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Thread: How hi (-fi) can you go?

  1. #1
    Join Date: Oct 2012

    Location: The Black Country

    Posts: 3,759
    I'm Alan.

    Default How hi (-fi) can you go?

    An EE’s progress over the last few months for system improvement.
    A lot has happened over the past months with sometimes startling success.

    Firstly I want to champion the case for synergy. It’s not something that you can order or compute but it can have such an impact on ultimate results, particularly if you haven’t got it. For example a power amp not coping with an awkward part of a specific speaker load, it doesn’t need to be over a wide frequency range to upset things. Or a mismatch of impedances between pre and power, or with a passive pre.

    Certain design approaches can mitigate possible problems, in general low output impedances and high input impedances go a long way to help prevent problems.

    The other important factor IMO is having a chain of components that are of equal performance, such that improvements throughout the chain can be heard and appreciated. Having low distortion wide bandwidth amplification helps here.

    I love valves for small signal amplification. Choosing the best can be tricky, see the developments made further on. Good circuit design is crucial for best results.

    As a techie I do have test equipment (obviously) but only use it to confirm functionality, check bandwidth and measure gain figures. The ultimate tool for performance evaluation is a good pair of ears and here I have a secret weapon. A younger and more acute pair of ears by the name of Bigman80, who has been extremely helpful, apart from pushing me down the path of lightening the wallet to achieve the improvements.

    A quick run down of the kit in use and some background details.
    The speakers. The ubiquitous Quad ESL57, not perfect by any means but what they do well is beyond reproach. Exceedingly low colouration and no enclosure resonances. As a lot of folks say, mid-range to die for, but the extremes can be bolstered as shown later.

    The power amp. My own design dual mono valve hybrid using a valve for amplification and MOSFETS for output drivers. Good low output impedance, a bit of overkill with 90W driving Quads so easy going on the output levels. Not much to look at but the case was a donor.




    The sub woofer. A copy of the REL Stadium, a kit enclosure from Wilmslow Audio many moons ago fitted with a 10 inch car subwoofer with a good response down to 25Hz.
    Downward firing, the legs are the originals from the ESL57’s.




    The sub amplifier. Rather than build it into the sub enclosure I chose to have it in a separate enclosure, the original one wasn’t pretty and the twin toroidal transformers had an annoying mechanical hum. So recently I rebuilt it into an AIR case and replaced the mains transformer with a single quiet one. MOSFET output putting 50W into 4 ohm.




    The preamp. My own design KIN valve hybrid with ‘super linear’ triode amplification stages. The unit uses a mu circuit that tricks the valves into thinking they are in valve utopia. The result is better linearity, more gain and vanishingly low distortions. MM and MC capability via a JFET cascode input, improvements later.




    The turntable. A humble Goldring Lenco GL 75 in stock form apart from new V blocks and a delrin ball in the main bearing. Oh and additional weight on the counterweight necessary for the fitting of a DL-103, it’s a heavy beast.




    The cartridge. One of the recent additions, a fabulous ZYX R-100. It does everything that the 103 does with fantastic drive but so much more. More detail, separation, frequency extension and image depth, fabulous. A bonus was that I didn’t have to remove the extra counterweight, with the combined weight right up against the bearing assembly the R-100 balanced perfectly. Synergy or what?





    So the improvements over the last few months:

    The purchase of the Z-100. I won’t be looking to better this, all the detail and tremendous imaging are first class. Helped of course by the balance of performance with the rest of the kit, see further on.
    This really is a stella performer, with the final improvements the music detail and focus are some of the best I have ever heard.
    ___________________

    Re-building the sub amplifier. I managed to lower the bleed through of the internal variable clock and the background noise as well as removing the transformer hum.
    ___________________

    Adding tweeters to the ESL57’s. One of the limitations is the treble dispersion and adding the additional tweeters has so overcome this. The crossover components are mounted behind the tweeters and the variable L pads at the bottom rear of each panel within easy reach for adjustment.






    ___________________

    Re-visiting the design of the KIN preamp. After attending the bake off at Huddersfield it was realised that the performance was lacking and could be improved.
    One comment made was a lack of downward dynamic range (DDR), a term used by Nick Gorham. It’s difficult to detect if you are not sure what to listen for or it’s not something that is pointed out. An analogy is contrast in a picture, you might get a lot of brightness in the picture but without portraying the darker areas correctly.

    After consulting the design notes for the mu circuit I realised I had made too much of a compromise in limiting device dissipation, both valve and FET. Increasing the current levels brought back the DDR. I also lowered the anode voltages to better match published characteristics. More image depth and better dynamics ensued, this really was a worthwhile step.


