# Torpedo III Build Thread



## tomb

Some of you have built a Torpedo, designed by Dsavitsk of ECP Audio.  The Torpedo has been around for awhile now and represents a true, output-transformer-coupled tube headphone amplifier.  What made the Torpedo unique is that except for a single volume pot ground wire and a PCB safety ground wire, the entire high-voltage, tube-transformer coupled design is contained on a single PCB - no other wiring, no point-to-point construction, and with the supplied enclosure - no casework fabrication.  The combination provided a lot of DIY-ers with the ability to construct a full-function, high-voltage tube/transformer amplifier _*safely and easily*_. (I count myself among the ones scared to death to ever try high-voltage construction with point-to-point!)
  
 The Torpedo went through some teething pains early on in trying to reduce noise and hum.  However, with the help and patience of many along the way - Dsavitsk, Morgan Jones, Kevin Gilmore, and Jim Cross of vacuumtubesinc.com, several tweaks were discovered that resulted in a noise-free and high performance design. These consisted of 1) the zener diode tweak, 2) the rectifier snubber tweak, and 3) the discovery of the E90CC/5920 tubes.  The result is a noise-free, high-performance tube-transformer (parafeed) amplifier.
  
 Meanwhile, Dsavitsk continued to refine the basic planform using tubes, Edcor transformers, and 4 x 14" PCB.  The Torpedo II was created and a couple of prototypes built.  These used 6922 tubes, but resulted in more expense without a significant performance advantage over the Torpedo I, especially compared to a Torpedo I using the E90CC tubes.
  
 Back to the drawing board, Dsavitsk decided to use elements of a solid-state, differential circuit in a tube-hybrid arrangement, all tied into output transformers, again in a parafeed arrangement.  This is a singular and - to my knowledge - totally unique amplifier design.  Learning from our previous experience in teething pains with the Torpedo, we built several prototypes ourselves and went through a number of changes before arriving at the DIY kit that you will see here.  We think that many of you will find the cost and effort of assembling this kit well worth your while.
  
 I won't go over the construction in excruciating detail as with the Torpedo I.  That build thread is highly documented and building the two amps are very similar.  This is more an effort to note the differences in assembly from the Torpedo I.
  
 Starting as I always do, you will note the assembly setup below:

 We went with Red PCB and Gold plating/pads this time, all of which is ROHS compliant.  To the right, you can see my trusty Hakko - still going strong after 9 years!  Brass wool, which let me stop using the sponge altogether and it does not reduce the temperature of the iron tip very much, so the work goes much more quickly.  Solder and de-soldering braid is to the left.
  
 In the center, the PCB on my piece of high-quality 1 x 10 pine (also 9 years old!).  The first thing you notice is that the PCB is longer than the building board.  That's OK - we only need to access certain portions of the PCB at a time.
  
 At the left, my collection of standard tools for assembling a through-hole PCB: scissors for opening the parts packs, cutting part tapes, etc., a lead-bending tool, flush cutters, and smooth-jaw needle-nose pliers.  In addition, for those things that always seem to crop up that can't be handled by all the other tools - a trusty Leatherman multi-tool knife.
  
 Solder, as always, is Kester 63/37 rosin core, 0.025" diameter.  This is good for both through-hole and SMD work, too.
  
 Besides the window, there is ample task-lighting both in the bench and a task lamp in the upper corner of the building bench.  I simply used a table in the past, but moving a year ago gave me enough room to improve my setup.  It's not needed just for the Torpedo III, though - a table with a lamp will do just fine.
  
 EDIT: forgot a zero in that solder diameter.


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## tomb

Standard through-hole construction usually begins by soldering in the lowest-height parts first, following by remaining parts in gradually increasing heights.  This is done with the method I use - the pine board - because I place the part, turn the PCB over and then press down on the PCB and board while soldering.  This ensures the part is soldered flush to the PCB, without purchasing one of those expensive Panavise units.  However, it does mean you need to progress linearly with the height of the parts.  That doesn't mean I don't make a mistake and solder something out of order - as you will see - but it helps.
  
