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    system synergy

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    oldvstar

    Posts : 14
    Join date : 2014-01-02

    system synergy

    Post by oldvstar on Mon Mar 02, 2015 6:07 pm

    I have read most of the posts in this forum ( took awhile but worthwhile), especially posts concerning what tubes to use, I read posts until my head hurt and still didn't have decisive answer. The big thing I took away from this is the need to find proper synergy between the different components. So far I haven't been able to accomplish this, and lacking unlimited funds to do extensive tube rolling, and cable swapping, I'm reaching out to this group for suggestions. My VTA ST-70 sounds much too bright, for the purpose of dialing in the ST-70 I am running a minimal system of Laptop -> Audioquest Dragonfly DAC -> Blue Jeans IC -> ST-70 -> Audio Art SC5 -> ADS L710. I'm using Russian 6P3S-e and RCA clear top 12AU7 tubes in the ST-70. Normally I have a Music Hall MMF 2.2 w/Ortofon 2M blue -> LesBox modified Yaqin MS32b phono pre-amp -> modified Bottlehead Quickie preamp -> Blue Jeans IC -> ST-70 -> Audio Art SC5 -> ADS L710.
    The brightness is harsh and makes it difficult to listen for an extended period of time. I have over 100 hours on the Audio Art cables and the Dragonfly DAC, and over 150 hours on the tubes and the rest of the system. There are some positives to what I'm hearing; there is tremendous detail, clarity, and overall musicality to what I'm hearing, the top end is just too dang bright and edgy.
    Thanks for any suggestions.
    Terry

    sKiZo

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    Location : Michigan USA

    Re: system synergy

    Post by sKiZo on Mon Mar 02, 2015 7:28 pm

    The RCA clear tops are a bright tube ... that's the first thing I'd change. The 5963's are much more sedate on the top end and might be a good option. Same could be said for the 12BH7. Either is plug 'n play in your amp and easy on the pocketbook.

    Another potentially cheap fix - stick a sock in your tweeters. Really. A couple layers of woolies taped over the drivers can work wonders for killing the harsh.

    Bob Latino
    Admin

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    Location : Massachusetts

    Re: system synergy

    Post by Bob Latino on Mon Mar 02, 2015 9:37 pm

    Hi Terry,

    The VTA amps do not have a bright top end nor are they rolled off in any way ..

    Your ADS L710 speakers are from the late 1970's so they are probably 35+ years old. It is possible that the crossover inside the speakers needs to be rebuilt? Another thought for brightness are room treatments to absorb some of the high frequency output. Carpeting, drapes and/or sound absorbing foam panels can tame the highs in a room with too much high frequency energy ..

    As for tube changes > You could try a Mullard CV4003 in just the CENTER driver position of your amp. These have a beautiful mid-range. This is what I have in my own VTA ST-120 and in the front (voltage amplifier) position of my M-125 monoblocks

    Bob

    skriefal

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    Join date : 2011-09-20
    Location : Utah, USA

    Re: system synergy

    Post by skriefal on Mon Mar 02, 2015 10:00 pm

    I agree that swapping to CV4003s may tame the top end a bit.  Maybe also the RCA 5963s (haven't tried these myself).  It could also be tired crossover components in the speaker, as Bob states.  Before trying any of those, though, you may wish to try repositioning your speakers -- height, tilt, toe-in / toe-out, distance between the speakers (and between the speakers and you), etc.  These can have a significant impact on the sound of your system.

    j beede

    Posts : 316
    Join date : 2011-02-07
    Location : California

    Re: system synergy

    Post by j beede on Mon Mar 02, 2015 11:20 pm

    Hello Terry,
    How did you come to attribute the brightness to the amplifier? What are you comparing it to?
    ...j

    10-E-C

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    Age : 62
    Location : upper east tn

    Re: system synergy

    Post by 10-E-C on Mon Mar 02, 2015 11:29 pm

    Hi Terry

    I to had a harsh top end on my ST-70 and replaced the center tube with a 50s era RCA 5963. I was well please with the tone after the change.

    TM

    oldvstar

    Posts : 14
    Join date : 2014-01-02

    Re: system synergy

    Post by oldvstar on Mon Mar 02, 2015 11:41 pm

    10-E-C, I'm not familiar with the RCA 5963, I'll have to check it out.
    Thanks.

