Ok. Now I really need your help, guys. I have connected a Svetlana 6N1P according to the technical notes. 250VDC, 430ohm cathode resistor and I have checked the drop over the same resistor. Everything looks good. Then I have connected it via a 0.22uF cap to a Texas Instrument BUF634. I have tried many different resistors after the cap but nothing seem to really make it sing. In my single ended KT88 amp I used 470kohm. I have also tried a potentiometer so I can set the signal going into the buffer, but Im nowhere near what I think the limit SHOULD be. However I have a couple of problems. First of all I am feeding the buffer output directly to an 8ohm speaker. Second I don't have an oscilloscope so I have NO idea where in the circuit the signal gets distorted. Could you help me out with some resistor and cap values and other ideas? Right now Im using 10k fixed resistor on the tube input because Im feeding the signal from a CD player but I guess I shuold be closer to 0.5Mohm when I use my bass guitar.
http://www.goodwill.com.tw/showproductdetal-e.asp?pd1_sn=56&p1sn=4&p2sn=4
this one has been on my wish list for a couple of years.
this one has been on my wish list for a couple of years.
Please forgive me zafira for hijacking your thread
My preamp planning is coming along pretty good. I have reached the point where Im pretty confident my idea will work very well. No I need a really really good solid state PSU for it. I have never used chokes before but since this curcuit will only draw a few milli amps I thought this time I will spend those exta bucks. Could someone please help me suggest one or more good chokes from the link and also good cap values. I have tried the duncan PSU software but I couldnt really figure it out.
http://www.hammondmfg.com/153.htm
Right now I think my circuit draws roughly 4mA so there should be some physically small chokes that suit my need. My idea is to fit everything in a 1U rack chassi.
My preamp planning is coming along pretty good. I have reached the point where Im pretty confident my idea will work very well. No I need a really really good solid state PSU for it. I have never used chokes before but since this curcuit will only draw a few milli amps I thought this time I will spend those exta bucks. Could someone please help me suggest one or more good chokes from the link and also good cap values. I have tried the duncan PSU software but I couldnt really figure it out.
http://www.hammondmfg.com/153.htm
Right now I think my circuit draws roughly 4mA so there should be some physically small chokes that suit my need. My idea is to fit everything in a 1U rack chassi.
It's OK Mikael!!!
what I dont know is if you're building the same amp than me (Messa Boggie Bass 400)
Now i'm going to buy two 12ax7a, could anyone post a PSU schematic that fits to the circuit? Remeber that I'm only using the preamp. I will not build the buffer, driver and power stage.
So, I need a power supply for the preamp.
I have an "iron" that is 220 to 220 volts, can I use it? It will not generate the 370V specified on the original circuit, but I think it's no need to use that high voltage for a pream...... am I right?
thanks,
Jorge.
what I dont know is if you're building the same amp than me (Messa Boggie Bass 400)
Now i'm going to buy two 12ax7a, could anyone post a PSU schematic that fits to the circuit? Remeber that I'm only using the preamp. I will not build the buffer, driver and power stage.
So, I need a power supply for the preamp.
I have an "iron" that is 220 to 220 volts, can I use it? It will not generate the 370V specified on the original circuit, but I think it's no need to use that high voltage for a pream...... am I right?
thanks,
Jorge.
Because I'm bored at my work, I decided to re-draw the amp. This is the first try, It's not 100% done. I'm using VISIO to draw it.
take a look
http://img473.imageshack.us/img473/7762/preampnc5.png
take a look
http://img473.imageshack.us/img473/7762/preampnc5.png
Well I finished making the schematic in VISIO.
Here is the result.
Can anyone check it for strange values or any mistake? I think it's ok.
please, any comment will be welcome
http://img115.imageshack.us/img115/9294/preampav1.gif
thanks
Jorge
Here is the result.
Can anyone check it for strange values or any mistake? I think it's ok.
please, any comment will be welcome
http://img115.imageshack.us/img115/9294/preampav1.gif
thanks
Jorge
It looks good to me. Im very curious about how it sounds. Please tell us as soon as you get it together. I have run som listening test on my setup here today, but since I don't have a bass yet I fed the signal from my CD player instead. I also hooked up my 600 ohm headphones. It sounds REALLY good. If the pre/headphone amp also sounds good with a bass will be revealed the next week I hope.
Keep up the good work Jorge
Keep up the good work Jorge
I opened this thread
http://www.diyaudio.com/forums/showthread.php?s=&threadid=83853
where I will post about the project.
thanks!!
http://www.diyaudio.com/forums/showthread.php?s=&threadid=83853
where I will post about the project.
thanks!!
I know it's been a few years since this thread has been in use, but I'm taking on the exact same project. I want to make a bass preamp with tubes. I've read good things about the Fender Blackfaced amps and am interested in Alembic schemo, but I need to know for sure that it's not flawed. I'm struggling to understand what these forums are even saying because I'm so new to electronics. If I could get a functional schematic and possibly the wiring layout for the Alembic(F2-B?) I'd be set. Thanks guys, hope your build worked out back in 2006.
-BF
-BF
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