[wushuliu]

http://glass-ware.stores.yahoo.net/aikidolv.html

I received just about all the components sooner than expected, so I got going on the project tonight. I wanted to try this preamp primarily because with my AD1865 DAC now running with a passive I/V, I need some additional gain. So far I get decent volume with the DCB1, but it's clear that some additional amplification is needed. The other reason is I have always wanted to try out tubes and this seemed like a great opportunity. I recently heard an EE Integrated tube amp at a fellow audiophiles and was really struck by the added dimensionality to the music. Not to mention tubes just look really cool. I don't expect the Aikido to sound like the EE, but I am curious to hear what it will add to my system. I'll also be setting up my Hagerman Bugle soon and a tube pre will hopefully be a good balance for the solid state sound.

I'm still trying to learn the basics about tube wiring, so having this board is great. Can't imagine tackling point to point for something like this, although I think I may try a simple tube stage for the TDA1541 Dac on the way. My biggest fear about tackling tube projects has been the high voltages involved. Now that I feel more comfortable handling power supplies, I'm ready to give it a shot (but not shock!). Still, for my first time I figure it best to try this Low Voltage Aikido; I only need 48v for the 12BH7 tubes and I'll be using a wall-wart - as recommended by the designer John Broskie. So this makes things muuuch easier for this first outing. Wall-wart was only $20 to boot.

The build is super easy and straightforward (so far) so there's really not much else to say at this time. Only took a couple of hours, most of which was spent on cap decisions  Enclosure, etc. will be tackled later. Glassware has full documentation pdf. Very simple parts list. It's 80% resistors, 20% caps, and some tubes. Not to mention you can buy all the components direct from Glassware (linked at top), except the PS. Just want to pop in some pictures...



First resistor in. I just used what spare resistors I had lying around with some add'l ones
ordered from Digikey, so it's a hodgepodge of Dales, PRPs, Riken, Shinkoh... still learning about
what the most critical areas are for sound, so this'll have to do for now.





Caps are placed on the bottom, this way I can maximize tube height through the enclosure...










TUBES!  12BH7

[grubyhalo]

Good luck with the build! As someone who's eyeing the Octal stereo flavor of the Aikido's i'd be very interested in your build... 

[kingnubian]

I am very interested in your build. Just as you, I have been admiring tube gear from afar but this seems like and relatively easy way to get my feet wet. Seems like it would be a nice preamp paired with an SDS series or one of Connexelectronics class D offerings as well.

Primarily it would be great to know how this fares against the B1.

I would, and I'm sure others will as well, appreciate a parts list with links as you did with the amazing B1 build thread when you get things done.

[wushuliu]

I am very interested in your build. Just as you, I have been admiring tube gear from afar but this seems like and relatively easy way to get my feet wet. Seems like it would be a nice preamp paired with an SDS series or one of Connexelectronics class D offerings as well.

Primarily it would be great to know how this fares against the B1.

I would, and I'm sure others will as well, appreciate a parts list with links as you did with the amazing B1 build thread when you get things done.

I don't think you can really compare the B1 and Aikido. The DC/B1 is zero-gain, and the Aikido LV has something 17/18(?)db gain. That much gain and a classdaudio amp - which has 32 or 36db voltage gain last I knew - would be overkill with a standard source like CD player, etc. A better comparison would be with the ACF buffer that Broskie sells...

Also, Glassware has full documentation pdf, so I won't be doing a BOM. Very simple parts list. It's 80% resistors, 20% caps, and some tubes. Not to mention you can buy all the components direct from Glassware, except the PS.

[kingnubian]

I don't think you can really compare the B1 and Aikido. The DC/B1 is zero-gain, and the Aikido LV has something 17/18(?)db gain. That much gain and a classdaudio amp - which has 32 or 36db voltage gain last I knew - would be overkill with a standard source like CD player, etc. A better comparison would be with the ACF buffer that Broskie sells...

Also, Glassware has full documentation pdf, so I won't be doing a BOM. Very simple parts list. It's 80% resistors, 20% caps, and some tubes. Not to mention you can buy all the components direct from Glassware, except the PS.

