[Tabascosauce]

Hugh,

After much contemplation, I was about to pull the trigger on the DIYHifi Cole phono preamp kit.

Then, a chance visit to your website informed me that you are about to release your own phono preamp.

Are you able to release any more details about the product?

Is it tube based, solid state or opamp?

Is it configured to use with MM cartridges, or restricted to low output MC cartridges?

Does it come as a kit, or a completed product?

Regards,

Paul.

[AKSA]

Hi Paul,

Thanks for your inquiry about the 'Paris' MC head amp.

It's designed for use with the Swift hybrid preamp, which comes stock with a MM phono stage.

Is it tube based, solid state or opamp?

Is it configured to use with MM cartridges, or restricted to low output MC cartridges?

Does it come as a kit, or a completed product?

It uses the 2SK369 Toshiba jfet in a novel single ended circuit, extremely low noise.  Tubes for MC head amps are problematic because of noise considerations;  it's designed to operate from a 250uV source, which is very, very low amplitude and thus highly susceptible to noise.  It's battery powered, but I'm working on a power supply for use with a wall wart, very likely 24Vdc.

It's restricted to MC cartridges, and merely amplifies the cartridge output by either 20 times (26dB) or 40 times (32dB), that is, it's selectable.

It will be completed product, not ready yet, waiting on diecast cases and artwork at this stage.

Anticipated cost is around $US600 for a completed, warrantied product.

Interestingly, these head amps are one of the toughest design challenges in audio.  This design is ground referenced throughout, so does not suffer poor PSRR, the bane of these designs.

Cheers,

Hugh

[andyr]

Hugh,

After much contemplation, I was about to pull the trigger on the DIYHifi Cole phono preamp kit.

Then, a chance visit to your website informed me that you are about to release your own phono preamp.

Are you able to release any more details about the product?

Is it tube based, solid state or opamp?

Is it configured to use with MM cartridges, or restricted to low output MC cartridges?

Does it come as a kit, or a completed product?

Regards,

Paul.

Hi Paul,

Sorry but I believe you're a bit confused with your terms, so let me give you "Vinyl 101"  ) :

* a "phono stage" is the device which provides the gain and RIAA equalisation needed for vinyl playback.

* I guess if it ALSO provides the "normal" preamp functions of more gain and source switching then it might be called a "phono preamp".  Otherwise, a phono stage would feed into a line-stage preamp.

* Hugh's GK-1 is a line-stage preamp which has an optional MM phono stage (the 5th input!).

* the majority of "phono stages" are built for (high output) MM cartridges - ie. they like to see an input signal of 3-5mV.  You can certainly use them for a low-output MC cartridge (typically 0.3-0.9mV) but you need a preceeding amplifying stage.  This can either be a passive device (step-up transformer) or an active device (a "pre pre amp" aka "head amp").

IE. Hugh's "Paris" is a head amp.  It not "limited to" low output MC cartrdiges ... it is typically required by them!! )  However, if you have a MM cartridge then most phono stages - or preamps which have an inbuilt phono stage, like Hugh's GK-1 or Swift - will be compatible.

Regards,

Andy

[Tabascosauce]

Hi Paul,

Sorry but I believe you're a bit confused with your terms, so let me give you "Vinyl 101"  ) :

* a "phono stage" is the device which provides the gain and RIAA equalisation needed for vinyl playback.

* I guess if it ALSO provides the "normal" preamp functions of more gain and source switching then it might be called a "phono preamp".  Otherwise, a phono stage would feed into a line-stage preamp.

* Hugh's GK-1 is a line-stage preamp which has an optional MM phono stage (the 5th input!).

* the majority of "phono stages" are built for (high output) MM cartridges - ie. they like to see an input signal of 3-5mV.  You can certainly use them for a low-output MC cartridge (typically 0.3-0.9mV) but you need a preceeding amplifying stage.  This can either be a passive device (step-up transformer) or an active device (a "pre pre amp" aka "head amp").

IE. Hugh's "Paris" is a head amp.  It not "limited to" low output MC cartrdiges ... it is typically required by them!! )  However, if you have a MM cartridge then most phono stages - or preamps which have an inbuilt phono stage, like Hugh's GK-1 or Swift - will be compatible.

Regards,

Andy

Thanks Andy, obviously my terminology was incorrect.

I'm thinking of upgrading my current phono stage,a MuFi X-LPS.  My query was really to see whether Hugh's product meets my needs, i.e. RIAA equalisation, and usable with both MC and MM cartridges. 

[andyr]

Thanks Andy, obviously my terminology was incorrect.

I'm thinking of upgrading my current phono stage,a MuFi X-LPS.  My query was really to see whether Hugh's product meets my needs, i.e. RIAA equalisation, and usable with both MC and MM cartridges. 

Hi Paul,

No problem!!  Nice to see another vinyl listener!!     There's so many people out there who still believe in the "perfect sound forever" mantra of the early '80s marketing push for CDs!!   

OK, to probe a bit deeper ... what cartridge do you have - ie. MM (~3-5mV output) or MC?   

Regards,

Andy

[Tabascosauce]

An AT440ML, which is MM.  It's specs claim a 5.0 mV output.

