[PSP]

I've had my GK-1R running for about six weeks now eight weeks including break-in.  During break-in, I listened, but not critically... I just left it playing most of the time, with occasional short power-down periods just in case that would speed settling in of the caps.  

So, how does it sound?  Waaaay good   !!!  Absolutely extraordinary!  

When I have a few solid hours to spend (so I can do a decent job) I will be a bit more disciplined in my listening and reviewing.  For now,  a quick report.  Last night, I listened to:

 - Nancy Wilson, "With My Lover Beside Me"... I could locate essentially every instrument in the band, every instrument "correct" in terms of attack and timbre.

 - Concerto Italiano on "Bella Itallia".... oh, my... the lushness of this small orchestra, when they want to play "lush", and the sharpness of the strings when they want to "cut"... holy moly Rocky, the music is absolutely incredible!  The harpsichord, each note like a star in the sky, an absolute pin-point of sound, no mush or blur whatsoever.

The magic that I hear from the GK-1 is:
 - detail without harsnhess.  A bad recording can sound harsh, but most of my recordings sound very, very good indeed.  The excellent recordings sound extraordinarily good.
 - layering... this is detail, observable even when the passage is complex and the orchestra large.
 - extraordinary imaging.  The image is sharp, stable, and "right".
 - emotion... I listen to music for its emotional impact, and this preamp has impact.
 - instruments and voices are "just right"...

Although I bought the GK-1R almost 18 months ago, it took me a very long time to get started... honestly, most nights I would rather listen to my previous system (preamp = TLP) than solder all night working on the GK-1R.  Jens told me that I would really like the GK-1, and so did Hugh... but I was happy most nights listening to the TLP.  It's a nice, extremely nice preamp.. but the GK-1 is a great preamp.  I should have listened more to Jens and Hugh...

Peter


Equipment:
Philips 763SA CDP
ART DI/O DAC
GK-1 Preamp
AKSA 55-N
GR Research Paradox 3 floorstanders
ChrisVH Pulsar interconnect w Eichmann bullet RCAs
Jon Risch CC89259 speaker cable
VMPS New Original Sub (XM-9 XO, 100w AKSA mono sub amp)

[AKSA]

Hi Peter,

Many thanks for your assessment of the GK1 - I appreciate the care you've taken, and the critical factors you assess are almost exactly the ones I go for;  imaging, timbre, emotional impact, layering, 'organic' feel.  These are the highly subjective factors which I believe separate a good preamp from an excellent preamp.

As most know, the GK1 was developed with Darl Singh, of Hamilton NZ, doing the prototype and critical assessment.  I did the design, and we communicated several times a week via Skype using broadband net access.  In the finish the GK1 shared many common aspects with the TLP, its progenitor, but it is actually much, much more because there is unique circuitry in the tube section of the GK1 which processes the music in ways quite different to any other preamplifier.

This has given the GK1 very powerful, almost snarly bass, of the kind you would not normally associate with tube gear, yet with the very same 'organic' and engaging feel to the midrange and top end expected with tube gear.  That these two extremes have been combined is the real trick and the most noticeable feature of the GK1.

Cheers,

Hugh

[PSP]

Hi Hugh,
In my brief comments above, I did not intend to slight the GK-1's excptional handling of the lower registers.  I'm now running my Paradox 3s full range with the sub (XO at 32Hz) only filling in at the very bottom.  When I put the GK-1 into the system, at first I had way too much bass.  I had to turn the sub way down, and now the whole spectrum sounds extremely nice (I've listened to a lot of live music, especially symphonic, so I know roughly where the target is).  I have not yet fully dialed in the bass (i,e., measure, listen, refine) but--judging by the sound--I'm pretty close.  The bass is very deep, tight, and you can feel it in your guts when someone winds up and whacks a big bass drum.  That said, my bass is currently nowhere close to the bass in Jens' system   .  

By the way, my favorite recording to assess bass performance are:
  B B King, Deuces Wild
  Mussorgsky, Pictures at an Exhibition (pipe organ, on Dorian)... thanks to Jens for bringing my attention to this incredible recording!
  Sousa Marches, Dallas Wind Ensemble, on Reference Recordings

Take care,
Peter

[Jens]

Hi Peter,

I think you know now what I meant when I told you that my system had been greatly improved after inserting the GK-1R  

I should mention that I am making full use of the GK-1's capabilities, as in my bi-amped system I am using it's SS output to feed the bass section and it's tube output to feed the treble/mid section of my Equilibrium speaker system.

