Thoughts on Marantz 7 Tube Preamp Kit?

codycatalist
codycatalist Posts: 2,662
edited April 2018 in 2 Channel Audio
Anyone had their ears on them? They can be had for cheap so I am not expecting a world beater, just something to add some flavor into the mix.

Link: https://www.ebay.com/i/162328754380?chn=ps

Finished one here: https://www.ebay.com/i/132598587751?rt=nc&_trkparms=aid=222007&algo=SIM.MBE&ao=1&asc=20160908110712&meid=e0712a2f23684aa7b8710a85cee1efcf&pid=100677&rk=10&rkt=30&sd=162328754380&itm=132598587751
Just a dude doing dude-ly things

"Temptation is the manifestation of desire which equals necessity." - Mikey081057
" I have always had a champange taste with a beer budget" - Rick88
"Just because the thread is getting views don't mean much .. I like a good train wreck doesn't mean i want to be in one..." - pitdogg2
"Those that don't know, don't know that they don't know." - heiney9
"Audiophiles are the male equivalent of cat ladies." - Audiokarma Member
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  • mhardy6647
    mhardy6647 Posts: 33,776
    edited April 2018
    Other than the fact that they have absolutely nothing substantive to do with the Marantz 7 circuit design -- and that the Marantz 7 was an OK but not life-changing preamp, albeit an exceedingly beautiful one -- no.


    vfjdrf2xcy78.png

    But if you feel like spending some money, go for it.
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  • codycatalist
    codycatalist Posts: 2,662
    mhardy6647 wrote: »
    Other than the fact that they have absolutely nothing substantive to do with the Marantz 7 circuit design -- and that the Marantz 7 was an OK but not life-changing preamp, albeit an exceedingly beautiful one -- no.


    vfjdrf2xcy78.png

    But if you feel like spending some money, go for it.

    I trust what you say Doc. I was looking at some of the cheaper Bottlehead models too just a bit farther off than a quick premade kit.
    Just a dude doing dude-ly things

    "Temptation is the manifestation of desire which equals necessity." - Mikey081057
    " I have always had a champange taste with a beer budget" - Rick88
    "Just because the thread is getting views don't mean much .. I like a good train wreck doesn't mean i want to be in one..." - pitdogg2
    "Those that don't know, don't know that they don't know." - heiney9
    "Audiophiles are the male equivalent of cat ladies." - Audiokarma Member
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  • mhardy6647
    mhardy6647 Posts: 33,776
    edited April 2018
    The Chinese things may sound fine (I have not heard one nor seen one in the flesh), but associating them with the Marantz 7 oughta be a crime, I'd say.

    If you don't need a lot of gain, the goofy little battery-powered BH "Quickie" is not bad -- the only trick is finding 3S4s that aren't too microphonic.

    hwbtsq2vfts5.png
    (from the BH website)

    One came to visit here one day and it sounded mighty fine driving the "Simple 2A3" amplifier.

    2x4w9g9gcci6.png

    photo from http://forum.polkaudio.com/discussion/26433/show-me-your-****-embly-and-let-me-get-in-your-guts-baby/p36

    (Vanilla's censor may butcher the URL :( )

    Which reminds me -- one of these days I need to build the Quickie that's sittin' in a box in the closet, not ten feet from where I am sittin' as I type this :)

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  • codycatalist
    codycatalist Posts: 2,662
    mhardy6647 wrote: »
    The Chinese things may sound fine (I have not heard one nor seen one in the flesh), but associating them with the Marantz 7 oughta be a crime, I'd say.

    If you don't need a lot of gain, the goofy little battery-powered BH "Quickie" is not bad -- the only trick is finding 3S4s that aren't too microphonic.

    hwbtsq2vfts5.png
    (from the BH website)

    One came to visit here one day and it sounded mighty fine driving the "Simple 2A3" amplifier.

    2x4w9g9gcci6.png

    photo from http://forum.polkaudio.com/discussion/26433/show-me-your-****-embly-and-let-me-get-in-your-guts-baby/p36

    (Vanilla's censor may butcher the URL :( )

    Which reminds me -- one of these days I need to build the Quickie that's sittin' in a box in the closet, not ten feet from where I am sittin' as I type this :)

    In layman's terms what applications would I need more gain over a lower gain?
    Just a dude doing dude-ly things

    "Temptation is the manifestation of desire which equals necessity." - Mikey081057
    " I have always had a champange taste with a beer budget" - Rick88
    "Just because the thread is getting views don't mean much .. I like a good train wreck doesn't mean i want to be in one..." - pitdogg2
    "Those that don't know, don't know that they don't know." - heiney9
    "Audiophiles are the male equivalent of cat ladies." - Audiokarma Member
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  • pitdogg2
    pitdogg2 Posts: 25,424
    codycatalist wrote: »
    mhardy6647 wrote: »
    The Chinese things may sound fine (I have not heard one nor seen one in the flesh), but associating them with the Marantz 7 oughta be a crime, I'd say.