Down the track, I can see myself trying a low output MC.  My last cartridge was a Sumiko Bluepoint.  The AT440ML tracks better and reveals more detail, but the Bluepoint had nicer mids.  I have been told that in general, MC cartridges excell in the midrange.

The Cole kit appeals to me because it comes with a step up transformer, but loving my AKSA as I do, I had to enquire about Hugh's new product.

[andyr]

An AT440ML, which is MM.  It's specs claim a 5.0 mV output.

Down the track, I can see myself trying a low output MC.  My last cartridge was a Sumiko Bluepoint.  The AT440ML tracks better and reveals more detail, but the Bluepoint had nicer mids.  I have been told that in general, MC cartridges excell in the midrange.

The Cole kit appeals to me because it comes with a step up transformer, but loving my AKSA as I do, I had to enquire about Hugh's new product.

Hi Paul,

Mmmm, I don't know that low-output MCs just "excel in the midrange" ... I think it depends which perticklar MM or MC!!     I personally like MC ... but I do also have a Grado Platinum Signature MM which I use when I have to send my Benz Ruby/Ebony back to the factory every coupla years, for retips!   

OK, unfortunately Hugh (at present!!     ) doesn't package the phono-stage part of the GK-1 as a stand-alone phono stage.  I keep suggesting to him this might be a good thing to do ... so you may as well press him to build one for you!!   

If he doesn't want to do this (bcoz he does have quite a few new things on at the moment!  ), I can suggest a couple of other alternatives.

Any MM phono stage will be fine for your AT440ML and then, if you get a low-output MC, you'd have to add a step-up (transformer) or a head amp.

I personally love the "Paris" head amp.  Many years ago, I used to have a Trevor Lees tube head amp but got rid of it bcoz I just couldn't cope with the "tube rush" ... as Hugh said, low noise is a real problem with the tiny signal voltages involved in a head amp.

Yet "SuperMart" prefers this same head amp over "Paris" ... I guess there's no accounting for taste, eh!!     (Well, he is a Pom!!    )

You said "The Cole kit comes with a step up transformer" ... however, I would suggest this is not necessarily a good buy if you don't have a choice!!     Firstly, you don't need a step-up tranny with your AT440ML and, secondly, when you do buy a low-output MC, you might prefer:
*  some other step-up transformer, or
*  a head amp like "Paris".

Personally, I had some English step-up trannies with one of my phono stages (sorry, forget the name!!) but one day I removed them and upped the gain in the MM phono stage instead ... and found that I got a much wider soundstage.  So I poysonally am not a fan of step-up transformers!

Regards,

Andy

[Tabascosauce]

Andy,

Thanks for your wise words of advice.

This is a hard decision for me, and one I've been thinking long and hard about.

The difficulty is I have such limited options to audition phono stages.  What has been your experience with tube phono stages in general? 

[andyr]

Andy,

Thanks for your wise words of advice.

This is a hard decision for me, and one I've been thinking long and hard about.

The difficulty is I have such limited options to audition phono stages.  What has been your experience with tube phono stages in general? 

Hi Paul,

Mmmm ... very little experience with tube phono stages, per se.  Do you have a GK-1?  If you do then I personally would think that a ss unit before the GK-1 would be better (bcoz the GK-1 has that output tube stage); if you don't then a tube phono stage might be very good with a ss line-stage preamp.

Yes, there is about zero chance to audition phono stages - tube or ss!!     The good phono stages which I've heard about - and some of these (if not all??) are tube - are Graham Slee, EAR 834?? and Hagerman ... this latter one comes as a kit.

Regards,

Andy

[Tabascosauce]

Hi Paul,

Mmmm ... very little experience with tube phono stages, per se.  Do you have a GK-1?  If you do then I personally would think that a ss unit before the GK-1 would be better (bcoz the GK-1 has that output tube stage); if you don't then a tube phono stage might be very good with a ss line-stage preamp.

Yes, there is about zero chance to audition phono stages - tube or ss!!     The good phono stages which I've heard about - and some of these (if not all??) are tube - are Graham Slee, EAR 834?? and Hagerman ... this latter one comes as a kit.

Regards,

Andy

I have a Metaxas Charisma preamp.

I've just thought that if I'm looking for more of a tube sound, should I just upgrade to a GK-1?  This will allow my digital front end to also benefit from the tube output stage. 

Has anyone compared Hugh's phono stage in the GK-1 to my X-LPS?

Selling both my Charisma and X-LPS will come a long way to the cost of a GK-1 with the phono stage.

[andyr]

I have a Metaxas Charisma preamp.

I've just thought that if I'm looking for more of a tube sound, should I just upgrade to a GK-1?  This will allow my digital front end to also benefit from the tube output stage. 

Has anyone compared Hugh's phono stage in the GK-1 to my X-LPS?

Selling both my Charisma and X-LPS will come a long way to the cost of a GK-1 with the phono stage.

Hi Paul,

A Metaxas, eh!     Did you know, Kostas M at one stage about 12 or 15 years ago decided to branch out from hi fi and become a restauranteur!  He created a restaurant at a famous pub near my place called the Station Hotel (which had part of a train engine "poking out" through the front wall!).   