This gives me very tight control over the bass section whilst the treblem/mid almost sings angelicly. If anyone should think that using the GK-1R in this manner might create problems, I can only say that in my system everything is absolutely seamless using this combination, and I can only recommend doing this to anyone if they have the possibility to biamp in this fashion. Sure, you will need an extra amp, but I'm certain Hugh will be happy to supply yet another kit  

As far as I remember (Hugh, correct me if I'm wrong), Hugh included the SS output as an option exactly to feed to a sub section. I can only say that again he has proven to be very foresighted.

Apart from the above, I wholeheartedly agree with your description of the GK-1's properties and can only recommend that anyone wanting a state-of-the-art preamp give the GK-1 a listen.

Personally, I was truly astounded that there was so much to be gained over my previous handbuilt preamp, which had beaten off any competition - until the GK-1R came along

Cheers,

Jens

[EchiDna]

Can you explain that a bit more Jens?

you are using the GK-1 tube outputs to run an amp for treble and mids, and the SS output for running an amp for the bass?

how do you find the volume control in this scenario? - I had thought that only in HT bypass mode the sub outputs were active - no real reason why I guess.... I just did *sigh*

I've not got a sub (or two) (yet) but I'm intrigued by this option for biamping through the one preamp - I'd never thought of it in using the GK-1 before and if it works as I'm thinking it does, Hugh, you aint playing this feature up enough!

I've got visions of an active crossover for bass duties in my future now...

[Jens]

Hi Echidna,

No sweat, the volume control works for both set of outputs. This has nothing to do with the HT bypass, which a separate function.

You are right, perhaps Hugh should advertise the additional SS output a bit more. However, now I've done it and has proven that it work extremely well.

Cheers,

Jens

[Greg Erskine]

Although I bought the GK-1R almost 18 months ago, it took me a very long time to get started... honestly, most nights I would rather listen to my previous system (preamp = TLP) than solder all night working on the GK-1R. Jens told me that I would really like the GK-1, and so did Hugh... but I was happy most nights listening to the TLP. It's a nice, extremely nice preamp.. but the GK-1 is a great preamp. I should have listened more to Jens and Hugh...

Peter, what got you off your arse to finish your GK-1 because I need a fix of it to finish my AKSA 55 N+  

I've been wasting my time building Gainclones and other kit amps. I don't know WHY    None of them are a patch on my standard AKSA 55. I really get a buzz plugging the AKSA back in after listening to my other stuff for a few weeks. Am I sick?

OK, I'll pack my Gainclones away, finish my N+ then I'll buy a GK-1. Good plan...

[EchiDna]

Hi Echidna,

No sweat, the volume control works for both set of outputs. This has nothing to do with the HT bypass, which a separate function.

You are right, perhaps Hugh should advertise the additional SS output a bit more. However, now I've done it and has proven that it work extremely well.

Cheers,

Jens

Thanks Jens... hmm this has got me thinking how I can use these SS outputs more effectively.

[AKSA]

Glen,

The philosophy behind this feature is simple.  Tubes give wonderful midrange and top end, but since they are capacitively coupled and traditionally use high impedance power supplies with intrinsic voltage 'sag', the deep bass is often lacking in attack.  What was needed was the magical qualities of tubes in the top end and midrange, with the attack and heft of solid state in the bass.

Traditionally the input to a preamp incorporates the volume control, which, being a potentiometer, requires low impedance drive and high impedance feed.  I rearranged the order in the GK1, with a discrete opamp input stage running unattenuated at line level, driving a single ended tube output stage.  This gave the optimum impedances for this vital component, removing some of its baleful influence on the sonics.  But it also gave a solution the problem identified in the first paragraph......

Since the tube grid, which exhibits an impedance of many megohms, was driven from the wiper of the pot, why not drive a sub-woofer amplifier at this point, circumventing the tube and giving the full attack and heft of an all SS system?  The midrange and top end would still be processed through the tube;  by taking the output from the wiper the levels would be simultaneously controlled.

Darl and I tried this arrangement and exhaustively tested it.  It gave close to what we believed was the ideal.  Henceforth it became a feature, and all those who have used it have been astonished to get the best of all possible worlds......  audio design by Dr Pangloss, no?

For those running their GK1s full range, don't be concerned you draw the short straw.  Not at all!  The trick configuration of the GK1 ensures that the bass coming off the tube is still tight and fast like good SS anyway.  That's another feature;  the antiphase shunt power supply we worked on over quite a period.  We tried all sorts of power supplies but this one had it all and is a feature of the GK1.  As Smokey Yunick once said (some may remember this legendary man who pioneered development of the NASCAR Chev V8), 'Look carefully at this design and you'll find more tricks than a monkey on a mile of jungle vine!'

