Tube Question

AudioFilet
AudioFilet Posts: 235
edited January 2010 in Electronics
Bonehead tube question of the week here.

I have a Chinese-made tube integrated that uses 4x KT88, 2x 12AU7 and 2x 12AT7. All the tubes are the original Chinese ones that came with the amp new. I've had this thing about 2 years, and it has always sounded great, and it has plenty of power. So anyway, I couldn't help but wonder how it would sound with some different tubes. So I went & bought a matched set of Genalex Gold Lion KT88 tubes for it (re-issue, Russian made). My question though is, do these things need to have a burn-in time for them before they are optimal for listening? Also, are there adjustments that need to be made (offset, gain, whatever) or are they just plug & play?
2 Channel rig:
LSi9"s (modified xover's) & HSU Sub
Harman Kardon HK 990 Amp
Onkyo C-S5VL SACD
Music Hall MMF 5.1
Furman Elite 15

HT rig:
HK AVR-745 & Polk Monitor Series
Post edited by AudioFilet on
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Comments

  • treitz3
    treitz3 Posts: 19,959
    edited January 2010
    Yes, they will change [burn in] from hour 1 to up to 500 hours. From what I understand, most will be good to go after around 200 hours depending on the tube and voltage. As for adjustments? It depends on whether it's a self biasing integrated or not.
    ~ In search of accurate reproduction of music. Real sound is my reference and while perfection may not be attainable? If I chase it, I might just catch excellence. ~
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  • thsmith
    thsmith Posts: 6,082
    edited January 2010
    If you can upgrade the output caps that will make it sound better too.
    Speakers: SDA-1C (most all the goodies)
    Preamp: Joule Electra LA-150 MKII SE
    Amp: Wright WPA 50-50 EAT KT88s
    Analog: Marantz TT-15S1 MBS Glider SL| Wright WPP100C Amperex BB 6er5 and 7316 & WPM-100 SUT
    Digital: Mac mini 2.3GHz dual-core i5 8g RAM 1.5 TB HDD Music Server Amarra (memory play) - USB - W4S DAC 2
    Cables: Mits S3 IC and Spk cables| PS Audio PCs
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  • AudioFilet
    AudioFilet Posts: 235
    edited January 2010
    thsmith wrote: »
    If you can upgrade the output caps that will make it sound better too.

    Upgrade them to what??
    2 Channel rig:
    LSi9"s (modified xover's) & HSU Sub
    Harman Kardon HK 990 Amp
    Onkyo C-S5VL SACD
    Music Hall MMF 5.1
    Furman Elite 15

    HT rig:
    HK AVR-745 & Polk Monitor Series
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  • AudioFilet
    AudioFilet Posts: 235
    edited January 2010
    treitz3 wrote: »
    Yes, they will change [burn in] from hour 1 to up to 500 hours. From what I understand, most will be good to go after around 200 hours depending on the tube and voltage. As for adjustments? It depends on whether it's a self biasing integrated or not.

    Thanks for that treitz3. I think it is a self-biasing amp. There are no accessible test points or adjustment pots there.
    2 Channel rig:
    LSi9"s (modified xover's) & HSU Sub
    Harman Kardon HK 990 Amp
    Onkyo C-S5VL SACD
    Music Hall MMF 5.1
    Furman Elite 15

    HT rig:
    HK AVR-745 & Polk Monitor Series
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  • treitz3
    treitz3 Posts: 19,959
    edited January 2010
    AudioFilet wrote: »
    There are no accessible test points or adjustment pots.
    Plug and play baby, plug and play. ;)

    Just be sure not to touch the tubes with your bare hands.
    ~ In search of accurate reproduction of music. Real sound is my reference and while perfection may not be attainable? If I chase it, I might just catch excellence. ~
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  • AudioFilet
    AudioFilet Posts: 235
    edited January 2010
    treitz3 wrote: »
    Plug and play baby, plug and play. ;)

    I'm curious as to what I can roll with the 12AU7 & 12AT7 tubes. I'm guessing that these are the preamp tubes?
    2 Channel rig:
    LSi9"s (modified xover's) & HSU Sub
    Harman Kardon HK 990 Amp
    Onkyo C-S5VL SACD
    Music Hall MMF 5.1
    Furman Elite 15

