Hypex Ncore Listening Impressions

[Lil Caesar]

Introductions...

I’d like to begin by sending out a BIG thank you to ajst2duk for his selfless generosity. AJ has very kindly offered to share his DIY Ncore MonoBlocs with bhobba and myself – despite having only heard them himself for a little over two weeks after completing the build.

AJ has done a marvellous job in creating a pair of reference Class D amps, utilising the Hypex NC400 (400WPC into 8 Ohms) and SMPS600 (600 Watt output) modules available directly from the manufacturer. These units are Class 2 wiring compliant, meaning that they are not grounded – the PCBs “float†on spacers within the handsome CNC machined and anodised aluminium enclosures that AJ has chosen.

The package is completed with a standard IEC connector, XLR jack and the classy inclusion of Eichmann cable pod binding posts. They are small, light and dead silent. A modest amount of heat is generated, as the enclosure is constantly warm to the touch – there being no perceivable change when under heavy load.

Contrast and Compare...

I will reference two other pairs of monoblocs I have on hand – the Channel Islands Audio (CIA’s hereon in) D200 mk2’s and Valvet A3.5 mk1’s. Thanks must go to SNAer Yoshio who has allowed me to retain use of the Valvets for such a long period of time.

The CIA’s use the older Hypex “UcD†modules – featuring heavily modified input buffer coupled to 600 Va linear PSUs feeding discrete Schottky barrier diode bridges and 40,000 microfarads of capacitance, producing 200WPC into 8 Ohms. The Valvets are a 50WPC Class A design with a single pair of transistors in push-pull. These are a modestly biased configuration using 300 Va transformers, 100,000 microfarads of capacitance into a short signal path of pure silver cable with no caps or resistors in the signal path.

I had before me the opportunity to gauge high frequency performance between A & D, and whether the newer Ncore with SMPS would best the older, modified UcD architecture running linear PSU.

Casa Del Caesar...

My system comprises of HTPC running Win7 & Foobar into an AP2, coupled to a BNC-to-RCA cable. I also use an iPod Classic via Cambridge Audio iD100 digital dock using AES/EBU. I run fully balanced to the monoblocs courtesy of Transparent Audio XLRs and matching speaker cable.

My processing is handled by the NAD M51 DAC/Pre. 'Nuff Said. Plenty here in SNA about this device. I personally consider it to be reasonably neutral, though recent experience in a number of fellow members' systems' would lead me to believe that it too - warms the 1's and 0's ever so slightly. Highly resolving, accurate, yet musical.

The Sonus Faber Luito’s are a warmer speaker, voiced with a notion of romanticism in mind, though to a lesser extent then earlier examples from the Sonus Faber stable, particularly when Franco Serblin was still in charge. The Luito’s retain a sense of the SF signature sound, but they clearly resolve to a higher degree than their grand piano forebears, and provide scope for considerably better dynamics.

The sonic signature from M51 DAC/Pre and Luito’s is best described as having elegantly bevelled edges. Through this combination there is subtle rolloff in the treble and bass is limited to around 35 Hz in-room response. The stage is reasonably deep and wide, with excellent potential for resolving detail. There is a specific synergy in terms of reproducing acoustic instruments and small ensembles.

The Ncores cannot be simply described as either contributing to – or detracting from – the overall tonal presentation of my system. This was going to be more complex. Switching between them and the Valvets did not initially lead me to believe that one was inherently warmer or colder, in terms of tonal presentation - than the other.

The Ncores exercise a supreme level of control over the signal which they are fed. The leading edges and eventual decay of transients are handled with such astute resolution and finesse that it was in fact alarming as to how close they came to match the Class A Valvets in most regards.

Shimmering, textural effects like brushed cymbals are an excellent example. Take "Have Trumpet - Will Excite" from Verve's recording of Dizzy Gillespie. The CD remastering has an enormous amount of ambient tape noise, over which one must persist to appreciate Dizzy’s muted trumpet and the layered highly percussive rhythm section.

Discernible characteristics lay in PRaT and soundstaging – The Valvets sounded more forward in the upper mids and the treble – providing a faster delivery of the incisive dynamics which felt like the performance was being rendered in your presence – an ever so slightly brighter, livelier sound. Whilst this rendering proved to be ultimately more satisfying – the Valvets could not compete with the Ncores on detail – particularly spatial information.

