Like Seano, I understand in principle where you are coming from but any impracticalities aside, the GK2 is a simply stunning piece of kit and it partners the Soraya a treat. Besides, Hugh has designed the NAKSA's to sound good stand alone as I understand it.
Hugh's problem would be to simplify its construction and packaging for marketing and there is not as big a market for preamps as there is for power amps so I could see that finding time and motivation could be difficult for him. Pity though, it's certainly reference standard for me.
Thank you for your comment Sean. You've confirmed that I am right in imagining I am 65-going-on-35, as I certainly have no interest in 'simplisticising'.
Having 'known' you for some time through this place and Audiocircle...you have never been in any danger of 'simplisticising'.
Thanks Patrick, AJ,
Good to see the interest still. Steve in WY has been testing this very hard over the last six months and it is bulletproof. This is critical to Aspen as it has to be perfect.
It is very simple because the development has taken so much time and effort. Complexity is simple, simplicity is darned hard. (Reminds me of an old Jewish Comedian who lies dying with he old friend Joe in attendance asking, 'David, is dying hard?' David tries to get his words out with difficulties, and croaks out, 'No, dying is easy, it's comedy that is hard'.)
My next attempt is to get all the organisation together to have these new amps into sales..... I love designing amps, but I struggle, particularly these couple of years, with the business process.
Ciao,
Hugh
Good to see the interest still. Steve in WY has been testing this very hard over the last six months and it is bulletproof. This is critical to Aspen as it has to be perfect.
It is very simple because the development has taken so much time and effort. Complexity is simple, simplicity is darned hard. (Reminds me of an old Jewish Comedian who lies dying with he old friend Joe in attendance asking, 'David, is dying hard?' David tries to get his words out with difficulties, and croaks out, 'No, dying is easy, it's comedy that is hard'.)
My next attempt is to get all the organisation together to have these new amps into sales..... I love designing amps, but I struggle, particularly these couple of years, with the business process.
Ciao,
Hugh
Hi Jens,
Thanks for the post!
Ah, 2R is an absurd impedance for a speaker. Amps that can drive that are pretty special. I will not admit the N125 can do 2R, but it can be 3R. Maybe into the future I might have something!!
Steve has been very thorough and conservative. He is an incredibly careful, detailed worker, and his monoblocs are wonderful. He seems to like the sound, very musical, resolving, and with surreal depth of image.
Reviewing will by Johnny Darko at Digital Audio Review, where I advertise.
Cheers,
Hugh
Thanks for the post!
Ah, 2R is an absurd impedance for a speaker. Amps that can drive that are pretty special. I will not admit the N125 can do 2R, but it can be 3R. Maybe into the future I might have something!!
Steve has been very thorough and conservative. He is an incredibly careful, detailed worker, and his monoblocs are wonderful. He seems to like the sound, very musical, resolving, and with surreal depth of image.
Reviewing will by Johnny Darko at Digital Audio Review, where I advertise.
Cheers,
Hugh
Hi Hugh,
Yes, a 2ohm load is not "friendly" - or common - but it can appear in active setups (when the amp only 'sees' the one driver). As you know, my Maggie ribbon is 2ohms - so if the N80 is able to drive this (which is what you told me!) ... what's the difference with the N125?
Or is it simply the extra power delivered by the N125 requires it to have at least a 3ohm load?
Regards,
Andy
Is the Maggie ribbon a reactive load (like moving coil speakers and their crossovers), or is it substantially resistive?
An 8ohms capable amplifier should easily drive a 4r0 test load. Most good 8ohms amplifiers will drive a 2r7 test load for a short while, or at low duty cycle, to keep the output stage at a sensible temperature.
There is a big difference between 4r0 and 4ohms as far as amplifier capability is concerned.
Similarly between 2r0 and 2ohms.
An 8ohms capable amplifier should easily drive a 4r0 test load. Most good 8ohms amplifiers will drive a 2r7 test load for a short while, or at low duty cycle, to keep the output stage at a sensible temperature.
There is a big difference between 4r0 and 4ohms as far as amplifier capability is concerned.
Similarly between 2r0 and 2ohms.
Hi Hugh,
I agree, 2R is an absurd impedance. Although it does say something about the stability of an amp. But then, stability has never been an issue with any Aspen amp I have owned, and I suspect that most of your amps will actually be able to cope with 2R, although perhaps not for extended periods
Marketing? Well, it starts right here in this forum, doesn't it? And then my suggestion would be to get your website updated as quickly as possible with info and pricing on the new babies - that's where people go for information these days
I'll definitely mention the new N125 at my end once there is some information available
Cheers,
Jens
P.S. Still working on the 200 watt version?