    If you don't need a lot of gain, the goofy little battery-powered BH "Quickie" is not bad -- the only trick is finding 3S4s that aren't too microphonic.

    hwbtsq2vfts5.png
    (from the BH website)

    One came to visit here one day and it sounded mighty fine driving the "Simple 2A3" amplifier.

    2x4w9g9gcci6.png

    photo from http://forum.polkaudio.com/discussion/26433/show-me-your-****-embly-and-let-me-get-in-your-guts-baby/p36

    (Vanilla's censor may butcher the URL :( )

    Which reminds me -- one of these days I need to build the Quickie that's sittin' in a box in the closet, not ten feet from where I am sittin' as I type this :)

    In layman's terms what applications would I need more gain over a lower gain?

    Ha ha ha Doc layman's terms ....... yea maybe the first 5 words.
    LOL
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  • mhardy6647
    mhardy6647 Posts: 33,776
    It really depends on your amplifier's "drive" requirements.

    (how was that?)

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  • codycatalist
    codycatalist Posts: 2,662
    edited April 2018
    I knew layman's terms would be bait, I'll have to set aside some time and get my read on. Time...something that seems to be disappearing from me quite a bit lately.
    Just a dude doing dude-ly things

    "Temptation is the manifestation of desire which equals necessity." - Mikey081057
    " I have always had a champange taste with a beer budget" - Rick88
    "Just because the thread is getting views don't mean much .. I like a good train wreck doesn't mean i want to be in one..." - pitdogg2
    "Those that don't know, don't know that they don't know." - heiney9
    "Audiophiles are the male equivalent of cat ladies." - Audiokarma Member
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  • Faustin
    Faustin Posts: 1,149
    I put together a Bottlehead Quickie last year and it is a surprisingly good sounding pre. I did upgrade the coupling caps and have another potentiometer to install (when I have time) and generally hook it to an Adcom 555 ss amp. Yes, as mhardy stated the 3S4 tubes are microphonic but are pretty cheap so you can experiment. I found some nos Brimar 3S4 tubes that are pretty darn good, quiet unless you tap on the base of the pre. I make it a point to not tap on the base. :):)
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  • heiney9
    heiney9 Posts: 25,165
    I'd stay away. Nothing to do with the Marantz 7. This would be a better kit if you are looking to build your own

    http://wallofsound.ca/audioreviews/review-elekit-tu-8500-tube-preamplifier-kit/

    Or Bottle Head has some great units too.

    H9
    "Appreciation of audio is a completely subjective human experience. Measurements can provide a measure of insight, but are no substitute for human judgment. Why are we looking to reduce a subjective experience to objective criteria anyway? The subtleties of music and audio reproduction are for those who appreciate it. Differentiation by numbers is for those who do not".--Nelson Pass Pass Labs XA25 | EE Avant Pre | EE Mini Max Supreme DAC | MIT Shotgun S1 | Pangea AC14SE MKII | Legend L600 | BlueSound Node 3 - Tubes add soul!
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  • mhardy6647
    mhardy6647 Posts: 33,776
    edited May 2018
    heiney9 wrote: »
    I'd stay away. Nothing to do with the Marantz 7. This would be a better kit if you are looking to build your own

    http://wallofsound.ca/audioreviews/review-elekit-tu-8500-tube-preamplifier-kit/

    Or Bottle Head has some great units too.

