Why do say think that?
Amps, current, ohms and whatnot.
- Thread starter tommyt
- Start date
Why do say think that?
Obi1
Swedish HiFi enthusiast
Just go: http://www.rotel.com/product/rb-1590
And never worry again.
It will drive any speaker and sounds great.
And never worry again.
It will drive any speaker and sounds great.
The 127W /8 ohms handbook spec for the MK1 was very conservative - lower than reality. Why it was not too difficult to uprate to 180 Watts for the mk2 version still using same transistors and transformer. What I was told.
The HX100 has an uprated transformer and other stuff. Also balanced I believe. Its a step up.Pretty rare. Don't even know if currently available new ? I'd love to have a shot of one.
Any thoughts/experiences on leema tucana 2? Anyone using with shahinian?
Output Power: 150W rms 8 Ohms/Ch
Output Power: 290W rms 4 Ohms/Ch
Output Power: 320/520W rms 2 Ohms/Ch
THD: 0.004%
Noise: < -100 dB:
Minimum load impedance: 2 ohms.
Output Current: greater than +/- 50 Amps
Slight discrepancy between retailer specs and leema spec on the 2ohm rating. Leema site says 320. Several retailers show 520.
If it says minimum 2ohm, does that mean there is a risk of it cutting out if it dips below?
Output Power: 150W rms 8 Ohms/Ch
Output Power: 290W rms 4 Ohms/Ch
Output Power: 320/520W rms 2 Ohms/Ch
THD: 0.004%
Noise: < -100 dB:
Minimum load impedance: 2 ohms.
Output Current: greater than +/- 50 Amps
Slight discrepancy between retailer specs and leema spec on the 2ohm rating. Leema site says 320. Several retailers show 520.
If it says minimum 2ohm, does that mean there is a risk of it cutting out if it dips below?
Well it's excellent to hear they are sounding good, and so one wonders, why are you wanting to change your amplifier? Are you concerned that since they are hard to drive, you are not getting the best from them?
The problem is that without knowing how loud you are playing them, any limitations will be hard if not impossible to determine.
For what it's worth i'm using nc400 based amps with my obelisks and they sound great. I'd certainly recommend hypex designs for these style speakers, but it's not clear if you will get more out of them than your existing amps.
The problem is that without knowing how loud you are playing them, any limitations will be hard if not impossible to determine.
For what it's worth i'm using nc400 based amps with my obelisks and they sound great. I'd certainly recommend hypex designs for these style speakers, but it's not clear if you will get more out of them than your existing amps.
I'd like to keep my D7s for another room so I'll need another amp anyway and the roksan drove them well. I strongly suspect a stronger amp would bring more from the Hawks. They sound very nice at the moment but I Suspect more to come.. Some aspects, particularly percussion not quite as focussed/snappy as on the d7. It's a fuller sound though. I'll need some time to get used to change in presentation too. I'm in no rush anyway but like to know my options.
I play low volume at night and loud as possible when I can get away with it!
I play low volume at night and loud as possible when I can get away with it!
Hi Teddy, elsewhere on this thread it's been suggested that the power should ideally double for each drop of 2 ohms. Is it therefore sufficient to be delivering 200watts at 1/2 ohms? Is this only really relevant at very high volumes?
Do you think my caspian would suit well as a preamp to the mb100s?
James
Lord of the Erg\o/s
You seem preoccupied with a 2-ohm rating. Your Shahinians might dip that low in the HF, but unless you are playing only HF at ear-piercing levels, your amplifier will be seeing more than 2-ohms on full bandwidth audio.
You are worrying about a technicality that makes very little difference for any competent amplifier, including the Capsian you presently use.
Julf
Facts are our friends
No - power should ideally double for each halving of load impedance (so it is divide-by-2, not subtract-2).
Of course full current capability is only needed at full power, so if you play at a lower power, current delivery is less of an issue.
Sibbers
Earthling
I noticed that without enough current, my speakers would sound less than their best even at low volumes but it was only when you turned it up it became obvious something wasn't right. I spent a long time being convinced by smart people that I didn't need any more current, but with an amp that doubled wattage as impedance halved I got to find out just how good my speakers really were. Also placement became much easier too.
If you can, test an amp that can do that so you can put your mind at rest. It was necessary for me, and it was the accuracy of the bass that it fixed, sounding both too bassy and not bassy enough. Hard to describe but obvious to hear.
If you can, test an amp that can do that so you can put your mind at rest. It was necessary for me, and it was the accuracy of the bass that it fixed, sounding both too bassy and not bassy enough. Hard to describe but obvious to hear.
Jim Audiomisc
pfm Member
That seems to imply there was a problem due to the amp having either a high output impedance or a stability problem. As distinct from current limiting.
