[netaron]

I am seriously considering the purchase of a GK-1 preamp with the phono option to mate with my 55N+. First off, I would like to hear some comments on the sound, especially what preamp the GK-1 replaced in your current set up. Also is the phono option all tube and are all tubes provided with the kit? I will be using a step-up transformer to drive a .23mV cartridge signal, will this present a cha. Any input is greatly appreciated.


Haron

[ShinOBIWAN]

Whenever I think of the GK-1, I always seem to remember this review taken from the Testimonials page on the AKSA webpage:

Over 18 months ago, a respected friend in the hifi industry suggested I take a good look at the products being offered by a Melbourne based company called Aspen Amplifiers. With mild interest I took a look at the website and read about Hugh Dean, his philosophies and products, and the rave reviews from his customers. Having no DIY skills myself, the notion of buying kits and building them myself was quite daunting. Besides, these kits were ridiculously inexpensive (less than many of my "tweaks"). Surely they were only good performers "for the price" and not serious contenders, let alone upgrades, to expensive audiophile brand components that come complete with rave reviews from professional audiophile magazine reviewers? Interesting, but I think I'll pass.

That is where things stayed until early 2002 when the same friend was in town and visiting Hugh. I tagged along for the ride. I guess I expected to hear "reasonable" sounding equipment that would impress non-audiophiles or suit hobbyists who couldn't (or weren't prepared to) pay for "real" high-end gear. After all, we all know that we more or less get what we pay for don't we? As much as I hate to admit to being a victim of audiophile snobbery, I guess I was until that day.

Needless to say, I was completely knocked off my audiophile perch. My head kept telling me that Supermarket priced gear couldn't sound any good, but my ears and tapping foot were telling me otherwise. Here was a system without special power cables, interconnects, speaker cables, dedicated lines, footers, anti-resonant bases, room treatments, fairy dust and so on, that sounded more lifelike and emotional than many "audiophile priced" systems I had heard before or since. What was going on? Although I knew the writing was on the wall, I wasn't prepared to accept the obvious easily.

I fetched my trusty audiophile pre-amp (US$3500) complete with NOS tubes, my favourite test music, and headed back to Hugh's for a showdown. Now we'll see what's what! Well, Hugh and my friend were very gentle, but the proverbial egg was all over my face. In several areas, the TLP was clearly better than my reference pre-amp. If it were not for the fact that the GK-1 was under development, I may have signed up for a TLP right then.

After many months of anticipation, the GK-1 was finally released. Back to Hugh's for an audition. Wow! As good as the TLP is, the GK-1 is in another league. It clearly surpassed my reference pre-amp in every technical area. But more importantly (or perhaps because of this) it was more musical, lifelike and emotional than any pre-amp I have ever heard regardless of price. You don't hear "solid state" sound or "tube" sound, just real vocals and real instruments in real space.

With Hugh's invaluable help, I have built my GK-1 with a few simple modifications and, with the addition of a modified TKD stepped attenuator (as used on the US$12k+ CTC BlowTorch & US$14k Lamm L2 Reference) last week, it has gone to yet another level. Unbelievably, it is getting even better as this attenuator goes through its lengthy break-in process. Yes, it is serious money for an attenuator, but the GK-1's circuitry rewards it and even deserves it ….it is that good. I actually doubt that there are many pre-amps under US$10k that could embarrass a thoughtfully assembled GK-1 (depending on your choice of internal wire, layout, attenuator, etc).

Having lived with the GK-1 for 6 months now, I feel that as good as the Plinius SA100/3 (US$4500) power amp is, the GK-1 may shine even brighter with an even better amp. Hmmmm, perhaps passive bi-amping with an AKSA 55w Nirvana on top and a 100w Nirvana below ….now there's an idea. Another AKSAphile has already achieved better mids and highs by doing just that and relegating his Plinius SA100/3 to subwoofer duty.

It is a huge leap of faith for an audiophile to choose an inexpensive kit pre-amplifier over much more expensive and well-known models from the "big boys" of hifi. It is very doubtful I would have done it had I not lived within driving distance of Hugh and been able to audition the GK-1 first hand. After that, I couldn't swap my designer label bragging rights for far better sound quality quickly enough (or without grinning stupidly). My friend also bought one to replace another very highly regarded Australian tube pre-amp.

The prices included above are simply to give readers some idea of the price/performance of Hugh's products and those with which they rank.

My sincere thanks go to Hugh for his time, patience, and wonderful sounding products at ridiculously low prices. Bravo!

Darren

Shame hugh doesn't do a 10 channel version!

[andyr]

I am seriously considering the purchase of a GK-1 preamp with the phono option to mate with my 55N+. First off, I would like to hear some comments on the sound, especially what preamp the GK-1 replaced in your current set up. Also is the phono option all tube and are all tubes provided with the kit? I will be using a step-up transformer to drive a .23mV cartridge signal, will this present a cha. Any input is greatly appreciated.


Haron

Hi Haron,

Looks like I'm the right man to answer your Q, as I have a 0.28mV Benz Ebony LP!!  