    H9


    The Elekit stuff is generally quite nice -- at that price point, there are (or at least were) other options, too. Besides Bottlehead (which we've both mentioned), e.g., there's Bruce Rozenblit's Grounded Grid preamp.
    http://www.transcendentsound.com/Transcendent_Sound_Grounded_Grid_Preamp.html


    tg4rpexc9787.png
    (borrowed photo -- this one has some upgrades relative to stock, e.g., some coupling capacitors)

    Interestingly/ironically, there are Asian-sourced, very inexpensive Grounded Grid preamp knockoffs out there in cyberspace -- they are rather literal rip-offs of the real thing. :(

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  • mhardy6647
    mhardy6647 Posts: 33,776
    Oh, I'd be remiss were I not to mention this kit as well. A little further up the ladder, but I did have a chance to play with one of these and I was pretty favorably impressed with the way it sounded here.

    http://www.tubes4hifi.com/pre11.htm#SP14

    Gettin' into some fairly serious money, though -- so, of course, there are ever-more options as the budget goes up! :)

    32650125070_3866df6a74_b.jpgDSC_7135 (2) by Mark Hardy, on Flickr
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  • mhardy6647
    mhardy6647 Posts: 33,776
    Faustin wrote: »
    I put together a Bottlehead Quickie last year and it is a surprisingly good sounding pre. I did upgrade the coupling caps and have another potentiometer to install (when I have time) and generally hook it to an Adcom 555 ss amp. Yes, as mhardy stated the 3S4 tubes are microphonic but are pretty cheap so you can experiment. I found some nos Brimar 3S4 tubes that are pretty darn good, quiet unless you tap on the base of the pre. I make it a point to not tap on the base. :):)

    1) It was your preamp kit build from which I borrowed the photo posted earlier in this thread! :)
    (thanks!)

    2) Thanks for mentioning that the good news about 3S4s is that they're not very expensive! I believe I forgot to mention that part. :p
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  • motorstereo
    motorstereo Posts: 2,130
    mhardy6647 wrote: »
    [quote=" Yes, as mhardy stated the 3S4 tubes are microphonic but are pretty cheap so you can experiment. I found some nos Brimar 3S4 tubes that are pretty darn good, quiet unless you tap on the base of the pre. I make it a point to not tap on the base. :):)

    2) Thanks for mentioning that the good news about 3S4s is that they're not very expensive! I believe I forgot to mention that part. :p
    [/quote]

    I'm just thinking out loud here; if a particular type of tube is known to be problematic then why not avoid them altogether even if they are inexpensive?

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  • mhardy6647
    mhardy6647 Posts: 33,776
    Well, as an example, because Dynaco decided to use 7199s in some of their amplifiers! ;)

    7199s are notorious for microphonics -- and not particularly common nor cheap.


    As to Doc Bottlehead and the 3S4. Who knows why the tube was chosen, but I assume he/they chose to use them because they are cheap, plentiful and they're designed to be used in battery powered equipment (e.g., the portable and "farm radios" of long ago), and they are good performing, linear triodes.

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  • motorstereo
    motorstereo Posts: 2,130
    Hmmm; ok so "7199's are notorious for microphonics and not particularly common or cheap". Wouldn't that be a great reason to avoid them?
    Then you say the 3S4 are "good performing linear triodes". If they're microphonic wouldn't that take the "good performing" part out of the equation? Are there substitutions for these tubes that don't have problems?
    I'm not trying to be argumentative just trying to understand the justification of using a problematic tube or for that matter anything that has a known issue.
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  • codycatalist
    codycatalist Posts: 2,662
    Faustin wrote: »
    I put together a Bottlehead Quickie last year and it is a surprisingly good sounding pre. I did upgrade the coupling caps and have another potentiometer to install (when I have time) and generally hook it to an Adcom 555 ss amp. Yes, as mhardy stated the 3S4 tubes are microphonic but are pretty cheap so you can experiment. I found some nos Brimar 3S4 tubes that are pretty darn good, quiet unless you tap on the base of the pre. I make it a point to not tap on the base. :):)

    How long do you normally go without having to change the batteries. Something to me seems silly about battery operated Hifi equipment ha!
    Just a dude doing dude-ly things

    "Temptation is the manifestation of desire which equals necessity." - Mikey081057
    " I have always had a champange taste with a beer budget" - Rick88
    "Just because the thread is getting views don't mean much .. I like a good train wreck doesn't mean i want to be in one..." - pitdogg2
    "Those that don't know, don't know that they don't know." - heiney9
    "Audiophiles are the male equivalent of cat ladies." - Audiokarma Member
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  • mhardy6647
    mhardy6647 Posts: 33,776
    motorstereo wrote: »
    Hmmm; ok so "7199's are notorious for microphonics and not particularly common or cheap". Wouldn't that be a great reason to avoid them?
    Then you say the 3S4 are "good performing linear triodes". If they're microphonic wouldn't that take the "good performing" part out of the equation? Are there substitutions for these tubes that don't have problems?
    I'm not trying to be argumentative just trying to understand the justification of using a problematic tube or for that matter anything that has a known issue.

