Author Topic: C-19 OP Amps  (Read 3798 times)

Offline wkhanna

  • Double Secret Probation!
  • **
  • Posts: 225
  • Practicing Curmudgeon & Audio Snob
    • View Profile
C-19 OP Amps
« on: January 31, 2015, 11:26:03 AM »






After years of pure joy with my Tom/Anders modified C-19 I have begun further pursuit of end-game performance from this marvel of audio equipment.

First was my installation of musician-grade Portuguese cork between the chassis & transformer.
Next was encapsulating the transformer in mu-metal http://en.wikipedia.org/wiki/Mu-metal along with the installation of PEARL tube coolers.

The next step is taking advantage of the sockets Tom installed to try some new op amps .
After some time investigating available options I have decided to give the Burson Discrete http://www.partsconnexion.com/opamp_burson.html units a try.

My question (hello Tom) is which op amps to replace for the pre section?
Are they single or dual?

....just an "ON" switch, Please!

Offline schwarcw

  • Ready For Intervention!
  • ******
  • Posts: 1552
  • No one here gets out alive!
    • View Profile
Re: C-19 OP Amps
« Reply #1 on: January 31, 2015, 12:59:33 PM »
Hey Bill!

Tell us about those tube dampers!
Carl

Offline Kingman

  • Southern Commander
  • *****
  • Posts: 2860
  • OCCD...I GOT IT BADD!!!!!!!!!
    • View Profile
Re: C-19 OP Amps
« Reply #2 on: January 31, 2015, 01:12:32 PM »
I've never seen shit like that...hell, I've never even HEARD of shit like that!  :o  :o  :o
IN REALITY IT ONLY MATTERS WHAT IT SOUNDS LIKE TO YOU!!!!!

Offline bearjew

  • Audio Connoisseur
  • ****
  • Posts: 613
  • Half bear, all Jew
    • View Profile
Re: C-19 OP Amps
« Reply #3 on: January 31, 2015, 01:40:04 PM »
I've never seen shit like that...hell, I've never even HEARD of shit like that!  :o  :o  :o

Kingman, you really are living proof that ignorance is bliss :P
-Audeze EL-8 Titanium headphones
-Everything else is on loan to PBJ!

Offline Kingman

  • Southern Commander
  • *****
  • Posts: 2860
  • OCCD...I GOT IT BADD!!!!!!!!!
    • View Profile
Re: C-19 OP Amps
« Reply #4 on: January 31, 2015, 02:01:48 PM »
I've never seen shit like that...hell, I've never even HEARD of shit like that!  :o  :o  :o

Kingman, you really are living proof that ignorance is bliss :P
I bet 1 in 500 have heard of that metal stuff around the tubes...I got tube dampeners like the rubbers on there so I have an idea of their purpose...
IN REALITY IT ONLY MATTERS WHAT IT SOUNDS LIKE TO YOU!!!!!

Offline MacGeek

  • Ready For Intervention!
  • ******
  • Posts: 1102
    • View Profile
Re: C-19 OP Amps
« Reply #5 on: January 31, 2015, 03:00:14 PM »
Well, what kind of difference did it make?  Tell us how it sounds.
MAC C-46 pre, MQ 108 eq, MC 352 amps (2), MR 78 tuner, MCD 500 CD, MPI-4 scope, LS 352 speakers, Sony HDR-F1HD AM/FM/HD tuner, Denon DRS 810 cassette, Denon CDR-W1500 CD recorder, Music Hall MMF-9 w/B&O MMC2, Revox A-77 R to R.

Offline Sir Thrift-a-Lot

  • Ready For Intervention!
  • ******
  • Posts: 2762
    • View Profile
Re: C-19 OP Amps
« Reply #6 on: January 31, 2015, 03:00:59 PM »
The tube coolers are common fare, but what exactly makes a piece of cork "musician-grade" (he asked hesitantly, awaiting the pummeling that is sure to follow).

Offline OldiesButGoodies

  • Administrator
  • *****
  • Posts: 2419
  • Be nice, it is free!
    • View Profile
Re: C-19 OP Amps
« Reply #7 on: January 31, 2015, 03:33:12 PM »
the c19 uses dual op amps, I think.  better check w tom or someone in the carveraudio forum.  those burson supremes look awesome.  no idea if they sound better but they sure look badass.

Spkr: VMPS RM40
Pre: McCormack RLD-1, Rotel 970BX Phono
Amps: Channel Islands Audio D-200 MkII 
Phono: VPI Aries 1,  Van de Hul Frog
CD: Oppo BDP-83 DAC: Young DSD DAC
Cass: Tascam 122MkII
R2R: Revox B77
Sub: Rhythmik FV 15HP

Offline wkhanna

  • Double Secret Probation!
  • **
  • Posts: 225
  • Practicing Curmudgeon & Audio Snob
    • View Profile
Re: C-19 OP Amps
« Reply #8 on: January 31, 2015, 04:43:13 PM »
The PEARL tube coolers are excellent heat sinks. Now the pre-section tubes are low power & the C-19 uses 'soft-start' so there is not as great an issue with heat degradation, but these are OS Mulards (from Tom) that I want to last as long as possible.
Interesting reading on tubes & the effects of heat here, for those interested. http://www.partsconnexion.com/PDF/pearl_tc.pdf

The PEARL's also act as dampers, which affects vibration & 'micro-dynamics' which low-power signal-level tubes demonstrate. Minimizing any vibration is a good thing in audio. More so for signal-level.

My friend Dan & I both noticed increased detail, imaging and a sense that the instruments had a more three dimensional quality. They were slightly, but noticeably more focused & yet removed from the speaker, more established in their own place in the air. Also, there was a V slight roll-off in the very upper end of the frequency, which worked well for my system.

