tube, solid state, and hybrid kit ratings/reviews

I know you mean well, but I'm sort of against having reviews/comparisons of DIY stuff in the DIY section.  Many of us operate on small margins - not like some of the big guys who manufacture built stuff.  If you really solicit nothing but DIY product reviews, this thread could have the potential of getting mean and locked fairly quickly.  It's happened just recently over in another thread that shall go nameless for the time being.  Somebody was banned, too.  I sometimes suspect it's why people like AMB have started their own forums and others like Tangent have started dropping some of their designs.  I choose to continue supporting Head-Fi as much as I can, but not if it turns into a hostile environment.

What you're asking is for people to start putting the DIY designers head-to-head in arguments about their beloved creations. 

Anyway, enough of my soapbox routine.  Do a search - there's a thread that catalogs almost every DIY design available.  Then go look in the Amplifier section here on Head-Fi.  That's where outright comparisons are made and our DIY stuff is sometimes put up against all the other manufactured amps.  It will give you an idea.

you could just build a few types and give em a listen...its pretty easy to sell stuff here too.

Quote:

Originally Posted by shrimants 

I would be much obliged if someone could point me to some measurements for a couple in particular. I'm interested in the Millet Hybrid Mosfet Maxed measurments and the Bijou All Tube Fetterman's measurements.
Also, I'm a bit confused on the EHHA Rev A Hybrid Headphone amplifier 6GM8-Mosfet. Is this a mosfet only amp or is this a hybrid tube+mosfet? The glassjar audio website makes it seem like this can be configured to be a mosfet only amp, which is terribly confusing.
EDIT: never mind. i was getting amplification mixed up with power transforming. it is a hybrid amp, uses the tube for low level amplification and opamps for "high level" amplification. There are 2 versions. One will use a plastic transformer while the other uses a mosfet to control power, but the amplification circuit itself remains the same between the two.
It also seems that there is no dedicated power supply so a wall wort or a DIY power supply is necessary to make this work. I dunno if the MHMM needs its own power supply or if it accepts 120V AC. It seems that the Bijou All Tube Fetterman seems to accept 120V AC. At least thats what it sounds like, considering you have to sign a waiver to order one.

There are power supplies and then there are power supplies.  Even if something plugs directly into the wall, there is still some sort of power section needed on the PCB - or it has to be purchased separately.  With a few exceptions, true tube amps have the power section built in.  No one sells separate high-voltage power supplies because of 1) liability and 2) there are two many variances as to how high [the voltage].

In the case of the EHHA, it runs on low voltage (solid-state), but you can't just plug in a walwart and expect reasonable performance.  A separate power supply such as AMB's Sigma's or the r1 would be necessary for best performance.  I suppose you could try to supply it with a couple of Elpacs (Miouser-DigiKey) or linear-regulated DC walwarts (available at Jameco), but it would ruin the potential of something like the EHHA.  Note that the "6GM8" is the tube.  It was probably the finest low-voltage (12-24V) tube in existence, but its availability is unicorn-like these days.  There are other tube possibilities with the EHHA, but I'm not an expert on it and you should research Alex Cavalli's website to be sure.  Also - it does not use opamps as the power section - rather, there is a choice between BJT transistor or MOSFET outputs.  The opamps are there to zero out the offset (too complicated a subject to discuss here).

With few exceptions, an offboard, linear-regulated power supply will be needed for most non-portable solid-state and hybrd amps - M3, DynaLo/Hi, PPAV2, B22, SOHA II, etc.  The Millet MiniMAX/MOSFET-MAX and CTH are exceptions, in that the linear-regulated power supply is on the amplifier PCB.  With those all you need is a low voltage AC walwart (24VAC).  An AC walwart can also provide the primary wall connection for the offboard low-voltage power supplies, too, such as AMB's Sigma's or the r1, but most people seem to go ahead and use a transformer directly.  They can get a bit higher voltage (30V?) and higher amps (2+ amps) than most readily-available walwarts by doing that.

