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Thread: Marco's 'tube rolling' and valve power amp adventure

  1. #11
    leo's Avatar
    leo is offline Circuit Junkie & DIY Room Forum Leader
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    I use NOS GEC KT88's in my valve amp, a work mate had a quad set of unused ones sat in his shed gathering dust! Also have a set of Svets

    The OPTX's are important as the valves, I upgraded mine to a pair of custom wound from Sowter, they wasn't cheap but made quite an improvement over the standards

  2. #12
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    I'm AudioAl'sArbiterForPISHANTO.

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    I use NOS GEC KT88's in my valve amp, a work mate had a quad set of unused ones sat in his shed gathering dust!
    Nice find! How much did you offer him?

    Btw, any idea why my 'upgrading' the voltage regulator valve in my preamp would have made a difference (an improvement) to the sound? I'm a bit puzzled as to why this has happened as (as far as I'm aware) it's not in the audio signal chain. A brief idiot-proof explanation (if there is a technical one!) would be appreciated

    Marco.

  3. #13
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    Quote Originally Posted by Marco View Post
    Nice find! How much did you offer him?

    Btw, any idea why my 'upgrading' the voltage regulator valve in my preamp would have made a difference (an improvement) to the sound? I'm a bit puzzled as to why this has happened as (as far as I'm aware) it's not in the audio signal chain. A brief idiot-proof explanation (if there is a technical one!) would be appreciated
    Because the power supply in any amp is one of the most important sections, you can have the greatest designed amp in the world but if you aint got the juice department upto scratch, no use really.

  4. #14
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    Because the power supply in any amp is one of the most important sections, you can have the greatest designed amp in the world but if you aint got the juice department upto scratch, no use really.
    I totally agree with that statement, as it has always been my experience, however I'm just a tad surprised at how much that particular component has impacted on the sound. Changing the Yugoslavian-derived Ei ECC83 above it for a NOS Mullard version was even more significant!

    I will put a couple of them in the Yaqin to replace the new stock Electro Harmonix 12AX7s and report back in due course.

    Marco.

  5. #15
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    I'm InSpace.

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    Quote Originally Posted by Vinyl Grinder View Post
    You tried 6550 in it?
    No - But it's on the 'to do' list!

    Quote Originally Posted by Marco View Post
    That's interesting, Mike. The Golden Lions are supposedly much revered. However I suspect that the current re-issues are manufactured by a division of Sovtek and bare little resemblance to the original Genlex (or GE) design from the 1950s.



    If you don't mind, then yes definitely. It will allow me to hear the difference between those and the Electron KT88s in the Yaquin before shelling out on new set of cryo'd Svets.

    I'll send you a PM



    Indeed. I prefer the Electro Harmonix 12AX7, but my favourite is the NOS Mullard ECC83 - yummy!
    The current Gold Lions are "recreated down to the finest detail" (allegedly) by New Sensor Corp:

    http://www.newsensor.com/ProductHigh...spx?ProId=1149

    With regard to the Mullard ECC83 - I'm busy hoarding them

    Try to get hold of a/some Mullard CV4004 types, they're based on the SQ version of the ECC83 - The M8137. The most yummy of all!

    Brimar's are very very close too, as are smoothplate Telefunkens. If you're very lucky/flush you might find a Telefunken ECC803S - but don't hold you're breath!

    Cheers,
    Mike.
    Shian7
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    Kudakutemo
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    ari mizu-no tsuki

    Though it be be broken -
    broken again - still it's there:
    the moon on the water.

    - Choshu.

  6. #16
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    I'm Neal.

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    Quote Originally Posted by Marco View Post
    Nice find! How much did you offer him?

    Btw, any idea why my 'upgrading' the voltage regulator valve in my preamp would have made a difference (an improvement) to the sound? I'm a bit puzzled as to why this has happened as (as far as I'm aware) it's not in the audio signal chain. A brief idiot-proof explanation (if there is a technical one!) would be appreciated

    Marco.
    Actually it is Marco, at least as far as AC is concerned it can have a big effect on sound quality. It's more noticeable with SE amps than PP admittedly but even with PP amps it's still necessary to consider the PSU as part of the signal chain.