The Ncores could be described as seemingly withholding something or subtly restrained by comparison on those leading edges – their iron grip over the music proving ever so slightly counter-productive. What’s interesting is that they did not appear to produce any “hashâ€, “grit†or “grain†in the process.

Listening to Richard Tognetti's take on the Bach partitas for violin was a fatigue-free exercise. The Ncores’ resolving capabilities shone - such that one instinctively knew that gut stings were in use on that Stradivarius. Once again the recording environment was rendered clearly and the sensation of the performer earnestly working their instrument is conveyed with resolute distinction. This beguiling presentation provides the listener with microdynamics lost on the Valvets and CIA's alike. Importantly - there was nothing mechanical about the performance - it was emotive and lyrical, BUT lacking a certain liquidity when compared to the Valvets.

Where the CIA’s do noticeably “feather†or “air-brush†the transients in the treble – the Ncores alternatively offer a very satisfyingly natural sense of acoustic decay. The CIA’s appear sweeter and mellow by comparison – the Ncores the more technically accurate – almost to a fault – whilst the Valvets win this contest. By a nose.

Julie London singing "light my fire" via the Valvets gives a delicious liquidity to the dark-tinted-glass qualities of her voice on this recording. A certain lack of resolution and refinement coupled with the noticeable distance of the venue in this presentation is altogether a more romantic and intimate rendering. The Ncores meanwhile DO NOT sound cold or clinical - they just present every miniscule detail with glowing aplomb. You can choose to notice the reverberation of the venue, the channel separation in the orchestral accompaniment, or the microdynamics of her phrasing.

There is such a wealth of information via the Ncores that sometimes their intense precision distracts for the sheer joy of the music.

To use a photographic analogy - the Ncores are Ansell Adams in Yellowstone – a scene captured with huge depth of field, rendering the blade of grass at your feet to the majestic snow-capped peaks in the distance. You are simply in awe and somewhat overwhelmed by the sheer level of detail. Are you prepared to wander into this visage on numerous occasions to absorb all there is on offer? The Valvets are altogether more personal - a shallow depth-of-field portrait that is personal and intimate. What they lack in raw dynamics and outright power – is more than compensated through a sense of presence.

From a technical perspective, the supposed response of the Valvets - from DC to 300 KHz - no doubt heavily influences this perception. Both the Hypex devices are brick-walled at 20 KHz with some deviation in output at the frequency extremes. The Class D's inherently lower noise floor and seemingly effortless dynamics lends itself to certain strengths in terms of outright detail and the overall dynamism of the presentation.

The Ncores demonstrated that they could compete with Class A in the treble – surpassing the CIA’s in this critical test. Even if the Ncores do not eclipse the linear competition, via fabric dome tweeters at least – they come damn close. The fact is that treble was rendered as organically as I’ve ever heard from Class D.

The Ncores stage deeper than the Valvets, their resolving abilities providing the listener with a wealth of information about the recording space that is simply lost on the Valvets. This Class D device places you in the recording session – describing it to you in minute detail. I would surmise by saying that the Valvets convey a sense of presence through intimacy, whereas the Ncores transport you to the recording, allowing you to wander in and focus your attention on specific elements of the music.

Where the Ncores truly excel however – and leave one both completely smitten and in total awe – is there effortless delivery of bass. The absolute mastery of all that power simply must be experienced to be believed. If you want to drive difficult, full-range speakers these are your weapon. I initially could not comprehend the amount of low frequency information that my Luito’s were producing.

Having played cello for a number of years, I turn to Yo-Yo Ma's recordings of the Bach Cello Suites. His instrument is presented with the sonority and physical (bass) presence I myself have experienced, when the G-String is engaged (stop sniggering) and some self-indulgent vibrato is infused on those baroque flourishes.

I could hear multi-layered textures within the lower octaves. The Ncores dug deeper than the CIA’s and held on with a vice-like grip. Here the Valvets were completely irrelevant, their 50WPC just no match for the 400 WPC Ncores.

Jennifer Warnes' The Hunter – “Way Down Deep.†The Ncores presented fully formed percussion; there was body, weight and depth. The drums were for the first time - fully formed. The leading transient of the initial hit to the skin resulted in the most satisfying reverberation and decay I had heard of this recording. The CIA came close but textural information and a certain degree of PraT was absent.

