Hi,
I would like to ask for advice on what of the 3 Aikidos that glassware offers (octal, noval and 12v) is easier to put together. I am a long time audiophile and I know how to solder and I am learning how to read a schematic, but I have some doubts as to what is the best Aikido line stage from those 3 you offer for my specific needs.
For my needs, I just need one single line level input, because I mostly listen to music from my DAC.
Regarding those 3 Aikido's, are there any evident differences in sound between the ones that require a power supply (Octal and Noval) in comparison with the 12v one?
How hard is it to put together the Noval or Octal kit with the PS-21 that glassware also offers?
Thanks,
Alan
I would like to ask for advice on what of the 3 Aikidos that glassware offers (octal, noval and 12v) is easier to put together. I am a long time audiophile and I know how to solder and I am learning how to read a schematic, but I have some doubts as to what is the best Aikido line stage from those 3 you offer for my specific needs.
For my needs, I just need one single line level input, because I mostly listen to music from my DAC.
Regarding those 3 Aikido's, are there any evident differences in sound between the ones that require a power supply (Octal and Noval) in comparison with the 12v one?
How hard is it to put together the Noval or Octal kit with the PS-21 that glassware also offers?
Thanks,
Alan
They should all have about the same number of parts, just different ones.
You are unlikely to actually need any voltage gain using just a DAC though, and these have high gain.
What is your speaker, and what is the power amplifier and its gain?
Many in your situation only need a passive volume control, not a line amplifier.
Or your DAC may have a built-in volume control that you could use,
and then you could just directly connect the DAC to the power amp.
You are unlikely to actually need any voltage gain using just a DAC though, and these have high gain.
What is your speaker, and what is the power amplifier and its gain?
Many in your situation only need a passive volume control, not a line amplifier.
Or your DAC may have a built-in volume control that you could use,
and then you could just directly connect the DAC to the power amp.
For a DAC with an output of the order of 2V RMS, I would take an Aikido cathode follower, ACF1 or ACF2. In particular, No gain - no pain. I have been using ACF1 with 6N6P for many years. Importantly, I am using a DC stabilized B+ power supply (200VDC) with the TL783C. The first version was with CRCRC, but I had the phenomenon of moving the bass membrane in response to the change in the 230V AC voltage in the network. It disappeared with the stabilization of the B+ voltage. My power amplifier is DC coupled, without the input capacitor.
The choice of tube is subjective, I chose 6N6P with the option to use the 6N1P, 6N23P and E88CC I have, changing the cathode resistors only. My post is basically related to the fact that a DAC with 2V+ RMS probably does not need voltage amplification, and two tubes are enough for that, not four. So the money can be invested in better components instead of two additional tubes and their power supply. I also made an Aikido preamp with four tubes, before the ACF. I had to reduce the voltage gain with the NFB because it was extremely impractical to use. Also (if it matters to anyone) ACF does not reverse the phase and Aikido does.
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Thanks to all for the already very helpful advice. I appreciate it.
My system currently is a Mini DSP Flex that I use as a DAC with WIIM Pro connected through it via SPDIF. Mini DSP sends one low pass signal to subwoofer, and a high pass to an Elekit TU-875 tube preamplifier (which is use as a sort of tube buffer for tube flavor more than anything, because I select sources with the Mini DSP). And from the Elekit, it goes into an Apollon NCx500 and then to a pair of NHT C3 speakers (around 84db sensitivity).
I control the level of the system with the Mini DSP, and leave the Elekit at a constant fixed in the volume knob, and I have my subwoofer adjusted for that level.
System sounds pretty good, but as much as I love the sound of the Apollon, it benefits a lot from having a tube preamplifier. I use the line stage of the Elekit with a 1960 Mullard 12AU7, and with that particular tube it sounds pretty good. I used to have an Aiyima T7 preamplifier with WE396A tubes instead of the Elekit. Currently, I use more the Elekit in that position, because the Elekit has more depth and provide more nuance to the sound, it is more laid back sound compared to the Aiyima T3 with the W396As, although the particular tube warmth of the W396As is hard to beat.
So, I was looking for a better tube preamplifier, because having had other tube equipment in the past (Conrad Johnson MV50, Sonic Frontiers, Custom built 300b amp, custom built 45 SET amp, and others), I know the sound still can improve, mostly in the midrange area. I find the Elekit a bit not open enough in the midrange.