    MontanaWay

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    Location : Cameron, Montana

    Re: system synergy

    Post by MontanaWay on Mon Mar 02, 2015 11:53 pm

    oldvstar wrote:10-E-C, I'm not familiar with the RCA 5963, I'll have to check it out.
    Thanks.

    I have used the 5963 in my version of the ST70 and thats the tube of my choice....really nice sounding tube...to my ears much better than any 12AU7 I have tried.

    Maintarget

    Posts : 208
    Join date : 2013-02-10

    Re: system synergy

    Post by Maintarget on Tue Mar 03, 2015 12:04 am

    All great suggestions for me personally I had the same issue with ST-120 rebuilt cross overs made improvement, I went with a 12BH7 in center position and Improvement, I would also say the Dragonfly DAC is not bad for entry level low volume listening however anything approaching mid or higher volume levels and it's limitations show.
    Your headed in the right direction with a little experimentation you will find the optimal set up for you.
    Have fun.

    peterh

    Posts : 642
    Join date : 2012-12-25
    Location : gothenburg, sweden

    Re: system synergy

    Post by peterh on Tue Mar 03, 2015 3:04 am

    oldvstar wrote:I have read most of the posts in this forum ( took awhile but worthwhile), especially posts concerning what tubes to use, I read posts until my head hurt and still didn't have decisive answer. The big thing I took away from this is the need to find proper synergy between the different components. So far I haven't been able to accomplish this, and lacking unlimited funds to do extensive tube rolling, and cable swapping, I'm reaching out to this group for suggestions. My VTA ST-70 sounds much too bright, for the purpose of dialing in the ST-70 I am running a minimal system of Laptop -> Audioquest Dragonfly DAC -> Blue Jeans IC -> ST-70 -> Audio Art SC5 -> ADS L710. I'm using Russian 6P3S-e and RCA clear top 12AU7 tubes in the ST-70. Normally I have a Music Hall MMF 2.2 w/Ortofon 2M blue -> LesBox modified Yaqin MS32b phono pre-amp -> modified Bottlehead Quickie preamp -> Blue Jeans IC -> ST-70 -> Audio Art SC5 -> ADS L710.
    The brightness is harsh and makes it difficult to listen for an extended period of time. I have over 100 hours on the Audio Art cables and the Dragonfly DAC, and over 150 hours on the tubes and the rest of the system. There are some positives to what I'm hearing; there is tremendous detail, clarity, and overall musicality to what I'm hearing, the top end is just too dang bright and edgy.
    Thanks for any suggestions.
    Terry

    If it sounds too bright one could turn down the treble a bit(that what tone controls are made for)
    But it seems to me that what you have a distorsion together with a "normally bright" speaker
    ( i guess ADS710 == brAun L710, 2 bass, 1 middle dome and 1 dome highfrequency speaker).

    Have you tried with an all tube ( or high quality pre) on a clean ( non compressed) source?

    audiobill

    Posts : 271
    Join date : 2014-03-13
    Location : Philadelphia

    Re: system synergy

    Post by audiobill on Tue Mar 03, 2015 11:32 am

    How old are your speakers?

    Capacitors still fresh?

    arledgsc

    Posts : 330
    Join date : 2012-11-30
    Location : SF Bay CA

    Re: system synergy

    Post by arledgsc on Tue Mar 03, 2015 11:47 am

    My ST-120 took a while to run in and the tubes I used initially and what I use now are much different. Also the Mullards do have a gradual roll off of the highs so may be a good choice to give a try.

    sKiZo

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    Location : Michigan USA

    Re: system synergy

    Post by sKiZo on Tue Mar 03, 2015 1:10 pm

    Yup ... there is some break in required. Most tubes are well set at no more than 100 hours, but filter caps can take a whole lot more before they're done sweetening up.

    Looks like a lot of votes for the 5963. Not just the RCAs either - my favorite set are a matched triplet of Westinghouse "Stars" (military grade - low microphonics) ...



    * I'm actually running that with a 50's production GE 12BH7 in the middle. That opens up the holographic stage considerably.


    Last edited by sKiZo on Wed Mar 04, 2015 12:51 am; edited 1 time in total

    corndog71

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    Re: system synergy

    Post by corndog71 on Tue Mar 03, 2015 1:51 pm

    My suggestion is to try if possible more modern speakers. If you really want to keep your speakers then consider updating the crossovers in them. ERSE caps are very inexpensive and have a nice, warm quality to them. They might be just the ticket.