  7. #17
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    Hi Neal,

    I agree, and it's definitely what I'm hearing. Last night at a friend's house we compared three different voltage regulator valves in a Croft preamp - all NOS, from Amperex, Mullard, and an unmarked military spec one, and they all sounded different.

    However, where it's really at is the output valves. There are five inside the Croft, and NOS Mullard ECC35 brown base are, so far, much better than anything else I have heard.

    Mike,

    Try to get hold of a/some Mullard CV4004 types, they're based on the SQ version of the ECC83 - The M8137. The most yummy of all!

    Brimar's are very very close too, as are smoothplate Telefunkens. If you're very lucky/flush you might find a Telefunken ECC803S - but don't hold you're breath!
    Regarding the Mullard, that's very interesting. I will look into that. Now that I'm on a journey 'maxing-out' the Croft (and Yaqin), valve-wise, I know that I'll not be satisfied with anything but the best!

    We tried a Brimar ECC83 last night and found it a bit warm sounding and 'polite' compared to the Mullard. What I've found with Mullards is that they just sound 'right', with no emphasis on any part of the frequency range - they have a lovely natural 'tone'. I've had no experience of Telefunken so far.

    Marco.

  8. #18
    leo's Avatar
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    Quote Originally Posted by Marco View Post
    Nice find! How much did you offer him?

    Btw, any idea why my 'upgrading' the voltage regulator valve in my preamp would have made a difference (an improvement) to the sound? I'm a bit puzzled as to why this has happened as (as far as I'm aware) it's not in the audio signal chain. A brief idiot-proof explanation (if there is a technical one!) would be appreciated

    Marco.
    He said I either take them or they are to be chucked in the bin, they was a spare set brought years ago for a big guitar amp which was long gone

    As Neal mentioned the psu is part of the signal chain so the quality has an audible effect, upgrading the PSU's in almost all equipment influences the sound quality, some much more than others.

    One of the reasons why a lot of solid state amplifiers,CDP's sound poor because of the cost cutting and poor implementation of the PSU, improve the PSRR and it usually improves the sound

  9. #19
    Join Date: Jan 2008

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    Default Yaqin MC100B - feel the force!

    He said I either take them or they are to be chucked in the bin...
    Drats, what an inconvenience, eh?

    I trust you replied along the lines of: "Oh ok, I suppose I can help out and take them off your hands..."

    I totally agree about PSU quality being hugely important to performance - it's just that I didn't think changing a little voltage regulator valve would have such a profound effect on the sound.

    I'm really enjoying this valve malarkey. This Yaqin Chinese amp is a phenomenal bargain. Frankly, its performance makes the price paid for it (£300 direct from China) a total joke. Even in its current state it's as good as any valve integrated or power amp I've heard up to £2K, and hooking it up to the Croft and using it as a pre/power combo takes it into a different league again.

    Upgrading the relatively poor quality Chinese valves raises its game further and removes an annoying brashness in the midrange which opens up the sound quite dramatically, and by the time I've finished with it, having the unnecessary solid-state integrated circuitry removed and replaced with point-to-point hard wiring, a solid copper chassis designed to replace the current brass one, and the unit converted to 240V (without needing to use a step-down transformer) which I should be able to do for around £1500, I'm confident it will compete with some respected hi-end designs up to £5k.

    Once this has been done I will write a full review for the benefit of anyone else considering going down this route. Make no mistake, this amplifier is a REAL giant-killer and is set no doubt to ruffle a few feathers in the UK valve scene!

    Stay tuned, folks...

    Marco.

  10. #20
    leo's Avatar
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    I've been trying to find info on this amp, is this the one you have

    http://www.hi-end.on9mart.com/produc...YQ-100B-01.jpg


    http://www.hi-end.on9mart.com/produc...YQ-100B-09.jpg

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