[DaveC113]

OK, better late then never, I had an issue with heater voltage that took a while to work out, it was low and causing hiss. It's been running great with no hiss and no hum for a while now. I had the frequency response and THD tested, it is ruler flat with about .05% THD.

Also, I recently disconnected the input stage of my SET amp and am using the Aikido to drive my EL34s directly. The input stage of my amp used to be a 12BH7 with a CCS plate load, this is a very good tube with a plate load that makes it even more linear, but the Aikido is a much, much better gain device and sounds worlds better than the 12BH7 input. With the Aikido driving the power stage there is much less distortion, less HF roll-off and faster transients. There is just enough gain to reach speaker breakup, and I can adjust output level for material with less than normal gain using foobar's "preamp" (in 6.1 dB increments to avoid loss of resolution) if needed. I am using a Schiit Bifrost DAC, which I believe has a max 2V output.

Even with the 12BH7 driver in place the amp sounded better with the Aikido in front of it, with the 12BH7 driver out of the circuit the improvement is quite large, so this has been a very successful project even though I wasn't thinking of replacing my amp's driver circuit when I built it. This preamp is a pretty large improvement over the Anthem Pre1 I was using, and it should be considering the premium parts used vs the Anthem.

I would definitely recommend the Aikido as a high-end preamp project, I think it's good rep is well deserved.

[poseidonsvoice]

Fantabulastic build and thanks for the great review! A number of my colleagues have replaced their input/driver stages with the Aikido and with great results as you have found. It's just a good circuit. Top it off with better parts and you are in bliss.

Best,
Anand.

[mjock3]

I enthusiastically agree  thanks for the review and follow up. Very exciting!! I really like the wood you are using for plinths, what kind is it?

Mark

[DaveC113]

Thanks for the kind words.

The wood is maple with burled, quilted and spalted patterns in it. The corners of the amp and preamp are walnut.

[bunky]

I love the build and the look of the contrasting woods against the black knobs.beautiful work all around.

[Jazzman53]

Beautiful work!

[tull skull]

Fantastic work Dave! Love the look of your cables too.

[djbachelor]

Beautiful ensemble you've built here, I love the matching figured maple and accents throughout the preamp, amps, and speaker stands. I am finishing a set of DIY speakers dressed in maple bolivian rosewood, and recently latched onto the idea of building my own tube preamp and equipment rack with matching accents. Now I think I should add matching tube monoblocks to that little fantasy! Anyway, really terrific work; I am inspired and hope to follow behind. Did you have to custom-order that top plate for the preamp? It looks machined and maybe power coated; that sure isn't going to happen in MY garage, anyway...

[DaveC113]

Thanks dj!

I do all the "machining" with a drill in the garage     and the paint is a textured spray paint, forget which one exactly but there's a lot of cool spray paints these days. There's a company that will do custom machined and printed chassis parts/panels for electronics:

http://www.frontpanelexpress.com/index.html?gclid=CNqw9ILdvLsCFa4-Mgod7W0AOA

The Aikido is a very good preamp and is doing a great job driving my EL34s. I have some plans to build a larger SET amp and will likely use the Aikido or a close variation as an input/driver stage.

[Freo-1]

Excellent work, Dave.   

I had a Aikido preamp a couple of yeard ago that sounded very good, and measured great on the O-Scope.  It's a good circuit.

Enjoy it!   

[DaveC113]

Yeah, measurements are great and it can put out about 30V rms before the output gets messy.

[cags]

I am in the process of obtaining parts to build Aikido Octal Preamp. I am using for a guide the parts list that you [DAVE C113] posted awhile back on the forum. Do you have a schematic of the project you could send me to use as a guide . I see the pdf from Aikido has a good amp schematic but I,m in need to see the PS section in detail.
 I,m an old school point to point builder but pc boards would be an option for me if necssary. Any suggestions would be greatly appreciated.

Thanks,

Regards,
Cags

[DaveC113]

I am in the process of obtaining parts to build Aikido Octal Preamp. I am using for a guide the parts list that you [DAVE C113] posted awhile back on the forum. Do you have a schematic of the project you could send me to use as a guide . I see the pdf from Aikido has a good amp schematic but I,m in need to see the PS section in detail.
 I,m an old school point to point builder but pc boards would be an option for me if necssary. Any suggestions would be greatly appreciated.

Thanks,

Regards,
Cags

I don't have a schematic besides what is in the Aikido instruction manuals... I have not seen a complete schematic either, it's in several pieces spread throughout the manuals. If you check out the manuals and have any questions I'd be happy to help. 

[JohnR]

One option would be to get a PSU kit from Broskie, e.g. Janus or PS-1  -

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