Because 60 amps is a massive current. To put that through a transistor amp needs multiple transistors sharing the current and huge heat sinks etc like say a Krell. A Caspian has none of this.
Darth Vader
From the Dark Side
But but but the James Bond transistors in the Naim 300 and 500 are said to be 80A devices rated at 350W each. However I doubt very much if the Caspian has these or anything like them. What confuses me is the said 60A peak to peak. Methinks this is a ruse of 30A in each direction.
I wonder if these Bond transistors are really several in parallel inside the one can?
Oooo looky here a 100A tranny but also see the derating graph. https://www.digchip.com/datasheets/parts/datasheet/1070/SFT1004-pdf.php
Cheers,
DV
Jim Audiomisc
pfm Member
No idea above the above devices. But IIRC it became routine many years ago for high power bipolars to be 'multiple emitter' devices - essentially many smaller transistor junctions in parallel - in order to share out the current and reduce the risk of secondary breakdown, etc. FWIW I used pairs of these back circa 1980 to get the order of 30A rms and higher peaks. The real question with these high currents is how long they can be sustained. Really mean for transients, not sustained sinewaves.
JensenHealey
pfm Member
Everyone here is focusing on current, when really the issue of hard speaker loads is reactance - causing voltage and currents to be out phase. The ability to survive those loads is not simply measured by how many amps it can deliver at 2 Ohms, for even milliseconds. It might give a clue about a tough amplifier. But what protection circuits will kick in to limit things...and so on.
Dowser
Learning to bodge again..
Why? When I first got an A&R A60 amp I tried it in my main system with original SF Concertinos after recapping it - in my workshop system with more efficient Wharfedale speakers it sounded fantastic. Trying to drive the SFs it was truly woeful at any volume - swapping the SFs for a pair of Mordaunt Short (MS20i's? Don't remember exactly, biwire versions) returned a decent sound.
However, my normal setup of ~30w DIY valve push-pull with mosfet driver stage, or ML No. 29 (50w only
) sounded far, far better with the SFs than the MSs.Conclusion - not all 25w amps are the same. I still have the A60, with the right speakers it is a stunning amp. But not with a difficult load. Equally, I would use my Mark Levinson in preference to any "on paper" higher output amp - I suspect it could deliver its 50w across a spanner and cause it to vibrate.
As mentioned up thread - speakers, amp and (to a lesser extent) cables should be considered as a single entity - in much the same was as a cartridge and phono stage should be. Industry specifications do not tell the whole story.
Richard
teddy_pardo
Trade: Teddy Pardo
Normally power should double when impedance is divided by two, our amps have overpower/overheating protection mechanism which prevents it.
When people/manufacturers say that a speaker requires at least 100 or 200W, what they really mean is that the amp should have enough current drive capabilities, which usually high power amps have. Power amps with regulated power supply have however much higher current drive capabilities at lower power. It is similar to torque in car engines, once when you wanted high torque you needed a big engine, then there are turbo engines like VW TSI that deliver a higher torque with much smaller engines.
For this reason even our small ST60 power amp drives very well difficult to drive speakers such as the Shehinians
You can read more about it here
I see no reason why the MB100 will not work well with your pre-amp, or with any other pre-amp
Thanks all for advice and recommendations given. In the end I went for a set of used Nord One Ups and found a Weiss Dac202 on ebay to use as a dac preamp (replacing my Chord Mojo in the process). End result sounds quite special.
The one thing I thought was slightly missing moving from my Spendors to the Hawks was the very top end - the airiness seemed to have gone compared to my D7s. I thought maybe it was a trait of the speakers, I had read that Obelisks had a more airy feel to them. However, the dac202 has brought that airiness back plus everything has gone up a notch in terms of detail and texture.
Currently running mac laptop running roon/spotify->supra usb->Singxer F1->spdif->dac202->atlas->hawks. Planning to get a firewire 400/800 cable to see if firewire is any better/worse than going via the F1.
Need to setup the mojo/roksan/spendors in the other room to see if the airiness of the mojo returns with the spendors and whether its a synergy thing or just I didn't realise it was missing before.
The one thing I thought was slightly missing moving from my Spendors to the Hawks was the very top end - the airiness seemed to have gone compared to my D7s. I thought maybe it was a trait of the speakers, I had read that Obelisks had a more airy feel to them. However, the dac202 has brought that airiness back plus everything has gone up a notch in terms of detail and texture.
Currently running mac laptop running roon/spotify->supra usb->Singxer F1->spdif->dac202->atlas->hawks. Planning to get a firewire 400/800 cable to see if firewire is any better/worse than going via the F1.
Need to setup the mojo/roksan/spendors in the other room to see if the airiness of the mojo returns with the spendors and whether its a synergy thing or just I didn't realise it was missing before.