Next Build - Some DIY Tube Amp

Getting bored while waiting for my enclosures to come in and my soldering hand is getting itchy for a another project already. I really enjoy building stuff obviously and want to support the DIY scene during this state of the industry. I listed some kits in the poll that i read were popular. I am open to additional suggestions because i don't think i got everything.

My entire lineup consists of solid state equipment and frankly i don't know anything about tube amps: topology, brands and types of tubes, biasing, heater circuits, triodes, diodes, pentodes, OTL, etc. So complicated. Solid state's that i'm used to are straight forward, it's either Fairchild, Toshiba, or Linear transistors (FET, BJT, or MOSFET).

My very first desktop amp was an entry level tube hybrid, but i gave it away as a gift. I am open to learning and exploring the ropes. My rack has space for one more project and i'll probably sell off something or put it towards the loaner program.

I think the DAC1 sounds fine and the analytical sound/brightness doesn't bother me at all. Amps that i am most familiar with Dynalo (the most transparent, neutral and quite sterile), AMB M^3 w/ OPA627's (Extremely warm for my taste, but very pleasant sounding - i think bassheads would appreciate this amp), and the AMB Beta22 is very well balanced overall.

Looking for a kit around $1,000 that'll result in something near or actually end game, don't care of it's single ended or balanced as long as it sounds good. I have a few DIY projects under my belt, but never built a tube amp before. Doesn't have to come with an enclosure but complete objective2 style kit is a bonus. I don't plan to roll tubes; i want to find one type that works great enough for general use and stick with it...hopefully nothing rare. Price vs performance is highly regarded.

Amp will be used with these dynamic headphones only - HD6x0 and HD800s. No plans for orthos or speakers.

The T3 size and form factor looks perfect for my desk at work (approx footprint of M^3 w/ psu). Looks like a build that i can whip out in a few hours between my full time job and changing diapers. Single ended only. Parafeed output transformer topology appears to go against the grain of the OTL FOTM. Gold plated PCB board looks nice. Oil filled Cap upgrades....i thought opamp upgrades were expensive. This is going against everything that i know and i like it.

The mainline looks hideous IMO. Balanced output (not fully balanced) + SE outputs. Dedicated headphone amp. Parafeed output transformer topology appears to go against the grain of the OTL FOTM. Stepped attenuator. Point to point wiring eeek. Most expensive option.

The S.E.X. looks like the mainline and will run speakers. SE only. Parafeed output transformer topology appears to go against the grain of the FOTM. Point to point wiring eeek. Approx same price as the T3.

The Garage1217 variants seem like they might not be on the same level as the other choices. PCB board looks nice. Enclosure and LED looks a little bit fast and furious - i'd rather it look plain jane as possible as to not attract unwanted attention. They appear to be extremely adjustable for many headphones and tubes. My impression from reading about these is that these can get it loud. Do they actually put out quality? Looks like the most inexpensive options on the list.

 

The T3 was a fun build that I completed a week or so ago. It was about half a day or so, all told. But I didn't do it in one sitting. The Mundorfs were not bad to fit in at all. TomB's instructions are superb. Just don't forget the pot grounding wire because he mentions that out of order and you don't want to have to desolder the Cinemag. I'd also love to hear the Mainline and that build looks fun as well. It might take a little longer with the stepped attenuator and p2p wiring if you want to do a tidy job. I don't know how these two parafeed amps sound next to each other, but I can't really find fault in the T3.

As much as I'm curious to hear the Mainline, I think I'll do something significantly different next. Maybe a 300b amp. I don't know what that single ended experimenters kit is... Will take a look! Have fun in whatever you choose!!

EDIT: I looked at the single ended experimenter's kit, and it looks a bit meh. I voted for the t3 because, well, it's awesome. I think the Mainline is a winner too, but you didn't allow multiple votes.. Oh, and yeah, the form factor for a work desk highly favors the T3. I've got it and a DAC side by side right under a monitor stand. Totally out of the way.

EDIT2: Just noticed you mentioned the AMB Beta22. I've always been curious about it. What have you compared it to and how does it match up? Thanks!

 

The S.E.X. was recently discontinued. Bottlehead have sold the final kit.

 

Hard for me to compare against anything, except the M^3 that it superseded.

If perfectly neutral is 5/10 then the Beta22 is a 5.5/10 very slightly warm...it's almost transparent but doesn't strip away anything or reveal too much of the unpleasant. It has MOSFET output stage like M^3 but not nearly as warm - its balanced out by the coldness and transparency of discrete jfet input stage 1st and 2nd bjt vas transistors. Obviously the m3 is super warm because of the opa627s which is amplified by the MOSFET which are slightly warm themselves - warmness can be significantly toned done by rolling out the Opa627s...but imo loses key qualities that make the m3 special.