I had a Naim 32-5 preamp which was replaced by the GK-1.  Moreover, I have a very fine phono stage (basically, the old Bill Beard BBP100 phono stage) which has been replaced by the GK-1 phono stage.  

The phono stage is not tube - it's op-amp based (and very low noise).  With a very low output cart (like a Benz Ebony), you don't want tubes in the phono circuit.  You get a tube on the output stage of the GK-1 ... and it makes the sound much more engaging to listen to, compared to bypassing the tube (which the "sub out" does, in order to give you deep, tight bass!).  

However, it is a MM phono stage - ie. you will need to amplify your 0.23mV-output cartridge in order to make it work.

You said you "will be using a step-up transformer to drive the 0.23mV cartridge" ... yes, this is certainly a favourite choice of many but I personally prefer Hugh's "Paris" head-amp.  This is an ACTIVE amplifying device (mosfet based, I think, and driven by a 12v gel-cell rechargeable battery) instead of a passive device (which a transformer is).  It is very fast, and deadly quite - all good qualities for a step-up device, IMO.

I had Sowter step-up transformers at one stage but I found (with the BBP100 phono stage) that I got a much wider sound-stage when I ditched them!  

A GK-1 phono stage will make your vinyl sound absolutely rivetting!  If I didn't have to go to work to earn money, I'd sit at home listening to my LPs all day!!  

Regards,

Andy

[netaron]

Thanks for the reply Andyr and ShinOBIWAN

So Hugh, what is this Paris Head-Amp thing all about? Is this for a low output MC cart?

[andyr]

... so what is this Paris Head-Amp thing all about? Is this for a low output MC cart?

Yes, netaron,

If you have a low-output MC (say, output 0.25mV), you typically need some sort of amplifying device to raise the voltage to that of a MM cartridge (which typically has an output of 5mV), before it can be used in a typical Phono Stage.  (However, some Phono Stages are very flexible and already allow for low-output MCs, as well as MMs.)

There are two ways of achieving this gain:
* passive - using a step-up transformer
* active - using a "head amp" otherwise known as a "pre-pre-amp".

Hugh's "Paris" (you can guess the origin of the name!   ) is an extremely low noise, gel-cell driven, solid-state gain stage.

Whether you choose the passive or active approach is basically a "faith" thing.  There are good technical reasons why each is good; people who choose one, generally passionately believe that this "the Chosen" way!

Regards,

Andy

[AKSA]

Haron,

Damn!!  My cover is blown again.......

Some time ago, as an intellectual exercise I developed a MC head amp.  The challenge of low noise, low distortion and adjustable input impedance really is interesting.

The result is the "Paris", so named by Andy, who together with a man from Belgium (Hi Uwe!) was a beta tester.  Paris is battery 12V gelcel powered, uses selected JFETs and low noise bipolar devices.  It has a gain of 22, taking 0.3mV cartridges to the same level as MM, ready for driving the GK1/Swift phono input.  For super low output cartridges, you can double the gain without circuit changes with no noise penalty.  I'm still deciding what to do with it;  kit, or retail product?  Performance is up there with the greats, better resolution than most transformers, much quieter than tube designs, better sounding than most SS.  As a finished product I suspect it could sell well, particularly if installed in a novel, interesting enclosure.  I need to get rid of the battery, so it can be powered from a wall wart, and to this end have recently been working on a feedforward power supply.

I have no inventory for the parts, Haron, not at this stage, and need to get JFETs from the one batch.  

Hmmm.  Don't know what to say.......

Cheers,

Hugh

[soitstarts]

I suppose the Lewinsky head amp is a bit of a mouthfull......

Paris head amp??? No substance, no soul, no class, overexposed and over paid... Doesn't sound much like an AKSA product to me...

Perhaps the "Lovelace head amp...." Innovative, classic and no frills..

What size imputs would it need to accept Hugh???

Sorry, I can't contribute in a technical fashion..

But I did just order my GK1M yesterday after Hugh ran me around the block a few times trying to expose my folly gently to me on some ideas I had.. And I can't wait.

[andyr]

I suppose the Lewinsky head amp is a bit of a mouthfull......

Paris head amp??? No substance, no soul, no class, overexposed and over paid... Doesn't sound much like an AKSA product to me...

Perhaps the "Lovelace head amp...." Innovative, classic and no frills..

What size imputs would it need to accept Hugh???

Sorry, I can't contribute in a technical fashion..

But I did just order my GK1M yesterday after Hugh ran me around the block a few times trying to expose my folly gently to me on some ideas I had.. And I can't wait.

What are ya, mate ... a stand up comic?  

The "Monica" ... very good!     Just shows the truth of the old adage "Any publicity is good publicity"    Unfortunately ML has been overshadowed in the press recently by PH ... so all we could think of was "Paris"!  

"No substance, no soul, no class, overexposed and over paid" you say?  A bit harsh, mate ... after all, she's supposed to be good in the head department - maybe we should ask that Oz Idol guy she met up with at the Melbourne cup in 2004!!  

As I'm sure you're aware, the Oz description of a "perfect" bird is a blonde nymphomaniac who's father owns a pub ... so PH scores on all 3!!  In fact her father owns many pubs!  

