[ghamel]

Hugh,

I'm getting my ducks lined up for a GK-1R, and I've a few questions for you...

Can the remote control the power to the unit?  Any ability to present a  source/sink interface to power an external relay (like to toggle power to an  AKSA?) I know that might not be the purist approach, but imo any noise that a relay imparts to the ac power will be way more than swamped by the existing line noise...

Do you have a layout template of any sort for the front panel? I'm wondering how big and what sort of freedom i'll have to lay things out..

I notice on several posts that the volume pot is occasionally mounted deep in the enclosure, is there any special hardware that I'll need to source locally (like shaft extenders)?

Saving... saving...

Thanks,
Greg

[AKSA]

Hi Greg,

Thank you for your post.  Good questions!

Can the remote control the power to the unit? Any ability to present a source/sink interface to power an external relay (like to toggle power to an AKSA?) I know that might not be the purist approach, but imo any noise that a relay imparts to the ac power will be way more than swamped by the existing line noise...

No.  We did a careful analysis of this based on the fact that most would not leave a valve preamp on all the time, and would, nine times out of ten, move to the co-located CD/DVD player to put on a CD.  At this time it made perfect sense to throw the switch on the preamp.

A remote facility on the GK1R would complicate the power circuitry very considerably, much of it at mains voltage, and we considered it unjustified.

Do you have a layout template of any sort for the front panel? I'm wondering how big and what sort of freedom i'll have to lay things out..

Yes, the push button template is 128mm x 70mm, with five push buttons evenly spaced along a 88mm line, and two push buttons beneath spaced at 22mm.  When you receive the kit, you use the push button pcb to mark out exactly the positions of these pushbuttons (which are supplied, BTW).

I notice on several posts that the volume pot is occasionally mounted deep in the enclosure, is there any special hardware that I'll need to source locally (like shaft extenders)?

Only on the manual control version of the GK-1, the M variant.  The extender bar is included in the kit...  

Cheers,

Hugh

[Mark_Walsh]

Regarding the GK1-M:

I know the source selection is manual, but is the volume control manual as well??  I read between the lines as much as my eyes would allow, but I was unable to find that.

Oh, and just confirming, the circuitry/sound of the TLP is different from the GK1 series, yes?  (I got that from reading only 45 degrees out of phase from the lines.)

Regards,
MW

[EchiDna]

I had an early version of the manual GK-1 and everything is manual, including the volume...

otherwise, where would the need for a remote version come from?

since then, I bought the gk-1r upgrade kit and now every control is remotified...

and...
the TLP is the pre-cursor to the GK-1, something like the refined grandfather of the family whose offspring have benefited greatly from the extra genes available through marriage with a new group of ideas

[Grumpy_Git]

I've decided to ressurect an old thread rather than to start a new one.

Anyway, Hugh sold me the last GK-1R and I've now decided to start assembly, slowly as I dont have much free time.

Anyhoo, I've started installing resistors and would like to know why there are two options for R18 of 220k and 261k.

Should I hve any more stupid questions or need any more help I shall come here and ask again.

Nick.

[AKSA]

Hi Nick,

Good question, and one which comes up from time to time!

This is a tie down resistor, which references the capacitive output of the tube to ground.  It serves only to prevent large thumps as you connect a power amp to the GK1, nothing more.  No influence on sonics at all.

Since the tail load on the tube  is just 5K (the 2 x 10K resistors in parallel), a ground referencing resistor, which is seen as a load by the tube, should be around 10 times larger than this value, say around 50K minimum.  But there is no purpose to using a very small resistor here as its time constant need not be better than half a second or so.  In truth, R18 can be anything from about 100K up to about 1M, so either 220K, or 261K, or 270K is just fine!

Cheers,

Hugh

[Grumpy_Git]

New Question.

I'm off to spain for a week on saturday for a break and my girlfriend wont let me take my Iron, plus I'm not sure customs would like to see a pile of resistors et all in hand luggage, BOOM! so I'm working on it now rather than packing.

I've started on the relay board and I just cant get the phono blocks to fit, its really starting to get my goat. Every time I try to push the blocks in I just bend the gold pin, I've given up for the moment cos I dont wanna break it.

Any advice where I'm going wrong?

Please Help I want toplug it all in when I get back to get over my return to work.

Nick


edit:
Dunno if it helps any but placing the blocks in position, all the pins/clips line up fine except for the two gold pins where the holes are about 2 to 3mm nearer to the edge of the pcb than they should be.

Nick.

[AKSA]

Nick,

Drill out the centre pin to 1mm.  This often makes things easier.

Cheers,

Hugh

[andyr]

Nick,

Drill out the centre pin to 1mm.  This often makes things easier.

Cheers,

Hugh

Hugh,

We gotta remember Nick is a Pom ... all those years of chip butties must surely have clogged up his brain arteries!

If "all the pins/clips line up fine except for the two gold pins where the holes are about 2 to 3mm nearer to the edge of the pcb than they should be" ... how come?  My Relay PCB was certainly AOK ... did you make a second "printing" run?

Regards,

Andy

[RonR]

Andy,

You may well be one prawn short of a barbi on this one, what if the boards are the same, but the phono blocks are different?

Cheers from the land of the Pom,

Ron.

[andyr]

Andy,

You may well be one prawn short of a barbi on this one, what if the boards are the same, but the phono blocks are different?

Cheers from the land of the Pom,

Ron.

Maaate,

I know you probably rush home from work every day to catch "Neighbours" but it's ackcherly "one prawn short of a barbiE" ... or "one sanga short of a picnic" ...  

