Pre-amp Modification Review

Collapse
This topic is closed.
X
X
 
  • Time
  • Show
Clear All
new posts
  • wkhanna
    Grumpy Old Super Moderator Emeritus
    • Jan 2006
    • 5673

    Pre-amp Modification Review

    The following is a rather winded review of the effects resulting from the modifications that were recently finished on my nearly 30 year old Carver C-19 tube hybrid pre-amp with a built-in phono pre-amp.

    Tom is the owner of the shop and creator of the modification specifications. He is a master technician and also V highly regarded by the designer of my pre-amp, Bob Carver.
    link to Vintage HiFi of Pittsburgh

    The Parable

    The following epic is an account of my continuing quest for audio nirvana and the result of the help I received from Tom at ‘Vintage HiFi of Pittsburgh’ towards reaching my goal.


    The Provenance

    In 2006 I was visiting my best friend, Rod Nicholas, a retired luthier who in 1994 was responsible for infecting me with this horrid OC audio disease. While at his home, I was presented with a relict that had been banished in the closet of an upstairs bedroom. Rod had replaced his Carver C-19 years before with some trinket from an obscure company in Canada. Bryston I think is the trade name they go by.

    Of course I was humbled and grateful to the point of speechlessness, along with now having a great story about the experience of transporting this unit as carry-on baggage during our return flight home from North Carolina.

    This wonderful pre amp immediately transformed my system and I have been using it continuously ever since.


    The Predicament

    I have what I considered a decent system. My priority is vinyl. I also have a See Dee player, FM analog tuner, DVD/SACD player and an A/V Pre-Pro for 4.0 surround duties.

    Over the years I have hosted a few get-togethers with local enthusiasts and have been to a few others, too. Between hearing other components demoed in my system, visiting audio shops and hearing what other people’s systems sound like, I have always felt mine was a bit on the bright, almost edgy side, and a bit anemic in the low end. Not good for someone who cherishes the ‘warmth’ that analog is supposed to have.

    For the longest time I thought it was my room &/or my speakers that were the culprit. Regardless of the source, whether digital or analog, this characteristic never really changed. I tried some tube rolling in the C-19, and that helped a small amount, but no matter what tweaks I tried, (speaker placement, room treatments, phono cartridges, deferent brands of source equipment, cables, etc.) I could never get my system to mellow out in the HF and tighten up in the LF. Though small incremental improvements were realized, the core issue never went away.

    Meanwhile everyone kept saying my system sounded good. But I was beginning to have trouble enjoying my music. All the while I was being menaced by a little voice inside of my head saying, “You know this should sound better, don’t you?”


    The Prescription

    I had known Tom for about a year. It didn’t take long to realize not only his obsessive passion for good sound, but also the skill he posses for repairing and modifying gear. Especially Carver gear. My confidence in Tom to do some work on my cherish C-19 finally overcame my fear of having someone actually take a soldering iron to this component that once belonged to the same person who has made instruments for the likes of Yo-Yo Ma.

    I figured if I were to ever have my system sorted out, I needed to know the C-19 was performing properly. It is more than 25 years old. And aside from a few lonely years in his closet, it has been lovingly used, as it should, playing music almost daily since the day Rod bought it.

    So I figured why not; just get a couple of pots cleaned, a few caps replaced here, a few resistors there…….can’t hurt. Right? No big deal. At the very least I will have the satisfaction of knowing the C-19 is working at its best, & I should look elsewhere for the solution to my dilemma.



    The Proposal

    I got the sense that the C-19 was one of Tom’s favorite pieces. By the time I was ready to bring to the unit in, he had developed a list of improved components & modifications, relocation of this, upgrade for that, IEC power socket installation, conversion to sockets which allow OP amp rolling, new pots, different valves and…….well, you get the idea by know I’m sure. This will be the test mule for Tom’s soon to be standard offering of his “One-of-a-Kind’, Super Duper, Bob Carver Approved C-19 make over.”

    “Ok” says I with naïve adulation. Let’s go for the ‘Whole Kahuna!”

    So, ah…..Tom…….

    …..about how long should this process take, du ya think?


    The Patience

    Look, when you’re laying on the operating room table it’s probably not a good idea to tell your neurosurgeon, “Hey! Can you hurry this up? I got a $25 voucher for Jerry’s Used Records that is about to expire today, and I’d like use it if you don’t mind!”

