Warwick BC combos

[heminder]

they recently re-did their BC combo line.
[url="http://www.warwick.de/modules/produkte/produkt.php?submenuID=14673&katID=24179&linkID=47449&cl=EN"]http://www.warwick.de/modules/produkte/produkt.php?submenuID=14673&katID=24179&linkID=47449&cl=EN[/url]

so what's the lowdown on these?
no reviews anywhere, just product demos.

[Leakim]

Here is one:
[url="http://kitarablogi.com/2012/03/06/review-warwick-bc-40-and-bc-150-bass-combos/"]http://kitarablogi.c...50-bass-combos/[/url]

[Warwick_Official]

The new line of BC combos has, indeed, had a total makeover. Extensive R&D was done in a joint effort between Celestion and Jonas Hellborg, and utilizes many features of the high-end Hellborg Amp line in its design. Its a very well thought-out design with special attention given to circuit and component layout, which results in a very musical sound with low noise and no hiss/hum. With its symmetrical circuit layout - meant to reduce resistance, create as low impedance as possible, and provide proper grounding, it creates less thermal noise and needs less filtering of high frequency feedback - which equals a more responsive and musical sounding amp. The box/cabinet size is matched to its specific driver, and great consideration was given to every detail - including box/cab material and covering material. They really sound incredible!

[heminder]

[quote name='Warwick_Official' timestamp='1338318760' post='1672749']
The new line of BC combos has, indeed, had a total makeover. Extensive R&D was done in a joint effort between Celestion and Jonas Hellborg, and utilizes many features of the high-end Hellborg Amp line in its design. Its a very well thought-out design with special attention given to circuit and component layout, which results in a very musical sound with low noise and no hiss/hum. With its symmetrical circuit layout - meant to reduce resistance, create as low impedance as possible, and provide proper grounding, it creates less thermal noise and needs less filtering of high frequency feedback - which equals a more responsive and musical sounding amp. The box/cabinet size is matched to its specific driver, and great consideration was given to every detail - including box/cab material and covering material. They really sound incredible!
[/quote]

is there a reason you guys went with Class A topology? it's rather old, and crossover distortion is pretty much a non-issue with modern AB designs. Class A also burns twice the energy that it puts out to the speaker, even when idle.

there's comments on the Youtube demos and Warwick forums that they are really quiet. what are the speakers in these? the BC-40's driver is rated at 89 dB SPL in its manual, which is pretty low. Andy Irvine and the reviewer in Leakim's link both had the amps past half way up.

[Warwick_Official]

[quote name='heminder' timestamp='1338484219' post='1675306']
is there a reason you guys went with Class A topology? it's rather old, and crossover distortion is pretty much a non-issue with modern AB designs. Class A also burns twice the energy that it puts out to the speaker, even when idle.

there's comments on the Youtube demos and Warwick forums that they are really quiet. what are the speakers in these? the BC-40's driver is rated at 89 dB SPL in its manual, which is pretty low. Andy Irvine and the reviewer in Leakim's link both had the amps past half way up.
[/quote]
Class-A amplifiers are typically more linear and, as such, less complex than other amplifier classes. The amplifying element is biased so the device is always conducting to some extent. This means the amplifier is always on, avoiding the problem of crossover distortion associated with class-AB and -B designs. [size=4][font=arial, helvetica, sans-serif][color=#000000]Distortion occurs when an amplifier works beyond its range, when the power supply cannot supply the power any more to take the amp higher. A common method to control distortion in amps is to use a limiter, a device that stops the signal going beyond a specific level. Audio limiters work by setting a threshold signal level where the circuit kicks in and keeps signal levels within the capabilities of the power supply. This method is not very precise and often causes audible effects such as pumping and thumps. Warwick designed a circuit that instead reads the distortion level in the power amp and starts limiting as soon as the amp shows even miniscule amounts of distortion. This means our amps always stay within 0.3% distortion (THD) when most amps are rated at between 5-10% distortion (that means that to get your 20 Watt out of a 20 Watt amp you will get it audibly distorted and if you want a clean signal the power will be a lot less).[/color][/font][/size] As a result of the extensive effort put into the circuit design and layout, the amps are very quiet in terms of hiss/hum. The speakers and cabinets are specially designed by Celestion and Jonas Hellborg to be responsive and musical, full frequency with lots of headroom, and without added noise. The BC combo amps were designed for a few target audiences: A beginners first amp, an experienced players "home" amp, a backstage practice amp, as a tool for teachers wanting 2 inputs as well as an aux in, and a small space rehearsal amp. Thanks for your question!

[heminder]

hmm. you just copy-pasted some marketing :\

[Warwick_Official]

Yes, most of the text above is from the write up we did. It makes sense without getting to technical, but if there is something else you'd like to know I would be happy to elaborate! If there are any specific technical questions you'd like answered I can ask Jonas Hellborg directly. I didn't play a role in the development, but have an in-depth knowledge of the amps themselves. Some of these points can get very technical, and I wanted to present information that can be easily understood. Just let me know, and I will gladly get any specifics you'd like.