I thought he was talking about the relays (which fit into holes drilled into the Relay PCB) whereas you - probably rightly - are referring to the RCA "blocks" for the Phono input.

I myself think they are the work of the devil (with their nickel plating), so used solid gold RCA sockets and connecting wires instead.     Just kidding - actually I use Vampire RCA sockets.

Regards,

Andy

[RonR]

Andy,

I must admit to being a complete Soap-a-phobic, and as I'm also allergic to reality TV, I find I'm watching the box less and less nowadays.

Sorry about my mis-spelling of the shortened version of barbecue (not barbIecue). We only use them here whe we want to guarantee that it will rain!

Coming back to the GK-1, I've toyed with the idea of replacing the RCA sockets, but never taken the plunge. Did you notice a significant improvement?

Cheers,

Ron.

[andyr]

Andy,

Coming back to the GK-1, I've toyed with the idea of replacing the RCA sockets, but never taken the plunge. Did you notice a significant improvement?

Cheers,

Ron.

Sorry, Ron,

With me it's kind of a "religious" thang!  I use what I consider to be high quality RCA plugs and sockets - but I hardwire if this doesn't produce a usage problem - and I don't use stranded hookup/IC wire or caps with stranded leads (like Auricaps)!

So I built my GK-1 with the Vampire RCAs from the start ... so I have no comparison.

Regards,

Andy

[AKSA]

Ron,

I've heard Andy's GK1 and it is certainly a wonderful sound   , but then the quality of his sources, room,  speakers and cabling is also premium so it's hard to identify precisely where the sonics are coming from!  Perhaps it's worth mentioning that if anything in the chain was below par the sound would not be as good as it is.....

My own feeling is that while there is considerable sonic improvement with high quality male RCAs (such as Vampires and Eichmanns), the female panel mount sockets don't seem to suffer the same effect.  I wouldn't dismiss the RCA blocks supplied out of hand;  they sound just wonderful to me, and if you cannot induce them to fit, just drill out the mounting  holes a little.   You should find that the centre, thinner ground terminal can be bent to position with long nosed pliers quite easily.  To be honest, while I've occasionally found assembly fiddly, this is to be expected as I wanted them to be a tight fit for reasons of mechanical strength, since they actually support the input/output pcb.  I use them on the Swift, the retail GK1, as well.

Hope this is helpful,

Cheers,

Hugh

[Grumpy_Git]

Hello all

I'm back from my break and got straight back to the soldering iron.

My next question relates to the GK1 relay Board.

I've been fitting the wire links and I'm not sure what I'm supposed to be doing about the link resistor. Do I put something in or not bother or is there a wire link to the analogue board, if so where to?

Nick.

[RonR]

Hi Nick,

Welcome back to the real world!

The need for an extra wire link between the Relay and Analogue boards was first discovered by Jens et al in this thread: http://www.audiocircle.com/index.php?topic=9581

The link resistor is part of the earthing scheme, for which there are at least 2 possible solutions. If you don't have the Phono section installed, I can recommend the earthing scheme outlined here: http://www.audiocircle.com/index.php?topic=17487 leaving out the Phono bits.
This is how my GK-1 is wired, it keeps the Power earth and Signal earth separate (joined by a 10 Ohm resistor), and resulted in a slightly lower noise floor.

If you have the Phono section then I wouldn't recommend this approach if you're at all nervous about PCB surgery. Hugh came up with a very good work-around, but it can get a bit messy - reworking the PCB by cutting lands to separate Power and Signal earths.

If you do have the Phono section and you're still interested, let me know and I'll PM you the details.

Cheers,

Ron.

[Grumpy_Git]

thanks everyone, im nearly there. just need something to bolt it to so i can  wire it up.

more questions first...

does the remote use the codes for any existing equip as i dont want to open the packing just to teach my pda, that seems silly.

where do i take power from for the potentiometer motor.

finallly does anyone know where i can get a perspex case made in the uk?

cheers in advance.

Nick.

[AKSA]

Does the remote use the codes for any existing equip as i dont want to open the packing just to teach my pda, that seems silly.

where do i take power from for the potentiometer motor.

Nick,

The codes are RC5 from Philips.  Some products in the market might have conflicting control coding;  this has happened once.  However, while this is inevitable, where it happens we will offer an alternative set of codes in time, but the present protocol is quite conventional.  

Power for the pot motor is from CON4 on the digital control pcb.

Hope this is helpful,

Cheers,

Hugh[/quote]

[Grumpy_Git]

Thats great Hugh.

I've just looked for replies to my qs and noticed That I've posted up 3 times, I'll try and get rid of them but I appologise for the incompetence of my pda and wireless network.

Many thanks to all.

Nick.

[Grumpy_Git]

Hey all

I've started to fudge a layout to get the amp tested ( a combination of books blu-tac etc...

Anyway, most of the numbers seem ok except one. Please have a look through and make some suggestions.

LEFT CHANNEL

Across R12   1.26v
o/p to gnd    0.8v
across R8     0.62v   (sure i got 2,5v here at one point)
across R4     1.54v
gnd and R12 14.42v
gnd and R8   -14.49v

Across R31    33.5v
gnd to R31     139.4v
*** gnd to R23     49.5v(dc)  109.3v(ac)
*** across R26b-R27b  2.4v

RIGHT CHANNEL

Across R12   1.28v
o/p to gnd    0.9v
across R8     0.62v
across R4     1.545v
gnd and R12 14.09v
gnd and R8   -13.86v

Across R31    33.3v
gnd to R31     141v
*** gnd to R23     47.6v(dc)
*** across R26b-R27b  0.2v

Any suggestions, some of these look weird, and I'm so close, I just want my gk1 now.........................