That is how I got to the Aikido. I was first planning to build a Elekit TU-8550 kit, but I read many reviews saying that the Aikido line stage, even the 12v one, sounded better than that particular Elekit.
I know how to solder, I have made all my RCA cables, and last week I put together a ¨color box¨ using 2 Western Electric 111C transformers in 150:600 configuration. But, for real electronics, I am still learning so I am not sure if the Aikido is that complex. I learn fast but I have read about a lot of Aikido builds that had issues with hum, and/or ground problems. That is why I was asking about the easiest build.
My system currently is a Mini DSP Flex that I use as a DAC with WIIM Pro connected through it via SPDIF. Mini DSP sends one low pass signal to subwoofer, and a high pass to an Elekit TU-875 tube preamplifier (which is use as a sort of tube buffer for tube flavor more than anything, because I select sources with the Mini DSP). And from the Elekit, it goes into an Apollon NCx500 and then to a pair of NHT C3 speakers (around 84db sensitivity).
I control the level of the system with the Mini DSP, and leave the Elekit at a constant fixed in the volume knob, and I have my subwoofer adjusted for that level.
System sounds pretty good, but as much as I love the sound of the Apollon, it benefits a lot from having a tube preamplifier. I use the line stage of the Elekit with a 1960 Mullard 12AU7, and with that particular tube it sounds pretty good. I used to have an Aiyima T7 preamplifier with WE396A tubes instead of the Elekit. Currently, I use more the Elekit in that position, because the Elekit has more depth and provide more nuance to the sound, it is more laid back sound compared to the Aiyima T3 with the W396As, although the particular tube warmth of the W396As is hard to beat.
So, I was looking for a better tube preamplifier, because having had other tube equipment in the past (Conrad Johnson MV50, Sonic Frontiers, Custom built 300b amp, custom built 45 SET amp, and others), I know the sound still can improve, mostly in the midrange area. I find the Elekit a bit not open enough in the midrange.
That is how I got to the Aikido. I was first planning to build a Elekit TU-8550 kit, but I read many reviews saying that the Aikido line stage, even the 12v one, sounded better than that particular Elekit.
I know how to solder, I have made all my RCA cables, and last week I put together a ¨color box¨ using 2 Western Electric 111C transformers in 150:600 configuration. But, for real electronics, I am still learning so I am not sure if the Aikido is that complex. I learn fast but I have read about a lot of Aikido builds that had issues with hum, and/or ground problems. That is why I was asking about the easiest build.
Let me tell you just this, any Aikido which I made doesn't really have a typical tube sound. I would rather describe it as neutral, detailed, fast and dynamic, rather than "tubelike" warm and soft. Especially this version with four tubes and global NFB does not have the "typical" tube sound. And ACF has total negative current feedback and very little THD. And the sound depends a lot on the tube you use, regardless of NFB and low THD.
Alan,
I am glad you detailed your system, particularly your NHT C3 speakers (spec is 87dB) and your Apollon NCx500 Class D amplifier.
Can you detail what overall closed loop gain you have selected for your Apollon amplfiier? That’s an important detail.
Nixie62 is bringing an important point and that is looking at the overall gain of your entire system (after your digital source, I am assuming). You clearly have enough power, which is dictated by the output stage of your Apollon. But there is a balance between playing with overall system gain, and signal to noise ratio. And I do understand that we want some tube flavoring here, particularly due to the design architecture of the Apollon which is basically a very well implemented application of Purifi’s latest and greatest.
Best,
Anand.
I am glad you detailed your system, particularly your NHT C3 speakers (spec is 87dB) and your Apollon NCx500 Class D amplifier.
Can you detail what overall closed loop gain you have selected for your Apollon amplfiier? That’s an important detail.
Nixie62 is bringing an important point and that is looking at the overall gain of your entire system (after your digital source, I am assuming). You clearly have enough power, which is dictated by the output stage of your Apollon. But there is a balance between playing with overall system gain, and signal to noise ratio. And I do understand that we want some tube flavoring here, particularly due to the design architecture of the Apollon which is basically a very well implemented application of Purifi’s latest and greatest.
Best,
Anand.