    HT rig:
    HK AVR-745 & Polk Monitor Series
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  • doctor r
    doctor r Posts: 837
    edited January 2010
    There is a hugh selection of 12au7 and 12at7 tubes avaliable. They atually can make a bigger change in the sound you are hearing than the power tubes might. You want to find NOS or used pre 1970 vintage tubes for these areas. Mullard, Telefunken, Amperex, Tung Sol, RCA, Sylvania ect.
    integrated w/DAC module Gryphon Diablo 300
    server Wolf Alpha 3SX
    phono pre Dynamic Sounds Associates Phono II
    turntable/tonearms Origin Live Sovereign Mk3 dual arm, Origin Live Enterprise Mk4, Origin Live Illustrious Mk3c
    cartridges Miyajima Madake, Ortofon Windfeld Ti, Ortofon
    speakers Rockport Mira II
    cables Synergistic Research Cables, Gryphon VPI XLR, Sablon 2020 USB
    rack Adona Eris 6dw
    ultrasonic cleaner Degritter
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  • heiney9
    heiney9 Posts: 25,421
    edited January 2010
    You really should upgrade the driver and input tubes as well...................definitely before you do any kind of cap upgrades.

    Dumping those Chinese 12AU7 and 12AT7's should be first because you'll never get the full potential out of the new KT88's. I have a nice used pair of Orange Globe Amperex I'll sell you cheap to get you started if you are interested. Also do you have the manual? Because if the amp is not self biasing then you need to bias it when you put in new power tubes. The bias points and adj. may not be easy to get to, maybe on the pcb under the bottom plate. The manual should mention whether its manual or self biasing.

    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 | Puritan Audio PSM136 Pwr Condtioner & Classic PC's | Legend L600 | Roon Nucleus 1 w/LPS - Tubes add soul!
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  • AudioFilet
    AudioFilet Posts: 235
    edited January 2010
    heiney9 wrote: »
    You really should upgrade the driver and input tubes as well...................definitely before you do any kind of cap upgrades.

    Dumping those Chinese 12AU7 and 12AT7's should be first because you'll never get the full potential out of the new KT88's. I have a nice used pair of Orange Globe Amperex I'll sell you cheap to get you started if you are interested. Also do you have the manual? Because if the amp is not self biasing then you need to bias it when you put in new power tubes. The bias points and adj. may not be easy to get to, maybe on the pcb under the bottom plate. The manual should mention whether its manual or self biasing.

    H9

    I don't have any kind of manual for it even though I bought it new. I did have a schematic at one time, but can't find it right now. I have sent an email to the guy I bought it from to try & find out about the biasing.
    2 Channel rig:
    LSi9"s (modified xover's) & HSU Sub
    Harman Kardon HK 990 Amp
    Onkyo C-S5VL SACD
    Music Hall MMF 5.1
    Furman Elite 15

    HT rig:
    HK AVR-745 & Polk Monitor Series
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  • treitz3
    treitz3 Posts: 19,959
    edited January 2010
    What is the make and model of the unit? This will help us to help you.

    Good call Heiney.
    ~ In search of accurate reproduction of music. Real sound is my reference and while perfection may not be attainable? If I chase it, I might just catch excellence. ~
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  • AudioFilet
    AudioFilet Posts: 235
    edited January 2010
    On the front it says "Music Angel".

    Made by Sheng Yi
    Model XD-SE
    2 Channel rig:
    LSi9"s (modified xover's) & HSU Sub
    Harman Kardon HK 990 Amp
    Onkyo C-S5VL SACD
    Music Hall MMF 5.1
    Furman Elite 15

    HT rig:
    HK AVR-745 & Polk Monitor Series
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  • organ
    organ Posts: 4,969
    edited January 2010
    Check your manual to be sure it's auto bias. I have a SET int amp that is manual bias. I have to take the bottom cover off to get to the pots. If you don't have the manual, there is another way for you to find out if it's auto or manual. Check the internals for any variable pots installed. If you see pots, it's manual. No pots, auto.

    IME, power tubes take about 50-100 to break in. Biggest difference is the music becomes more effortless, open and smooth sounding. There is usually a big improvement on bass as well. Those Genelex you purchased are pricey but they are considered the best of its type. Some say they sound as good as the old ones. Be careful if you decide to inspect the inside. The caps hold a lot of charge even with the amp unplugged and can be very dangerous.

    For the 12AU7, it depends if you're looking for new production or NOS/used. For NOS I really like the Siemens military 5814 with triple mica. The Mullard ECC82 are great as well.
    For current production the JJ ECC82 are very nice. They have a nice warm tone.