    Good tube with, perhaps, poor QC. Throw away the bad ones.

    You'd have to ask David Hafler about why he/they chose to use 7199s -- he's on the other side of the rainbow bridge now, though, unfortunately.

    Generally, I think choices are made in sort of a net-benefit manner. If the pluses are felt (objectively or subjectively) to outweigh the minuses, the net result may be considered good.

    Heck, people still buy Chrysler FCA products.


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  • Faustin
    Faustin Posts: 1,149
    How long do you normally go without having to change the batteries. Something to me seems silly about battery operated Hifi equipment ha!

    The batteries last around 150 hours. I am not an expert on battery operated amps and pre amps, but I think someone can chime in on the benefits of battery power. I chose this kit because it was my first attempt at a build and being battery powered I had less of a chance of an electric jolt and magic smoke. ;). As for the 3S4 tubes, evrything is quiet. It is only when you tap on the base you will hear a ringing. Sonically they are a very nice tube.
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  • mhardy6647
    mhardy6647 Posts: 33,776
    edited May 2018
    Batteries, at one level, make a lot of sense for hifi. No AC to DC power supply -- no DC ripple, no residual hum.

    In a DC powered (analog) device, it could be argued that the only AC in the circuit is the signal -- all of the infrastructure is pure DC. In theory, the best situation imaginable.

    There've been a few battery-powered line-level preamps and (particularly) phono preamps.

    Sutherland comes to mind, e.g.

    2wpwwk68boma.png
    t6hwhe68he98.png


    Other than heating the filaments, the current requirements aren't bad for a preamp.
    Battery powered transistor devices probably make incrementally more sense, though, of course -- but that's another topic entirely ;)

    In total fairness, it's been pointed out to me in past discussions that the noise level of a battery powered component won't necessarily be vanishingly low -- at some level, a battery will manifest some "chemical noise" (but we're getting into pretty esoteric territory).
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  • mhardy6647
    mhardy6647 Posts: 33,776
    edited May 2018
    I've thought about harnessing my local source of HV DC to power, say, a 2A3 stereo power amplifier ;)

    27123272659_699596d5d7_b.jpgDSC_9961 (2) by Mark Hardy, on Flickr

    Truth be told, though, a decommissioned battery pack from a hybrid or electric car would probably be a more pragmatic option. :p
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  • mhardy6647
    mhardy6647 Posts: 33,776
    edited May 2018
    Oh, in case it's not obvious -- the Quickie uses two D cells to heat the tube filaments and a bank of 9 volt "transistor radio" batteries in series to supply the high-ish voltage DC required for the tubes' plates.

    I assume that the four nine volt batteries are wired to provide 36 VDC.

    It might be argued that a hybrid P/S scheme (i.e., rechargeable batteries that can be trickle-charged when not in use) might be the most practical "solution" to the "ephemeral" :) nature of electrochemical DC power (i.e., 'dry cell' batteries).

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  • lightman1
    lightman1 Posts: 10,788
    Hardy!


    Go outside! Get some air!
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  • mhardy6647
    mhardy6647 Posts: 33,776
    :)
    Indeed -- s'posed to be eighty degrees today -- I am in fact gettin' ready to go out and start tilling the good earth.
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  • tonyb
    tonyb Posts: 32,958
    lightman1 wrote: »
    Hardy!


    Go outside! Get some air!

    Right ? The Professor has been cooped up inside far too long.
    HT SYSTEM-
    Sony 850c 4k
    Pioneer elite vhx 21
    Sony 4k BRP
    SVS SB-2000
    Polk Sig. 20's
    Polk FX500 surrounds

    Cables-
    Acoustic zen Satori speaker cables
    Acoustic zen Matrix 2 IC's
    Wireworld eclipse 7 ic's
    Audio metallurgy ga-o digital cable

    Kitchen

    Sonos zp90
    Grant Fidelity tube dac
    B&k 1420
    lsi 9's
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  • mhardy6647
    mhardy6647 Posts: 33,776
    mission accomplished.

    I am now rehydrating on the porch, thank you very much.

