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Double Bass Class D "digital" amps. DB player Opinions on performance
- Thread starter bryanspkr
- Start date
A number of lightweight bass heads use the IcePower modules from Bang & Olufsen. What makes that interesting is that B&O publishes quite detailed data:
Link Removed
For the 50ASX2 module (in one popular bass head), an output impedance of 0.018 Ohms, when driving a 4-Ohm load, is a damping factor above 200. Thus it would be my guess that the differences you're hearing are elsewhere than damping factor or cone control. In fact, the most significant factor limiting cone control in a typical system is the series resistance of the voice coil.
If two amps sound noticeably different from one another, I'd start with looking for differences in preamp voicing.
I own two "micro" heads. They sound great. I'm never going back.
Link Removed
For the 50ASX2 module (in one popular bass head), an output impedance of 0.018 Ohms, when driving a 4-Ohm load, is a damping factor above 200. Thus it would be my guess that the differences you're hearing are elsewhere than damping factor or cone control. In fact, the most significant factor limiting cone control in a typical system is the series resistance of the voice coil.
If two amps sound noticeably different from one another, I'd start with looking for differences in preamp voicing.
I own two "micro" heads. They sound great. I'm never going back.
Thanks, Just what I am looking for. My only experience was with a Hypex power amp with a heavy toroid and an AI, using the same preamp. A huge difference. I though maybe it was an input impedance problem, but my experience with Home audio says no. To me it sounded like a lack of control.
Maybe this consideration of what components are in an amp can give a clue to which "micro heads" can handle rough and more reactive loads
Maybe this consideration of what components are in an amp can give a clue to which "micro heads" can handle rough and more reactive loads
I played SWR and GK amps for several years...there was a thickness of sound that I don't find in my micro amps. I've been using AI and EA for the past few years and don't plan to go back to conventional amps...much easier for doubling with their neutral EQ. I rarely tweak more than a tiny bit of tone controls now, while I'd been doing more EQing with my conventional amps. I actually appreciate an amp without an enhance/scoop knob. It's more than just the weight difference!
From what I can gather by perusing schematics, the SWR and GK are both scooped, even when the scoop control is disengaged.
Ana, if you're using the same preamp, then you're already ahead of most of us in terms of doing a controlled experiment.
I've watched the development of switchmode amplifiers for quite some time, hoping to maybe understand them well enough to design my own someday. That's a fleeting hope. But it seems that there have been a few "generations" of switchmode amps where the main trend is to increase the open loop gain and tighten up the feedback loop, making them hopefully behave more like ideal amplifiers. Some of the earliest designs were feedback free. Another trend is that some of the micro head makers who originally rolled their own designs are now using buy-in modules, and vice versa.
I'd be surprised if the Hypex module were problematic, as Bruno Putzeys is considered to be a guru.
Ana, if you're using the same preamp, then you're already ahead of most of us in terms of doing a controlled experiment.
I've watched the development of switchmode amplifiers for quite some time, hoping to maybe understand them well enough to design my own someday. That's a fleeting hope. But it seems that there have been a few "generations" of switchmode amps where the main trend is to increase the open loop gain and tighten up the feedback loop, making them hopefully behave more like ideal amplifiers. Some of the earliest designs were feedback free. Another trend is that some of the micro head makers who originally rolled their own designs are now using buy-in modules, and vice versa.
I'd be surprised if the Hypex module were problematic, as Bruno Putzeys is considered to be a guru.
I absolutely love the Hypex, but its was so freakin heavy.
It actually had a moveable 24dB/octave X-over, moveable to 300Hz. I built a system with 6 Volt B250.2's and 1 Lowther. My reference system. Well it was anyway. I was pestered to sell it and it was too big anyway. Sold it for an enormous amount.
Ana, if you're using the same preamp, then you're already ahead of most of us in terms of doing a controlled experiment.
