both relatively unimpressive into an 8ohm cab.

+1

I owned the shutte 6.0 as well as my LMII (which I still have and still love) and from my gigging experience the LMII is noticeably louder. I also have tried them both with a UL115 (8 ohms) and I definitely felt the need for more power with the 6.0. With the LMII I had all the volume I could ever need, for my situation, with the same cab at 8 ohms.

IMO/IME they are both great amps, but the volume issue is one of two reasons I chose the LMII over the shuttle. The other reason is that the LMII does a much better clean/warm tone than the shuttle. But again the shuttle is no slouch and I hope to buy another one or another micro GB amp... if for no other reason than the customer service is simply unbeatable.

To the OP, considering your prefrences, if I were you I'd use the shuttle 6.0 as a pre with a power amp and call yourself done.... either that or pony up the dough for one of the shuttle max models.

 

[B String]

Ken, are you saying " nothing " about the GK and Carvin heads because of all the problems they have had initially, or have you actually tried both of these heads and dislike them for other reasons?

I'll volunteer my experience with these heads.
The first GK I had didn't sound right, and had other issues.
Got a second one. All my basses seemed to overdrive the
input, but when I put the 10db pad, I lost much of my volume.
Also, the GK MB500 just didn't sound as good as my old 800RB
or newer 1001RB.

The Carvin BX500 took a ton of eq to make it sound balanced.
Mine had a ground hum and something that would take away
volume intermitently. I sent it back to exchange for a non
broken head, but decided to just get my money back. Even
though I had to send it back anyway, (it was broken) they
decided to charge me $20.00 shipping.

The Acoustic Image Focus I that I have has the most 8 ohm
headroom out of the heads I've used. Maybe not the best
electric bass sound, (not bad) but it can also be used as a
power amp and weighs nothing.

I'm hoping Markbass has solved the headroom limiting issue
at 8 ohms I've had on the new LMIII. Markbass, for the most
part, seems to be the leader in the light weight catagory.

 

[KJung]

I drop in on the GK and Carvin threads once in awhile and it seems as if, at least Carvin, has addressed the initial problems, and nobody is complaining about the latest versions. The GK still seems to have some issues here and there, but have largely been addressed. What made you so sure that the TECAmp would'nt have problems? They are relatively new on the scene, no?

They've been around forever. Only the TecAmp name is new.

Regarding reliability, given past performance, I have pretty high hopes that Carvin will get the glitches out of their product if they haven't already. I am less than hopeful with the GK product and the new EA heads.

IMO.

 

[KJung]

The Acoustic Image Focus I that I have has the most 8 ohm
headroom out of the heads I've used. Maybe not the best
electric bass sound, (not bad) but it can also be used as a
power amp and weighs nothing.

+1 The Focus, just like the Walter Woods, sounds equally good when pushed at 8 or 4, I assume due to the very high power ratings which allow for adequate power at 8ohms so you don't get that limiter clamping on transients, etc.

I didn't mention that one since it wasn't on his list.

Of course, there is the TecAmp Puma1000, that puts out its full 1000 watts bridged into an 8ohm cab. That would do the trick also!

 

[KJung]

4. Regarding the way the Shuttle gain and volume controls work... the execution is exactly as we intended it to work and how most of our customers use it. The Shuttle 6.0 is not designed to do the heavy overdrive thing, the tube circuit gain is adequate to getthe tube flavor and mild grind from most pickups, and with higher output pickups it is certainly possible to get significant overdrive. If the heavy overdrive thing is what you want, use a booster (preamp) pedal with ~12dB of additional gain. The ShuttleMax has this additional gain built into the high gain switch function, so it's more appropriate (without a pedal) for getting the heavy overdrive thing going. The tapers for the controls is to allow a good feel and operating range with a wide variety of today's pickup levels.

5. The CLIP/LIMIT LED has 2 function, the first is to indicate that the player has crossed the threshold of the output tube emulation limiter and that there is roughly 6dB of compliance left before output stage clipping is approached. It is an INFORMATIONAL indicator so that you as a player know where you are operating the power amp before you run out of steam. IMO, it is an important and useful bit of information that if understood makes perfect and logical sense.

+1 to your point 4. The increased gain mode of the Max head makes the dual input gain controls more useful, and that execution seems very good and makes that second gain control more useful than on the original Shuttle IMO. It also makes a lot of sense to have that secondary gain control in a two channel amp like the 12.