    Another initial compromise, as it turned out, was the choice of valves to use, originally chosen to enable JFET cascode operation for MC, with a very simple circuit. (KISS principle)
    Anyone who has had any Firebottle kit will know I avoid the most common valve types because obtaining the best examples can be fearsomely expensive.

    As it turned out the PCC189 originally used is bettered in the linearity stakes by the PCC88, so with the ‘super linear’ circuit the improvements are doubly good, as has been heard.




    So now we have PCC88’s fitted, getting top class NOS examples is easier. I have a Telefunken and a Tesla fitted to the KIN and 2 Tesla’s in the latest Vivant build.
    It’s not that I wasn’t a believer in tube rolling, as everything matters, it’s just that I have been trying for the best sound without reliance on the best performing valves.
    So when Bigman80 insisted I go down this route I was very pleased with the improvements made. Again more image depth and width and more detail, a palpable sense of placement accuracy and focus.
    ________________________

    One more big improvement to come, but some details of the stand alone phono amp design in the latest Vivant build first.
    The circuitry is essentially identical to that in the KIN after the improvements, but with very minor component value differences in some areas. Now fitted with Tesla PCC88’s it is indistinguishable from the performance of the KIN.








    Exceedingly good performance but ….. another small compromise was initially made to keep the MM to MC switching simple (KISS principle again). This was potentially restricting the ultimate performance achievable with a JFET input, as the operating characteristics couldn’t be altered. So to explore the alternative of using an SUT directly into a valve MM input (just the flick of a switch) I purchased a Denon AU-320 SUT.




    Discussion and testing has been undertaken on the loading of MC cartridges. As resistive loading is altered then different cartridges have different changes to their performance. Some seem to lose focus above say 300 ohm yet others are happy with loadings up to 1000 ohms. What I don’t quite understand is how a reflected impedance (through the SUT) of 470 ohms can can have such a dramatic improvement on the whole sound stage of the Z-100 in particular. I know it is now a reactive source (the cartridge coils) into a reactive load (the SUT) but the improvement is literally phenomenal.

    The design mods to the KIN gave good improvement, the change to PCC88’s gave good improvement, the change to quality NOS gave good improvement, but the change to quality SUT into MM has given an improvement equivalent to all the previous combined.

    I’m staggered, over the moon and an extremely happy bunny all at the same time.

    It’s brilliant.
    Last edited by Firebottle; 06-11-2017 at 08:07.

  2. #2
    Join Date: May 2012

    Location: Toulouse

    Posts: 3,877
    I'm GettingFunky.

    Default

    The Vivant build looks very neat.

    It's a shame you are further away now, as I would love to hear the ZYX. I would love to see how it compares to my DL-103 which is on steroids.
    Kevin

    Funkified Technics SL1200 Mk2 (Funk FX-1200+, Techne-Audio modified DL-103/AT33PTG/II/, Funk Firm "Strata" platter, "Spin" bearing and BO!NG Isolation feet, MCRU/LDA PSU).
    Pioneer PD-S703.
    Battery powered Beresford Caiman II.
    Firebottle KIN fitted with NOS Telefunken Valves.
    Firebottle Monoblocks fitted with NOS Telefunken Valves.
    Electric Beach FH3 with Taket BatPure super tweeters.
    Graham Slee Solo Ultra Linear Headphone amp.
    Sennheiser HD540 Reference II & HD650.
    DIY Klotz MC5000/MS Audio interconnects.
    Talk cable 3 speaker cable.
    Neotech hybrid mains cables from MCRU
    Power Inspired AG1500

  3. #3
    Join Date: Feb 2013

    Location: W Lothian

    Posts: 37,808
    I'm Grant.

    Default

    The viviant looks very classy Alan.. Glad youve made big inroads.
    Regards,
    Grant ....

    I've said it before and I'll say it again: democracy simply-doesn't-work
    .... ..... ...... ...... ................... ..... ..... ..... ..... .....
    DENON DV2900 - TWIN PRO MONOBLOCK AMPLIFIERS - XIANG SHENG DAC\PRE\HEADPHONE AMP - AVANTREE OASIS CLASS 1 BLUETOOTH - AUDIO TECHNICA ATH-MSR7 & OPPO PM-3 PLANAR HEADPHONES - WIN10 JRIVER23, SPOTIFY PREMIUM - ECHO DOT - SMSL M6 MINIDAC - FULL RANGE TWIN TELEFUNKEN's - Q ACOUSTIC BT3 actives - CANTON SUB - MAINS REGENERATED AND FILTERED.

  4. #4
    Join Date: Nov 2015

    Location: Wolverhampton

    Posts: 3,500
    I'm Oliver.

    Default

    I really enjoyed reading, what essentially a diary of evolution. I'm glad you've taken the time to write it.

