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Same rules as other roadshows (200 post minimum; must pay shipping to next on list)
Things to play with:
- Stock el cheapo chinese 6922's
- Amperex 'A' frame 6DJ8's
- Telefunken 6DJ8's
- Herbie's ultrasonic RX-9 tube dampers
- CARVER site! Zero Pointe silver interconnects
Hookup (rear facing you)
This buffer began as a CCA I bought from ebay (many preassembled available there too). It runs from a 12VAC input (supply your own) and takes the 12 VAC input, turns it into 12VDC to run the two tube heaters, and doubles it to run the tubes at + and - 24VDC.
Nominal heater voltage is 6.3VDC +/- 10%. Also, although +/-24VDC is alright for the tube rails,and well below the tube's rating (longer life), my other thought was to boost the rails a bit as well (higher dynamic range, lower noise floor).
The new supply feeds 12.6VAC in, doubles that to +/- 32VDC for the rails (still less than half tube's max rating) and then feeds the heater section of the supply; I added a diode after the voltage drop resistor to bring the heater voltage back down to 12.6VDC (nominal).
Here's the schematic and parts list .
I'm first; anyone else? Enjoy!  -----  ---------- http://carvermk2.com-------------------------- http://thecarversite.com---------
Source----Oppo BDP-83SE, homebrew media server
Preamp---Sunfire TG-IV
Procs------Carver C-9, BBE 2002R, Rane AD 22B, dbx 14/10, dbx 3BX-DS, dbx SNR-1, dbx 120x, Rane AC 23B,
------------Velodyne SMS-1, Audiocontrol SA-3050A
Amps------M-500t Mk II (X4), M-1.0t Mk II (X3), M-1.0Mk II opt. 002 (X1)
Speaks----Klipsch Cornwall II (X4), Klipsch RF-3 II (X2), Klipsch RS-3 II (X4), Klipsch RC-3 II, Klipsch KSW-12
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Interesting buffer there, Is that something you created rich?. Sure im in.
REGARDS SNOW
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Medals:
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snow wrote:
Interesting buffer there, Is that something you created rich?. Sure im in.
REGARDS SNOW
Yes, I built it; I was thinking
'why do the SDA 490t's go for $600 when the only difference is an internal tube buffer tacked on.....wouldn't it be cheaper to own a modern player and feed it to a tube buffer?'
So I hacked one together for us to try out. Enjoy! ----- ---------- http://carvermk2.com-------------------------- http://thecarversite.com---------
Source----Oppo BDP-83SE, homebrew media server
Preamp---Sunfire TG-IV
Procs------Carver C-9, BBE 2002R, Rane AD 22B, dbx 14/10, dbx 3BX-DS, dbx SNR-1, dbx 120x, Rane AC 23B,
------------Velodyne SMS-1, Audiocontrol SA-3050A
Amps------M-500t Mk II (X4), M-1.0t Mk II (X3), M-1.0Mk II opt. 002 (X1)
Speaks----Klipsch Cornwall II (X4), Klipsch RF-3 II (X2), Klipsch RS-3 II (X4), Klipsch RC-3 II, Klipsch KSW-12
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RichP714 wrote:snow wrote:
Interesting buffer there, Is that something you created rich?. Sure im in.
REGARDS SNOW
Yes, I built it; I was thinking
'why do the SDA 490t's go for $600 when the only difference is an internal tube buffer tacked on.....wouldn't it be cheaper to own a modern player and feed it to a tube buffer?'
So I hacked one together for us to try out.
Well I think that if you had a nice CD player or multi player that uses the Sabre or Wolfson DAC's you could easily achieve much better quality sound than you could with an older player with outdated chip technology with a tube buffer.
It will be interesting to see how it sounds allright especially with your IC's im convinced that their can be a perfect marriage of sound between SS and tube gear, to gain SS power and clarity but yet still have the warmth of tubes. I am even thinking about getting a tube buffer to use strictly on the tweeters with a seperate amp. Since the Carver C-1 has two sets of outputs that one can use simultaneously perhaps buy another M1.5T to use for the tweeters and bi amp. Also it would be fun to try different types of tubes in a buffer perhaps 12AX7's or EL84's etc until one found just that magical sound he was looking for.
REGARDS SNOW
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snow wrote:.....Well I think that if you had a nice CD player or multi player that uses the Sabre or Wolfson DAC's you could easily achieve much better quality sound than you could with an older player with outdated chip technology with a tube buffer.
my thought exactly.....
snow wrote:
Also it would be fun to try different types of tubes in a buffer perhaps 12AX7's or EL84's etc .....
