I built an aikido phono amp over the past few weeks. It's great! Never heard my records sound so good! But... I was using a dj mixer as my phono amp, and all of them I've tried have very poor sound quality.
My only complaint (and its not really) is that this thing has too much gain! Having the volume up 1/2 is where it would be at 100% w/ other sources (cd player, mp3 player, etc). I think part of the problem (maybe the whole problem) is that I'm using a DJ needle which is supposedly very loud/sensitive.
I don't have any questions.. just a bored xmas night show and tell..
I ordered some soviet caps which never arrived, so with my last mouser order I grabbed some orange drop caps. I'll replace them w/ something better some day.. (or use the soviet teflons if they ever arrive)
It's my first point to point, and it worked out great! Was a LOT of fun too..
The little circuit in the last picture is the DC heater. I was going to build it on some prototype board, but the leads on some of the components were too thick for the board I have. So, I just made it point to point as well.
It's all a little messy, but hey.. it's my first one
Now I want to build an all tube 4 channel mixer, complete w/ send/returns, headphone amp for queuing things, em-84(i think, display tube) VU meter etc. It'll be a HUGE project, but I'll just take it one piece at a time.
My only complaint (and its not really) is that this thing has too much gain! Having the volume up 1/2 is where it would be at 100% w/ other sources (cd player, mp3 player, etc). I think part of the problem (maybe the whole problem) is that I'm using a DJ needle which is supposedly very loud/sensitive.
I don't have any questions.. just a bored xmas night show and tell..
I ordered some soviet caps which never arrived, so with my last mouser order I grabbed some orange drop caps. I'll replace them w/ something better some day.. (or use the soviet teflons if they ever arrive)
It's my first point to point, and it worked out great! Was a LOT of fun too..
The little circuit in the last picture is the DC heater. I was going to build it on some prototype board, but the leads on some of the components were too thick for the board I have. So, I just made it point to point as well.
It's all a little messy, but hey.. it's my first one
Now I want to build an all tube 4 channel mixer, complete w/ send/returns, headphone amp for queuing things, em-84(i think, display tube) VU meter etc. It'll be a HUGE project, but I'll just take it one piece at a time.
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Wicked1,
Nice project, nice picks.
Too much Aikido Gain? Me too. So much so that I took the Aikido line stage completely out of the component chain. It goes Aikido phono RIAA amp, stepped attenuator then SET output tubes. The stepped attenuator in a box is a passive line stage.
DT
All just for fun!
Nice project, nice picks.
Too much Aikido Gain? Me too. So much so that I took the Aikido line stage completely out of the component chain. It goes Aikido phono RIAA amp, stepped attenuator then SET output tubes. The stepped attenuator in a box is a passive line stage.
DT
All just for fun!
right.. exact same situation! BUT.. I had planned to use the line stage as my source selector (pc, mp3 player, phono) and have my volume control built on it. And I do need the line stage for the mp3 (and like it for the PC).
owell.. It is all just for fun. I'll try some lower gain tubes in the phono.
owell.. It is all just for fun. I'll try some lower gain tubes in the phono.
Just like the old Precision Fidelity C7 preamps by Bruce Moore. I still have one in the storeroom which I occassionally put in the chain for old times sake.
Thanks everyone!
The tubes are: first four, 6n2p (12ax7-ish tube). Then 12sl7 to 12sn7. I wanted to mix 9 pin and octal (for no specific reason). Looking back, I should have done something slightly more interesting like 6n2p/12sn7 (mix 8 and 9 pin for each stage.. again, for no specific reason)
The pot I'm using is a cheap 50k stepped attenuator from ebay.
The tubes are: first four, 6n2p (12ax7-ish tube). Then 12sl7 to 12sn7. I wanted to mix 9 pin and octal (for no specific reason). Looking back, I should have done something slightly more interesting like 6n2p/12sn7 (mix 8 and 9 pin for each stage.. again, for no specific reason)
The pot I'm using is a cheap 50k stepped attenuator from ebay.
I would be really interested in doing this if I only had clear direction as to how.
The tubes are spendy for me but I can get a bunch of sockets and work on the wiring while I save money for tubes.
I find hand drawn diagrams with a hi resolution photo I can follow just about anything.
This is all of course if someone has the time/desire to help a Tooob Nooob.....LOL.
The tubes are spendy for me but I can get a bunch of sockets and work on the wiring while I save money for tubes.
I find hand drawn diagrams with a hi resolution photo I can follow just about anything.
This is all of course if someone has the time/desire to help a Tooob Nooob.....LOL.
Well.. call the schematics your hand drawn diagram. I'll see if I can dig up some more pics this evening. I can take some new pics, too..
Then i basically drew out the tube layout, my ground layout (the thick copper wire) and sketched where I'd attach the resistors and caps from the tube sockets to the grounds. I'll see if I still have any of my drawings, but I doubt it.. and they were very messy. Just to give me an idea of the layout.
It was a lot easier once I jumped in and started soldering, than my brain was making it out to be before I started. Plus the beauty of point to point is how easy it is to move and change components, if you do something wrong.
Just do it!
Then i basically drew out the tube layout, my ground layout (the thick copper wire) and sketched where I'd attach the resistors and caps from the tube sockets to the grounds. I'll see if I still have any of my drawings, but I doubt it.. and they were very messy. Just to give me an idea of the layout.
It was a lot easier once I jumped in and started soldering, than my brain was making it out to be before I started. Plus the beauty of point to point is how easy it is to move and change components, if you do something wrong.
Just do it!
Wicked1
Are you using 12SL7 in the line Stage ? Try using 12SN7 instead to reduce the gain. Depending on the resistor value you are using, you may be able to to plug in 12SN7 directly. I was able to reduce my gain from x29 to about x8. When I built my Aikido, I used the resistor valve that over lap between the SN7 and SL7 from the resistor chart in the Aikido manual. You can always change the resistor value to optimize the SN7 tube.
Are you using 12SL7 in the line Stage ? Try using 12SN7 instead to reduce the gain. Depending on the resistor value you are using, you may be able to to plug in 12SN7 directly. I was able to reduce my gain from x29 to about x8. When I built my Aikido, I used the resistor valve that over lap between the SN7 and SL7 from the resistor chart in the Aikido manual. You can always change the resistor value to optimize the SN7 tube.
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