Hi Anand,
I use the Apollon in the third position, 27.5db. Occasionally, I use it in the second position, 20.5db, but in that position, sometimes I get close to the zero attenuation in the Mini DSP volume control. That volume control in the Mini DSP controls the output volts, from negative to zero. That is why I changed it to 27.5db in the Apollon.
By the way, the NHT C3 is supposed to be 87db, but in reality (and this has been measured by different people, here and here) it is closer to 84-85db. So, it needs power to be moved properly and it actually sounds pretty good with good watts. Since it is a sealed design, it soundstages pretty well.
My Apollon uses the latest Hypex module, which is the NCx500.
And yes, I am just trying to improve over the bit of tube warmth that the Elekit TU-875 is providing. In my case, the sound of the system is radically different with or without the tube preamplifier. The Apollon sounds very good without the tube preamp, but the tube preamp makes it much better.
Regarding what Nixie62 mentioned, I understand that the archetypal definition of tubelike sound may be a bloated midrange, sort of boomy bass, and a 5db or so cut in the high frequencies. But, what I have been chasing and I am looking to improve, is to add that rounding of the edges and warmth, that tubes also do really well.
I use the Apollon in the third position, 27.5db. Occasionally, I use it in the second position, 20.5db, but in that position, sometimes I get close to the zero attenuation in the Mini DSP volume control. That volume control in the Mini DSP controls the output volts, from negative to zero. That is why I changed it to 27.5db in the Apollon.
By the way, the NHT C3 is supposed to be 87db, but in reality (and this has been measured by different people, here and here) it is closer to 84-85db. So, it needs power to be moved properly and it actually sounds pretty good with good watts. Since it is a sealed design, it soundstages pretty well.
My Apollon uses the latest Hypex module, which is the NCx500.
And yes, I am just trying to improve over the bit of tube warmth that the Elekit TU-875 is providing. In my case, the sound of the system is radically different with or without the tube preamplifier. The Apollon sounds very good without the tube preamp, but the tube preamp makes it much better.
Regarding what Nixie62 mentioned, I understand that the archetypal definition of tubelike sound may be a bloated midrange, sort of boomy bass, and a 5db or so cut in the high frequencies. But, what I have been chasing and I am looking to improve, is to add that rounding of the edges and warmth, that tubes also do really well.
I am satisfied. I have other DIY preamps without tubes, but I always go back to Aikido. I accidentally ran into two Foton 6N6Ps from the 60s on ebay, fantastic sound. These newer productions don't have such a rich sound, and they need maybe an hour or two to play properly. These new ones play well right away. 
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The following is just my opinion/experience:
With what you have, I would change the Apollon‘s gain setting to 2nd or 3rd position, build an octal Aikido (which is about 20dB gain with 6SN7’s or 13dB gain with 6BX7’s) and have your party. There are not too many octal tube types to play with though. If you are really addicted to tube rolling (no worries!), then build the 9 pin Aikido where the world is your oyster. Lots of gain options there and lots of tube options and varieties as well. But I will say Octal Aikido’s sound is special, very spatial and dimensional and that is specific to many Octal tubes, particularly the 6SN7.
Simply put, you want the gain in your tube preamp + the gain in your Apollon to be equal to about 26-30dB when used with zero attenuation of your MiniDSP output and the NHT C3 speaker.
If your speakers change, i.e. become more sensitive, let’s say 96dB, then suddenly your overall system gain needs decrease by about 96-84=12dB.
Thanks for the NHT measurements, that makes a difference but it is only about 2-3dB. I’m looking at your overall system gain in general, not power per se, which you have ample amounts of with the Apollon Purifi Class D output stage. Your Apollon will basically fry your NHT speakers if you let it, since those small drivers will go deep into compression territory. More power is always good to have since you never want your amplifier to be clipping (which will fry your tweeters) so you are fine.
I completely understand what Nixie62 is pointing out and that has to do with overall signal to noise ratios (which relates to system gain) but the detail here is to look at the overall system gain which includes the sensitivity of the loudspeaker, the output voltage of the source, the listening position of the listener and the overall habits of the listener which includes the recordings themselves. Some recordings are very quietly recorded where you need a little bit more volume, so flexibility is needed too.
And if you wanted to build the ACF instead, that’s fine, just change the gain setting of your Apollon back to the 1st position and do that.
You have multiple options!
Enjoy!