I believe it to be transparent where if i fed it a DAC1, it sounded like one. I spent most of the time with the Beta22 using the Opus DAC because i liked it better with that pairing. It's sound signature, if there is such a thing, is to add some dynamics and intensity to the source without upsetting anything or becoming ruthlessly revealing...it's a little laid back. It's got a huge amount of power and control and it should be able to drive anything without any effort. It's a pleasant sounding amp doesn't do anything wrong. I never found any grain with it and it doesn't have veil. I think it's better than the m^3 in all categories if well implemented.

The beta22 is very sensitive to noise and it's well documented by the designer and highly dependent on implementation and build quality. In my mind, the only compromise made by the designer was to use available and obtainable parts so the amp wouldn't go extinct like the dynalo. No other corners were cut or expenses spared from the standard BOM.

I haven't yet heard a solid state amp that was significantly better so I would regard it to be near end game. The Beta22 on preference level might get knocked for being too polite/laidback or not warm enough/solid state sounding.

I will cite another reviewer that I pretty much agree with - replace the word 'blur' with 'expand or transform' because I don't think it negatively affects clarity. Keep in mind the reviewer's perspective and reference is a dynahi.
http://www.head-case.org/forums/topic/10329-dynahi-vs/

I am in the process of upgrading/modifying my beta22 - changed gain, added an extra Sigma22, e21 backplanes, custom shielded SUMR trafos, and going back to a mechanical stepped attenuator. Waiting on new enclosures to fit all this...Gamma3 and Beta22 will probably finish the same time.

 

If you are looking end game t3 or mainline, with mainline getting slight edge because you plan using hd650 &hd800. T3 is also great choice, probably a bit more neutral sound from impressions here.

Check out OJ's cavalli EHHA build. I've heard one here on the east coast and it performs very well.

I am currently building a pete millet jonokuchi, a starter SET amp, kinda similar to the SEX. This is a less expensive amp to build, will post impressions / build pics once I get this wrapped up.

 

T1 or Mainline, given your set of constraints of course.

 

Curious why T1 vs T3?

 

I'd be interested in following that build in a progress thread if you wanted to start one.

Agree on the neutrality / slightly flat sound of the T3. I'm just starting to roll tubes to add some bloom to mine.

 

I appreciate neutrality. How flat? Like objective2amp flat? Tough choices....
I don't mind warm as long as it's not warmer than the M^3. I think that's my limit on coloration.

I can get over the looks. The point to point looks interesting on the mainline and a change of routine. If this is an end game amp, i don't mind paying the premium. There appears to be a 1 month lead time on this kit.


The Torpedo III is almost like a clean solid state build. Looks really good inside and out. For the money, i see the cost attributed to the cinemag trafos, the mundorf caps, and custom enclosure including plates. This is obviously sold at a very thin margin...a value purchase if it's performance is 90% of the mainline.


The Damn Good 300B SET. Haven't read any comparisons that i can relate to. Not sure where the BOM spreadsheet is so i can calculate a total cost. I would be on my own for enclosures, but since it's mainly a top panel i think i could execute on budget within a reasonable range even if i FPDed it.

Edit - I was considering this as it looks as well designed as a AMB setup but nevermind this thing costs $1,800 before enclosure. $800 in tubes (depletion item) cant do it. This is way over my budget by 2x. I have to save a project like this for mid life crisis.

My issue with non kitted tube amps is probably sourcing parts. Tube sockets, output transformers, and boutique caps that aren't purchasable from my usual mouser/digikey i would have to figure out and plan a lot more heavily.

Neurochrome is outta stock on board set.

 

Then there's this - http://www.neurochrome.com/300b-set-amp/

 

What have you found to be the right tubes?

 

Glass Jar has a EHHA and Rev A kits (tubes and trafos, 30volt LPU's included) for $175 to $300 bucks. Not sure where these rank on the chart of tube amp awesomeness.

on another note, UPS didn't deliver my par-metals enclosures today...lame

On the polls i have a 50/50 split between T3 and Mainline. I might have to just flip a coin on this.

 

I've started looking at the DG300b also... In that BOM sheet, I'm not sure why the 6N6P tubes would cost $200 each. That seems way to high. You could also save by not using Electraprint OPTs, etc. But, yeah, there is going to be some out of pocket expense here for sure... At least if you did a Mainline, you'd have the opportunity to A/B it against the T3 since there are many of those around in California ... mine included.

 

If anything - I wouldn't try to save cash on output iron. These amps only sound as good as the trannies.

One of the things why I haven't built any yet.

 

I think Lundahl is $100 cheaper than Electraprint ... What about the Electraprint Low IMD - how's the bang for the buck there? It'll add another 40% to the price.

 

Saw that the schematics for the EAR HP4 were out there. That's an amp I'd like to hear, and an amp I'd be interested in seeing someone attempt a DIY build of.

 

Alrighty, looks like T3 it is...i tried to give the mainline some help, but the price is right and the form factor has me sold on Torp.

As a bonus, I'm going to build a tricked out CK2iii like fishski's. I want a no global feedback solid state amp in my little collection. I will plan the entire thing out by Tuesday.