I didn't have enough money free to buy many choices, so settled on very inexpensive chinese tubes, and telefunken matched pairs. Enjoy! ----- ---------- http://carvermk2.com-------------------------- http://thecarversite.com---------
Source----Oppo BDP-83SE, homebrew media server
Preamp---Sunfire TG-IV
Procs------Carver C-9, BBE 2002R, Rane AD 22B, dbx 14/10, dbx 3BX-DS, dbx SNR-1, dbx 120x, Rane AC 23B,
------------Velodyne SMS-1, Audiocontrol SA-3050A
Amps------M-500t Mk II (X4), M-1.0t Mk II (X3), M-1.0Mk II opt. 002 (X1)
Speaks----Klipsch Cornwall II (X4), Klipsch RF-3 II (X2), Klipsch RS-3 II (X4), Klipsch RC-3 II, Klipsch KSW-12
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Medals:
Rank: Administration
Groups: Administration
Joined: 12/20/2008(UTC) Posts: 3,999 Location: Gretna, NE Was thanked: 108 time(s) in 89 post(s)
Gave Thanks: 94 times
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BTW, this buffer is designed around the 6DJ8 and compatible tubes. the 12AX7 isn't an option: the circuit connects pins 4 and 5 together, something not done with 12AX7's, so either the buffer won't work or it'll fuse the grid will fuse to the plate; bad news either way. Also, the 12AX7 runs on a much higher voltage, so if it were to work in an 6DJ8 circuit, it would be running at the low end of it's gain curve (noisy and non-linear) Enjoy! ----- ---------- http://carvermk2.com-------------------------- http://thecarversite.com---------
Source----Oppo BDP-83SE, homebrew media server
Preamp---Sunfire TG-IV
Procs------Carver C-9, BBE 2002R, Rane AD 22B, dbx 14/10, dbx 3BX-DS, dbx SNR-1, dbx 120x, Rane AC 23B,
------------Velodyne SMS-1, Audiocontrol SA-3050A
Amps------M-500t Mk II (X4), M-1.0t Mk II (X3), M-1.0Mk II opt. 002 (X1)
Speaks----Klipsch Cornwall II (X4), Klipsch RF-3 II (X2), Klipsch RS-3 II (X4), Klipsch RC-3 II, Klipsch KSW-12
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I'll definitely give it a whirl Rich.
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Did you just stick an LM7812 in there for a voltage regulator? What is your power source now? It should sound like it isn't there.
Making life enjoyable through expensive electronics.
__________________________________________________________________________
Carver: C-4000 and C-1 preamplifiers, PSC-60 tuner/preamp, M-400 (2), C-500, M-500, M-500-t, M-500t Mk.II, A-500x, AL-III loudspeakers (2 pr)
Sunfire:Theater Grand III processor, Ultimate Receiver, Cinema Grand Signature 400 ~ seven, True Subwoofer Mk. II
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Medals:
Rank: TO-247N Member
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Joined: 1/14/2009(UTC) Posts: 956 Location: alaska Was thanked: 16 time(s) in 9 post(s)
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RichP714 wrote:BTW, this buffer is designed around the 6DJ8 and compatible tubes. the 12AX7 isn't an option: the circuit connects pins 4 and 5 together, something not done with 12AX7's, so either the buffer won't work or it'll fuse the grid will fuse to the plate; bad news either way. Also, the 12AX7 runs on a much higher voltage, so if it were to work in an 6DJ8 circuit, it would be running at the low end of it's gain curve (noisy and non-linear) No I didnt mean using 12AX7's in this particular tube buffer  Just that it might be an interesting experemint to try different tube combinations for making tube buffers until one found the sound they preferred. Of course the one you have done is certainly the one that makes the most sense since you are trying to emulate as closely as possible the tube output of the 490T.
REGARDS SNOW
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Medals:
Rank: Administration
Groups: Administration
Joined: 12/20/2008(UTC) Posts: 3,999 Location: Gretna, NE Was thanked: 108 time(s) in 89 post(s)
Gave Thanks: 94 times
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I see; this CCA does have choices for those interested, but they have to be 6DJ8 compatible (6922, ECC88, E88CC, 7308, 6H23, etc.) Enjoy! ----- ---------- http://carvermk2.com-------------------------- http://thecarversite.com---------
Source----Oppo BDP-83SE, homebrew media server
Preamp---Sunfire TG-IV
Procs------Carver C-9, BBE 2002R, Rane AD 22B, dbx 14/10, dbx 3BX-DS, dbx SNR-1, dbx 120x, Rane AC 23B,
------------Velodyne SMS-1, Audiocontrol SA-3050A
Amps------M-500t Mk II (X4), M-1.0t Mk II (X3), M-1.0Mk II opt. 002 (X1)
Speaks----Klipsch Cornwall II (X4), Klipsch RF-3 II (X2), Klipsch RS-3 II (X4), Klipsch RC-3 II, Klipsch KSW-12
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