    Tom is a craftsman, an artist, & in his own mind, an above average philosopher (but we won’t go there right now). The point is, you don’t rush the maestro. If you do, it’s at your own risk. These creative artisan types can get riled up by the slightest & most mundane things sometimes.

    Still, I was forced to conspire …errr….aaah… I mean develop ways of kindly nudging Tom to carry forth with the project. One thing I found was that it never hurts to bring along a nice bottle of wine with two glasses when dropping by the shop.

    …….. “Hey Tom. I just happened to find myself near by (every detail of the trip planned and scheduled 5 days earlier) and figured I pop in just to say ‘waz-sup’…... Yeah Yeah, SOL. How’s business and all.”

    “Hey? Du ya remember that dirty old black box I dropped off a while ago?

    Sooooo….how’s that little project coming along?”

    And so it went. Minutes turned to hours, hours turned to days, days to months.
    Some parts were hard to find, some couldn’t be found. And the shop was busier than ever. Tom was swamped with repair work and struggling to just to stay in the black.


    The Product

    Don’t get me wrong. It won’t take you a year to get your stuff back from Tom. He is promising a seven day turnaround on the C-19 modification. He now has a fantastic new technician to help (Welcome to funny farm, Anders!). Mine was a special case in many ways. But now that all the Mods are vetted, the process for upgrading the C-19 is V straightforward. He will/does have all the components in inventory. I know cuz he showed me.


    The Performance

    Science says your short term audible memory is good for 3-4 seconds. This is the period of time you retain large amounts of auditory information. As soon as you hear something else after this short period, your ability to recall with great detail all the particulars or nuances of that sound are gone.

    Funny thing though, when my sister calls from California every month or so, I know it’s her voice right away, even after not hearing it for over 30 days and on the ever so poor fidelity of a phone. Go figure? Bullocks or not?

    Anyway, I had been using a nice loner pre-amp Tom was kind enough to lend me. As soon as I got home from dropping off the C-19, I hooked it up. Gee, this isn’t too bad. Ugh….. wait. Hello, soundstage? Where did you go? Depth. I thought I had depth rich enough to allow me to walk 6’ through the wall behind the speakers? Shy, flabby underweight mid & low bass. And the top end was strikingly similar to what I hear when I bump the pot rack in the kitchen. The only problem is I’m listening to music, not an episode of Julia Child’s French Chef. Cling, rattle, and clang. All the little nit-picking issues I had with the old C-19 were now far worse.

    My golden eared audio buddy takes a listen and says, “Hope you get the C-19 back soon.”

    That was 12 months ago, and since then I actually began to loose interest in listening to my music.

    A week and a half ago the C-19 finally makes it home. I was up till 3:00 AM that night.
    This doesn’t remotely sound like my system. If someone had given me $15k and said, “Here, go replace your pre-amp, your speakers & your turntable, & make sure you spend it all”, then maybe that can describe what I hear.

    I’ve gained what has to be a good octave in deep low end. And it has all the punch, energy and quickness you would expect being backed by my 380 watt dual mono chassis Rotel RB-1090 amp. But this is not boom bass, this some of most musical, tonally correct bass I have ever heard.

    The top end? Well, one of my favorite references is the very first track ‘Singing Winds, Crying Beasts’, from my Mobile Fidelity Sound Lab 200 gram pressing of the original mastering off of Santana’s Abraxas LP. This is the one with the sparkling wind chimes. Actually, they only genuinely sparkle when everything in your system and the universe are in perfect alignment. With the modified C-19, you don’t have to close your eyes to visualize a wind chime. In fact, it’s your eyes that you don’t believe because your brain is telling you there must be, and is, a wind chime in the room. It is exactly eight feet in front of you, just off to the left by 19 inches, four feet five inches from the floor.

    My eight month old shorthaired male Chihuahua who’s name is ‘Not Cho Dawg’ (we usually just call him NotCho) often sits with me in my ‘sweet spot’. When he heard this playing he started growling, head cocked to the side, staring exactly where C-19 was placing the chimes. Poor guy is going think he’s schizophrenic before too long.

    But as they say, ‘we live in the mids’. And the mids are alive, alright. The texture of bow on strings, fingers just coming in contact with wildly oscillating acoustic double bass strings. Horns caressed by the lips of angles. But the true test is piano. Known for being extremely difficult enough just to record properly, it’s a complex instrument that has percussive qualities as the hammer slams to the string. Then stringed instrument qualities as they vibrate. Then the resonance quality like an acoustic guitar as all the sounds mingle and writhe then exit the body of the instrument. Then this all interacts with the shape, size and textures of the room it is in. I have a few well-captured recordings of real piano in real rooms. Now I have a real piano in my room.