I've watched the development of switchmode amplifiers for quite some time, hoping to maybe understand them well enough to design my own someday. That's a fleeting hope. But it seems that there have been a few "generations" of switchmode amps where the main trend is to increase the open loop gain and tighten up the feedback loop, making them hopefully behave more like ideal amplifiers. Some of the earliest designs were feedback free. Another trend is that some of the micro head makers who originally rolled their own designs are now using buy-in modules, and vice versa.
I'd be surprised if the Hypex module were problematic, as Bruno Putzeys is considered to be a guru.
It was the AI power amp that was problematic.
I've had a Walter Woods amp since 1980. With my bass, strings, and current pickup, I'm able to get a very warm sound, with lots of clarity, and punch. Gallien Krueger amps used to have a very nice pre amp for DB, but years ago they abandoned that design to help sales in the EB market, IMHO. The older Woods amps only had a SMPS, the power amp was analog. Coupled with that pre amp, they sound amazing. So you can get a great sound and lots of volume from a Class D, but it comes at a pretty high price. Euphonic Audio's Doubler is certainly affordable. Personally, I feel that it's a tad underpowered. Just my take though
Ric
Is the OP implying that class D amps are digital? They are not. Amplifiers have different class ratings such as A, A/B, C, H, and so on.
I own a class D stereo power amp and couldn't be happier. It has more than enough power which is better than not enough. My tone comes more from my bass and preamps (which I set generally with flat) and by the way I play than the amp itself.
I own a class D stereo power amp and couldn't be happier. It has more than enough power which is better than not enough. My tone comes more from my bass and preamps (which I set generally with flat) and by the way I play than the amp itself.
Bryan,
If you're speaking of a MB200 they are similar sounding, but not the same. The MB500's and 800's have a lot of other pre amp circuitry that IMHO gets a different sound. I have an 200RCB ( the head only version of the 200MB) it's shockingly big compared to the 200MB because the power supply had to be moved up with the pre amp. Both the 200MB and RCB are analog amps.
Ric
Class D amps are a much debated topic.
IMO the lines of digital and analog are blurry in class D. I believe there is a difference in digital data flow vs digital function.
The Truth About Digital (Class D) Amplifiers — Reviews and News from Audioholics
http://www.talkbass.com/forum/f15/micro-bass-heads-why-doesnt-everyone-use-them-853646/
I owned a TC Electronics RH750 and to me it really altered the envelope of my bass by squelching out my fretless nuances. I returned the amp within a week of owning it. Although it did have other strengths, I need an amp that does it all!
I am not completely against class D, but for me, I am still waiting for the tone and musical characteristics to evolve to match my tube pre/toroidal power hybrid amp!
PEACE
IMO the lines of digital and analog are blurry in class D. I believe there is a difference in digital data flow vs digital function.
The Truth About Digital (Class D) Amplifiers — Reviews and News from Audioholics
http://www.talkbass.com/forum/f15/micro-bass-heads-why-doesnt-everyone-use-them-853646/
I owned a TC Electronics RH750 and to me it really altered the envelope of my bass by squelching out my fretless nuances. I returned the amp within a week of owning it. Although it did have other strengths, I need an amp that does it all!
I am not completely against class D, but for me, I am still waiting for the tone and musical characteristics to evolve to match my tube pre/toroidal power hybrid amp!
PEACE
Greg Clinkingbeard
Commercial User
I owned both for a bit and although I like the micro, the 400RB ate it for lunch. It went much louder and just sounded bigger. The MB200 is a nice sounding head within its limits but I can hear the compression kick in before noon and the amp is worthless beyond 2:00. However, I sold the old brick because a 400RB weighs 14lbs which is quite heavy by today's standards.
The MB150s is rated at 90 watts into its 8 ohm speaker and still sounds beefier to me than the MB200 into my MBX. I don't understand the science of it but it seems to me there's no substitute for iron and capacitors.
Sure, there's a tradeoff but I'm still firmly in the class D camp.
Did you ever compare the mb with the other heads into the exact same speaker? The problem too is the different voicing even when the frequencies are the same. In the case of the 150, not the same freqs. And forget about where things lie on the dial.
