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Arkless 640P "Dr T Mode"/current input version interest check

Discussion in 'audio' started by Arkless Electronics, Feb 15, 2020.

  1. Rug Doc

    Rug Doc pfm Member

    This is on the way to the next recipient now and I have bought a 620P already in preparation....

    I have never used a phono stage before, having always used the built in stages my preamps... Having got hold of a Denon cartridge, I wanted to see what could be achieved without a huge outlay. I was enjoying the cartridge already, but wanted to see if the Gti made a difference..

    Plumbed it in and the short answer is yes, of course it did. (Yamaha YP-D9 table with Micro Seiki arm and Denon 103r in Midas HS)

    I compared my other sources (CD and Tidal HIFI) to what the turntable could now achieve with the same albums and I'll be honest the GTi blew me away on most selections.. I don't spend my time listening to music to try and recreate the 'live' venue, or create a 'real' instrument in my home, I listen to music that I enjoy and my main musical tastes are Electronica, Ambient and EDM - not your usual audiophile record collection.. BUT please don't stop reading if Classical is your only favour... some music of this genre has been written, mixed and produced by people with the utmost love, care and attention... The producers thrive on creating a layered, enveloping soundfield.. And lots of them have very esoteric hifi at home, so are very used to listening to HOW music should be produced...

    I cannot imagine that the sounds from the mixing desk differ a huge amount from what I was hearing at home yesterday... With the Arkless in the loop the soundfield was wider, deeper and way more enveloping than Tidal for example.. Play Sasha's Involver on Tidal and it sounds great, - fast and powerful, switch to the GTi and the width increases and then depth of stage also elongates.. from listening to a flat plane of sound it's as if the straight line has got wider and has turned into a convex shape around you - sounds appear further off to the sides - at least 90 degrees so either side of me and the stage moved back about two feet. Amazing, and sounds like it should have 'always' been like that.. but I was missing it before.. I plugged in the CD player (same album) to compare and it all shrank and collapsed back into the same smaller size... I was after an hour of so playing the system quite loud (no neighbours) so much so that the bass was pressurising the room quite nicely, but I was sat on the floor basically listening to what the producers wanted me to and at the volume they intended... superb fun.

    So, on Saturday my second hand 620P arrived (which I bought on here last week) so I though well I MUST plug that in and see how it compares to the upgraded Gti.. what an opportunity..

    It wasn't a small change - the GTi increases on the strengths of the donor by increasing detail, depth, width and attack. It's such a fast and precise piece of electronics that opens up the whole soundstage and just delves deeper and clearer into the mix.. it's not like a 620p with a bit of extra sparkle to entice you in temporarily and then tire.. its a completely different beast with a far more involving way of presenting music that just gets you more involved... I've got to the stage in my system where I am very happy with my speakers and amp, I don't want to box swap any more as I've found such a resolving pairing (NS1000XW and B-2) that I don't think I'd improve it without spending thousands... But adding in the GTi in the phono section I do see as a very worthwhile addition so when he's doing more I'll send him mine in.
  2. Arkless Electronics

    Arkless Electronics Trade: Amp design and repairs.

    Tanks for the detailed review Rod:) You like it then:D

    It's a 640P or 651P and not 620P that is needed as a donor unit BTW. Oh and it sounds very different to a "standard" 640P because it isn't a 640P! It has completely different circuitry!

    Soooo.... anyone else want to book a home trial? I stress once more that if there are no comers and it has to come back to me in say a week or so, after SamS tries it, then requests for a home demo will be refused. Hence, anyone thinking "I may give this a go in a month or two" needs to do it now or the next opportunity will likely be around Feb/March next year.
  3. Rug Doc

    Rug Doc pfm Member

    sorry my memory isn’t what it was... I have a 640p!
    Arkless Electronics likes this.
  4. Colin123

    Colin123 pfm Member

    Hi Jez,

    I don't want you to bend your own rules but I do have an Arkless 640P I bought from you a couple of years ago
    and have messaged you privately about upgrading it back in July. You then mentioned you are fully busy until October some time.
    Any possibility of you reconsidering?
  5. Arkless Electronics

    Arkless Electronics Trade: Amp design and repairs.

    You should have said! Yeah no problem then:)
  6. Colin123

    Colin123 pfm Member

  7. SamS

    SamS pfm Member

    So, what can I say about Jez’s GTI, which I have just posted on to Colin?

    A bit of background – I am running a 47 Labs phono cube which has been mentioned a few times in this thread as it is also a current amplifying phono stage. It is expensive if purchased new (which thankfully mine wasn’t). I don’t see any UK prices but think it is currently around US$ 5,000 with its associated external power supply. It is a dual mono design with each circuit of the left and right channels encased in a separate chassis. For the ultimate dual mono performance (apparently), you can add another power supply so each PS would power its own circuit. Something I had hoped to try someday as I am susceptible to PS foo being a Naim user.

    The rest of the system is an SME Model 20.2A with a Lyra Kleos SL, Naim 552 DR/500 and Avalon Ideas. I spent a lot of time researching the 47 Labs before jumping in as cartridge matching for the required gain seemed important. The 47 Labs comes in 2 gain options - the standard, meant to be compatible with most cartridges, and a higher gain version. From their website,

    The standard version has 75dB and the high-gain version has 90dB of gain. Since it is a current amplification device with 0 ohm input impedance, output level is determined by the output amperage of the cartridge (output voltage divided by internal impedance).”