The Hypex Ncores offer everything we already know about Class D’s virtues – they are small, efficient and powerful. They dictate incredible control over speakers and deliver phenomenal handling of bass – in terms of both quantity AND quality. Where they inch closer to the ideal device is in their handling of high frequency information and excellent reproduction of musical nuances.

Not so much cold or clinical - merely accurate, but almost to a fault. An amplifier that takes you to the recording session rather than recreating the performance in your listening room. Here the YMMV disclaimer must rear its ugly head – my DAC/Pre and speakers no doubt take some edge off the frequency extremes so a demo will be essential, particularly if you’re running metallic/synthetic tweeters/ribbons etc.

The Ncores are NOT the death knell for linear amps, but they represent an advance that cannot be ignored. They represent incredible value – AUD$2k including import duties and the enclosures. By comparison the CIA’s cost AUD$4k from Bill Mclean in NSW. The Valvets cannot really be considered in the same argument – being produced by a boutique firm in Germany and imported outside of normal commercial channels. They cost about AUD$6,500 from SNAer Yoshio.

I have no doubt that that the Ncore is the equal of linear amps in terms of dynamic capability and bass response. In this regard, given the cost of ownership they represent an excellent investment. Based on my time with AJ’s devices and the respectable, comparative performance of my CIA’s - I intend to stick with Class D.

Regards,

Lil C.

Edited June 24, 2012 by Lil Caesar

[Nada]

Excellent review there thanks Lil. Its answered all my questions about the NCores and more.

I think your experience as an acoustic musician with your taste in music offers an excellent basis for you to give an opinion with high credibility. I imagine some professional reviewers will have to try and up there game if this get around..

Great quip as well about the G-string too .. the best laugh of the day for me though the image of Yo-Yo vibrating a G-string is rather disturbing. Cheers

[hochopeper]

Excellent review Ceasar!

I have a few diy amps to test out here in Bris in the next 6 months or so. I've been collecting a few while I procrastinate on choosing an active speaker design.

Hopefully when bhobba has these in Brisbane I can make an arrangement to hear them at his place also.

[A J]

Great review there - the purpose of these amps in chez AJ is to drive a set of ML1's in our A/V 2.1 system. In this setup, space is cramped, and dynamic range in output is big (movies etc) so I think they will be just the ticket. I enjoyed building them - easy as, and will enjoy listening to them. The system has a NAD M51 as dac/pre and Oppo 83 SE, HTPC (Mac Mini windoz 7), SBT via AP2, Apple TV as sources, with a REL T2 providing some sub-base.

[bhobba]

Hopefully when bhobba has these in Brisbane I can make an arrangement to hear them at his place also.

They may or may not be at my actual place because I am keen to compare them to my Arions that are elsewhere right now being checked out and burned in. However regardless arrangements can be made made to hear them and see how they compare to the other DIY amp I have that is also probably on your list - the NAKSA 100 if you drop me a line.

Thanks

Bill

[TheThingy]

Great write up Caesar, appreciated! Would love to try these out myself at some point too.

Paul

[Amar Dhall]

This certainly seems very promising. I look forward to hearing an Ncore amp sometime.

Thank you for writing up an excellent review.

[bhobba]

Hi Guys

Just checked and the amps are on-board for delivery and should be arriving soon.

The only issue is they are balanced. Have a number of balanced sources but will need to tee something up for cables.

Thanks

Bill

[DoggieHowser]

I bought a set of XLR ribbontek from Mike. You can use them first if you like.

Haven't picked them up. Was going to get them same time as the speakers.

Edited June 28, 2012 by DoggieHowser

[madamesimplifi]

Must say AJ was very kind to allow me to borrow the ncores whilst they were doing time at LCs but as I did not own XLRs, it was not a possibility.

[bhobba]

I bought a set of XLR ribbontek from Mike. You can use them first if you like.

Haven't picked them up. Was going to get them same time as the speakers.

Excellent solution - thanks Doggie. Can use my QOL completion stage to do the conversion from unbalanced to balanced. It most certainly does not detract from the sound in any way - quite the opposite - it makes a worthwhile improvement.

I have been told they have actually touched down and have arrived. ML's concern was to really check it out we need some decent cables - now it looks like that is solved.

Thanks

Bill

Edited June 28, 2012 by bhobba

[hochopeper]

Bill,

How long are these going to be in town for?