    I heard a Music Angel SET int. amp at my dealer several times. It was connected to Omega single driver speakers and it sounded really good. He said a rep dropped it off for them to play around with. Sounded very good. Does your logo show a cross with a circle, an x somewhere? I can't remember exactly how it looked.
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  • dorokusai
    dorokusai Posts: 25,576
    edited January 2010
    thsmith wrote: »
    If you can upgrade the output caps that will make it sound better too.

    How about letting the guy jump into tubes before you have him ripping open his gear. I know your on a 1uf buzz for your, recently sold Anthem....its not always that cut and dry.
    CTC BBQ Amplifier, Sonic Frontiers Line3 Pre-Amplifier and Wadia 581 SACD player. Speakers? Always changing but for now, Mission Argonauts I picked up for $50 bucks, mint.
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  • AudioFilet
    AudioFilet Posts: 235
    edited January 2010
    organ wrote: »
    I heard a Music Angel SET int. amp at my dealer several times. It was connected to Omega single driver speakers and it sounded really good. He said a rep dropped it off for them to play around with. Sounded very good. Does your logo show a cross with a circle, an x somewhere? I can't remember exactly how it looked.

    The only logo is a yellow music clef with angel's wings, on top of two of the xformers. There is a switch on the back to switch from triode mode (30wpc) or "ultra linear" (pentode?) mode (65wpc). It sounds great in both modes. It seems like these Chinese boys are out to prove something. This is the third Chinese amp I have seen, and all are of outstanding build quality. Hand made too. Really nice stuff.

    I'm getting ready for a trip to Singapore on Monday morning, so I really don't have the time right now to take it apart again to see if there are any adjustments inside, but I don't recall anything like that from the first time I looked at it.

    I have sent off a few emails to try & find out if it is auto-biasing, but no response yet.
    2 Channel rig:
    LSi9"s (modified xover's) & HSU Sub
    Harman Kardon HK 990 Amp
    Onkyo C-S5VL SACD
    Music Hall MMF 5.1
    Furman Elite 15

    HT rig:
    HK AVR-745 & Polk Monitor Series
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  • heiney9
    heiney9 Posts: 25,421
    edited January 2010
    This is what the insides of my Dared look like as far as manual bias for the power tubes. There is a "pot" for each of the four power tubes as well as four separate points for the probes of a DVM to measure the bias as you adjust the pots. The important info is what the factory states the bias number should be.

    bias1.jpg

    hero_open.jpg

    Hope this helps

    Chances are if it plays in both modes it's auto bias.............but you should find out fore sure if you can.

    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 | Puritan Audio PSM136 Pwr Condtioner & Classic PC's | Legend L600 | Roon Nucleus 1 w/LPS - Tubes add soul!
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  • michaeljhsda2
    michaeljhsda2 Posts: 2,200
    edited January 2010
    AudioFilet wrote: »
    The only logo is a yellow music clef with angel's wings, on top of two of the xformers. There is a switch on the back to switch from triode mode (30wpc) or "ultra linear" (pentode?) mode (65wpc). It sounds great in both modes. It seems like these Chinese boys are out to prove something. This is the third Chinese amp I have seen, and all are of outstanding build quality. Hand made too. Really nice stuff.

    I'm getting ready for a trip to Singapore on Monday morning, so I really don't have the time right now to take it apart again to see if there are any adjustments inside, but I don't recall anything like that from the first time I looked at it.

    I have sent off a few emails to try & find out if it is auto-biasing, but no response yet.

    Is this one similar to yours? http://cgi.ebay.com/MA-XDSE-Russian-KT88-Class-A-Integrated-Tube-Amplifier_W0QQitemZ260544777262QQcmdZViewItemQQptZUK_AudioTVElectronics_HomeAudioHiFi_Amplifiers?hash=item3ca9adcc2e. I'm seriously looking at buying one to run my SDA 1C's.
    SDA SRS 2.3TL's
    Silk Audio MS-90-BT integrated tube amp
    Yaqin MS-20L integrated tube amp
    SDA 2B TL's
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  • george daniel
    george daniel Posts: 12,096
    edited January 2010
    guys,, not to derail,, but when ya'll are adjusting bias,are you using a digital or analog meter?
    JC approves....he told me so. (F-1 nut)
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  • heiney9
    heiney9 Posts: 25,421
    edited January 2010
    George, I use a digital only because I feel it's easier and more accurate.
    "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 | Puritan Audio PSM136 Pwr Condtioner & Classic PC's | Legend L600 | Roon Nucleus 1 w/LPS - Tubes add soul!
    · Share on FacebookShare on Twitter
  • treitz3
    treitz3 Posts: 19,959
    edited January 2010
    Digital.
    ~ In search of accurate reproduction of music. Real sound is my reference and while perfection may not be attainable? If I chase it, I might just catch excellence. ~
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  • george daniel
    george daniel Posts: 12,096
    edited January 2010
    thanks guys-- i used to use a digital with mt anthems and vtl's,, but when using a digital with the vtl it seems to jump around a bit,,dunno if it's me,,or maybe the bias pot,or resistor,,so,,i got a analog--meter --vm that I'm gonna try.