    I have a feeling that when you get to hear the Vivant through my Slagle, your opinion on how close the KIN and Vivant are will change. When you hear it, that Alps pot will be on the way out

    Seriously, I've learned loads whilst listening to your gear through the stages. I'm glad we've both benefitted.

    Sent from my EVA-L09 using Tapatalk
    Technics SP10 MK2 > Phonomac AT-1010 tonearm > ZYX R50 Bloom cartridge > Jolida JD9 MKII > Firebottle Monoblocks > Creek OBH-11SE Headphone Amp > IXOS Speaker Cables > Pioneer CS-77A Speakers

  5. #5
    Join Date: Dec 2015

    Location: Alicante. Spain.

    Posts: 1,370
    I'm Adrian.

    Default

    Quote Originally Posted by Bigman80 View Post
    I really enjoyed reading, what essentially a diary of evolution. I'm glad you've taken the time to write it.

    I have a feeling that when you get to hear the Vivant through my Slagle, your opinion on how close the KIN and Vivant are will change. When you hear it, that Alps pot will be on the way out

    Seriously, I've learned loads whilst listening to your gear through the stages. I'm glad we've both benefitted.

    Sent from my EVA-L09 using Tapatalk
    +1
    Technics SP10 mk2
    Jan Allaerts MC 1 Boron mk1 cart
    Miyajima Shilabe cart
    Hashimoto HM-X SUT
    Siggwan (gimballed not unipivot) Cocobola 12"
    Aurorasound Vida LCR Phonostage
    The Truth linestage
    Dave Slagle Autoformer Volume Controller
    Cary 805c SET amps
    Audio Note ANe-SPX speakers
    Townshend Isolda speaker cables
    Cardas Golden Presence interconnects

  6. #6
    Join Date: May 2011

    Location: Glasgow

    Posts: 6,378
    I'm Brian.

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    Nice write up Alan . I had the pleasure if visiting you and Shirley last January and getting a good listen to your system which sounded excellent . I'm now very happy with one of your OTP phono stages . I would love to get down and hear your system again in the new year mate
    Regards
    Brian

    Sell your cleverness and buy bewilderment . (Rumi )


    Korus Computer Audio music server .
    DAC 3 French DAC
    Amplifier : Rega Brio R
    Speakers : Tannoy 637
    Interconnects : MS Audio / Klotz MC5000 .
    Speaker cables : Chord Epic Twin

  7. #7
    Join Date: Oct 2012

    Location: The Black Country

    Posts: 3,759
    I'm Alan.

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    You would be very welcome Brian and I think surprised at the improvements

  8. #8
    Join Date: Jan 2008

    Location: Wrexham, North Wales, UK

    Posts: 73,253
    I'm AudioAl'sArbiterForPISHANTO.

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    Great thread so far, Alan. I concur with many of your observations, which are interesting. Particularly this, which I can relate to myself:

    Quote Originally Posted by Firebottle View Post
    So to explore the alternative of using an SUT directly into a valve MM input (just the flick of a switch) I purchased a Denon AU-320 SUT.



    Discussion and testing has been undertaken on the loading of MC cartridges. As resistive loading is altered then different cartridges have different changes to their performance. Some seem to lose focus above say 300 ohm yet others are happy with loadings up to 1000 ohms. What I don’t quite understand is how a reflected impedance (through the SUT) of 470 ohms can can have such a dramatic improvement on the whole sound stage of the Z-100 in particular. I know it is now a reactive source (the cartridge coils) into a reactive load (the SUT) but the improvement is literally phenomenal.

    The design mods to the KIN gave good improvement, the change to PCC88’s gave good improvement, the change to quality NOS gave good improvement, but the change to quality SUT into MM has given an improvement equivalent to all the previous combined.

    I’m staggered, over the moon and an extremely happy bunny all at the same time.

    It’s brilliant.
    Remember the experience we had at my place with the Paul Hynes head amp/Croft and your KIN, and also the little Lentek head amp at MIBO (the meeting Martin organised in Stoke), where going the route of MM stage, with a head amp, 'cheered things up' no end, and was clearly better than direct into a standalone MC stage - *despite* seemingly complicating the signal path?

    I've known this for years, which is why my preferred way of amplifying the signal from a low-output MC cartridge is via, either a head amp or SUT, into (preferably) a valve MM phono stage. I'm not saying that it is *unquestionably* the best way of doing things, as there may be a standalone MC stage out there which disproves that theory, but to my ears so far, having heard and tried numerous different high-quality examples of the latter, over many years, the former approach always seems to produce the best (most musical) results.

