Bi-amping question

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walterslw

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Bi-amping question
« on: 2 Dec 2018, 03:34 pm »
Hello fellow VSA owners


As Ive posted in the bi amping thread, I am running tubes on top (kt150 upgraded Sonic Frontiers Power 1 SE) and class D Audio custom built monoblocs on the bottom of my VSA VR5 annies mk 2.  The class d audios have a custom matched TKD pot on their variable gain stage so that i can dial in the base.  All sounds amazing... but I am thinking it may be time to simplify.   I  am starting to get tired of tube amp maintenance.  I am thinking three options, and looking for some feedback and guidance.


Option 1: keep the bi amp config but replace the  tube amp with a class A solid state.   First amp that comes to mind based on what I have read is the Pass Labs XA30.8.  I have not heard the 30.8, but i have heard pass labs other AB amps in other systems.


Option 2: simplify the setup for solid state monoblocs or a stereo amp.   Bhk 300 monos from PS audio, VK650SE from BAT for example...    FWIW, I have tried running my class d amps full range, and my system did take a step back in terms of resolution and dynamics.  Ive resenttly heard the newest Macintosh monos at the Toronto Audiofest and they were stunning, but I believe their sensitivity ratings would not be a good match for my PS Audio BHK pre amp.


Option 3: do nothing....  keep what i got :)


Really looking for opinions and experience for anyone who used to bi amp and now does not, or those who have gone from tube to all solid state.


Thanks in advance.
Lou

Charles Calkins

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Re: Bi-amping question
« Reply #1 on: 2 Dec 2018, 04:37 pm »
 There is a very,very old saying. " If it is not broken do not try to fix it"
 IMHO trying to improve the sound of your system is like opening a big can of worms.
  Plus a BIG!! headache

                                            Cheers
                                           Charlie

walterslw

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Re: Bi-amping question
« Reply #2 on: 2 Dec 2018, 04:57 pm »
There is a very,very old saying. " If it is not broken do not try to fix it"
 IMHO trying to improve the sound of your system is like opening a big can of worms.
  Plus a BIG!! headache

                                            Cheers
                                           Charlie


I’m possibly thinking the same.  If nothing else it may be a good thought excercise.   If I do go with a solid state on the top, I may still keep the tube amp.   

Charles Calkins

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Re: Bi-amping question
« Reply #3 on: 2 Dec 2018, 06:09 pm »

I’m possibly thinking the same.  If nothing else it may be a good thought excercise.   If I do go with a solid state on the top, I may still keep the tube amp.

  From all I have read about  bi amping it seems that the ideal way is to have a solid state amp
  driving the bass and mid range and a tube amp driving the tweeter. The only problem is finding
   amps that can work together. Another can of big worms.

                                                  Cheers
                                                 Charlie

sebrof

Re: Bi-amping question
« Reply #4 on: 2 Dec 2018, 11:13 pm »
I  am starting to get tired of tube amp maintenance. 
Tube amp maintenance? What's that?
I just dust mine off every once in a while, but I do that with other stuff, too.

walterslw

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Re: Bi-amping question
« Reply #5 on: 3 Dec 2018, 02:04 pm »
... It seems that like every 6 months I have at least one cathode resistor that dies, and I cannot bias the tubes.   What's interesting is that my matched quad of KT150s test like new.   Just had a cathode resistor replaced on Friday, and I am again able to bias all four tubes.  The amp is sounding wonderful, but what a PITA every 6 months.  What is nice with the Sonic Frontiers, is that they had the foresight to allow for individual tube biasing instead of banks of two.  All tubes age differently...


In terms of bi-amping with a Pass XA30.8 - its not going to happen.  The input sensitivities are way too far off to be a good match.   I don't want to have anything in the signal path of the signal going to the amp feeding the mid/tweeters.   And the Pass is much to sensitive to be a match for my class D Audio amp.   So now I am thinking that I will keep my tube / class D set up, but explore a second all solid state amplification:


Can VSA owners chime in with amplifiers they are using?  I know there is quite a bit of information in the Bi-Amp thread, but any additional success with the following:


- PS Audio BHK 300 monos


- Pass Labs - X260.8 monos (or any other pass designs) - I have heard many great sounding systems with these amps, but never a VSA speaker.   Closest dealer is about 1.5 hours away, and I would prefer to buy second hand (thinking Reno HiFi when the time comes)


- Anyone using Mac gear (amps) with PS audio Pre amp (BHK)?