    Soundstage. Meh. I personally put more value in depth and imaging. So the fact that my soundstage is now discernibly wider should be of little consequence. Well, you can’t miss what you never had, they say. But now I know what I was missing!

    Concerning depth & imaging, we (plural because all of my observations have been confirmed & validated by my golden eared audio buddy, Dan) agree what was once one of my system’s greatest strengths is now in the range of true high-end rigs. And just as Tom has promised, things are only getting better as all the new components burn in. Image focus & detail are getting tighter and even more precise.

    And when you just sit back and stop analyzing every little detail, when you take in all of the parts as a whole, that’s just when all the details come through. The sum is greater than the total of parts. Pure music flows. All the players are watching the same conductor; everyone is in time, on the same page. Your toe is tapping before you even realize it. This must be thing they call PRaT (Pace, Rhythm and Timing). Every once in a while you will hear a system that has it. All the components of the music come through together. The kick drum is simultaneous with the brass rhythm section, with the keyboard, the strings and on and on. These are the systems that make you want to get up on your feet when you’re all comfy cozy, kicked back in you’re well broken in listening chair.

    The results are the same regardless of the source. See Dee’s sound like vinyl, the FM radio sounds like vinyl. (When Dan dropped by for a listen I had the Magnum Dynalab FT-11 analog FM tuner on, he thought I was spinning black pie.) Even the vinyl sounds like vinyl. And Oh does it! The phono section is absolutely superb. I have the AT150MLX moving magnet cartridge. Some feel this cart is a bit on the bright, lean side. I used to be Some. Now I think Some should come here and listen to the AT cartridge. Bright and lean are adjectives not used in my home anymore.

    Neither is noise. I live one block from radio station WDUQ’s mega watt transmission tower. I could hear the station bleeding into my system anytime I had the volume on zero or when playing at V low level. Now I can crank it to 11 with the selector on phono and it is dead quiet one foot from the speaker. Needless to say, backgrounds are blacker than Pennsylvania bituminous coal.

    My wife likes music. Her family has music in their genes. So she tolerates my obsession with understanding. Sometimes she even sits with me & I spin some of her favorites. I love it when we share music. The night I brought the C-19 home I ran a few tracks at low level off of See Dee to test all my connections. She was a bit perplexed that I didn’t go straight to my top 20 vinyl. Once I was sure everything was behaving properly, I pulled her favorite. Beethoven’s 9th on Deutsche Grammophon, Vienna Philharmonic, Arthur Fiedler conducting. She came into the room of her own free will. Sat in her favorite off axis position on the couch and began to listen. After about 30 seconds she says. “This sounds really good, just like last year when we went to Heinz Hall to hear the Pittsburgh Symphony play the 9th. But I don’t think the right speaker is working”. To which I responded with, “Yes dear, that is what a proper stereo is supposed to do”.

    The Pay Off

    It’s a simple conclusion. Thanks to Tom and Anders, I finally enjoy listening to music again.
    For that, I am forever thankful to Tom, Anders and Bob Carver.
    _


    Bill

    Practicing Curmudgeon & Audio Snob
    ....just an "ON" switch, Please!

    FinleyAudio
  • Glen B
    Super Senior Member
    • Jul 2004
    • 1106

    #2
    Nice essay.


    Comment

    • Hdale85
      Moderator Emeritus
      • Jan 2006
      • 16073

      #3
      Nice write up Bill, I can't believe you went that long without your pre haha! Great to hear you feel you're back on track with your goals for the listening room.

      The Chihuahua must be new as I don't remember it I should be hitting the burgh here in the next few weeks might have to swing by and catch up.

      Comment

      • Johnloudb
        Super Senior Member
        • May 2007
        • 1877

        #4
        Originally posted by Glen B
        Nice essay.
        Nice Book,

        Bill, I read it all and enjoyed reading about your preamp adventure. Sounds like you've got a good'n.

        Originally posted by wkhanna
        Don’t get me wrong. It won’t take you a year to get your stuff back from Tom.
        I know just how you feel. We sent an amp back to the manufacturer to be repaired, exactly 2 years ago. I called them after 6 weeks to see how it was going and they said they were really busy working on a new project and asked if we wouldn't mind waiting awhile longer. I agreed, as we weren't in need of it right then.