    :)

    15151102252_22159b8896_b.jpgDSC_9813 by Mark Hardy, on Flickr

    (artist's conception of what the porch will look like again in a few months :p )
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  • marvda1
    marvda1 Posts: 4,901
    if you want to try your hand at akit.
    http://oddwattaudio.com/owforewatt.html
    these guys came to the lone star audio fest for a couple of years.
    Amplifiers: Norma IPA 140, MasterSound Compact 845, Ayre v6xe, Consonance Cyber 800
    Preamp: deHavilland Ultraverve 3
    Dac: Sonnet Morpheus 2, Musical Paradise mp-d2 mkIII
    Transport: Jay's Audio CDT2 mk2, Lumin U1 mini
    Speakers: Rosso Fiorentino Volterra II
    Speaker Cables: Crystal Clear Magnum Opus 2, Organic Audio Organic Reference 2
    Interconnects: Crystal Clear Magnum Opus 2, Argento Organic Reference 2, Argento Organic 2
    Power Cables: Argento Organic Reference, Synergistic Research Foundation 10 and 12 ga.
    Digital cables: Crystal Clear Magnum Opus 2 bnc, Tellurium Q aes, Silnote Audio Poseidon Signature 2 bnc
    Puritan PSM156
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  • mhardy6647
    mhardy6647 Posts: 33,776
    marvda1 wrote: »
    if you want to try your hand at akit.
    http://oddwattaudio.com/owforewatt.html
    these guys came to the lone star audio fest for a couple of years.

    Neat-o. New to me (or maybe I've just forgotten about 'em :/ ).
    Thanks for the link.
    I didn't see a photo on the site of the innards -- but I shall google presently :)
    One is most curious -- as the price appears to be very right.
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  • marvda1
    marvda1 Posts: 4,901
    mhardy6647 wrote: »
    marvda1 wrote: »
    if you want to try your hand at akit.
    http://oddwattaudio.com/owforewatt.html
    these guys came to the lone star audio fest for a couple of years.

    Neat-o. New to me (or maybe I've just forgotten about 'em :/ ).
    Thanks for the link.
    I didn't see a photo on the site of the innards -- but I shall google presently :)
    One is most curious -- as the price appears to be very right.

    I think this is a picture of the insides.
    https://www.bing.com/images/search?view=detailV2&ccid=xhoXX689&id=B149BBDE3C7AFD8B5B12CDF737410867D102DC9D&thid=OIP.xhoXX6893_6nUsghLs2xUgHaFd&mediaurl=http://diyaudioprojects.com/Tubes/ECC802S-ECC82-12AU7-Tube-SRPP-Preamp/DIY-ECC802S-Tube-SRPP-Preamplifier.jpg&exph=571&expw=775&q=forewatt+preamplifier&simid=607987691471635551&selectedindex=5&qpvt=forewatt+preamplifier&ajaxhist=0
    Amplifiers: Norma IPA 140, MasterSound Compact 845, Ayre v6xe, Consonance Cyber 800
    Preamp: deHavilland Ultraverve 3
    Dac: Sonnet Morpheus 2, Musical Paradise mp-d2 mkIII
    Transport: Jay's Audio CDT2 mk2, Lumin U1 mini
    Speakers: Rosso Fiorentino Volterra II
    Speaker Cables: Crystal Clear Magnum Opus 2, Organic Audio Organic Reference 2
    Interconnects: Crystal Clear Magnum Opus 2, Argento Organic Reference 2, Argento Organic 2
    Power Cables: Argento Organic Reference, Synergistic Research Foundation 10 and 12 ga.
    Digital cables: Crystal Clear Magnum Opus 2 bnc, Tellurium Q aes, Silnote Audio Poseidon Signature 2 bnc
    Puritan PSM156
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  • mhardy6647
    mhardy6647 Posts: 33,776
    edited May 2018
    Yeah, I found that (with another search engine ;) ) -- it's a little ambiguous, as 1) it shows a higher-end morph (with some remote control functions) and 2) it may be a prototype or a DIY'ers "take" on building and tweaking the kit.

    It's helpful, but a plain-vanilla photo of the kit innards would be nice to see (and I couldn't find one). Is it based on PC boards, or perfboard or P to P? The web image has PC boards & perfboard. :|

    nsa4b94kbo3u.png

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  • sucks2beme
    sucks2beme Posts: 5,601
    The problem with Ebay Chinese knockoffs is the provided parts are complete crap.
    And design is often pretty poor. There's lot's of kit based stuff online that's not
    going to sound bad or burn the house down.

    "The legitimate powers of government extend to such acts only as are injurious to others. But it does me no injury for my neighbour to say there are twenty gods, or no god. It neither picks my pocket nor breaks my leg." --Thomas Jefferson
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