I'm having my first go at building an amplifier I'd like to build a power amplifier-I take it thats easier if anything than an integrated amp? Its to power a pair of older Acoustat electrostrostatic speakers that suck power like nothing else
so I was looking for recomendations for a simple kit or plan of a kit where I can buy the bits that has enough power to power the electrostatics
so I was looking for recomendations for a simple kit or plan of a kit where I can buy the bits that has enough power to power the electrostatics
You might want to go for an ICE power type amp kit if you need simple, powerful amps.
The following are just suggestions.
Monoprice Unity 450 Watt Bridgeable Power Amp - Monoprice.com
ICEpower 1000ASP Class D Audio Amplifier with Power Supply Module 1 x 1000W
Ghent Audio
The following are just suggestions.
Monoprice Unity 450 Watt Bridgeable Power Amp - Monoprice.com
ICEpower 1000ASP Class D Audio Amplifier with Power Supply Module 1 x 1000W
Ghent Audio
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Something to check on before going with an ICE powered amp. With the ICE powered amps I am familiar with the output impedance rises in the treble. Combine that with the falling treble impedance of a typical electrostatic speaker and you may find a lack of HF energy. I’m not sure if Acoustats have a falling HF impedance.
Used is another way to go when looking for an amp to drive a known demanding load. There may be known good pairings for amps with the Acoustat model that you have. The best choice could be an older high power amp with a proven track record.
If you want the latest in class D DIY try Purifi-audio.com. They make an evaluation board/kit that may be of interest. Not cheap, but SOTA performance. There is a thread on this amp running over on the class D amp forum.
Used is another way to go when looking for an amp to drive a known demanding load. There may be known good pairings for amps with the Acoustat model that you have. The best choice could be an older high power amp with a proven track record.
If you want the latest in class D DIY try Purifi-audio.com. They make an evaluation board/kit that may be of interest. Not cheap, but SOTA performance. There is a thread on this amp running over on the class D amp forum.
Electrostats have a very demanding impedance curve. Most have a very low impedance near resonance on the order of 1 Ohm. Check your speaker's impedance curve to see what load you will have. Due to the low impedance of mine, I built a pair of Pass F5 Turbo monoblocks. These work particularly well as they are capable of driving sub 1 Ohm easily.
Hi,
I wouldn't opt for a class D any more, apart if I knew I'd only listen to Rock/Pop.
Yes, they orovide for more than enough power and seem to control the stats very tightly, but any natural voice and instrument and classics sound sterile and lifeless.
They tend to form a resonant peak at the HF-end which can be as high as 12dB (if the output filter of the class D is not included in its FB loop) and might require equalization and that limits HF response.
Most ESLs drop to around 1Ohm impedance at the HF end, but that is typically no real issue for most amps, as the impedance is almost real here and not much power is required. Much more stressing for the amp are the phase shifts in the upper midrange/lower highs region.
Due to their segmented design and lossy audio transformer quality the Acoustats present a relatively easy to drive imdepance response on one hand, but due to their inefficient design they require comparatively lot of power.
As kit or module I often recommend the L12-2 from LJM (on taobao, ebay, etc) which not only performs with utmost stability into ESL loads, but also sounds very well and doesn't become grainy as so many other global feedback amps do.
You needed to test if its 100W suffice or if the Acoustats really need more.
Its a misbelief though that ESLs require much power ... they do require stable power.
jauu
Calvin
I wouldn't opt for a class D any more, apart if I knew I'd only listen to Rock/Pop.
Yes, they orovide for more than enough power and seem to control the stats very tightly, but any natural voice and instrument and classics sound sterile and lifeless.
They tend to form a resonant peak at the HF-end which can be as high as 12dB (if the output filter of the class D is not included in its FB loop) and might require equalization and that limits HF response.
Most ESLs drop to around 1Ohm impedance at the HF end, but that is typically no real issue for most amps, as the impedance is almost real here and not much power is required. Much more stressing for the amp are the phase shifts in the upper midrange/lower highs region.
Due to their segmented design and lossy audio transformer quality the Acoustats present a relatively easy to drive imdepance response on one hand, but due to their inefficient design they require comparatively lot of power.
As kit or module I often recommend the L12-2 from LJM (on taobao, ebay, etc) which not only performs with utmost stability into ESL loads, but also sounds very well and doesn't become grainy as so many other global feedback amps do.
You needed to test if its 100W suffice or if the Acoustats really need more.
Its a misbelief though that ESLs require much power ... they do require stable power.
jauu
Calvin
+1 with Calvin's response. My best audio friend went through 2 different Acoustat models (IIRC) and he used a Krell 100 W amp. After the Krell's were stolen, he got a pair of 2nd-hand Van Den Hull monoblocks, and they work a bloody marvel. We once tried my Bedini 25.25 on the Acoustats and apart from runing out of grunt they had a wonderful sound. I'm driving my stacked ESLs with the Bedini, but they are not power hungry like the 'Stats. My experience with all ESL speakers to date is to rather stick with a Class-A amp. My two cents worth. Kevin
How does the L20 from LJM rate into ESLs (Martin Logan Sequel IIs)?
The darlingtons (mj11015/6)on my Virtuoso power amp have failed and I'm considering replacing the amp boards for something more modern and better than the Virtuoso.
The power rails are +-56v dc with a separate regulated supply for the low power gain stages.
To put it into context, it's current build it is better than a rotel rb-991(more air and detail) and recently caused a friend to upgrade his Naim 140s. I haven't had the chance to compare it with anything else recently. My friend was supposed to bring his naim 250? over but covid got in the way....plus I blew my amp up
Alternatively I could consider alternative better darlingtons or mosfets (the amp was also designed to allow mosfets RFM10N15/P15 to be used with the removal of some parts and adding gate resistors.)
Any advice or suggestions appreciated.
The darlingtons (mj11015/6)on my Virtuoso power amp have failed and I'm considering replacing the amp boards for something more modern and better than the Virtuoso.
The power rails are +-56v dc with a separate regulated supply for the low power gain stages.
To put it into context, it's current build it is better than a rotel rb-991(more air and detail) and recently caused a friend to upgrade his Naim 140s. I haven't had the chance to compare it with anything else recently. My friend was supposed to bring his naim 250? over but covid got in the way....plus I blew my amp up
Alternatively I could consider alternative better darlingtons or mosfets (the amp was also designed to allow mosfets RFM10N15/P15 to be used with the removal of some parts and adding gate resistors.)
Any advice or suggestions appreciated.
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