The Bijou is a high-voltage OTL tube amp and the power section is included in the design.  Same with the Bottlehead amps and the just-available Torpedo.

I would highly recommend that you send some PM's to the designers directly, or post some more specific questions (perhaps in the particular design's Head-Fi support thread?) because none of the ones you're mentioning are what someone would consider "beginner" amps.  In particular, the ones that require working directly with wall power and transformer wiring can kill you under the right circumstances.  The walwart-supplied SS and low-voltage hybrid amps may be more complicated builds than a beginner can successfully complete.  Many of us will recommend that you build a CMoy (following Tangent's excellent tutorial), first.

I built the early beta version of the Bijou and I must say it is a beautiful sounding amp...mine uses a 750 volt transformer IIRC and was very dangerous. TomB is absolutely not kidding with his warning...the Bijou can kill you.

You may want to get something simple and safe working by yourself, before you attempt a more advanced build. You don't necessarily need to go as simple as a cmoy, and you may also want to go with something that will give you a taste for casework. AMB's projects like the M3 or CKKIII are a good option because of the fantastic documentation, or maybe one of the cheaper bottlehead kits.

Mini Max

_or_

If you are feeling adventurous, build your own 24V Aikido. You can purchase a pcb for the tube front end and do the LM317 headphone driver section on your own. A very simple and nice sounding amp. Sadly, it appears the original 24V Aikido pcb with headphone buffer is no longer made. The new pcb (just the tube part, no headphone buffer) from Glassware can be configured for 24v or 48v. 

Honestly, for someone who has never successfully completed a build on their own, I find it odd that you are looking down on a project because it is 'too simple.' I also find it odd that you are looking at some builds as too simple, then refuse to do anything other than a kit, especially for someone in the US where there are vendors such as mouser and digikey that sell almost anything you could possibly want. Learning how to go through a BOM and finding places to order the parts from, as well as learning what each part does is IMO a critical part of DIY that you lose by limiting yourself to kits. 

Quote:

Originally Posted by shrimants 

The bottlehead kits look WAY too simple to me. i feel like those would be akin to putting together lego blocks, except using melted metal to keep them stuck together :P. The Mini3 was a project I was gonna attempt at some point but for now I have a Fiio E11 and I dont see the point in getting the mini3. I was also hoping to wait for the X1 to get included in the Mini3 kit from glassjar before purchasing.
Regarding minimax, is that the same as http://glassjaraudio.com/product.sc?productId=21&categoryId=10 and if not, which kit is better? It looks like they are different, but I dont know the technical details of either.
I'm still heavily leaning towards the Bijou kit as my next project because it seems like that will be the most time consuming and rewarding experience, once I finish.
I'd really like to stick with kits, so it looks like Aikido isnt the right thing for me. once I know a bit more about electricity and what the schematic diagrams are telling me, how the amps work, and driver impedance and whatnot, I can get into the whole "choose my own parts" thing. Heck, I might even design my own and take it for a spin. Until then, I'd like to stick with kits.
I'm also upgrading my non-personal (speaker) audio rig on the side, so i have to include that into the costs calculation and upgrade tree.

You should check these two sites for comparison:

MOSFET-MAX

MiniMAX

The primary difference in KITS is that the MiniMAX comes with a completely custom-machined and silkscreened case (there are other differences).  That said, I don't currently offer any kind of kit at all for the MOSFET-MAX.  Take my word for it that, though, that it is fairly rare to have a kit include a custom-machined case - or any case at all, for that matter.

After reading some of your later posts in this thread, I'm more convinced than ever that you should start with something smaller than what you're currently targeting.  Make sure you have built something to completion that actually worked (without paying someone $170 to fix it), then come back and ask some more questions based on that experience.  If you set your sights too high, all you may end up with is a lot of frustration, wasted money, and perhaps worse.  Just MHO.

edited a dumb post