Moskido - Hybrid Aikido/MOSFET amplifier

[fierce_freak]

Which SET headphone amp did you compare to the Bada?

[beau2317]

Black Stuart : I am not sure that there is a "hybrid sound" as such. According to John, most hybrids are of the "oh no not again" design and don't sound that great. That's not to say that that the Bada is like this ... I don't know.

There is nothing particularly lush or warm about the aikido. I would more describe it as fast, transparent and accurate. The point about the moskido is that it's a power amp that manages to sound pretty much like an aikido preamp, which is a neat trick, as the aikido preamp is an amazing sounding device.

As far as the tubes go, the 9-pin tubes seem to be more warm/lush sounding than the octals.

What did you do to the Bada ?

I read their website ; it says that it uses "quality components like Solen capacitors" .... well imho Solen capacitors are rubbish.

As far as mounting an aikido PCB vertically, I am sure that would be OK. Valve life is not so much an issue in preamp tubes. They last for ages. It's power tubes that tend to get too hot.

Are you going to build an aikido front end for the bada?

[fierce_freak]

Does anyone have an opinion or a guess as to which would make a better headphone amp: the moskido, or an aikido with one of John Broskie's SE buffers (shown in latest blog)?

[beau2317]

I would guess that if your headphones can be driven by a plain aikido then that would be best.

But as I understand it, there are limits on impedance and sensitivity that a plain aikido can drive.

[fierce_freak]

I've heard a plain aikido driving headphones (with huge output caps), and it sounded great. I've heard a couple good comments regarding the moskido, though, so I was considering doing something similar for my own tube headamp.

[Black Stuart]

Beau,
I'm old enough to have rejected old style valve amps, when a knowledgeable friend tried to interest me in them at the end of the 80s' - I just wish I'd bought up all the valves that were going so cheap then.

I rejected them because all the amps I listened to and that included all the well known names were very soft, pleasant but 'not right' at all.

I was never happy with the sound of SS amps either and the prices being asked for some were ludicrous.

Then along came a new generation of valve kit amps and that's where I jumped in - the ability to share experiences with different caps,resistors the whole thing, simply means that you can tailor the sound to your own 'taste'.

Onto the Bada - I'm not sure why you brought up the Solen thing, it seems irrelevant to me. What's important is the design and the way it's implemented. Virtually any piece of commercially made equipment can be bettered using different components.

I built and modded with the best components a WAD SET h/amp - it is nowhere in comparison to the Bada.

It used 3 6SN7 valves, the Aikido uses 2 + 2 - this is what interests me. Someone on another forum is busily modding Hypex modules and is looking for a good pre to front it with.

I changed out 2 pairs of Solen caps in the signal path and changed the power cord for an own design using top quality American mil. spec s/plated copper wire. I got rid of the so-so signal chassis wire and used my own design I/C wire. It seems to make sense to keep as much continuity as possible in signal wire, which is something that a lot of those who build/design their own amps pay so little attention to - wire is wire - really!

Wire is the means of signal transfer and should be of the first importance, I make that statement from practice and not theory. Just a few years ago I was a skeptic but the reality of my experiments changed that.

The standard Bada came out ahead in a shoot-out against 20 other h/amps - the modded bada is totally head and shoulders above that. Those other amps were valve/SS and other hybrids.

You don't comment on the most important aspect of my previous post - fan cooling. That signal valves can last a long time is true but cooled they last even longer (probably doubling their working life) but it is'nt just the cool running of all components (not least the mosfets) that amazed me but this defineable uplift in sonics.

Cramming as much as possible into as little space as possible is just plain stupid but is an activity that many engage in - why.

I never implied that the Moskido would sound lush but your description of your Moskido is the reason I stated that the Shuguang was very very clean and detailed which may well not be suitable for an amp that is already clean and fast,one can have too much of a good thing.

Certainly for me valve front end, mosfet out put works and works so well in this particular h/amp that I am listening to the music and not the amp.

It seems ludicrous to me, that no one seems to question the rectangular box that is used for amp building, with little or no thought given to heat dissipation or proximity of power supplies and output being cheek by jowl with the delicate signal section - why not two box affairs that are linked by umbilicals.

That I will build an Aikido pre is a given, what I'm not sure about is using a PCB. Now that I am convinced of all the benefits of fan cooling a PCB is a real obstacle to using active cooling and to designing into amps effective channelling of cooler air. This really is something that the diy community should get into, after all, it's not in the interest of commercial hi-fi companies to make amps that will last and last.

It is'nt just the design or materials used but how the whole thing is created that is so important. The diy community needs to stand back and question all the 'received wisdom' and seperate what is real and what is BS.

[beau2317]

Black Stuart : Thanks for your interesting post. Just a few comments, etc:

-- I mentioned Solens as I searched the web for the amp you mentioned, found the page and that was part of the blurb. I get a bit suspicious when companies throw names like that around, as I had found solens to be among the worst sounding of the so called high end caps.

-- agree completely about wire. I mainly use kimber kable for internal wiring on my projects. I buy 8TC speaker cable and break it apart.

-- had not thought about fans as a means of improving the sound quality. Will have to give that a try as my moskido certainly puts out some heat.

-- the separation of PSU and signal parts is very important imho. But also umbilicals bring their own problems, so it's hard to know what is the best compromise.

I'd be very interested to hear your experiences of building an aikido. Most people are impressed. And I certainly know what you mean by listening to the music. Since I got my moskido on song I stay up far too late listening to music, and don't seem to feel the need to tweak right now.

Cheers
bob (beau)

[albertli]

Bob,

I gave up the pcb and hardwired all components to the mosfets. It did improve quite a lot on sound stages and the mids are found more natural and smooth. Now the sound is quite close to my IT 2A3 but with better lower ends. I really enjoy listening to this amp and I am more than happy to recommand this amp to anyone who doesn't want to spend money on expensive irons.
Thanks Bob for guiding me along and Special thanks to John Broskie who dared to answer my many silly questions

Albert

[albertli]

One more picture.

[albertli]

Oh !! I forgot to post the finish amp picture