Thanks
Lou

es347

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Re: Bi-amping question
« Reply #6 on: 6 Dec 2018, 12:09 am »




..I’ve got fhe Annie Mk IIs as well and have run the MC601s for 3 or 4 yrs now.  My preamp is the C500P.  IMO there is very good synergy between VSA and MAC...others have confirmed this.  Good luck in your search..

Charles Calkins

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Re: Bi-amping question
« Reply #7 on: 9 Dec 2018, 12:31 am »
... It seems that like every 6 months I have at least one cathode resistor that dies, and I cannot bias the tubes.   What's interesting is that my matched quad of KT150s test like new.   Just had a cathode resistor replaced on Friday, and I am again able to bias all four tubes.  The amp is sounding wonderful, but what a PITA every 6 months.  What is nice with the Sonic Frontiers, is that they had the foresight to allow for individual tube biasing instead of banks of two.  All tubes age differently...


In terms of bi-amping with a Pass XA30.8 - its not going to happen.  The input sensitivities are way too far off to be a good match.   I don't want to have anything in the signal path of the signal going to the amp feeding the mid/tweeters.   And the Pass is much to sensitive to be a match for my class D Audio amp.   So now I am thinking that I will keep my tube / class D set up, but explore a second all solid state amplification:


Can VSA owners chime in with amplifiers they are using?  I know there is quite a bit of information in the Bi-Amp thread, but any additional success with the following:


- PS Audio BHK 300 monos


- Pass Labs - X260.8 monos (or any other pass designs) - I have heard many great sounding systems with these amps, but never a VSA speaker.   Closest dealer is about 1.5 hours away, and I would prefer to buy second hand (thinking Reno HiFi when the time comes)


- Anyone using Mac gear (amps) with PS audio Pre amp (BHK)?




Thanks
Lou

  Hi Lou:
           I've been off line for a For a week or so but my answer to what amp I'm using to drive my VSA speakers is a McIntosh MC352.
            I also use this amp to bi amp the speakers. I'm a happy camper when I hear the music in my system. Like everybody who is an Audoholic
            we are all trying to improve the sound of our system. I hope this information helps.
             Have a Merry Xmas and a happy new year.

                                                                Cheers
                                                                Charlie
           
                                                         


walterslw

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Re: Bi-amping question
« Reply #8 on: 14 Dec 2018, 04:47 pm »
I _really, really_ like the latest series of MAC amps, but based on the 611s input sensitivity, they would not be a good match electrically to my BHK Signature pre.   All to do with input sensitivity of amp, versus output voltage of the pre.   I do not want to get into swapping pre amps  :) , that would make this exercise way more complex. 


I have the Pass Labs X260.8 monos on my short list, but surprisingly haven't seen much feedback from owners, I would like to purchase used.  The BHK 300 monos are also on my short list.  Just looking for user experience with VSA.


Thanks




es347

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Re: Bi-amping question
« Reply #9 on: 15 Dec 2018, 04:28 pm »
..a couple of thoughts..

As I understand it you’re running the BHK pre.  If so it would seem the BHK monos are a no brainer...

Regarding the MC611s, there was a thread posted on the MAC audio aficionado site where they made a direct comparison of the 611s to the 601s and found no discernible difference in sonics....just fyi

walterslw

  • Jr. Member
  • Posts: 81
Re: Bi-amping question
« Reply #10 on: 16 Dec 2018, 07:32 pm »
..a couple of thoughts..

As I understand it you’re running the BHK pre.  If so it would seem the BHK monos are a no brainer...

Regarding the MC611s, there was a thread posted on the MAC audio aficionado site where they made a direct comparison of the 611s to the 601s and found no discernible difference in sonics....just fyi


Thanks Es347


Im starting to think the same in terms of a "no brainer" upgrade...  why make things troublesome.... the last thing I want to do now is open the can of worms of hardware swap lifecycle. 