    Have you had your hearing checked? You could be developing a sensitivity to high frequencies.

    peterh

    Posts : 642
    Join date : 2012-12-25
    Location : gothenburg, sweden

    Re: system synergy

    Post by peterh on Tue Mar 03, 2015 2:11 pm

    The L710 has fronts of aluminium, these was held in place by magnets and could easily be removed.
    A strange effect with these was that treble was reduced when removing the grilles, explained
    by resonances in the aluminium grilles.
    I guess this raised treble gave brAun their characteristic brilliance, and shure it was needed by
    the recordings / music ideal of that era.
    I'ts unclear if ADS L710 has simular grilles.

    oldvstar

    Posts : 14
    Join date : 2014-01-02

    Re: system synergy

    Post by oldvstar on Tue Mar 03, 2015 5:35 pm

    I replied once but it seems to have disappeared so I'll try again.

    I did some research into the cross-overs and it seems that there is just one 100uf electrolytic cap that is typically replaced, the others are MKT caps and comments are that they don't deteriorate like electrolytics do and therefore don't need to be replaced. I don't know myself.

    Looks like some options to the Mullard CV4003's. The Mullards may sound great but they definitely cost quite a bit. Looks like the 5963, 12BH7 tubes should provide some more affordable options.

    Peterh, my usual configuration is turntable -> tube phono preamp -> tube preamp -> ST70, so yes, I have an all tube path with a good source.
    Also, my L710's do the the supposedly "acoustically invisible" metal speaker grills. I'll remove them when I get home and see what happens.

    corndog71, interesting you would mention my hearing. I have recently been experiencing a louder level of tinnitus on a continuous basis, as opposed to occasionally. I guess this could have an impact on what I'm hearing, except my system has been sounding this way for quite some time and my hearing issue is a recent development. (sucks getting older)

    Thanks everyone for your input, it'll keep me busy for awhile.
    I also have to say, this is a great forum!  
    Terry

    Maintarget

    Posts : 208
    Join date : 2013-02-10

    Re: system synergy

    Post by Maintarget on Tue Mar 03, 2015 11:38 pm

    * I'm actually running that with a 50's production GE 12BH8 in the middle. That opens up the holographic stage considerably.[/quote]
    sKiZo was that a test or do you have the same problem I do they put that dang 8 key to close to the 7 key for my fat finger, never heard of a 12BH8..........

    sKiZo

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    Re: system synergy

    Post by sKiZo on Wed Mar 04, 2015 12:50 am



    It's like a 12BH7, but it goes to 11 ... What a Face

    peterh

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    Re: system synergy

    Post by peterh on Wed Mar 04, 2015 2:43 am

    Is it possible that the preamp injects DC to the vta-70 ? That would be fatal for the sound as
    vta-70 ( or st-70) has no capacitor at input.

    Bob Latino
    Admin

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    Join date : 2008-11-26
    Location : Massachusetts

    Re: system synergy

    Post by Bob Latino on Wed Mar 04, 2015 10:01 am

    peterh wrote:Is it possible that the preamp injects DC to the vta-70 ? That would be fatal for the sound as
    vta-70 ( or st-70) has no capacitor at input.

    All modern preamps have a DC blocking cap on their outputs to prevent the introduction of DC into any power amp. It is interesting to note that although the Dynaco Mark II, Mark III, Mark IV and ST-70 do not have DC blocking caps on their inputs, the later designed Dynaco SCA35 integrated amps and ST-35 power amps DO HAVE a small .10 uF @ 16 volt DC blocking cap on their inputs.

    Bob

    peterh

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    Re: system synergy

    Post by peterh on Wed Mar 04, 2015 11:46 am

    Bob Latino wrote:
    peterh wrote:Is it possible that the preamp injects DC to the vta-70 ? That would be fatal for the sound as
    vta-70 ( or st-70) has no capacitor at input.

    All modern preamps have a DC blocking cap on their outputs to prevent the introduction of DC into any power amp. It is interesting to note that although the Dynaco Mark II, Mark III, Mark IV and ST-70 do not have DC blocking caps on their inputs, the later designed Dynaco SCA35 integrated amps and ST-35 power amps DO HAVE a small .10 uF @ 16 volt DC blocking cap on their inputs.

    Bob
    To "play safe" ( check all input for validity before processing) one should have DC blocking caps
    on inputs. Then any user who knows that their signal is free from DC could bypass those caps,
    but everyone else would at least be protected from "invalid" or "offset" input.


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