Hi,
The hairy chested amps that are around, Krell, Pass, McIntosh and the like, cost thousands to buy and frankly it is hard to make DIY build that can compete.. particularly in the enormous power drive needed for proper bass. This is a pity because it somewhat defeats the object of DIY if you know that you are building second-rate gear… even if it is a bargain.
So, here’s my (current) idea. It is the ability to deliver heavy bass power that causes most amps to be heavy ( = expensive). Transformers, heat sinks and the like are not economical and for high-power they are high cost. These amps have the challenge of delivering massive bass at the same time as delicate mid and highs, sometimes a bit difficult. So, why not relegate the bass power to an amp design which you can buy off-the-shelf, economically and focus the DIY on mid-range to high frequency delivery? The bass-amp is a one-time purchase and reusable, unlike the (usual) situation when you make a DIY high-power amplifier.
It would mean an active crossover.. probably more general than the one I am planning for my JBL 4343s. The bass amp, providing it does not need to deliver over around 300Hz is relatively easy to get … see my Crown K2 amp at http://www.crownaudio.com/media/pdf/legacy/136713.pdf . This thing offers a damping Factor better than 3000 from 10 to 400 Hz! It delivers up to 800 watts per channel into 4 Ohms and can deliver 1250 watts into 2 Ohms. Hence it is unlikely to run out of steam. To match this with mid – high type of an amplifier I can probably get away with no more than 100 watts.. sort of Quad 405 style. This is well within the range of hi-end DIY and also makes the hobby quite economical as you do not need to invest in massive power supplies and heat sink. My K2 cost me around £500 a few years ago. The mid / treble is poor. The bass is of the bowel-moving kind. So maybe this is an approach that might work. It does mean that all my loudspeakers would need to be wired for bi-amping but that is not unusual at the hi-end and also not too hard to achieve. The necessary active crossover is another factor, but these things are not too difficult.. I only need a two-way in any case.
What do you think of this? For a long time I have felt that I am building second rate stuff.. especially when you see what Krell and Pass are up to in their production gear. This approach might be a DIY God-send ... and in any case, I believe that the ambience, imaging and detail so appreciated in the hi-end is largely in the above 300-Hz domain anyway.
This would mean that my DIY environment has speakers wired for bi-amping and reusable bass-amplifier, such as the Crown K2 and reusable active crossover(TBA. Right now I am using a JBL crossover specifically for my 4343s, but that is too narrow a restriction for the general use that I am proposing here).
My part, in the power-amplifier part of the hobby at least, is restricted to the mid/high frequency amplification. This is a relatively economical area to "play" in and avoids many of the high-power issues of full-range amplifiers. So, let’s leave the provision of the earthquake sounds to the professionals and focus where we get the most bang for the bucks as our US colleagues might say.
Any thoughts on this approach?
The hairy chested amps that are around, Krell, Pass, McIntosh and the like, cost thousands to buy and frankly it is hard to make DIY build that can compete.. particularly in the enormous power drive needed for proper bass. This is a pity because it somewhat defeats the object of DIY if you know that you are building second-rate gear… even if it is a bargain.
So, here’s my (current) idea. It is the ability to deliver heavy bass power that causes most amps to be heavy ( = expensive). Transformers, heat sinks and the like are not economical and for high-power they are high cost. These amps have the challenge of delivering massive bass at the same time as delicate mid and highs, sometimes a bit difficult. So, why not relegate the bass power to an amp design which you can buy off-the-shelf, economically and focus the DIY on mid-range to high frequency delivery? The bass-amp is a one-time purchase and reusable, unlike the (usual) situation when you make a DIY high-power amplifier.
It would mean an active crossover.. probably more general than the one I am planning for my JBL 4343s. The bass amp, providing it does not need to deliver over around 300Hz is relatively easy to get … see my Crown K2 amp at http://www.crownaudio.com/media/pdf/legacy/136713.pdf . This thing offers a damping Factor better than 3000 from 10 to 400 Hz! It delivers up to 800 watts per channel into 4 Ohms and can deliver 1250 watts into 2 Ohms. Hence it is unlikely to run out of steam. To match this with mid – high type of an amplifier I can probably get away with no more than 100 watts.. sort of Quad 405 style. This is well within the range of hi-end DIY and also makes the hobby quite economical as you do not need to invest in massive power supplies and heat sink. My K2 cost me around £500 a few years ago. The mid / treble is poor. The bass is of the bowel-moving kind. So maybe this is an approach that might work. It does mean that all my loudspeakers would need to be wired for bi-amping but that is not unusual at the hi-end and also not too hard to achieve. The necessary active crossover is another factor, but these things are not too difficult.. I only need a two-way in any case.
What do you think of this? For a long time I have felt that I am building second rate stuff.. especially when you see what Krell and Pass are up to in their production gear. This approach might be a DIY God-send ... and in any case, I believe that the ambience, imaging and detail so appreciated in the hi-end is largely in the above 300-Hz domain anyway.
This would mean that my DIY environment has speakers wired for bi-amping and reusable bass-amplifier, such as the Crown K2 and reusable active crossover(TBA. Right now I am using a JBL crossover specifically for my 4343s, but that is too narrow a restriction for the general use that I am proposing here).
My part, in the power-amplifier part of the hobby at least, is restricted to the mid/high frequency amplification. This is a relatively economical area to "play" in and avoids many of the high-power issues of full-range amplifiers. So, let’s leave the provision of the earthquake sounds to the professionals and focus where we get the most bang for the bucks as our US colleagues might say.
Any thoughts on this approach?