[BillB]

Hey all.

I have been working on this project for a few days and finally got all the parts in yesterday and got it up and running.

As you can see it is just on a test board, no enclosure as of yet...I have not decided what I want to do with that either. Right now it is a single in/single out preamp and I don't even have the headphone section outputs connected yet either.

All resistors are 1% .5w Dale/Xicon/Vishay metal.
Output caps for line stage are 1uf Jantzen Z-superior
Headphone stage output caps are 4uf IC motor starters with 2500uf multi-comps and 150pf silver micas on the 4ufs as bypasses.

Other caps are 1500uf IC for heater caps, 1uf Jantzen Z-standard for C12,13 and a 2000uf Rubicon for C4. (cant remember off-hand what the noun-name purpose of these caps were for.)

Right now attenutation is handled by an Alpha 50k pot but this will be replaced by most likely an opti-vol. Source switching will be via a Twistedpear Darwin.

Valves are GE ECC86 made in Holland, identical in construction to the Amperex ECC86.

Power supply is a Lambda 24v medical SMPS.

I only have about 3hrs on it right now but I am very impressed. My previous pre-amp was a SS unit using a Burson discrete op-amp and Riken resistors powered by a similar Lambda supply but with +/- 15v. Detail is at least as good as the Burson pre and is very quiet...no hum or noise that I can hear.

The musicality of the pre is very impressive and I am very pleased to make this my full-time pre.

I have a high voltage 5687/6cg7 Aikido also in the works but with this one up and running it might be hard to finish...though if I crank up some tunes the time will probably fly by!





Plans are to have a little shootout between this, a Manley Shrimp, and an Odyssey Candela in the coming weeks...it should be fun, I think this will stand up to them in all but the looks department right now. 

[mgalusha]

Nicely done, I like the clear lexan for the jacks and the volume control.

[Occam]

Neat!
I'm curious as to why you picked those Jantzen caps? Do you have previous experience with them?  (I've used the earlier crosscaps and was very pleased, given their price)
Similar question regarding the ps. Have you chosen a switching supply because of the inherently high psrr of the Aikido circuit? Have you compared this to a linear supply?

TIA,
Paul

[TomS]

... Similar question regarding the ps. Have you chosen a switching supply because of the inherently high psrr of the Aikido circuit? Have you compared this to a linear supply?

I was curious about this too.  I've tried 3 different HV supplies on my Aikido - one cheapo no frills (during testing), one 6x4 toob with ASC oil caps, Mills resistors, CRCRC, and another SS Mosfet pass regulator and it's a stretch to describe any changes in sound and/or noise level from any of them.  Never tried a switcher though.

Very nice build by the way.

[BradJudy]

Nice to see you over here Bill.  The build looks nice - can't wait to see it all cased up. 

Do you know what the max current draw is for the 24v Aikido?

[BillB]

Whew...lotsa questions:

Total draw is 338ma or around 8w...I think I am using a 10w...cannot remember until I look at it.

Why the SMPS?

This medical supply has pretty low noise and ripple when compared to a normal SMPS (about 1/3 from what I could gather), I like it for its size mostly...about the size of a Plen-t-pack of gum...a similar linear would have taken at least double the space, if not more and once you add in tranny/regulator etc the cost would have been close to the $42 the SMPS cost. It is also spec'd for a 200,000-400,000 hour lifespan.

Why the Jantzens?

I used them in my Burson pre and was very happy with the sound. I went with the Z-standards for C12,13 because of cost and I knew the 1uf Superiors were quite large in comparison. I have never been pleased with Auricaps or Sonicaps (tried both in the SS pre) and I figured the Jantzens were a good cost alternative. I like the smooth sound of them.

Brad...ever get word on whether or not the Neos are coming to ATL? I will definitely pack this baby up and bring it out to where-ever we decide to listen.

[BradJudy]

Brad...ever get word on whether or not the Neos are coming to ATL? I will definitely pack this baby up and bring it out to where-ever we decide to listen.

I was waiting a little bit in the hopes there would be some news about X-amps shipping.  I figured it would be cool to have both at the same GTG, but I haven't seen any updates on X-amps (although the X-heads are apparently out). 

[BillB]

BTW the PSU is a 15w so nearly double what is needed...but it will give me enough to add the superfluous stuff (relay switching, optivol) later.

Model is KMS15-24

[Occam]

BTW the PSU is a 15w so nearly double what is needed...but it will give me enough to add the superfluous stuff (relay switching, optivol) later.

Model is KMS15-24

Bill,

IMO, the slickest thing about the Lambda supply is the fact it certified class II and encapsulated. Put it in its own insulated, fused box, hardwire a 2 prong polarized mains plug (or a fused shielded/conductive chassis grounded to the mains) and run a dc cable to the Aikido, and no STEENK'N ground loops, leastwise none caused by the preamp.

Thanks for the part #, its a really neat approach.

Regards,
Paul

[JoshK]

Bill,

IMO, the slickest thing about the Lambda supply is the fact it certified class II and encapsulated. Put it in its own insulated, fused box, hardwire a 2 prong polarized mains plug (or a fused shielded/conductive chassis grounded to the mains) and run a dc cable to the Aikido, and no STEENK'N ground loops, leastwise none caused by the preamp.

Thanks for the part #, its a really neat approach.

Regards,
Paul

And why not shoe-horn a Felix in it while your at it?   

[Kevin Haskins]

Great find... I've had the Aikido laying around here for awhile and need some incentive to finish it off.    Where did you source the SMPS? 

[BillB]

I get them at Newark...this is the 3rd one I have bought.

[Kevin Haskins]

I get them at Newark...this is the 3rd one I have bought.

Great... thanks.   I'll order one up and finish off my Aikido. 

[doggin]

I am looking to build a 24V Aikido linestage/headphone amp.  I was wondering whether the following Hammond transformer would work well for the 24V supply.  I would also get a separate 6.3V transformer for the heater supply.

Hammond 167L24

Thanks