    Now the question is, do you, as an EE, or any other EEs here, have a technical explanation for why that should be the case, when 'on paper' the more direct way of using a standalone MC stage, theoretically is better..? Why should shoving another box and set of cables into the equation improve matters, which so often it clearly does?

    Marco.
    http://www.thestainedglasscompany.com

    "A man is a success if he gets up in the morning and gets to bed at night, and in between he does what he wants to do" -- Milan Kundera.

  9. #9
    Join Date: Oct 2012

    Location: The Black Country

    Posts: 3,759
    I'm Alan.

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    Quote Originally Posted by Marco View Post
    Great thread so far, Alan.

    So far I think this is endgame as it is that good.


    Remember the experience we had at my place with the Paul Hynes head amp/Croft and your KIN, and also the little Lentek head amp at MIBO (the meeting Martin organised in Stoke), where going the route of MM stage, with a head amp, 'cheered things up' no end, and was clearly better than direct into a standalone MC stage - *despite* seemingly complicating the signal path?
    Marco.
    Ah-ha, I knew you would pick up on this
    I do remember very well and the the opinion has been in my mind ever since. With personal experience of lesser head amps plus the above mentioned I have thought there is something to this.

    As I have said the performance level of my pre is now at such a level where the MC input is a recognisable pinch point. For the reasons I have outlined I am loath to dive in to this part of the circuit, but Island Pink on here has done extensive experimentation, as well as Nick Gorham, to show gains can be had.

    The thing is with a JFET input, another active device is being added, along with the imperfections associated with the device. Now you say, you are doing the same with a head amp, but I think with a quality head amp the design imperfections are small enough to be non-intrusive.

    I think you will agree that the Lentek doesn't meet this criterion and does have a sound of it's own.
    The case of using a SUT is adding a passive device without the nasties of non-linear transfer curves to screw thing up.

    I think using a SUT allows the cartridge to 'breath' better IMO, but a better explanation is beyond me.

    Firebottle - for the no bottleneck approach.

    I love Hendrix for so many reasons. He was so much more than just a blues guitarist - he played damn well any kind of guitar he wanted. In fact I'm not sure if he even played the guitar - he played music. - Stevie Ray Vaughan

  10. #10
    Join Date: Jan 2008

    Location: Wrexham, North Wales, UK

    Posts: 73,253
    I'm AudioAl'sArbiterForPISHANTO.

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    Quote Originally Posted by Firebottle View Post
    As I have said the performance level of my pre is now at such a level where the MC input is a recognisable pinch point. For the reasons I have outlined I am loath to dive in to this part of the circuit, but Island Pink on here has done extensive experimentation, as well as Nick Gorham, to show gains can be had.
    Could you explain the highlighted text, Alan, as I'm unaware of what you're referring to. Also what do you mean by a "recognisable pinch point"?

    The thing is with a JFET input, another active device is being added, along with the imperfections associated with the device. Now you say, you are doing the same with a head amp, but I think with a quality head amp the design imperfections are small enough to be non-intrusive.
    I would agree, but not only is it subjectively non-intrusive, but to my ears and yours, sonically (and musically) beneficial. It's that last bit I'm trying to understand.

    I think you will agree that the Lentek doesn't meet this criterion and does have a sound of it's own.
    The case of using a SUT is adding a passive device without the nasties of non-linear transfer curves to screw thing up.
    In terms of the Lentek, no not really, as I find it to be a pretty neutral sounding device, which actually compares favourably with my much more costly PH head amp. The latter is still better in important areas, but the Lentek gets 85% of the way there. It's a remarkable little device, especially when subtly modded and used with a quality valve MM stage.

    I think using a SUT allows the cartridge to 'breath' better IMO, but a better explanation is beyond me.
    Yes, I would agree, although I also find that transformers (very much) have a sound of their own. Good head amps tend to 'peppier'/more dynamic, and it's an effect that I overall prefer. As ever in hi-fi, there's always a trade-off between one set of traits in equipment and another.

    The 'magic' with SUTs is in finding one that forms a true synergy with the partnering cartridge (and phono stage), and when the 'recipe' is right, the results can be breathtaking. However overall, even the best SUTs, to my ears, sound 'softer' than a good head amp, as they lack the 'balls' and 'get up and go' of the latter.

    In an ideal world, I'd probably use an SUT for jazz, acoustic and gentle male or female vocal music, and a head amp for rock, pop and dance - or anything that has a driving beat or rhythm. It's the PRaT thing again - and in my experience the best head amps have that in spades over even the most expensive SUTs.

    So simply employ your 'weapon of choice', in that respect, and enjoy the music!

    Marco.
    http://www.thestainedglasscompany.com

    "A man is a success if he gets up in the morning and gets to bed at night, and in between he does what he wants to do" -- Milan Kundera.

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