Cheers,

Chris

[bhobba]

How long are these going to be in town for?

I think AJ was kind enough to say I could have them for 3 weeks.

I have them in my car right now and will move them into my rat shack tomorrow and see if I can get them into my system. I managed to get some decent balanced cables and can use them with my QOL completion stage. I have few things to do tomorrow and to be frank carting stuff around with my arthritis poops me out and I need a bit of a rest so may not be able to check them out for a couple of days. The comparison amp at this stage is my NAKSA 100 but may be able to get Rob181 who has a Spectron to help out (especially since I am a bit drained) and we can compare them.

Thanks

Bill

[A J]

Yep three weeks is fine - at least they don't weigh a ton hey !! - good luck.

[bhobba]

Hi Guys

I got the Ncores in my system with the NAD M51 as source.

Well how do they sound - clear, clean, pure and neutral - very neutral. With the NAD 51 as source I heard the exact same setup with Mac 501's yesterday and know the sound of my NAKSA 100 very well. First how do they compare to the Mac's - very well thank you very much. Bass grip not quite as good - still pretty good mind you - but those Mac's have simply amazing bass grip. They have a slightly harder sound with maybe a trace of glare - maybe - than the Mac's but the Mac's to me have a slighly tubey midrange and a slight veil - this doesn't have the veil - but have a slight hardness and etched character the Mac's lack and the midrange isn't quite as enjoyable. The Mac's are better to listen to for long periods IMHO. The Trafomatic totally clobers it foir midrange divineness - but then again no amp I have heard touches it it that department - although the Arions come close. It's not like the NAKSA which Hugh has voiced to sound really good for long periods and is more the type of amp you go - ahh - that's nice when you hear it - this amp isn't. Its more the type of amp you go - hmmm - exactly what character does it have and you have to listen to it for a while to lock onto it and notice a few things like the slight hardness etc. How does it compare to the Arions? I will see if I can do a direct comparioson at some future date but most certainly a comparison with my aquantances that have heard the Arion's is on the cards. My view is the Arions simply sound real - this amp sounds slighly hard, etched and contrived in comparison. How does it compare to the NAD C4390DD - the NAD has greater slam but sort of sounds a bit thicker for want of a better word. But overall fed with the NAD M51 I would say they are about equal - just slightly different.

I hope to, when I have someone to give me a hand, be able to rig it up through my QOL Completion stage so we can check it out against my Bybeed up PDX. I will be taking it over to Rob181's place tomorrow for comparison against his Spectron on his Ambiance Ribbons.

I will also give it a go with my Playback Designs a bit later - it is extremely good with DSD having a very realistic natural sound.

Overall this is a very very good amp - up there with some of the better amps I have heard. If you prefer a highly neutral and accurate sound and are not worried it may not be relaxing to listen to for long periods then it could be just your ticket.

Thanks

Bill

Edited June 29, 2012 by bhobba

[Lil Caesar]

Thanks for that Bill .

I found them awfully compelling with my sonus faber Luitos and the m51. If your source and speakers tune the sound to taste then the ncores just deliver that sound to your ears with aplomb. They are the most neutral clean amps I have ever heard.

[A J]

Interesting feedback from Bruno over on DIY to Bills review - basically said he could voice the amp to sound like anything but chose to give it no flavor - it's purpose is just to amplify without distortion or manipulation whatever source signal is fed. They should be nicely run in when I get them back so I'll add my thoughts.

[tktran]

Anyone using 4ways, or WMTMW 3 ways, with a real low impedance ~2ohms, rather than easy 2 or 3 ways with 8 inch midwoofers with their nCores?

[bhobba]

Hi Guys

AJ mentioned the designer replied on another forum I posted this and here is his reply:

Thx Bill for the feedback.

Some background on why the NC400 sounds the way it does: it is always a dilemma whether an amp should be tuned for things like subjective bass control, sweet mids or not. One of the tricks a Mac does by design is to have a highish output impedance (because of the autoformer) which makes for a more liquid mid-range sound and then to add a subjective sense of bass control by allowing a slight THD rise in the top end. When things like those are really tastefully balanced, such an amp can really make life hard on a "straight wire" amp in a shootout. The signal actually comes out sounding nicer and more impressive than what went in. But on the other hand, I think that to make the greatest number of people happy, one can't afford to give an amp a sound of its own because the number of new fans is probably immediately offset by the number of people who don't like that particular tuning.

