Head-Fi.org › Forums › Misc.-Category Forums › DIY (Do-It-Yourself) Discussions › is there a tube equivalent to the cmoy?
New Posts  All Forums:Forum Nav:

is there a tube equivalent to the cmoy?

post #1 of 28
10/7/10 at 3:08pm
Thread Starter 

what i mean by that is pretty much the simplest circuit possible to do what you want it to with a tube. i know nothing about using tubes for amplification and would be interested in learning a bit and figured if there was something like this it'd be a good place to start smily_headphones1.gif


Edited by Soymilk - 10/7/10 at 3:42pm
Reply
post #2 of 28
10/7/10 at 3:59pm

For DIY it would probably be a SOHA or a Millet Starving Student.

Reply
post #3 of 28
10/7/10 at 4:07pm

I would argue that the super simple 6DJ8 is one of the most basic tube circuits about - even simpler than the YAHA. Pete Millets Starving student is similar but uses now hard to find tubes.

 

..dB

Reply
post #4 of 28
10/7/10 at 5:08pm
Thread Starter 

awesome, this'll give me something to look over / keep me busy while im at .. uh.. home.. >.>

Reply
post #5 of 28
10/7/10 at 5:23pm

No offense, but I disagree - the SOHA has way too many parts - either I or II.  Similarly, the super-simple 6DJ8 has its origins and application firmly imbedded in PCB design.  The essence of the CMoy is that it can be built point-to-point using a simple Radio Shack perfboard (or similar).  Given those differences, I think the only tube amp (or hybrid) that qualifies is the Starving Student.  It's the number one design using tubes that can be built with the cheapest of components. It's also unequaled - except by the CMoy - in the variety of creative/cheap case designs.  Pete Millett built the original using a wallet tin.

 

I agree that the tubes are now hard to find, which limits the Starving Student's original effectiveness.  However, many of the recent/current users have come up with a number of suitable replacements, including the ubiquitous 12AU7.


Edited by tomb - 10/7/10 at 5:28pm
Reply
post #6 of 28
10/7/10 at 5:29pm
Thread Starter 

the cmoy is pretty much just the simplest opamp based amplification circuit you can have (that also goes hand in hand with being able to go point to point on a perfboard). you can look at it and very easily see what every part is for, even from someone that isn't experienced in amplifier design (but has some knowledge of ee). oh, that's a dc filtering cap. those resistors are for the feedback gain loop. and we're pretty much done. i'm just looking for the tube equivalent of this (if it exists): the simplest circuit possible with the fewest components, so i can just look at it and easily figure out what each part is for.

Reply
post #7 of 28
10/7/10 at 5:34pm

starvi1.gif

6dj8-schematic-large.png

 

just sayin ..dB

Reply
post #8 of 28
10/7/10 at 5:47pm

Has anyone built one point-to-point?  Plus, that comparison in schematics is a bit misleading ... the 6DJ8 version is only showing one channel.

Reply
post #9 of 28
10/7/10 at 6:51pm

yes, folk have built it P2P. Honestly, I am not advocating one over the other , they are both pretty simple. The 6922 amp offers a little refinement in the CCS and uses a ubiquitous tube. But for simplicity of using a single power supply for tube B+ and heaters, mosfet output and ....from what I can gather, pretty decent results from the final product - the OP can't go wrong with either. The bonus, both have a pcb available and TomB can even supply a complete kit for the starving student, making it even more simple..dB

Reply
post #10 of 28
10/7/10 at 7:13pm
In terms of a simple amp, I'd look at the Kurt Strain OTL over at HeadWize. Not terribly expensive or complex. You'd have to go point-to-point, but that's another nice learning experience.
Reply
post #11 of 28
10/7/10 at 11:58pm
Thread Starter 

well i'm not quite looking to build one just yet, right now this is more of a thought / educational exercise to learn something new so as long as there's a schematic that's good enough smily_headphones1.gif


Edited by Soymilk - 10/8/10 at 9:31am
Reply
post #12 of 28
10/8/10 at 5:56am

The first headamp I built was a SOHA, because, at the time it was the simplest, and there was a PCB(and I wanted to try a hybrid) for it.  For someone new in the game who wants to step up from a CMOY, a PCB greatly simplifies the process, getting to the gratification of "it works"  in a much shorter time.  There are more choices now, and picking an amp that has lots of cheap tube options (ala the Simple 6DJ8) make it a very worthwhile choice for a toob noob..

 

 

  

Reply
post #13 of 28
10/8/10 at 4:14pm
Quote:
Originally Posted by tomb View Post

Has anyone built one point-to-point?  Plus, that comparison in schematics is a bit misleading ... the 6DJ8 version is only showing one channel.



I built it p2p and replace output SK310 with another LM317, like in 24V Aikido output stage.

Reply
post #14 of 28
10/8/10 at 4:36pm
Quote:
Originally Posted by Zigis View Post





I built it p2p and replace output SK310 with another LM317, like in 24V Aikido output stage.



Works and sounds pretty good, doesn't it.

They run cooler than mosfets also. Don't really even need heatsinks on mine.

Reply
post #15 of 28
10/8/10 at 5:08pm

I've built the following hybrids p2p

SOHA 1 : was NOT easy and not recommended as starter project.

SSMH : pretty easy, nice little amp

12AU7 + IRF510 with LM317 CCS : not too hard, pretty nice amp

12AU7 + IRF510 with resistor CCS : easier, almost as good as above

Reply
New Posts  All Forums:Forum Nav:
  Return Home
Head-Fi.org › Forums › Misc.-Category Forums › DIY (Do-It-Yourself) Discussions › is there a tube equivalent to the cmoy?