        We'll, 5 phone calls and just over a year later they finished fixing the amp. Because of the insane amount of time they took, they didn't charge us for the $400 repair fee, which was nice.
        John unk:

        "Why can't we all just, get along?" ~ Jack Nicholson (Mars Attacks)

        My Website (hyperacusis, tinnitus, my story)

        Comment

        • wkhanna
          Grumpy Old Super Moderator Emeritus
          • Jan 2006
          • 5673

          #5
          thanks, John.

          Tom at Vintage HiFi was V understanding when it came time to total up the bill. I basically got everything done for just the cost of the parts. I know he spent many hours on it. And he graciously threw in a perfectly matched set of German NOS 6922 valves for the pre section taken from his personal C-19. This guy is truly a class act.
          _


          Bill

          Practicing Curmudgeon & Audio Snob
          ....just an "ON" switch, Please!

          FinleyAudio

          Comment

          • Johnloudb
            Super Senior Member
            • May 2007
            • 1877

            #6
            This guy is truly a class act.
            Yeah, he sounds like it. Our experience was more frustrating as I wasn't talking to the person doing the work. And the front desk was short on answers. When I finally did talk with the engineer who did the work he was very cordial and offered us the freebee. I guess it's harder for me to understand a good size business taking so long to fix one of their products, but I'm sure they have their problems too. It was an older model amp so I guess I should be glad they were still willing to fix it.
            John unk:

            "Why can't we all just, get along?" ~ Jack Nicholson (Mars Attacks)

            My Website (hyperacusis, tinnitus, my story)

            Comment

            • r100gs
              Senior Member
              • May 2005
              • 321

              #7
              Sounds amazing! ;x( Any pics!
              Jay

              Comment

              • JonMarsh
                Mad Max Moderator
                • Aug 2000
                • 15304

                #8
                Great story, sounds like a wonderful experience you've had- wish I could hear the modified unit!

                Best regards,

                Jon
                the AudioWorx
                Natalie P
                M8ta
                Modula Neo DCC
                Modula MT XE
                Modula Xtreme
                Isiris
                Wavecor Ardent

                SMJ
                Minerva Monitor
                Calliope
                Ardent D

                In Development...
                Isiris Mk II updates- in final test stage!
                Obi-Wan
                Saint-Saëns Symphonique/AKA SMJ-40
                Modula PWB
                Calliope CC Supreme
                Natalie P Ultra
                Natalie P Supreme
                Janus BP1 Sub


                Resistance is not futile, it is Volts divided by Amperes...
                Just ask Mr. Ohm....

                Comment

                • wkhanna
                  Grumpy Old Super Moderator Emeritus
                  • Jan 2006
                  • 5673

                  #9
                  Originally posted by JonMarsh
                  Great story, sounds like a wonderful experience you've had- wish I could hear the modified unit!

                  Best regards,

                  Jon
                  Thank you for taking the time to suffer through my amateur-like attempt at audio journalism, John.

                  I wish you could drop by and take a listen for yourself. I have some fine Resperado tequila I got in Matamoras Mexico in 2000, and an absolutely wonderful vodka made from apple purchased from a tiny distillery while in Lunenburg, Nova Scotia last summer, both of which I’m sure you would appreciate.

                  Regarding the equipment, you should be pleased to know that I am using a pair of 68 liter, 1.5 inch solid poplar baffle, bottom ported Natalie Portman’s which I built to your exact specifications. My ‘golden eared’ friend, Dan (aka PewterTA) and I are eagerly awaiting your final BOM for the Ardents.
                  _


                  Bill

                  Practicing Curmudgeon & Audio Snob
                  ....just an "ON" switch, Please!

                  FinleyAudio

                  Comment

                  • wkhanna
                    Grumpy Old Super Moderator Emeritus
                    • Jan 2006
                    • 5673

                    #10
                    This is a link to an article about Bob Carver that appeared in Stereophile Magazine back in 1985.

                    He reminds me of someone who hangs out mostly at the DIY forum that goes by the handle of Evil Twin, don't you think?
                    _


                    Bill

                    Practicing Curmudgeon & Audio Snob
                    ....just an "ON" switch, Please!

                    FinleyAudio

                    Comment

                    • PewterTA
                      Moderator
                      • Nov 2004
                      • 2901

                      #11
                      Let me know once it's broke in more... I can't wait to come back and hear how the sound has changed as I have a pretty decent musical memory for some reason.