Cheers,

Hugh

[PSP]

Hi Greg,
All those months while listening to the TLP-N and 55N, I was also thinking hard about chassis layout.  When the layout issues (the tradeoffs that I had decided to favor) were resolved, I began to work a bit faster.  The layout struggle began to resolve last March-April, and I began drilling holes in metal about that time.

And secondly, I have a 1-2 year goal to build a set of Jens' Equilibrium speakers.  Getting the GK-1 built, with its ability to handle the bass seperately (if one chooses) was something I wanted to get done before I tackled the Equilibrium project.

I am running as follows:
  GK-1 SS output --> XM9 XO--> AKSA 100 Sub amp -->Sub
  GK-1 Tube output--> AKSA 55N --> Paradox 3s (full range)

To underline Hugh's comment about the bass on the Tube output... On the rare occaisions when I'm messing with the XM9 XO, sometimes I forget to turn the sub amp back on.  I can go a couple of days listening to music without realizing that the sub is still off... it really only adds a little bit of extra punch in the very deepest bass.  For sure, there is no lack of bass (quantity of quality) in the Tube Out signal.

Peter

[DSK]

I'm doing much the same thing here in my 2-channel system ...

GK-1 tube output --> AKSA 100N+ --> Ambience Ultra 1600's (full range)
GK-1 SS output --> Rhythmik Audio DirectServo sub

The Ambiences are a ribbon hybrid with very high resolution capabilities and readily show up anything in the signal path. So, I didn't want to hang them off the sub's circuitry. The GK-1 enabled me to add the subwoofer without compromising the signal to the Ambiences, and to control both with the TKD stepped attenuator in the GK-1. I stuffed the Ambience ports for a smoother rolloff and now have +/- 1.5db from below 20hz to above 200hz, measured at the listening position. The sub has a 12" driver, sealed 2.0 cu.ft. box with all 1.5" thick walls and full bracing, 385w RMS modified plate amp, and weighs in at 93lbs. With the sub set to Q=0.5 and high damping, driven by the SS output of the GK-1, the bass is very extended, and very tight, crisp, articulate and musical. It provides a great match to the realism of the Ambience ribbons.

Previously, I had considered bi-amping the Ambiences with an external active xover. But the performance of the Ambiences (they have the Special Edition Hovland xovers ) when driven by the GK-1 (with TKD attenuator and Siemens 7308 gold pin tubes) and integrated with a super tight and musical sealed sub driven by the GK-1 SS output, is as transparent, musical and real as I have heard anywhere and I have lost the urge to bi-amp.

If it gets any better than this, I most likely can't afford it  

I agree that Hugh should probably bring more attention to this feature and heartily congratulate him on the performance of both the GK-1 and the N+ amps ...truly stunning performance!  

[SamL]

Hi Echidna,

You are right, perhaps Hugh should advertise the additional SS output a bit more.

Agree! I have taken GK1 off my list due to various reason but now it might be back

Sam

[Rod]

Hi all, long time lurker, first time poster

This is interesting news. I too am planning a GK build for an active xover system and it would be really good to have the option to bypass the tubes for the bass drivers (2 x Peerless 10" XLS in dipole arrangement).

My question was is this 'SS' output included in the Standard GK-1 Entry level package?

[Lost81]

My question was is this 'SS' output included in the Standard GK-1 Entry level package?

Most excellent question!
I was about to ask it myself  


-Lost81

[AKSA]

No, only on the M and R version.....

Hugh

[Rod]

No, only on the M and R version.....

Hugh

Thanks for the quick response! Hmmmm can one upgrade a standard GK1 to include this at a later date? Such as what can happen with the Nirvana and Plus upgrades?

[AKSA]

Rod,

Yes, the EL can be upgraded to either M or to R, as you wish.  The model series was designed specifically for this upgrade path.......

Cheers,

Hugh

[SamL]

Hugh,

Will there be a GK1 Nirvana upgrade?

Sam

[EchiDna]

Hugh,

Will there be a GK1 Nirvana upgrade?

Sam

haha! Hugh you just knew this question would come sooner rather than later didn't you?  

[AKSA]

No problem Glen, I have the answer!

Sam, regrettably the answer is no.  I will give the Nirvana treatment to the retail GK1 Swift to foster retail sales.  The kit preamp, sadly being a humble DIY product, will not feature this value add benefit.

I really have to start thinking more like a businessman.........

Cheers,

Hugh