    I purchased mine thinking I was getting the Standard version as this seemed the correct match for the Kleos SL, but the seller was wrong and it is in fact the 90db high-gain version as confirmed by Jez when he had it in his shop to cure a persistent hum a couple of years ago. As such I use a -15dB attenuating cable to get a bit more usable range out of my preamp. The same cable was used when auditioning the GTI.

    The first thing to say about the GTI is that it was subjectively louder than the 47 Labs by say about 15% - 20%. Apart from that the 2 stages sounded remarkably similar, which isn’t too surprising given the common nature of the devices. I was drawn to a current amplifying stage because with other stages I never felt comfortable that the loading was spot on – is that too much treble or too much bass, who knows? There is a certain rightness to current amplifying stages that leaves you with the comfortable feeling that the overall tonality of the music is being reproduced correctly.

    I listened to a fair bit with the GTI and then a bit with the 47 Labs and then tried some back and forth of individual tracks or sides to try and discern any real differences. Well, there weren’t many, bar the loudness. Maybe a bit more stage depth with the 47 labs and maybe a tad more ‘space’ around the instruments. I thought the bass of the 47 Labs might have a touch more impact and texture but I am splitting hairs here, the GTI was in no way lacking in any of these areas, and whatever differences I felt I could hear I am pretty sure I would struggle to identify them blind. In the end I gave up looking for any differences and just enjoyed them both.

    So, congrats Jez – it certainly looks like you’ve cooked yourself a winner here.
    Tarzan and Arkless Electronics like this.
  8. Arkless Electronics

    Arkless Electronics Trade: Amp design and repairs.

    There you go folks, my £285 stage equals a $5000 one:)

    Any one else wanting to try the demo unit?
  9. Arkless Electronics

    Arkless Electronics Trade: Amp design and repairs.

  10. Colin123

    Colin123 pfm Member

    I’ve had the GTi in my system for a couple of days now so I had better pass on my feelings.

    Firstly, my system consists of a Nottingham Analogue Ace Spacedeck and Moerch DP6 tonearm with a Benz Micro Wood SL cartridge feeding into an Arkless 640P Phonostage bought exactly three years ago from Jez. The amp is a Puresound 2A3 with Heco Direkt Speakers.
    The system gives me a lot of pleasure.
    I listen to a mixed bag of LP’s mainly classical, acquired over quite a few years, some from charity shops, some inherited, some at auction, I have no high priced ‘audiophile’ pressings.
    Obviously installing the GTi was easy as it was a simple substitution job, even using the same power supply.

    First abundance.

    The soundstage is wider, deeper, the dynamics are fantastic but none of this is ‘in your face’, quiet passages can have great delicacy, I’m hearing detail in my recordings I’ve never heard before within an orchestral recording. Wonderful inner resolution.

    I have never experienced a really expensive phonostage in my system so cannot make any comparisons on that score but I can say that the GTi is a great improvement on the standard Arkless 640P and has given my LP collection a new lease of life. I can’t think of a better recommendation.

    I’ll be sending my Arkless 640P to Jez for an upgrade.

    Thanks Jez.
    Arkless Electronics likes this.
  11. Arkless Electronics

    Arkless Electronics Trade: Amp design and repairs.

    Thanks for the write up Colin and glad you like it:) You know what a really expensive phono stage sounds like now then.... just it happens to be cheap!

    Another call out then to see if anyone else wishes to try it? If not then in a day or two I'll be asking Colin to post it back to me and then whilst the Arkless GTI will remain available to buy you will not be able to try it at home until next year.
    Colin123 likes this.
  12. Arkless Electronics

    Arkless Electronics Trade: Amp design and repairs.

    Ok folks last chance Texaco as they say... Anyone wanting to try it at home?
  13. Glenn C

    Glenn C pfm Member

    PM sent Jez.
  14. Arkless Electronics

    Arkless Electronics Trade: Amp design and repairs.

    I haven't received it...
  15. Jo 90

    Jo 90 pfm Member

    Hi Jez - you sold me a "Turbo +" model - no idea what that is BTW - but it was a few yrs back. I'm using as PTG/II and would like to know firstly, the typical l/t from you recieving the phono stage and secondly if the upgrade is worth it ? specifically, I have no idea what the "Dr T" mod is... Finally, what is the upgrade price ? Thanks... .Steve
  16. Arkless Electronics

    Arkless Electronics Trade: Amp design and repairs.

    This may answer some of your questions

    I would advise starting again with a fresh 640P/651P donor unit in your case as the Turbo+ was not cheap and somw of what you paid for would have to be junked to turn it into the new GTI version. The new version is MC only I must stress.
    What with people having ebay purchased donor units sent to me directly I have a new pile of them waiting to be done and so I won't be taking any more in until next year now.
  17. Rug Doc

    Rug Doc pfm Member

    I have one waiting for you too Jez, so let me know when you want it.
  18. JTC

    JTC PFM Villager...

    Likewise. Do Mr Doc and I fall into the right side of the ‘new year intake’? Could do with supercharging my analogue!!!
  19. Arkless Electronics

    Arkless Electronics Trade: Amp design and repairs.

    Yes indeed.
  20. Jo 90

    Jo 90 pfm Member

    So, to be clear the £££ I spent on my turbo version is now.... wasted - if I want to got for the upgrade ? The link you sent me does not seem to explain the Dr T mod - unless it is on a white font / white background Jez :)

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