Oh yeah, that's actually the amp I would buy with this budget. I haven't heard it in action, but I love the basis of the design and feel confident that they pulled it off. Weird that I recommended the amps I have instead. :stupid: :thmbsp:
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Best high current amps in the 2-300 watts catagory
- Thread starter Isotonic
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sonix
Well-Known Member
I agree with automojo. Harman Kardon really does it for me. I got rid of my Yamaha PC 2002 which is a good amp but I got 4 HK 775 mono blocks and had them moded to where they are doubled up for each channel. In other words 2 mono blocks per side. I asked the tech to do a bench test for power and they benched 625W per channel into 4 ohms! My AR 90 have never been so happy. I mean I had a few defferent amps driving my AR 90 and some sounded better than other, but these HK mono block just do it right. I also have the HK PA 2400 which was mentioned and it does a very nice job at driving my AR 90's at only 170w per channel. The only region it slightly lacks is in the sheer base, but we are comparing 625w vs. 170 and it still does it right. The HK is very accurate, high current, ultrawide bandwidth, low negative feedback amplifier design. Anyway I am done looking for power amps, these HK's just simply do it for me. Some people like hafler, yamah, and etc., Hk's just do it right for me.:thmbsp:
SoCal Sam
Lunatic Member
we'll just agree to disagreeI could easily see a $600-$700 amp with a $1500+ preamp. Is just me though.
While not really "advertised" as a high current amp, my Spec 2 has yet to falter on anything, tho the only 1 ohm load it has seen is in the 18-20khz range.
I have also read many reviews on really hard to drive speakers, like the Quad, and the Adcom GFA-555 is usually mentioned as an amp that can handle the hard load and those can be found very inexpensive, tho they do need re-capped if not already done.
If you got any of the amps already mentioned in other posts, they should do the job.
Some may disagree, but I will throw in the Carver TFM-45 and TFM-55. The argument against these will be they don't handle a 1 ohm load well, BUT, for most speakers, especially most esl speakers (magnepans are actually not hard to drive, just give them lots of power) they are dipping down into 1 ohm at frequencies where there just isn't that much energy. It is usually in the 3.5-4.5 ohm range when they get into the funky phase angles that the amp had best be able to handle it - and the TFM-45 and TFM-55 should handle that with no problem. I personally like those amps and can be found relatively cheap for the power they have.
Sorry, even the best preamps can add something to the signal path. Variable output sources are the cleanest when driving the amps directly. The only time I use a preamp is for phono.
jn229
Super Member
My brother in law has a high power amp. A Peavy 3800; DJ power amp with almost 1000 watts. This has to be one of the best kept secrets in audio. Driving Gallo's 3.1; the sound is warm, extended and rock solid. Out worked a Bryston 4**. Your price range new, comes with clipping and short out protection.
If your not satisfied it will hold its value and sell used.
If your not satisfied it will hold its value and sell used.
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TejasRichard
Babies taste of chicken..
Then you are stuck using whatever DAC is included with your player. If you like it, fine..if not, you're stuck, or you buy a preamp. Not to mention the inconvenience, for a lot of folks, of not having source switching. Or the anecdotal accounts of the positive effects a good pre has on soundstage. I'm not saying your way is wrong...but it is not right, either. It is right for you, and that is cool. That does not mean it is right for me. There are plenty of people who have tried the direct source-to-amp route that have gone back to using a preamp, and not all if them did it for convenience. I believe marcmc has talked about his experiences with this a few times before.
Wow 625wpc!-awesome!:thmbsp: I agree the PA2400 lacks on bass compared to my H/K 1.5-but again there is quite a bit of reserve difference between the 2. The 1.5 seems only limited by how much curretn your wall socket can supply.
I have looked into the 775's in the past-looks like I should look a bit harder!:thmbsp:
avguytx
Lunatic Member
Ok.....I'm curious as to how this was done. Were they "sync'd" together in some fashion? When I was the rep for Rockford Fosgate, they had mono block amps that could be "strapped" together with a connecting cable that sync'd the power supplies and made it so one amp was the positive side of the waveform and the other was the negative. Just curious if this was done in some similar way....would be very cool for sure to know what was involved.
TejasRichard
Babies taste of chicken..
You can do this with some yamaha preamps. They have 2 sets of outputs, one is normal, the other is inverted. You can even do this to use both channels of a 2 channel amp as a monoblock. The user manuals show you how to hook this up correctly.
sonix
Well-Known Member
I basically copied the amplification of a tech. that has this set up in his house. He is actually an authorized carver repair service shop. He said he compared the HK mono blocks with many high name brand/power amps that cost thousands and the HK's always sounded better to him. I would not be surprised. At one point I will have him completely restore the mono blocks. He said that they should last me my whole life time or at least his lifetime.
I am done looking for power amplification, unless it's HK.
sonix
Well-Known Member
I don't know how the tech. did this mode but it cost me a bit. In the end what you pay for is what you get. I know it wasn't that simple he had to open them and move some stuff arround. He also had to cut in an RCA jack to use for the preamp on two of them. Basically what he told me is that one mono block is amplifying the negative half of the wave and the other is amplifying the positive half of the sine wave. Also I have a copper wire jumper between the negative terminals on each set. Instead of using 8 output power transistors in each channel, now it's 16 output transistors per channel, which is double obviously. And also an RCA jumper between the two.