Andy, Jens
A N125 outputting about 45Vpeak into 2R is 506 watts rms...... At 5Vpkeak, a 2R speaker only copes with 6.25W, so this is achievable.
How much spl would 100W produce into a 2R ribbon? It would be enough drive a hospital grade echograph!
I think the N125 would easily handle a 2R speaker at very moderate output, yes, but there would be some waveform compression since global negative feedback is quite small (around 20dB, compared to most amps around 50-70dB). However, this low loop gain confers monumental stability with difficult loads, although I have to admit a ribbon is almost completely resistive. The payoff is the wonderful stability with electrostatics.
Jens, lots of questions I am tired to answer in detail; I've just spent 5 days in bed with terrible flu - bad enough, but not Ebola thank God, poor people in West Africa - but, the start:
1. Website will start next week when my depression falls and my intellect rises,
2. Cost will be $1620 for complete fully tested, warranted, set up and fitted on heatsinks, same as the LF100, and
3. 125W//8R, clips 142W, around 210W into 4R, 2 x 35Vac secondary windings to run, Zin 33K, Zout is 0.2R/1KHz/12.5W, and 0.0145% THD 1KHz 12.5W, H2 dominate at -75dB, noise -109dB down.
Cheers,
Hugh
A N125 outputting about 45Vpeak into 2R is 506 watts rms...... At 5Vpkeak, a 2R speaker only copes with 6.25W, so this is achievable.
How much spl would 100W produce into a 2R ribbon? It would be enough drive a hospital grade echograph!
I think the N125 would easily handle a 2R speaker at very moderate output, yes, but there would be some waveform compression since global negative feedback is quite small (around 20dB, compared to most amps around 50-70dB). However, this low loop gain confers monumental stability with difficult loads, although I have to admit a ribbon is almost completely resistive. The payoff is the wonderful stability with electrostatics.
Jens, lots of questions I am tired to answer in detail; I've just spent 5 days in bed with terrible flu - bad enough, but not Ebola thank God, poor people in West Africa - but, the start:
1. Website will start next week when my depression falls and my intellect rises,
2. Cost will be $1620 for complete fully tested, warranted, set up and fitted on heatsinks, same as the LF100, and
3. 125W//8R, clips 142W, around 210W into 4R, 2 x 35Vac secondary windings to run, Zin 33K, Zout is 0.2R/1KHz/12.5W, and 0.0145% THD 1KHz 12.5W, H2 dominate at -75dB, noise -109dB down.
Cheers,
Hugh
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It's an almost purely resistive load.
So, Andrew, given the Maggie ribbon is 2.0 ohms ... what does what you state above, mean?
Regards,
Andy
The dissipation in the amplifier is much higher when driving a reactive load.
If an amplifier is designed to tolerate 8ohms reactive speakers, then it should tolerate driving a 4r0 load. The only proviso is that the heatsink be monitored to check for excessive temperature.
A 4ohms capable amplifier should thus be able to drive a 2r0 load, provided temperatures stay within design limits.
Aksa should be able to confirm whether his amps can support 8ohms, or 6ohms, or 4ohms loading.
He should also be able to confirm what heatsinking should be used to allow 4r0, or 3r0, or 2r0 for these amp capabilities when used for music reproduction in a domestic environment.
If an amplifier is designed to tolerate 8ohms reactive speakers, then it should tolerate driving a 4r0 load. The only proviso is that the heatsink be monitored to check for excessive temperature.
A 4ohms capable amplifier should thus be able to drive a 2r0 load, provided temperatures stay within design limits.
Aksa should be able to confirm whether his amps can support 8ohms, or 6ohms, or 4ohms loading.
He should also be able to confirm what heatsinking should be used to allow 4r0, or 3r0, or 2r0 for these amp capabilities when used for music reproduction in a domestic environment.
Hugh has done this. (BTW, given your comments, I would've thought you would've said: "AKSA should be able to confirm whether his amps can support 8R0ohms, or 6R0ohms, or 4R0ohms loading".
)And, from what you have said, I assume if it can drive a 2R0 load ... it can certainly drive a 2.0ohm load?
It seems to me, though (from a non-expert PoV), that there is a big difference - in terms of amp load - between driving a 2.0ohm woofer to driving a 2.0ohm tweeter? The power (amperage output) requirements for the tweeter will be very much less than the power (amperage output) requirements for the woofer?
Yes, Hugh supplies the appropriate heatsink for his amp modules.
Andy
You are misunderstanding what I have written.