Regarding the cork: Portuguese cork is the best in world (due to its climate).
Musician-grade is simply a grade rating for natural cork. It is the same stuff used for musical instruments like clarinets, saxes & other woodwind instruments.

Again, the reason for using cork is vibration control.
I have used it in all my gear for transformers & IC boards.
Dan & I have found it increases blackness (it makes passages with no sound quieter) & adds detail to subtitle elements like the shimmer of top-hats & cymbals & increases decay. You will notice it on well recorded piano immediately.

The mu-metal is amazing.
By far the most cost effective upgrade I have yet come across.
I put it on all my gear, digital, amps pre, everything.

Many super hi-end units use it to isolate nasty stuff coming off of high-power elements that contaminate sensitive components like chips, caps & resistors.
Nothing new, but seldom implemented on mid-level gear.
Other companies will totally isolate the high-power sections in separate chassis.
Put in the mu-metal yourself gets you a little closer to the last 2% of what is achievable.

Dan & found it gives much tighter, musical sounding bass, better detail, imaging & separation.
One of the first things you will notice is how the sound stage goes way back behind the speaker.













....just an "ON" switch, Please!

Offline Sir Thrift-a-Lot

  • Ready For Intervention!
  • ******
  • Posts: 2762
    • View Profile
Re: C-19 OP Amps
« Reply #9 on: January 31, 2015, 07:29:32 PM »

Regarding the cork: Portuguese cork is the best in world (due to its climate).
Musician-grade is simply a grade rating for natural cork. It is the same stuff used for musical instruments like clarinets, saxes & other woodwind instruments.


Thank you, that makes sense to me.

Offline schwarcw

  • Ready For Intervention!
  • ******
  • Posts: 1552
  • No one here gets out alive!
    • View Profile
Re: C-19 OP Amps
« Reply #10 on: January 31, 2015, 11:53:07 PM »
Bill,

Great write up and interesting information.  I have never heard of the mu metal before.  I've used the tube dampers and have definitely heard the impact.  A very inexpensive tweak.  I think the best results that I have heard have been on the dampers on the signal or preamp tubes.  I have not tried dampers on power tubes, but I may give that a shot on my small EL84 integrated amps.
Carl

Offline Rockman Rock

  • Double Secret Probation!
  • **
  • Posts: 74
  • How about a taxi grab.....
    • View Profile
Re: C-19 OP Amps
« Reply #11 on: February 15, 2015, 11:16:11 PM »
IIRC the LME49720 is a great op amp that can be used in there. Is that what you had in there?

The Bursons are great. I used the Bursons in a Music Hall 25.3 DAC I modded.

Carl, you have the LME49720 in the Twisted Pear Legato v3.1 I/V output in your DAC, specifically the SE and headphone out. Your balanced out is discrete output, no op amps there.
« Last Edit: February 15, 2015, 11:21:35 PM by Rockman Rock »
Salk SoundScape 8's / Audio Research Reference 3 / Bottlehead Eros Phono / Krell KSA-250 / diy Lenco w/AA MG-1 arm / diy Dual Mono Buffalo III DAC / Denon 3910 I2S/DSD out mod / SB Touch 12S out mod / diy Cinemag SUT

Offline Rockman Rock

  • Double Secret Probation!
  • **
  • Posts: 74
  • How about a taxi grab.....
    • View Profile
Re: C-19 OP Amps
« Reply #12 on: February 15, 2015, 11:27:25 PM »


The Bursons are great. I used the discrete Burson op amps in a Music Hall 25.3 DAC I extensively modded. Your power supply needs to be up to the Bursons. IIRC the Bursons imposed a 700% increase in mA over the stock op amps. I upgraded the op amp supply with Belleson Super regulator with larger heat sinks. It is based on the Jung regulator and was a drop in swap for TO-220 regs. Burson has a new design discrete op amp now so unsure of mA specs.



« Last Edit: February 15, 2015, 11:32:40 PM by Rockman Rock »
Salk SoundScape 8's / Audio Research Reference 3 / Bottlehead Eros Phono / Krell KSA-250 / diy Lenco w/AA MG-1 arm / diy Dual Mono Buffalo III DAC / Denon 3910 I2S/DSD out mod / SB Touch 12S out mod / diy Cinemag SUT

Offline schwarcw

  • Ready For Intervention!
  • ******
  • Posts: 1552
  • No one here gets out alive!
    • View Profile
Re: C-19 OP Amps
« Reply #13 on: February 16, 2015, 07:15:43 PM »
Rockman, you do some great work!

I know that Music Hall DAC.  IIRC somebody put the opamps in backwards with not so good results.  I'm just glad it wasn't me.

Carl

Offline Rockman Rock

  • Double Secret Probation!
  • **
  • Posts: 74
  • How about a taxi grab.....
    • View Profile
Re: C-19 OP Amps
« Reply #14 on: February 17, 2015, 06:39:19 PM »
Rockman, you do some great work!

I know that Music Hall DAC.  IIRC somebody put the opamps in backwards with not so good results.  I'm just glad it wasn't me.

Thanks Carl! I didn't either. The fellow I sold it to let somoene borrow it. He got it back and stuck one in backwards. I had them puppies marked for proper orientation too.

Fortunately the DAC still works. The new owner purchased the new design Burson op amps. I have one of the Burson survivors to try in my Legato I/V board.
Salk SoundScape 8's / Audio Research Reference 3 / Bottlehead Eros Phono / Krell KSA-250 / diy Lenco w/AA MG-1 arm / diy Dual Mono Buffalo III DAC / Denon 3910 I2S/DSD out mod / SB Touch 12S out mod / diy Cinemag SUT

 

Namecheap.com
Fight Spam! Click Here!