But yes, absolutely (given Hugh's and my age!   ) we should've remembered poor old Linda!  Hugh, I think we should rename it - or maybe you call the Retail version the "Linda"??     Advertising copy "Sucks you deep into the music"??

You'll love your GK-1, soitstarts!    With or without Linda!  

Regards,

Andy

[AKSA]

Martin,

What size imputs would it need to accept Hugh???

Your elegant lewdness, on this our Australia Day, struck me as entirely appropriate and truly representative of our Australian Values.......

Onya, mate.......    

Hugh

[bluesky]

Hi Hugh

I'll put my hand up for one of the "Paris" units.  Last year, when I briefly had some money to spare, I bought myself an Ortofon Kontrapunkt B cartridge.  And so........ I need a good step up device of some sort, and the lack of noise  in your design appears to be manna from heaven!  

Cheers

Bluesky

[andyr]

Hi Hugh

I'll put my hand up for one of the "Paris" units.  Last year, when I briefly had some money to spare, I bought myself an Ortofon Kontrapunkt B cartridge.  And so........ I need a good step up device of some sort, and the lack of noise  in your design appears to be manna from heaven!  

Cheers

Bluesky

Hi Blueskymate,

Youse won't regret it!     It's the best!

What output does the Kontrapunkt B have?

Regards,

Andy

[soitstarts]

As I'm sure you're aware, the Oz description of a "perfect" bird is a blonde nymphomaniac who's father owns a pub ... so PH scores on all 3!! In fact her father owns many pubs!  

My Mother in law owns a pub and my wife's blonde...... 'spose 2 out of 3 'aint bad.....

[andyr]

As I'm sure you're aware, the Oz description of a "perfect" bird is a blonde nymphomaniac who's father owns a pub ... so PH scores on all 3!! In fact her father owns many pubs!  

My Mother in law owns a pub and my wife's blonde...... 'spose 2 out of 3 'aint bad.....

Good one, Martin!!  

Well ... my wife's father was in the army - no pub! ... but she's certainly blonde (sometimes!) ... but also blue, red, orange and striped...  

Regards,

Andy

[RonR]

Hi Hugh,

Count me in for one of these!

I was using a Battery-powered Marshall Leach Head-Amp (until my other half managed to wipe the sticky-out cantilever off of the front of my Benz Glider   )

The replacement, a Benz Wood-body L2 should arrive soon (the wood body will shield the sticky-out bits, I hope), so the AKSA head-amp would be a fitting addition to this and my GK-1.

BTW, Cartridge Output is 0.3mV, Internal resistance is 13 Ohms, Recommended loading is 100 Ohms.

Happy Oz day all.

Cheers,

Ron

[bluesky]

Hi Andy

The output of the Kontrapunkt B is 470uV according to the Origin Live website.  I got it from Gene at Take Five Audio (in Canada), of whom I can't recommend highly enough, both for service and pricing!    

I am currently building my "audio system for life" (as I can no longer work and rely on a disability pension) so I got what I could with the accident insurance I received (not much after the legal fees, medical expenses etc were taken out).  I then thought long and hard on what to get.  This is what I came up with:

Shanling CD-T100 - second hand and much modified by me with caps,  a Tent clock etc, etc,

Michell Gyro SE - Tecnoarm and Kontrapunkt B cartridge and I am currently upgrading it with Gert Pedersens's kit and Pete Riggle's VTAF,

Aksa TLP - I would love to build the GK-1 (maybe sometime in the future),

Cornet phono stage,

Aksa 55 watt Nirvana Plus

Aksonics speakers - but I would like to build the Ellis 1801's (again maybe sometime in the future).

The cabling is all DIY but I have become good friends with Keith Eichmann who lives in an adjacent suburb to me here in Brisbane.  Keith is a really nice person and yes, again, maybe sometime in the future, I will get some of his cables.      

It is my hope that this system will give me musical pleasure for many years to come!  

Bluesky

[andyr]

Hi Andy,

The output of the Kontrapunkt B is 470uV according to the Origin Live website. ...

Hi Bluesky,

0.47mV is higher than mine so you'd only need a gain of 11 on the head amp to get it up to around 5mV (the typical output of a MM).

My Benz Ebony is 0.28mV so my gain is 20.

Regards,

Andy

[AKSA]

Ian, Ron,

Thank you for your orders.  This is something I now must inventory, and set up the instructions.

The design is unusual.  It uses a JFET, selected for transconductance, and cascoded with a low noise NPN.  Input is direct coupled to the gate of the JFET, output is cap coupled to the MM input, and there is one adjustment for operating point which is not critical.  Board incorporates both channels with ground plane separation, around 3 inches square, and power is from a 12V gelcel.  Vcc is not critical;  it will work down to about 6V without obvious degradation.  A single LED indicates operation, and current draw is just shy of 30mA for two channels.

I'm try to get a batch of 250 or so of the selected JFETs (2SK369) at a reasonable price;  anyone got any ideas?

I won't give a price just yet until I have costs all figured out but it will probably be similar to the phono upgrade price on the GK1.

Cheers,

Hugh