peranders said:
your power supply seems to be very week since you need current compensation??
Strange, but I can't remember having disclosed anything about 'my power supply' in the above thread.
The schematic was an indication of a concept, and as such, no power supply is attached to it.
OK, but suppose you HAVE a very powerful voltage source like a Jung, Sulzer regulator or even a big fat cap, why trying to draw constant current?
At work have a similar thing but in that case it's about discharging smooting caps because the current consumption is very unequal when a relay is on or off.
At work have a similar thing but in that case it's about discharging smooting caps because the current consumption is very unequal when a relay is on or off.
x-pro said:Hi all,
here is the link to the article (unfortunately, in Russian) I've published in 1999 in "RadioHobby" in Kiev about the original idea behing Creek Audio OBH-8 preamplifier. Since that time newer versions of this circuit are used in the current line of OBH preamps. However, this circuit is a good example of what could be done with few transistors. The sound of this circuit is good and it is very DIY friendly 🙂 .
http://vlab.netsys.ru/audio/lpcor7.stm
It is single-ended class A with passive EQ. What else would you wish? 🙂
Technical Data of this preamp:
Gain - 90
SNR - better than 70 dB A-wtd ref 5 mV 1kHz input
RIAA deviation +/- 0.5 dB 50Hz-30kHz, -3 dB at 20 Hz
Max. output 5V RMS
Distortion for 1V output - less than 0.01% at 1 kHz
To prevent possible questions - it is my own design and the original publication was made with permission from Creek. The circuit is copyright of Creek Audio Limited (it is printed in the original article, unfortunately on the linked web site they cut the picture and lost it... .
Enjoy
Al
Anyone who knows where the schematic went to? The page above is removed, or moved.
Re: Re: Simple MM only RIAA preamp
It is now here:
http://vlab.netsys.ru/index.php?option=articles&task=viewarticle&artid=81&topid=3&Itemid=3
x-pro
peranders said:
Anyone who knows where the schematic went to? The page above is removed, or moved.
It is now here:
http://vlab.netsys.ru/index.php?option=articles&task=viewarticle&artid=81&topid=3&Itemid=3
x-pro
uniuniunium said:so is this a clone of the current production OBH-8?
It is the circuit of OBH-8 as it was in 1996 🙂 . Current production may be a bit different.
x-pro
Component values in X-pro's preamp?
X-pro, thanks for the interesting schematic. The Creek phono preamp has consistently received quite favourable reviews in the magazines I have read.
Unfortunately the picture resolution makes is difficult to read some of the resistor values. I'd rather get them directly from the source than guess them myself...
Could you perhaps post the values of:
R2, R3, R7, R9, R11, R14 and R16.
The transistors are BC550B, I suppose?
Best regards,
Pekka U.
X-pro, thanks for the interesting schematic. The Creek phono preamp has consistently received quite favourable reviews in the magazines I have read.
Unfortunately the picture resolution makes is difficult to read some of the resistor values. I'd rather get them directly from the source than guess them myself...
Could you perhaps post the values of:
R2, R3, R7, R9, R11, R14 and R16.
The transistors are BC550B, I suppose?
Best regards,
Pekka U.
Re: Component values in X-pro's preamp?
No problem:
R2 = 150K
R3 = K62
R7 = 68K
R9 = K33
R11 = 100K
R14 = 22K
R16 = K22
Transistors are BC550B or C . It may be nesessary to adjust the value of R5 (1M2) in the range from 1M0 to 2.2M depending on the actual make of transistors, otherwise there could be some deviation from correct RIAA curve below 50 Hz.
x-pro
pekka said:X-pro, thanks for the interesting schematic. The Creek phono preamp has consistently received quite favourable reviews in the magazines I have read.
Unfortunately the picture resolution makes is difficult to read some of the resistor values. I'd rather get them directly from the source than guess them myself...
Could you perhaps post the values of:
R2, R3, R7, R9, R11, R14 and R16.
The transistors are BC550B, I suppose?
Best regards,
Pekka U.
No problem:
R2 = 150K
R3 = K62
R7 = 68K
R9 = K33
R11 = 100K
R14 = 22K
R16 = K22
Transistors are BC550B or C . It may be nesessary to adjust the value of R5 (1M2) in the range from 1M0 to 2.2M depending on the actual make of transistors, otherwise there could be some deviation from correct RIAA curve below 50 Hz.
x-pro
Hello,X-pro
Hello,X-pro,Can you give me X-pro's preamp's schematics?I can't give it ,,Thank you very mach ...
Hello,X-pro,Can you give me X-pro's preamp's schematics?I can't give it ,,Thank you very mach ...
schematic
Hi X-Pro,
if is possible i would like to have the schematic of your riaa and i would like you to look at this thread and what do you think about it. Thank You! Maxpou
http://www.diyaudio.com/forums/showthread.php?s=&threadid=114886
Hi X-Pro,
if is possible i would like to have the schematic of your riaa and i would like you to look at this thread and what do you think about it. Thank You! Maxpou
http://www.diyaudio.com/forums/showthread.php?s=&threadid=114886
Re: schematic
I'll have a look, thanks.
No, OBH-15 was made after I've left and I have no information about what is inside, sorry.
Cheers
Alex
maxpou said:Hi X-Pro,
if is possible i would like to have the schematic of your riaa and i would like you to look at this thread and what do you think about it. Thank You! Maxpou
http://www.diyaudio.com/forums/showthread.php?s=&threadid=114886
I'll have a look, thanks.
arnoldc said:Hi x-pro, did you design the OBH-15 too? Are they discrete like the 8 or opamp based?
No, OBH-15 was made after I've left and I have no information about what is inside, sorry.
Cheers
Alex
New link is here:
http://vlab.netsys.ru/index.php?opt...task=view&id=77
x-pro
Can everyone open it????
http://vlab.netsys.ru/index.php?opt...task=view&id=77
x-pro
Can everyone open it????
Wizard said:Can everyone open it????
Unfortunately the site has changed hosting. New address of this page is:
http://www.vegalab.ru/index.php?option=content&task=view&id=77
Cheers
Alex
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