And per your point 5, the rather unusual 'informational' nature of your clip light design seems not very useful IMO, but is a minor design issue to me. I understand the logic and I guess it is reasonable if again a bit unusual. Regarding power amp clipping, that's best left to the ears IMO, and in this day and age of safety limiting circuits, you will hear the amp compressing a bit as you get into the 'too much volume for the amp' anyway. So, I don't really see this as a negative. Minor issue.

 

[tombowlus]

We could revisit that but I got the impression that Bowlus himself finally admitted there were flaws in his testing that could explain the difference. The failure to account for power fluctuations being one. I encourage anyone reading this to go back and read the thread and see if you really think that the 1200 got a fair shake.

We have made some changes to how we test our amps in Bass Gear Magazine, and we do plan on retesting the GBE 1200 (and all the heads from issue #1).

For now, our new tests still rely upon unregulated power (as we do feel that most players in the field will not be plugged into a regulated power supply), and still rely upon a resistive load (I'd love to work in some reactive load tests, but they are very dependent upon the load used for the testing and may in some ways be more prejudicial than probative; but we are still working on this possibility).

The testing done in issue #1 was technically accurate, but other aspects of the test methodology were not as representative of what an amp in the field would encounter, and so we refined the tests in issue #2. And to be fair to the amps tested in issue #1, we wanted to retest all of them. This has not been finished yet, but when it is, we will publish all of the new data and results.

Tom.

 

[jnewmark]

It was'nt my intention to limit the discussion to just those 3 heads, that's what the " option " selection in the poll is for. Great responses so far, keep it going! And thanks to Agedhorse for chiming in, I hoped he would comment!

 

[tombowlus]

FWIW, I voted "other," but my vote was a very expensive one: the TecAmp Puma 1000, bridged.

 

[greenboy]

For now, our new tests still rely upon unregulated power (as we do feel that most players in the field will not be plugged into a regulated power supply)

I'll relegate my comments to this bit. As is always the case with ANY higher-rated power amp section, one has to be aware that local AC service and configuration may limit its output. But that doesn't always invalidate its advantage over a lower-power unit.

 

[tombowlus]

I'll relegate my comments to this bit. As is always the case with ANY higher-rated power amp section, one has to be aware that local AC service and configuration may limit its output. But that doesn't always invalidate its advantage over a lower-power unit.

Absolutely. And when you are playing on a gig without a regulated power supply, you should expect to experience this as well.

 

[greenboy]

Absolutely. And when you are playing on a gig without a regulated power supply, you should expect to experience this as well.

Or when just using good AC service. Some venues have it, after all ; }

 

[tombowlus]

Or when just using good AC service. Some venues have it, after all ; }

Yes, and we use a very good (but unregulated) AC source for our testing, and we now report the maximum voltage sag observed during the testing.

Tom.

 

[agedhorse]

I would like to comment that "technically accurate" and providing useful information to the intended user of the information are two totally different issues. You can be technically accurate but completely useless and (unintentionally) misleading when the information is not fully understood. It does everybody a disservice, both the readers and the manufacturers.

Anytime a complex subject is "translated", it better be done in a clear, unambiguous, and meaningful way or you can end up creating greater misunderstanding and confusion.

I stand by my recommendation that a regulated source is essential when comparing power output between various products. Since varying input voltage causes change in measured output, this is a critical flaw in a direct comparison between competing products IMO.

 

[tombowlus]

I would like to comment that "technically accurate" and providing useful information to the intended user of the information are two totally different issues. You can be technically accurate but completely useless and (unintentionally) misleading when the information is not fully understood. It does everybody a disservice, both the readers and the manufacturers.

Anytime a complex subject is "translated", it better be done in a clear, unambiguous, and meaningful way or you can end up creating greater misunderstanding and confusion.

I stand by my recommendation that a regulated source is essential when comparing power output between various products. Since varying input voltage causes change in measured output, this is a critical flaw in a direct comparison between competing products IMO.

I fully understand your position, and welcome your input. We may add a regulated AC test in the future, but it will not replace the "typical" AC test (with voltage sag reported). The two tests, taken together, would pretty helpful, I would think. But I do see some drawbacks to both tests (regulated versus unregulated power), if relied upon solely.

 

[B String]

FWIW, I voted "other," but my vote was a very expensive one: the TecAmp Puma 1000, bridged.

Oh mama, that's one impressive head. The Puma 1000 blew
me away at NAMM. It just killed. BUT!!!! Many many dollars.

 

[9mmMike]

My .5 cents....

If I needed a guaranteed regulated power supply for my amp to perform the way I expected, I'd buy a different amp. I cannot control that part (the power) of the equation but I can control my own gear.
If I were setting up a studio, that might be different.

Just my (very) simple opinion.