Escott1377

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Re: Bi-amping question
« Reply #11 on: 25 Dec 2018, 04:05 pm »
I own a pair of VR4jr's that are the Gen IV upgrade from VSA.

I use a pair of Prima Luna Dialogue 7 blocs on the top and a pair of Wyred 4 Sound mAmps on the bottom in a bi-amp set up.

I have run them as bi-wire and the b-amp is the way to go IMO.

Just need to make sure to adjust for your amps and when you find the right spot is it magic.

I also run 2 x 500 W subs in the set up to finish up the bottom up end.

I have 2 yr. olds so in actuality, this all sitting in a closet.

Merry Christmas all :)

kernelbob

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Re: Bi-amping question
« Reply #12 on: 25 Dec 2018, 06:00 pm »
Hi walterslw.

There have been several threads recently discussing biwiring and biamping. My comments below are distillation of my experience with VSA speakers and various amplifiers.

VSA speakers that have both M/T and bass terminals have separate crossovers for each input.  The M/T crossovers present very high impedance in the frequencies below those handled by the M/T units.  This means that if you biwire, the bass frequencies current is greatly attenuated and as a result there is very little magnetic interaction with the M/T signal.

Biamping provides this same benefit with the M/T amp seeing a very high input impedance in the bass frequencies.  This also means that the M/T amp doesn't have to supply all that bass current and so has more headroom in the M/T frequencies.

Biamping lets you select a bottom amp that excels in the bass and a top amp that excels in the M/T.  Finding an amp that does both in one box is an engineering and financial challenge.

With the VSA speakers, the dynamic bass drivers are fast and dynamic.  They sound the best with amplifiers that have a very high damping factor via negative feedback in the amp.  None of the tube amps I've tried excel in the control of the bass compared with good solid state amps.

By comparison, the M/T drivers don't need an amplifier's damping factor.  In fact negative feedback loops in the M/T are, in my opinion, very detrimental and prevent the VSA M/T drivers & crossovers from achieving their potential.  My latest selection of an M/T amp has been revelatory.  This amp is the Lampizator True Balanced 211 Monoblock amp.

Each monoblock essentially consists of two single ended amps using a 300B tube as a driver and a 211 output tube.  The amps only accept a balanced input with each input phase going to one of of the 211 "single ended amps".  There's no phase splitter and the amplified phases are only combined in the single output transformer.  There's no local or global feedback which makes the amp less than ideal as a bass amp, but in a biamped system, this is irrelevant.  What is most important is that this lack of feedback eliminates time smearing of the M/T signal.

The quality of the resulting midbass, midrange, and treble is something to hear.  Coherence and focus is a hallmark of the VSA speakers.  However, the dynamics, realism, and timbre of instruments over the Lampi 211's is striking compared with any other M/T amp I've used or heard.  This, combined with the impact and articulation of the well controlled bass drivers results in a performance level that I've never heard from any system.

Getting back to your current system, it looks like you've got the bass under control (pun intended).  I'd recommend finding an amp that excels in driving the midrange and treble drivers.  A single ended amp with as little or no feedback be a key feature in a M/T amp for your system.

Best,
Robert

walterslw

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  • Posts: 81
Re: Bi-amping question
« Reply #13 on: 9 Jan 2019, 07:03 pm »
Hi walterslw.

There have been several threads recently discussing biwiring and biamping. My comments below are distillation of my experience with VSA speakers and various amplifiers.

VSA speakers that have both M/T and bass terminals have separate crossovers for each input.  The M/T crossovers present very high impedance in the frequencies below those handled by the M/T units.  This means that if you biwire, the bass frequencies current is greatly attenuated and as a result there is very little magnetic interaction with the M/T signal.

Biamping provides this same benefit with the M/T amp seeing a very high input impedance in the bass frequencies.  This also means that the M/T amp doesn't have to supply all that bass current and so has more headroom in the M/T frequencies.

Biamping lets you select a bottom amp that excels in the bass and a top amp that excels in the M/T.  Finding an amp that does both in one box is an engineering and financial challenge.

With the VSA speakers, the dynamic bass drivers are fast and dynamic.  They sound the best with amplifiers that have a very high damping factor via negative feedback in the amp.  None of the tube amps I've tried excel in the control of the bass compared with good solid state amps.