This would explain why his set spanks most of the highly praised amps. The whole secret is in that HK used quite a bit of scientific research when they designed their amplifiers. In fact they hired Dr. Matti Ottala to help them develop their circuit topology. I don't want to go off on a tangent on this thread but now my little secret is out and I hope the priced don't start running up!:tears::thmbsp:
Also I recently got a new HK receiver, HK 3490 and I must say sonically this unit has spanked every vintage receiver I ever owned, and I had many. Very good phono section in this unit. I just wish HK would start producing amplifiers and mono blocks again! Read up on Dr. Matti Ottela and (TIM)
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budgetaudio6
Addicted Member
Is it any wonder i enjoy my HK HT AVR 146? BOTL though it is. It kicks serious hiney! Very clean aand can get loud as all frick!
hatrack71
distracted by everything
we'll just agree to disagree
While not really "advertised" as a high current amp, my Spec 2 has yet to falter on anything, tho the only 1 ohm load it has seen is in the 18-20khz range.
I have also read many reviews on really hard to drive speakers, like the Quad, and the Adcom GFA-555 is usually mentioned as an amp that can handle the hard load and those can be found very inexpensive, tho they do need re-capped if not already done.
If you got any of the amps already mentioned in other posts, they should do the job.
Some may disagree, but I will throw in the Carver TFM-45 and TFM-55. The argument against these will be they don't handle a 1 ohm load well, BUT, for most speakers, especially most esl speakers (magnepans are actually not hard to drive, just give them lots of power) they are dipping down into 1 ohm at frequencies where there just isn't that much energy. It is usually in the 3.5-4.5 ohm range when they get into the funky phase angles that the amp had best be able to handle it - and the TFM-45 and TFM-55 should handle that with no problem. I personally like those amps and can be found relatively cheap for the power they have.
The Quad is not a difficult speaker to drive being a 16 ohm load (ESL-57). They are actually meant to be run with the Quad II amps at 16 watts each. The problem arises when these are pushed over their 50 watt limit and begin to clip and ARC ( DEATH TO THE AMP). The Quads are not a loud playing speaker like a horn speaker and should never be pushed in that manner. Listeners need to realize that or they will keep burning up their electronics. I've never had a problem with mine with any amp I've used on them. You just have to know when to say when.
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hatrack71
distracted by everything
I basically copied the amplification of a tech. that has this set up in his house. He is actually an authorized carver repair service shop. He said he compared the HK mono blocks with many high name brand/power amps that cost thousands and the HK's always sounded better to him. I would not be surprised. At one point I will have him completely restore the mono blocks. He said that they should last me my whole life time or at least his lifetime.
I am done looking for power amplification, unless it's HK.
Yes H/Ks kick some serious ass! I have had the 430, 730, Citation 12, Citation 19 and Citation 16. Currently I have 2 Citation 16Bs I am trying to restore. The build quality is very good and the power supply is dual mono and huge. Especially for it's 150 watt/ch rating. Lifetime keepers and becoming fairly scarce- just ask me how easy it is to find cosmetic parts.
charles 1973
Super Member
I have a retired Audio design PA100 Power Amp Designed and assembled in Canada 1n 1979 that safely drives a 2 ohm load. It's a 100 wpc amp with 2x - 3x the heat sinking of my bryston 100 wpc Integrated, and a Beautiful Tube like warmth. It' got enough current that in bridged mono mode mine tested at 375 Watts at 8 ohms. It can still drive a 4 ohm load even bridged! While it does'nt have the soundstaging, or the sharp imaging of the bryston in stereo mode, it gives up nothing else, including the great bass from the bryston. It's my guess a pair of these picked up on the internet, refurbished with matching components and used as mono blocks would sound great. I just don't need that much power. The thing weigh's 35 lb. its got a big Iron core Transformer and main caps siightly smaller than coke cans. I shot circuted the speaker terminals once and when the arcing stopped, it continued to play music as if nothing happened. When I did that to my AVR it shut off, flashed lighs and would'nt power up for 20 min.
OBTY I believe most bryston Amps and many other good amps are meant to operate safely down to 4 ohms, maybe 3 for brief periods, that should cover 90% of the most popular speakers out there. If you know your speakers have an unusauly low impedance (I've seen some that dip to .7 ohms) than keep that in mind when buying an amp, or use different speakers. There are a ton of great speakers out there that don't dip bellow 4 ohms.
OBTY I believe most bryston Amps and many other good amps are meant to operate safely down to 4 ohms, maybe 3 for brief periods, that should cover 90% of the most popular speakers out there. If you know your speakers have an unusauly low impedance (I've seen some that dip to .7 ohms) than keep that in mind when buying an amp, or use different speakers. There are a ton of great speakers out there that don't dip bellow 4 ohms.
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whoaru99
Epic Member
From a technical standpoint, it's not the positive and negative half of the waves that are amplified separately when bridging (or in a balanced amp), a whole wave is being amplified in each amp it's just that one is a normal wave and one is an inverted (think morror image) wave.
When the two waves are recombined, the peak of the normal wave and peak of the inverted wave coincide with each other in opposite polarities thus the voltage is 2x what either wave is on its own, hence more power. In theory 2x voltage is 4x power but since few amps actually can sustain the 2x voltage across decreasing load impedance, few amps actually deliver the theoretical 4x power increase.
For example, say you had an amp rated---
100wpc @ 8 ohms
150wpc @ 4 ohms
200wpc @ 2 ohms
If the speakers are 8 ohm speakers, then in a bridged situation the amp in the above example would put out 300 watts into the 8 ohm speaker (2x the 4 ohm, per-channel rating).
In your specific case, you mention 625W into 4-ohm speakers. This would imply that each amp is capable of producing/running at 312.5 watts at 2 ohms. Does that match up with the specs of the amp?
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