With the SDS-254's variable input gain controls, isn't the adjustable range enough to better match it to the LV Pre?

[strider]

Looking good! I didn't see that version of the Aikido when I was ordering mine.  My octal Aikido is done to the point where it is functional (not finished cosmetically yet) and is burning in right now. It also replaced a B1 in my system. The voltages of the PS were pretty imposing, but so far I'm not dead.

Have fun with it, I really enjoy the sound so far.

[wushuliu]

With the SDS-254's variable input gain controls, isn't the adjustable range enough to better match it to the LV Pre?

I'm not sure what the range is for the SDS variable gain (really wished Tom provided more info on things like that).

[wushuliu]

Looking good! I didn't see that version of the Aikido when I was ordering mine.  My octal Aikido is done to the point where it is functional (not finished cosmetically yet) and is burning in right now. It also replaced a B1 in my system. The voltages of the PS were pretty imposing, but so far I'm not dead.

Have fun with it, I really enjoy the sound so far.

Well, I got the tubes a-glowing for a minute, then when I moved the Aikido over to my gear, nothing. The heaters don't come on. So now I'm stumped and I've looked over the whole board. I ordered a different PS (the one i got was .52A vs. .82A Broskie used), but the 350mA current draw of the 12BH7 should work fine with it. So I'm bummed. I'm sure the issue is simple, but I hate having to do these troubleshoots.

[wushuliu]

Ok, it's working now...

[JohnR]

Wow, that was fast. Looks like a nice option 

[wushuliu]

Wow, that was fast. Looks like a nice option 

Yeah, can't believe how easy that was! Only trade-off is only one other tube option, ECC99, for tube rolling...

[parodielin]

Yeah, can't believe how easy that was! Only trade-off is only one other tube option, ECC99, for tube rolling...

How does it connect to the AD1865K?  Geez, you're marching at light speed.

[wushuliu]

How does it connect to the AD1865K?  Geez, you're marching at light speed.

I just go from the audio outs from the enclosure to the aikido.

[wushuliu]

Don't know much about tube gear and break-in. I am guessing the standard '100 hours' is applicable. For the time being I have the Aikido on 24/7. Mostly because the turn on 'thump' is a little too pronounced for my taste and I'd rather not blow any speakers at this time.

What I hear so far is a tradeoff w/ the DCB1 of 3-dimensionality vs. clarity. Definitely a 'warmer' presentation. Very pleasing and engaging, just lacking the some of the dynamics and snap of the DCB1. The DCB1 did present a 3-D soundstage, but it was flatter and behind the speakers. The aikido so far has moved things forward. DCB1 more lean and clean, Aikido a bit more diffuse. How much of this is the design vs. components like caps, resistiors, etc. or even the wall-wart, we''ll see. There'll be some cap swapping to come, as well as better interconnects to replace the cheap stuff going from DAC to Aikido.

Love to see the tubes glow when the lights are low, too.

Maybe I'll try Broskie's CCDA next so I get some experience w/ high voltage power supply and be able to tube roll inexpensively and without the restraints of the LV Aikido...

[wushuliu]

Swapped out 2 of the Harmonix tubes for NOS Sylvania 12BH7As for my first tube roll and man, they do sound better! I have some Tung Sol that I got for $5 coming next.

[grubyhalo]

Did you mod anything else on the board other than the tubes? Would love some impressions if anything has changed. Thanks!

[wushuliu]

Did you mod anything else on the board other than the tubes? Would love some impressions if anything has changed. Thanks!

No, just played around with output caps and tubes. The Aikido has been offline for a while, having been replaced by the lightspeed attenuator, and now I'm working on speakers and... I hope to come back full circle at some point and re-evaluate. The high point for sure was I believe the tung-sol tubes and Vitamin Q .68uf output caps. Delicious.

[grubyhalo]

Thanks!

[BillB]

The best way to do a tube pre for start up is to turn it on by itself and let it warm up for 10-15 minutes before turning on the amp and other components.

I have a 24v aikido and a 5481 aikido that I populated but never built a PSU for.

I use a SMPS power supply for the 24v.

The aikidos do a great job for very little money (especially when you can run a wall wart!)