|
|||||||
| Home | Forums | Rules | Articles | Store | Gallery | Blogs | Register | Donations | FAQ | Calendar | Search | Today's Posts | Mark Forums Read | Search |
| Tubes / Valves All about our sweet vacuum tubes :) Threads about Musical Instrument Amps of all kinds should be in the Instruments & Amps forum |
| diyAudio Sponsor | ||
|
||
 |
|
|
Thread Tools | Search this Thread |
20th October 2011, 09:06 AM
|
#1 |
|
diyAudio Member
Join Date: Sep 2011
|
help on 12AU7 Preamp circuit
Hello all,
I'm planning to add a tube preamplifier for my solid state power amp. the supply is +-25V. I designed a preamp circuit but not sure it will works fine. Can any one help me to check the design? many thanks
__________________
www.siliconray.com High Quality Audio Enclosures, Amp Kits, Amplifiers, PCB Fab Services Chat with me |
|
|
20th October 2011, 12:08 PM
|
#3 |
|
diyAudio Member
Join Date: May 2007
|
With the right value for anode resistor the smoothly non-linear second-order distortion created by the valve characteristic could be partly cancelled by clipping caused by grid current. The result would be low THD, at a particular volume level, but awful sound.
Astonishingly, this technique was actually advocated in an IRE Transactions paper in 1955 by J Z Knapp "Low Distortion Operation of Some Miniature Dual Triodes". I guess back then they didn't know how awful high-order distortion sounds. |
|
|
|
20th October 2011, 12:23 PM
|
#5 |
|
diyAudio Member
Join Date: Sep 2011
|
I searched the web found a 12V 12AU7 headphone design so I think the 50V won't be a problem
DIY 12AU7 (ECC82) Tube - IRF612 MOSFET Hybrid Headphone Amplifier NP-100v12: DIY 12AU7 (ECC82) Tube / IRF510 MOSFET Headphone Amplifier
__________________
www.siliconray.com High Quality Audio Enclosures, Amp Kits, Amplifiers, PCB Fab Services Chat with me |
|
|
|
20th October 2011, 12:25 PM
|
#6 |
|
diyAudio Moderator
|
It also won't like the bias arrangement. Hint: Look at the potential between the grid and cathode - should be a few volts at most. (Need input cap and one more resistor..)
A 6DJ8 would work a lot better here.
__________________
www.kta-hifi.net |
|
|
|
20th October 2011, 12:26 PM
|
#7 | |
|
diyAudio Moderator
|
Quote:
__________________
www.kta-hifi.net |
|
|
|
|
20th October 2011, 12:32 PM
|
#8 |
|
diyAudio Member
Join Date: Sep 2011
|
But I have another design, 6N11 + IRF510, the sound is fairly good. Powered by single 24V.
__________________
www.siliconray.com High Quality Audio Enclosures, Amp Kits, Amplifiers, PCB Fab Services Chat with me |
|
|
|
20th October 2011, 12:34 PM
|
#9 | |
|
diyAudio Member
Join Date: Sep 2011
|
wooo
a big mistake. grid shold be tite to VSS, not GND look at this one should I add a small positive voltage (vs VSS) to grid? Quote:
__________________
www.siliconray.com High Quality Audio Enclosures, Amp Kits, Amplifiers, PCB Fab Services Chat with me Last edited by siliconray; 20th October 2011 at 12:50 PM. |
|
|
|
|
20th October 2011, 02:25 PM
|
#10 |
|
diyAudio Member
Join Date: Sep 2011
|
I think I should also try with 6N8P(6NS7)
__________________
www.siliconray.com High Quality Audio Enclosures, Amp Kits, Amplifiers, PCB Fab Services Chat with me |
|
|
|
| Currently Active Users Viewing This Thread: 1 (0 members and 1 guests) | |
| Thread Tools | Search this Thread |
|
|
Similar Threads
|
||||
| Thread | Thread Starter | Forum | Replies | Last Post |
| 12ax7 12au7 preamp | Bengali | Tubes / Valves | 17 | 8th January 2012 07:46 PM |
| Preamp tube SRPP 12AU7 VS preamp tube Aikido 12AU7 = all use rec 6X5GT | spiritm2r | Tubes / Valves | 1 | 6th March 2011 02:53 PM |
| 3 - 12AU7 Preamp. Is there such an animal? | cbj591 | Tubes / Valves | 12 | 25th October 2010 10:03 PM |
| Look for 12AU7 Preamp Circuit . | RCA245 | Tubes / Valves | 2 | 2nd June 2006 02:02 PM |
| 5814/12AU7 Preamp? | JojoD818 | Tubes / Valves | 15 | 13th April 2004 04:04 AM |
| New To Site? | Need Help? |
| Page generated in 0.09538 seconds (81.47% PHP - 18.53% MySQL) with 11 queries |