Best,
Anand.
With what you have, I would change the Apollon‘s gain setting to 2nd or 3rd position, build an octal Aikido (which is about 20dB gain with 6SN7’s or 13dB gain with 6BX7’s) and have your party. There are not too many octal tube types to play with though. If you are really addicted to tube rolling (no worries!), then build the 9 pin Aikido where the world is your oyster. Lots of gain options there and lots of tube options and varieties as well. But I will say Octal Aikido’s sound is special, very spatial and dimensional and that is specific to many Octal tubes, particularly the 6SN7.
Simply put, you want the gain in your tube preamp + the gain in your Apollon to be equal to about 26-30dB when used with zero attenuation of your MiniDSP output and the NHT C3 speaker.
If your speakers change, i.e. become more sensitive, let’s say 96dB, then suddenly your overall system gain needs decrease by about 96-84=12dB.
Thanks for the NHT measurements, that makes a difference but it is only about 2-3dB. I’m looking at your overall system gain in general, not power per se, which you have ample amounts of with the Apollon Purifi Class D output stage. Your Apollon will basically fry your NHT speakers if you let it, since those small drivers will go deep into compression territory. More power is always good to have since you never want your amplifier to be clipping (which will fry your tweeters) so you are fine.
I completely understand what Nixie62 is pointing out and that has to do with overall signal to noise ratios (which relates to system gain) but the detail here is to look at the overall system gain which includes the sensitivity of the loudspeaker, the output voltage of the source, the listening position of the listener and the overall habits of the listener which includes the recordings themselves. Some recordings are very quietly recorded where you need a little bit more volume, so flexibility is needed too.
And if you wanted to build the ACF instead, that’s fine, just change the gain setting of your Apollon back to the 1st position and do that.
You have multiple options!
Enjoy!
Best,
Anand.
Thanks Anan and Nixie62!! I guess then that I will try to build the Octal Aikido since I actually know and like the sound of the 6SN7.
One question, I finished building this Western Electric 111C color box, which I plan to use between the Mini DSP and the tube preamp, or between the tube preamp and the Apollon. It is just a two RCA (left and right) going into the line side of the transformers (150ohm) and going out in the drop side (600ohm) and then to output RCAs, no resistors, no capacitors.
Would that gain change or affect your calculations?
and more important, does anybody know if I can order from glassware? or they run out of kits long time ago. I know they also see a PS-21 power supply that fits with the octal Aikido, that would make things easier for me. Although still the building is a daunting journey.
One question, I finished building this Western Electric 111C color box, which I plan to use between the Mini DSP and the tube preamp, or between the tube preamp and the Apollon. It is just a two RCA (left and right) going into the line side of the transformers (150ohm) and going out in the drop side (600ohm) and then to output RCAs, no resistors, no capacitors.
Would that gain change or affect your calculations?
and more important, does anybody know if I can order from glassware? or they run out of kits long time ago. I know they also see a PS-21 power supply that fits with the octal Aikido, that would make things easier for me. Although still the building is a daunting journey.
I don't have a schematic of the WE 111C color box but it sounds like something that generates some 2nd harmonic distortion using transformers along with impedance changes. That's all fine and dandy, but my advice is this. I don't advise using it, until you have built your version of the Aikido (Aikido 8 pin or Aikido 9 pin or ACF 9 pin) and finalized it in your system. It's just another box that includes other distortion producing elements including the interconnects, etc...i.e. might be too much of a good thing.
If the transformers are wired 1:1 ratio, the gain doesn't change. If the they are wired in different ratios, then it does and it depends on the ratio. If the impedance ratio is 150:600, that implies a turns ratio of 2 or about 6dB. Depending on how you connect it, you can either have +6dB of gain or -6dB of gain. I certainly wouldn't want more gain.
Baby steps first. And one change at a time is my advice.
Broskie continues to run his business, he can be a bit slow about responding to emails but product is still being sent to consumers from what I understand. I haven't ordered from him in a while.
Best,
Anand.
If the transformers are wired 1:1 ratio, the gain doesn't change. If the they are wired in different ratios, then it does and it depends on the ratio. If the impedance ratio is 150:600, that implies a turns ratio of 2 or about 6dB. Depending on how you connect it, you can either have +6dB of gain or -6dB of gain. I certainly wouldn't want more gain.