I never ate there but one Saturday morning, I did see him having a furious argument with a chef, outside the pub!     Shortly after, the restaurant closed!

Anyway ... you're over in the west, aren't you, so you can hardly borrow my GK-1 for a direct comparison!     But you know what Hugh's products are like so I would say, yes, if you're looking for more of a tube sound, you should upgrade to a GK-1!!     And if you can sell your Charisma and X-LPS for almost the cost of a GK-1/phono stage, you're a lucky man!

Regards,

Andy

[Tabascosauce]

Anyway ... you're over in the west, aren't you, so you can hardly borrow my GK-1 for a direct comparison!     But you know what Hugh's products are like so I would say, yes, if you're looking for more of a tube sound, you should upgrade to a GK-1!!     And if you can sell your Charisma and X-LPS for almost the cost of a GK-1/phono stage, you're a lucky man!

Regards,

Andy

Yes.  My only concern is that I spend about one third of my music listening time using headphones.  I have a stand alone headphone amp that I really like.  My Charisma has a tape out, which I use as the input for my headphone amp.  This gives me easy switching between my sources without having to swap cables everytime I want to use my headphones.

From what I have read, it seems to me that the GK-1 can't easily do this.  Am I correct?

[andyr]

Yes.  My only concern is that I spend about one third of my music listening time using headphones.  I have a stand alone headphone amp that I really like.  My Charisma has a tape out, which I use as the input for my headphone amp.  This gives me easy switching between my sources without having to swap cables everytime I want to use my headphones.

From what I have read, it seems to me that the GK-1 can't easily do this.  Am I correct?

Hi Paul,

S'no problem!!   

If you buy a GK-1 and build it yourself (instead of buying a retail Swift    ), you simply do what I did and have two pairs of RCA "outs" (not counting the sub out!).

I use this second pair to drive a small amp which powers speakers in other rooms; when I'm listening to my main system, this amp is turned off.  You would use them to feed your headphone amp.

Regards,

Andy

[Tabascosauce]

Hi Paul,

S'no problem!!   

If you buy a GK-1 and build it yourself (instead of buying a retail Swift    ), you simply do what I did and have two pairs of RCA "outs" (not counting the sub out!).

I use this second pair to drive a small amp which powers speakers in other rooms; when I'm listening to my main system, this amp is turned off.  You would use them to feed your headphone amp.

Regards,

Andy

I was planning on DIY.

This is my headphone amp:

http://www.amb.org/audio/mmm/

As you see, it is designed for a line stage input, and has it's own volume and tone control (bass boost).  I wasn't sure that it would work out if I have an input to it from a GK-1 that has been through a tube output.

Is there any signal degradation by having two RCA outputs?

[andyr]

I was planning on DIY.

This is my headphone amp:

http://www.amb.org/audio/mmm/

As you see, it is designed for a line stage input, and has it's own volume and tone control (bass boost).  I wasn't sure that it would work out if I have an input to it from a GK-1 that has been through a tube output.

Is there any signal degradation by having two RCA outputs?

Hi Paul,

Good, so you were thinking of a GK-1.  I'm pretty sure there is no degradation from feeding the output of the tube stage to two devices (in my case, 2 power amps and in yours, 1 power amp and 1 headphone amp) but you should perhaps ask Hugh to confirm this?   

If you don't want to feed your headphone amp with a signal that's gone through the tube stage ... feed it from your "sub out" RCAs (ie. the wiper of the GK-1 volume pot).  Alternatively, if you don't want the headphone signal to go through 2 volume controls ... feed it from the input pin of the GK-1 volume pot and just use the volume pot on your headphone amp.

Regards,

Andy

[Tabascosauce]

Good, so you were thinking of a GK-1.  I'm pretty sure there is no degradation from feeding the output of the tube stage to two devices (in my case, 2 power amps and in yours, 1 power amp and 1 headphone amp) but you should perhaps ask Hugh to confirm this?   

If you don't want to feed your headphone amp with a signal that's gone through the tube stage ... feed it from your "sub out" RCAs (ie. the wiper of the GK-1 volume pot).  Alternatively, if you don't want the headphone signal to go through 2 volume controls ... feed it from the input pin of the GK-1 volume pot and just use the volume pot on your headphone amp.

Hugh????

Other than in cases of forgetfulness, I would not be running both the headphone amp and my AKSA 55N+ at the same time.

[AKSA]

Hi Paul,

Andy is quite right (thank you Andy!!);  there is no penalty feeding two amps, one each from the level control, just before the tube, or after the tube - depending on preference.

If driving both amps from the tube output stage of the GK1, you do need to ensure that combined input impedance is not less than 15K.

This constraint is somewhat relaxed if driving an amp from the level control in front of the tube, which is nominally 20K but can be as low as 10K.

With the GK1, you can make a choice about whether you want accurate but cold sound from the input SS section, or tubey, warm sound from the tube.  The options are there for you to have both with a simple plug in arrangement.  Most prefer the tube sound - no surprise I guess!

Cheers,

Hugh