                      Well you know me well enough that I can come back months later and tell you the differences in your system with any changes you've made without me even knowing the changes you made. lol

                      Jon M. You should DEFINITELY be proud of your Nat Ps. I have to say they went from wow... to OMG WOW!!! The speakers are truly a work of art when you put the right components backing them.

                      And Bill has found the right components!! It's enough for me to keep an eye out on a C-19 and have the mods done. I'd say the only system I've ever heard is maybe a full Cary system that comes to mind... I'd say it's very very close to that...at a fraction of the price!
                      Digital Audio makes me Happy.
                      -Dan

                      Comment

                      • wkhanna
                        Grumpy Old Super Moderator Emeritus
                        • Jan 2006
                        • 5673

                        #12
                        Originally posted by r100gs
                        Sounds amazing! ;x( Any pics!

                        Back panel with new IEC power socket.




                        Phono-amp section is on the Right-hand side.




                        The two capacitors in the pre section that used to be between the two heat sinks & the fuse have been upgraded and moved to the bottom side of the circuit board. They were damaged due the heat given off from the heat sinks. That won’t happen again.





                        Here are the upgraded caps in their new location.




                        Some of the 'majic' that was performed on the phono section,




                        Every component in the phono section has been replaced with hand-picked electronics, many of which were recommended by Bob Carver when Tom consulted with him on the upgrades.




                        Same with the pre-section, along with all six op-amps now mounted in sockets which allow experimenting with various optional replacements.



                        The next and final step will be upgrading of the volume & balance pots with the addition of Cardas terminals for the RCA input & output connections.
                        Last edited by wkhanna; 06 May 2011, 00:04 Friday.
                        _


                        Bill

                        Practicing Curmudgeon & Audio Snob
                        ....just an "ON" switch, Please!

                        FinleyAudio

                        Comment

                        • r100gs
                          Senior Member
                          • May 2005
                          • 321

                          #13
                          Sweet! ;x( Thanks for the pics! :T
                          Jay

                          Comment

                          • Glen B
                            Super Senior Member
                            • Jul 2004
                            • 1106

                            #14
                            Looks great. Thank you for sharing.


                            Comment

                            • Chris D
                              Moderator Emeritus
                              • Dec 2000
                              • 16877

                              #15
                              Very cool. :T
                              CHRIS

                              Well, we're safe for now. Thank goodness we're in a bowling alley.
                              - Pleasantville

                              Comment

                              • wkhanna
                                Grumpy Old Super Moderator Emeritus
                                • Jan 2006
                                • 5673

                                #16
                                Time for an update……..

                                I have been running the C-19 daily for over three weeks now. It’s been run-in for well over 150 hrs at this point.

                                All I can say is just multiply everything I already said about its performance by a factor of 1.5. The high-end is smoother, the low-end even more extended and powerful and the mids simply so realistic it’s creepy.

                                I find myself listening at reduced volume levels now. It’s because the response in so flat I find I don’t need to crank it up to compensate for the low-end punch that was missing before. Even late at night when I am listening at V low levels (~50 dB), every minutia of detail within the music comes through. No loss of any content at all as the microdynamic performance is just absolutely amazing.

                                Also, I’m listening to the radio more. I knew my Magnum Dynalab FT-11 was a decent analog tuner, but now it comes within respectable range of my vinyl section. And I have lost count of the times I have been startled by a sound in the room while on my laptop, only to realize my rig has fooled me again into thinking some one or thing is in there with me.

                                I really don’t know what else to say other than I just wish there were more hours in the day so I could spend more time with my music.
                                _


                                Bill

                                Practicing Curmudgeon & Audio Snob
                                ....just an "ON" switch, Please!

                                FinleyAudio

                                Comment

                                • Alaric
                                  Ultra Senior Member
                                  • Jan 2006
                                  • 4143

                                  #17
                                  Great thread! Now I want to find a C 19.....dagnabbit!
                                  Lee

                                  Marantz PM7200-RIP
                                  Marantz PM-KI Pearl
                                  Schiit Modi 3
                                  Marantz CD5005
                                  Paradigm Studio 60 v.3

                                  Comment

                                  Working...
                                  Searching...Please wait.
                                  An unexpected error was returned: 'Your submission could not be processed because you have logged in since the previous page was loaded.

                                  Please push the back button and reload the previous window.'
                                  An unexpected error was returned: 'Your submission could not be processed because the token has expired.

                                  Please push the back button and reload the previous window.'
                                  An internal error has occurred and the module cannot be displayed.
                                  There are no results that meet this criteria.
                                  Search Result for "|||"