Baby steps first. And one change at a time is my advice.
Broskie continues to run his business, he can be a bit slow about responding to emails but product is still being sent to consumers from what I understand. I haven't ordered from him in a while.
Best,
Anand.
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Right now, your choice is the Aikido Octal or the Aikido 12Vac. The Aikido Noval is out of stock. Sometimes Broskie has a considerable gap between runs of certain kits. The Octal will limit your tube choices somewhat and require a power supply as well. The 12Vac has the PS built right onto the board and all that's required is an approx. $30 to $40 transformer. Another advantage of the 12Vac is that it can be configured for 4 different tubes. All tubes on any one 12Vac board must be the same, I.E. : four 6DJ8 family, four 6CG7 (a rough 9-pin equivalent of the 6SN7), four 12AU7 or four 12BH7, so lots of choice. As well the latest 12Vac has two gain options (configured with a change of resistors).
The advantage of having the PS, both filament and HT, on the same board as the amplifier is the reduced chance of running into hum issues due to ground loops. The part spacings on the latest 12Vac board is quite tight but still allows for an upgrade of output caps to 1.0uF, 200v Auricaps.
See link below to build instructions of previous generation 12Vac. It's a bit different than the current 12Vac but the principles are the same.
Whatever you decide, if you're going to purchase one of Broskie's kits, don't procrastinate. Once Broskie's current stock of kits is exhausted you might have to wait many months for him to order more boards.
Cheers, S.
https://wallofsound.ca/misc/diy/battle-of-the-cheap-line-stages-part-3/
The advantage of having the PS, both filament and HT, on the same board as the amplifier is the reduced chance of running into hum issues due to ground loops. The part spacings on the latest 12Vac board is quite tight but still allows for an upgrade of output caps to 1.0uF, 200v Auricaps.
See link below to build instructions of previous generation 12Vac. It's a bit different than the current 12Vac but the principles are the same.
Whatever you decide, if you're going to purchase one of Broskie's kits, don't procrastinate. Once Broskie's current stock of kits is exhausted you might have to wait many months for him to order more boards.
Cheers, S.
https://wallofsound.ca/misc/diy/battle-of-the-cheap-line-stages-part-3/
If you choose the octal build, I'd strongly recommend the three-way volume control Broskie sells. This has left and right attenuators and a master volume. This allows you to control the gain of the preamp and also adjust the balance. I need both options in my system. I tried feedback in mine but didn't care for it, but that is an option, easy to add or remove.
I think the Aikido is one of the great inventions of audio. ;-) Especially for the DIYer, it offers a first-class sound at a very decent price. It's really not a complicated circuit, so don't be worried. ;-)
I think the Aikido is one of the great inventions of audio. ;-) Especially for the DIYer, it offers a first-class sound at a very decent price. It's really not a complicated circuit, so don't be worried. ;-)
I use the Akido noval and construction is easy and the same for whichever I expect.
I do use a PS21 too, also an easy build. The transformer is a 115-0-115.
I use it as the gain stage for my EL34 SE tube amp where it works very well.
I have no interest in 12v tube designs.
Jayme,
Broskie, in one of his blogs, showed a method of reducing gain. The blog is difficult to find, so the last time I did I grabbed it and saved it. In the PDF attached, scroll down to the second last page where the 12dB Aikido Line-Stage Amplifier is shown. By changing out the two typically 1 Meg resistors between the two tubes for 200K AND hacking the board to install a 124K resistor you can drop the gain down to 12dB.
This option is included in the latest version of the 12Vac.
Broskie, in one of his blogs, showed a method of reducing gain. The blog is difficult to find, so the last time I did I grabbed it and saved it. In the PDF attached, scroll down to the second last page where the 12dB Aikido Line-Stage Amplifier is shown. By changing out the two typically 1 Meg resistors between the two tubes for 200K AND hacking the board to install a 124K resistor you can drop the gain down to 12dB.
This option is included in the latest version of the 12Vac.
Thanks! Interesting.
Unfortunately my aikido is in a state of unfinished half rebuild, as I was in the process of moving the volume pot and selection switch to the back of the case (with long connection rods to the knobs at the front). I was also going to redo the PSU to address that motorboating issue.
I have been considering revisiting it tho. I have a couple of speaker projects to finish first.