TomB

Dimensioned endplates: http://www.diyforums.org/Les/construction/templates/TorpedoEndplates-dim.pdf

OK - first step ... it was late and I didn't realize the templates weren't plotted to scale. That's now been fixed.

It gets very messy, Nate. Also, you guys need to check every bit of it. I did a better job on Doug's endplates than I did on mine. I think it's drawn more carefully than the first time I did it (Doug's and mine), but you guys will still be testing things if I dimension in detail. Coming up ...

http://www.diyforums.org/Les/construction/templates/TorpedoEndplates.pdf http://www.diyforums.org/Les/construction/templates/TorpedoTop1.pdf http://www.diyforums.org/Les/construction/templates/TorpedoTop2.pdf Note that I put two vertical rows of 1/4" holes ( 8 holes, total) on the side of the case adjacent to the heaters supply heat sink (next to all those 3/16" top holes). All of the above addresses the heat issues, except that some side holes at the tube positions could help. It depends on how much heat you're willing to accept at the coupling caps, I guess (maybe Doug can add some opinions here). Mine ran without any side holes at the tubes all day, both days at CanJam.

5 x 20 mm, 0.25A slo-blo. Mine is also 250V, but anything sufficiently over 120V will be OK. Centered over the PT. Hmm ... I guess Doug and I are reading this at the same time. I'll try to post a template momentarily ...

Well, if you go by my BOM, check the quantities on every item. I can confirm that the items themselves are OK - that's what's inside my amp that's been running for months now (RN55's definitely used at R4). Even in cases where I ordered double, I sometimes get extras beyond that. For instance, there's a qty of 4 listed for the RCA jacks, but only 1 is needed. The pic on Mouser is mis-leading. If you click on the data sheet, you'll see that it's an integral assembly with both Left and Right jacks imbedded in the single assembly. Sorry about not listing the heat sinks - I keep a bunch of those on hand already, so I didn't need to order them. I've added the 1-1/2" version to the Mouser BOM. Part # is 532-531102B25G. The 1" one is 532-531002B25G. I think the 1" one is probably not enough if you put the lid on the case, but remember that you'll have to grind off the top corner of the 1-1/2" one if you use it. Also, Doug already mentioned the little slip-on BJT heat sinks - those are only at DigiKey, I believe.

Sorry about that. Seems I always order two of everything!

Yeah - that looks like a great choice on the switch. I searched for days on Mouser - even asked them for a quote to manufacture another 100 or more of the original one we used, but to no avail. So, way to go!! I'm a gutless coward when it comes to sarcasm through digital communication, so let me be clear: Nate helped tremendously with his idea on the Google spreadsheet and I am certainly kidding about slacking on the BOM. Between work and a baby girl (been there, done that twice), I'm surprised he gets anything done. I should've done the BOM before and kept Nate or Doug from the work in doing one. But hey - at least I got 'em packed and shipped.

Wow - I didn't see Doug's post before I sent you all the link to my Mouser project, but maybe with both of them it will make things much simpler. I forgot about the little heat sinks, too - I think Doug sent me the ones I used. I've sent you all the Priority Mail Delivery Confirmation #'s, too. Please let me know if there's any problems with receiving the kits.

The prototype 1/2 kits have been shipped. I'll send you each a Delivery Confirmation # when I get home tonight.

Hopefully, I'm getting caught up now after CanJam and will send the stuff out for the L'espressivo Torpedo this weekend. Refreshing my memory by looking through this thread, it looks like the volunteers PM'd Doug. So, if Doug can get me that list I can go about contacting you guys for shipping addresses and Paypal payments. I'll supply the following: Power transformer (PT) and two output transformers (OPTs) Custom length Hammond case (unfinished) PCB PT heat sink Tube sockets Matched and tested tubes (6J6 - secret's out after CJ) BOM for the remaining parts (not many!) I can also supply the RK27's and headphone jacks if any of you are interested in those, too. It's been so long since I ordered the other components, I don't remember the costing, but I'll have that figured out when I contact each of you. Of course - we're not intending to make any profit on the prototyping.

Any of the MAX/MiniMAX websites will have a page on the "Millett Hybrid" tube types. Beezar also has short descriptions of each of the three tube types, their advantages and disadvantages. As you discovered, scratchiness and imbalance on a Millett Hybrid type amp is not the fault of the RK27. Imbalance can be caused by lack of proper bias adjustment or improperly matched tubes. Bad bias adjustment will result in an off-center focus, but improperly matched tubes will usually result in one channel not sounding as lively as the other, even though the sound may be centered. As for scratchiness, maybe Pete Millett, Dsavitsk, or Colin can explain it, but there's a scenario where high-gain tubes and or speed of the caps in certain parts of the circuit will result in scratchiness. It's almost as if the tubes are unable to keep up with the gain changes when turning the volume and scratchiness results. I've had MAXes with BlackGates that had scratchiness on any volume change, regardless of tube brand, but then almost never experienced it with ES's. Almost always, this is with high-gain 12AE6's when it happens. It's a nuisance, but does not affect the sound when the volume position is stable.

That's a shame. The originator of power pop - gone. I wish I hadn't been so ignorant growing up in Memphis in the '60's and '70's. Big Star to me was just the grocery store down the street.

Finally cased it up - Note: Hammond supplied us with these special length cases "unofficially." Hence, the black endplates and unanodized extrusion.

Ditto - take care!!

Ooh - almost missed this. Happy Birthday, Fitz! :D

You guys are too funny. Actually, it's all the LED's that are the most dazzling.

I said "cruiser" or "submarine" the other night, but Doug thought that I was saying the amp was goofy looking.;) Not True! Seriously, this is very cool amp. I'm not used to having sound this good at volumes this low. It's very quiet, the volume knob is perfectly gained for 32ohm Grados (with the impedance switch set to low) and the bass at low volumes is as if there's a loudness switch thrown in, but it's perfectly attenuated as you crank the volume up (stays flat, iow). High end detail is great with Grados, too - I've been listening with HF-2's, HF-1's, and SR225's - they all sound wonderful with no bite, no hint of sibilance. The really unique thing that Doug has done is to put all of this on a PCB. The length has a purpose - to separate the power xfmr from the rest of the things that might pick up interference from that and it works. Most important - I've admitted publicly many times that I was scared sh*tless to build a high-voltage amp, but this was a snap. The only wire anywhere on the amp is the little ground wire for the Alps pot. Nothing could be simpler - or safer (considering). Not that I'm saying don't respect it, of course, but it sure let me get over my fear. It was a pleasure to build. :)

:D:D

Yep - good point. That will certainly work.

I think Doug means that the PCB sticks out by 0.5mm. If I'm not mistaken, the shim in the bezel is going to cover the slots, meaning it will stick out, too. Still, trivial in the scheme of things and Hammond just supplied us a couple of one-offs straight from the production line. We'll get them custom-machined and have them in good shape, eventually, I hope.

Once they anodize them, that'll probably add back the 0.5mm. ;)

13", to be exact. That's a d*mn good guess just from the pics.

Yep it's long. I had to beg Hammond to send us a couple of special length extrusions of the 1455-series cases. They actually sent Doug and I two for free! They're hoping we'll order a lot more like them. I'm looking forward to this one.

Grainger supplies Beezar with all of our hardware. Top notch and quality stuff all around - much nicer to deal with than McMaster-Carr, too.