2r0 loading is not as severe as 2ohm loading.
An example of your misunderstanding is your statement
8ohms is not the same as 8r0.
6ohms is not the same as 6r0.
4ohms is not the same as 4r0.
The next part again confirms you have misunderstood.
And I too am sure that AKSA (his Forum Name) has fitted the correct heatsinks for the loading that his company recommend and rate their amps at.
i.e. if they are rated at 8ohms and you fit 8ohms speaker, then the amp will not overheat if you don't abuse it.
If they are rated at 4ohms and you fit a 4ohms speaker that too will not overheat if you don't abuse it.
But the question is "can a 2r0 rated speaker be used with an Aksa amplifier?"
On the basis of what I said, it is very likely that a 4ohms rated amplifier can drive a 2r0 ribbon (may be upper mid and treble) and not suffer any stability issues and not run into current clipping.
But there is an issue of continuous heavy current output that could require a bigger heatsink. If that is the case then Aksa should be able to confirm what is required.
Aksa in these last few posts has not yet confirmed that their amplifiers can drive a 2r0 rated speaker.
They have confirmed that a 2ohms is not suitable.
2r0 loading is not as severe as 2ohm loading.
An example of your misunderstanding is your statement
where you have edited the stated values to something I did not say.
8ohms is not the same as 8r0.
6ohms is not the same as 6r0.
4ohms is not the same as 4r0.
The next part again confirms you have misunderstood.
I said the opposite.
And I too am sure that AKSA (his Forum Name) has fitted the correct heatsinks for the loading that his company recommend and rate their amps at.
i.e. if they are rated at 8ohms and you fit 8ohms speaker, then the amp will not overheat if you don't abuse it.
If they are rated at 4ohms and you fit a 4ohms speaker that too will not overheat if you don't abuse it.
But the question is "can a 2r0 rated speaker be used with an Aksa amplifier?"
On the basis of what I said, it is very likely that a 4ohms rated amplifier can drive a 2r0 ribbon (may be upper mid and treble) and not suffer any stability issues and not run into current clipping.
But there is an issue of continuous heavy current output that could require a bigger heatsink. If that is the case then Aksa should be able to confirm what is required.
Aksa in these last few posts has not yet confirmed that their amplifiers can drive a 2r0 rated speaker.
They have confirmed that a 2ohms is not suitable.
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No. I have not tested the amp with a 2R ribbon. I imagine it would cope at low power, within output device current ratings, and heatsinking. However, like any complex machine, an amp requires a battery of tests to release it and in due course I will publish this information.
BTW, I did NOT design the amp for a 2R ribbon. I designed it for a 8 ohm nominal speaker and safety with a 4 ohm nominal speaker. It is designed to cope with reactive speakers - most speakers are in fact - and because the global feedback regime the output impedance of this amp is not particularly low (around 150 milliohms) the current capacity trends down at high loading and high output because of the rdson limitations of the output devices, which are not masked as much in the very high loop gain conventional amps.
I don't like to talk about these esoteric issues; some of these aspects go to the core of my IP, and my brain hurts with writing these days.
Cheers,
Hugh
BTW, I did NOT design the amp for a 2R ribbon. I designed it for a 8 ohm nominal speaker and safety with a 4 ohm nominal speaker. It is designed to cope with reactive speakers - most speakers are in fact - and because the global feedback regime the output impedance of this amp is not particularly low (around 150 milliohms) the current capacity trends down at high loading and high output because of the rdson limitations of the output devices, which are not masked as much in the very high loop gain conventional amps.
I don't like to talk about these esoteric issues; some of these aspects go to the core of my IP, and my brain hurts with writing these days.
Cheers,
Hugh
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Andrew, I am indeed "misunderstanding what you have written"!
So I'm wondering if you are a current AKSA customer ... or just someone who likes to parachute into various on-line threads and ... well, the phrase that comes to mind is ... "crap on them"?Can I suggest that if you wanted to impart some of your amazing knowledge, you would've explained that 2R0 is easier to drive than 2.0 ohm drivers. Me - I haven't the faintest idea whether a 2R0 driver is easier for an amp to drive than a 2ohm driver ... and I assumed the latter was. My bad.
From using 2 different versions of AKSA amps over the last 12 years or so, I know that Hugh doesn't overstate what his amps can do. So I fully expect that - whereas currently with my 'Lifeforce 55' modules on my ribbons, I have a series 1ohm res to make them a 3ohm load - N80 modules will be able to drive the ribbons directly (ie. with no 1ohm resistor in place), with no issues.
Regards,
Andy
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