But it's tough to resist the occasional sonic touch-up. I can emulate the sound of pretty much any amp out there if I wanted. But so far I'm resisting. If ever I give in, it'll be obvious from the measurements and I hope someone calls me out on it...

Anyhow that's why I decided I actually wanted the NC400 to have this unvarnished, dead-pan delivery.

Thanks

Bill

Edited June 30, 2012 by bhobba

[A J]

Some describe it as clear window to the source - I guess it is the kind of amp that won't paper over any cracks - but would be stunning in the right setup.

[Art Vandelay]

Hi Guys

AJ mentioned the designer replied on another forum I posted this and here is his reply:

Thx Bill for the feedback.

Some background on why the NC400 sounds the way it does: it is always a dilemma whether an amp should be tuned for things like subjective bass control, sweet mids or not. One of the tricks a Mac does by design is to have a highish output impedance (because of the autoformer) which makes for a more liquid mid-range sound and then to add a subjective sense of bass control by allowing a slight THD rise in the top end.

I can't fully support this generalisation. Higher output impedance will produce any number of outcomes depending on the load presented. Furthermore, (from my experience) the most liquid mids and treble I've heard came from an amp with a very low output impedance and with no output transformer, and the amp also presented very low thd.

You really need to compare the Ncore's with the Macs and other amps and into a variety of different speakers in order to correlate a signature.

FTR, I'm not a fan of the Mac sound (or design approach)

[bhobba]

Hi Guys

Just returned from Rob181's place where we did a few comparisons with his Ambiance Ribbons. First was a WFS DAC2 into a Modright valve pre amp and a bybeed Spectron digital amp. Thought I heard the Saber signature of a slight dryness and sibilance but as many have noted is was much more palatable feeding it into valves - although not totally eliminated. Next we put in the NAD M51. A wetter more honeyed sound with the M51 but interestingly the sibilance control was not as good as the WFS which was interesting. It was thought that overall they were pretty equal. OK we popped in the NCores. Unfortunately the sound immediately dropped away - voices became very recessed and everything was closed in. Detail not as good.Treble was not as clean. Next we put the M51 direct into the Ncores. Immediate improvement - better detail, voices not closed in and a bit cleaner - but at the cost of a slight hardness to the sound. It looks like the Ncores may not like valve pre-amp's but of course more experimentation would be required to form any firm conclusions. We then put the WFS direct into the Spectron. Yea the dryness and sibilance was now there in full force - but the detail was improved.- I personally preferred the valve pre-amp. Then the M51 was tried direct to the Spectron. I preferred the M51 that way over the pre-amp. The Spectron revealed more detail, the slight hardness of the Ncores were gone and the imaging was more refined but compared to the WFS it was a bit dull and not as transparent - I preferred the WFS.

The bottom line here is yes the Ncores are excellent value for money and sounds very good, but when compared to the MUCH more expensive Spectron the Spectron was clearly better.

Thanks

Bill

Edited June 30, 2012 by bhobba

[Rob181]

As per usual, Bill has done an excellent job of “telling it like it isâ€. The most interesting things for me from the afternoon were:

How the M51 reminded me of a more McIntosh type of sound it provided via the Modwright. I am not a fan of the McIntosh sound and I sold my MC 252 because the mid range was much too rich to sound “liveâ€. I use a Butler valve/mosfet hybrid as my Surround amp and as it is built by a man that made his name selling esoteric valve guitar pedals this amp is “voiced†sensationally for guitars and was much better to listen to than the Mac, so it left the premises. My opinion was the WFS sounded better through the Modwright.

The biggest surprise of the day was the Ncores. Beautifully put together and are a credit to their “makerâ€â€¦well done AJ…I would have preferred a power switch but that is just me. I was shocked how much the sound collapsed via the Modwright with the vocals moving to the back of the stage and the stage itself shrinking significantly….probably more noticeable using the dipole Ambience ribbons. What a change there was when the M51 was wired direct to the little Ncores…the sound stage widened considerably and the vocals were much more forward…now somewhere near where they should be. Bill said they sounded a little hard…maybe just a little but you have to remember they are around 50% of the Spectron’s cost. I was very impressed with these little “pocket rockets†being fed directly from the DAC’s.