    Oops-- back to our regularly scheduled programming.
    JC approves....he told me so. (F-1 nut)
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  • heiney9
    heiney9 Posts: 25,421
    edited January 2010
    george daniel wrote: »
    thanks guys-- i used to use a digital with mt anthems and vtl's,, but when using a digital with the vtl it seems to jump around a bit,,dunno if it's me,,or maybe the bias pot,or resistor,,so,,i got a analog--meter --vm that I'm gonna try.

    Oops-- back to our regularly scheduled programming.

    It does jump a bit I have biased between 220 and 223 mV even moving the probes around in the air produced some weird readings, but they settle right in when actually measuring the dc mV.
    "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 | Puritan Audio PSM136 Pwr Condtioner & Classic PC's | Legend L600 | Roon Nucleus 1 w/LPS - Tubes add soul!
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  • george daniel
    george daniel Posts: 12,096
    edited January 2010
    good piont Brock,,mine seem to "bounce around" when i'm actually trying to adjust the pot,,hmmm,, maybe it's the pot,, i'll shoot some cleaner in it and see if they normalize--thanks
    JC approves....he told me so. (F-1 nut)
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  • AudioFilet
    AudioFilet Posts: 235
    edited January 2010
    heiney9 wrote: »
    Chances are if it plays in both modes it's auto bias.............but you should find out fore sure if you can.

    H9

    Thanks H9 -- after my Singapore trip I should have some time to check all this out, plus the new tubes should be here by then. Actually, I should have 4-5 weeks off from work to do whatever I want.
    2 Channel rig:
    LSi9"s (modified xover's) & HSU Sub
    Harman Kardon HK 990 Amp
    Onkyo C-S5VL SACD
    Music Hall MMF 5.1
    Furman Elite 15

    HT rig:
    HK AVR-745 & Polk Monitor Series
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  • AudioFilet
    AudioFilet Posts: 235
    edited January 2010
    michaeljhsda2 wrote: »
    Is this one similar to yours? http://cgi.ebay.com/MA-XDSE-Russian-KT88-Class-A-Integrated-Tube-Amplifier_W0QQitemZ260544777262QQcmdZViewItemQQptZUK_AudioTVElectronics_HomeAudioHiFi_Amplifiers?hash=item3ca9adcc2e. I'm seriously looking at buying one to run my SDA 1C's.

    That's the one. I guess he's calling it "Russian" because it comes with Russian tubes. I actually bought mine from a Canadian seller who imports them, checks everything out (a "QA" check), then re-sells them with a guarantee. Not sure what he has in stock right now:

    http://stores.ebay.com/Canadian-HiFi-Online?_rdc=1

    Buying from the Canadian guy will also ensure the unit you buy will be the 115 volt model.
    2 Channel rig:
    LSi9"s (modified xover's) & HSU Sub
    Harman Kardon HK 990 Amp
    Onkyo C-S5VL SACD
    Music Hall MMF 5.1
    Furman Elite 15

    HT rig:
    HK AVR-745 & Polk Monitor Series
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  • AudioFilet
    AudioFilet Posts: 235
    edited January 2010
    Although I've had this tube amp for almost 2 years, I have only recently (within the last 2 weeks) finally got it set up the way I like it & actually started to listen to it in comfort. I know the turntable still needs some setup work done to it, but this might just be my best-sounding 2 channel system (I have 4 of them).

    Anyway, I thought you guys might like a peek at it, so here it is.
    2 Channel rig:
    LSi9"s (modified xover's) & HSU Sub
    Harman Kardon HK 990 Amp
    Onkyo C-S5VL SACD
    Music Hall MMF 5.1
    Furman Elite 15

    HT rig:
    HK AVR-745 & Polk Monitor Series
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