By comparison, the M/T drivers don't need an amplifier's damping factor.  In fact negative feedback loops in the M/T are, in my opinion, very detrimental and prevent the VSA M/T drivers & crossovers from achieving their potential.  My latest selection of an M/T amp has been revelatory.  This amp is the Lampizator True Balanced 211 Monoblock amp.

Each monoblock essentially consists of two single ended amps using a 300B tube as a driver and a 211 output tube.  The amps only accept a balanced input with each input phase going to one of of the 211 "single ended amps".  There's no phase splitter and the amplified phases are only combined in the single output transformer.  There's no local or global feedback which makes the amp less than ideal as a bass amp, but in a biamped system, this is irrelevant.  What is most important is that this lack of feedback eliminates time smearing of the M/T signal.

The quality of the resulting midbass, midrange, and treble is something to hear.  Coherence and focus is a hallmark of the VSA speakers.  However, the dynamics, realism, and timbre of instruments over the Lampi 211's is striking compared with any other M/T amp I've used or heard.  This, combined with the impact and articulation of the well controlled bass drivers results in a performance level that I've never heard from any system.

Getting back to your current system, it looks like you've got the bass under control (pun intended).  I'd recommend finding an amp that excels in driving the mid-range and treble drivers.  A single ended amp with as little or no feedback be a key feature in a M/T amp for your system.

Best,
Robert


Happy new year fellow VSA community


Hi Bob,


I couldn't agree with you more!   In fact, after several weeks of thinking about this, some tweaking, and lots of listening I have decided to keep the equipment I have.   The class D Audio amps, have >2000 damping factor, and these amps with brand new Synergistic Quantum Blue Fuses, just smack the hell out of those drivers.   I have also changed the power cord on my tube amp and pre-amp from Audio Sensibility Signatures, to Lessloss C-MARCs and Firewall Filters.   This was not an insignificant change (for the better).   I also installed Synergistic Quantum Blues into the Sonic Frontiers, Class D Audio, as well as BHK Pre.    I was skeptical and scared, as those dam fuses are bloody expensive, but my gosh!  Truth be told, I think the SR Blue made the largest improvement!   Combined with the LessLoss cables on my Amp and Pre, and replacing stock AC cables with Audio Sensibility Signature AC cords on my Class D amps, the entire system moved several notches up in performance.    The LessLoss cables only have about 100 hours on them, but on the tube amp what they do is incredible.   Instruments, are placed within their own space, without any change in timber or tone.  In addition, complex music passages, do not trip up amp at any volume.  The top end is more extended without a shift in tone.  Noise floor.... what noise floor, it is non-existent.    I went with LessLoss C-MARK and Firewall again, because I was so impressed with what they did on my PS Direct Stream DAC.  I have had all of the cathode resistors replaced, and the amp has been thoughtfully tested / checked over as well as my 1.5 year old KT 150 power tubes.   The tubes are testing as new, and the amp is sounding FINE.    Over the the past couple of weeks, I've done allot of listening, and I really love how my system sounds now.  I think it will get even slightly better as the power cords fully break in - although I think they are probably nearly there now.   I think changing amps could possibly ruin what I have now.   The reason I started tweaking AC cords and fuses is that I thought my issues may have been related to AC, and if I could improve on what I already had without negative impact, that would be a good starting point.  Plus, Lessloss offers 30 day money back guarantee.


So my Sonic Frontiers Power 1 SE - which has been heavily modified and upgraded by Parts Conexxion about a year ago, is barely doing anything (driving the M/T), and the class D Audio Amps which are matched to the SF can output 300W into 8 ohms, and 600 W into 4 ohms, so I am more than covered for the bass.   The class D amps have the damping factor that the VR5 Anni's love, but also a fairly large linear power supply, so there is a nice power reserve...   I think replacing the stock AC cables on the Class D Amps in addition to the fuses, really opened up the system.  I had assumed incorrectly, that I wouldn't hear the difference replacing the AC cables on the Class D amps....  Live and learn ;) .   At this point, I am not sure any single (non-biamped) config can deliver the sound I am getting now.


Thank you all for your insight and input ;)


Lou Walters