This is my predicition for the future…Hypex type amps being fed directly from a DAC/Preamp like the M51…WFS or similar and the days of “esoteric†Pre Amps may well be numbered. Interestingly this is a “blog†from Paul Mc Gowan (PS Audio)…

“My friend and fellow audio designer Jeff Rowland came by to say hi the other day. Jeff’s always a welcome guest as he and I manage to nearly always be on parallel paths when it comes to product designs. I found Jeff and friend Tim Jerome in our listening room playing music on the new amp we’re working on developing. I’ve written before that this new amplifier is a stunning breakthrough in audio reproduction and to date I haven’t heard anything close.

The amp technology I am referring to is, as many of you guessed, based on the new Hypex class D technology and sure to form Jeff had independently made the same decision and was on a parallel path to building his own version.

I bring this to your attention because I want to illustrate a point about where we are in the scope of things. To both Jeff and I this new amplifier technology represents a stunning achievement – one that is immediately obvious in its benefits to the listener – one that single handedly blows away all the years of work we’ve lavished on polishing our analog amp designs. And yet, it moves us closer to live sound in our homes not by miles but by inches.â€

It is obvioous there will be a lot more main stream Hypex based power amps in the future...Rob

[A J]

That's interesting feedback - I might look at tweaking the Ncores when I get them back just to make sure they are fully optomised. I am planning to put power switches in - or at least amp-mute switches to allow for changing speakers around and that sort of thing. I will also shorten the input signal mogami cable as its currently at about 60cm long and just tied in a bunched loop while I made up my mind whether to keep the current cases or go a bit funky. It is definitely a compromise to have the extra length like that bundled within the case. In terms of front panel work, I need to see if there is someone that could do aluminium CNC for me - I'll probably get the Ncore logo on them and possibly a cutout for an LED and power/mute switch.

In any case, something about the way you guys found them doesn't sound quite right, in my system they were very punchy, transparent and well staged. In any case I have a very open mind and happy to hear others views on these, good or bad. To be honest, the system they will live in spends 80% of its time providing sound for programs like Home & Away & Masterchef as I am the lone male in the house, but does occasionally get to run through some music (via SBT/Audiophilleo/NAD) and movies (Oppo 83SE). The NAD is the control centre/pre in this system so the Ncores will be connected directly via balanced cables. Basically this is not the main music system, so the objective was for reasonable cost, compact, and heat-efficient power. This system currently has a Fetzilla (cousin of Naksa) which actually sounds really great, but does have a 50WPC capability, despite this it does an unbelieveable job and will definitely achieve family heirloom status (thanks again Hugh, you are a genius).

One other thing I should note is that the amps seem to sound better when fed with power directly rather than through any form of conditioning (at least the Furman and Rose Voix ones I have) and this is something that is mentioned in the supplied info sheets. I tried them fed by NAD, also fed by Teddy Pardo Dac with Synchromesh (SBT source) through a Plinius pre via balanced again into ML1+'s.

[bhobba]

Hi Guys

Finally got to check out the NCORE's on the reference system down the Gold Coast with two other Audiophiles using some ML2 Reference. Afraid the same result - very very neutral but a bit dull and hard. Also one person felt the bass lost its stomp compared to the MAC 501's that system normally uses. In order to use the balanced inputs the QOL completion stage was used. For some reason when it was engaged it made a huge difference - you would swear you had a different amp - the hardness seemed to magically disappear - I conjecture on why a bit later.

That's the end of my time with the amps - they are going back to AJ. Again many thanks to AJ - it has been a very interesting experience hearing these much talked about amps. IMHO they are very very neutral, absolutely free of any nasties, but a bit dull and bland with a slight bit of hardness. From what the designer said he deliberately designed it to be a bit deadpan which may or may not be your bag - I personally am neutral towards that characteristic - its the slight trace of hardness that I found was its achilles heel when compared to much much more expensive amps like $20K Mac 501's. Extremely good value if you like a very very neutral amp that some may classify as lifeless, but in reality is what the designer wanted. If you plan to use it with the QOL completion stage it improves considerably with the harness pretty much gone. People have mentioned the problem with digital amps is the output filter mucking about with phase - the QOL does tricks to fix up phase issues and I conjecture this is why it was so effective with this amp.

Thanks

Bill

Edited July 17, 2012 by bhobba