 Using that strategy then, the first parts to go in are the small diodes, D1 and D2 -

  
  
 Next up are the heater rectifier snubbers, just like the final tweak on the Torpedo I.  In the case of the Torpedo III, bridge rectifiers are used, so only two snubbers are needed.  As with the Torpedo I, these are on the bottom of the PCB.  As with any SMD soldering, the first step is to tin one of the pads for each of the snubber caps, as you see in this pic:

  
 And as follows with DIY-SMD soldering, melt the solder you just placed on one of the pads and while holding the iron keeping it melted, use your other hand (holding the SMD part with tweezers) to move the SMD cap in position.  Then while continuing to hold the chip in position with the tweezers, remove the soldering iron.  This allows the solder to cool on that one side and the SMD chip is locked in place.  Go back and add solder to the other pad and you've soldered the SMD part!  It's a lot easier than it sounds.  You can re-heat to your heart's content until you get the SMD chip correctly positioned - _as long as you don't solder the other pad_.  When you're happy with the position, then solder the other side.  Here we are with them soldered:


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## tomb

Next up in the part height sequence are the V-D resistors (Vishay-Dale).  The V-D resistors on the Torpedo III are all RN-55 size, so no worries about different sizes.  However - as always - please, please solder the V-D resistors with their ohms value clearly on top.  Unlike traditional resistors, V-D resistors are not color-coded.  If you have to go back and trouble-shoot,  and the ratings of the resistors are not top-oriented, you are at a loss to perform one of the easiest trouble-shooting checks: whether the resistors are mixed up.  Measuring is often not productive, either, because many resistors may be in parallel with something else, complicating any reading you might make with a DMM.
  
 There are basically four rows of V-D resistors in various orientations (one all by itself) as shown -

  
  
 Next are the higher-wattage resistors -

  
 Finally, there are a few 2W resistors that are even larger:

 There are basically two rows of these resistors and one by itself, for a total of 9.
  
 Finally, there are three large diodes:

 Be certain to match the orientation of the diodes on the silkscreen.  I must've not been paying attention and soldered two of them in backwards.  De-soldering braid to the rescue!
  
 That finishes it for resistors, diodes, and other small parts ... Wait!!  I forgot something, as usual:

 Just as with the Torpedo I, the Torpedo III can be configured for either 110V or 220V.  This is accomplished by soldering jumpers at the Power Transformer (PT) position.  The jumper pads are labeled A, B, C, and D:

To configure for 110V house voltage, solder two jumpers, one from A to B and one from C to D.
To configure for 220V house voltage, solder only one jumper from B to C.
 I'm in the United States, so the photo shows the two jumpers that will configure the PT for 110V mains.
  
 More later!
  
 By the way, you may notice some extra diode positions on the PCB: *D7, D8, D9, and D10 are not populated.*  The Torpedo III is complete without them.


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## tomb

Back to it!
  
 Next are the TO-92 parts:

 Note the two by the tube sockets.  These are actually integrated circuit regulators.  DO NOT SOLDER THEM COMPLETELY FLUSH TO THE PCB.  We'll show why later when we solder in the tube sockets.  Again, if you are using my pine board method, you should be able to insert all of the TO-92 devices, flip the PCB over and have the TO-92 devices support the PCB upside down while you solder the joints.
  
 The smallest electrolytic capacitor goes in next.  The ones supplied with the kit and on the BOM have the type of leads with the "kink" or "knee-bend" in them.  So, don't worry about trying to get the cap flush to the PCB.  Just make certain the cap is securely soldered and is stable.

  
  
 Next up in height are the tube sockets and the Z-switch.  All three are about the same height:

 As in mentioned in many of my build threads and on the website, remember that the tube sockets are just as much a mechanical/structural connection as they are electrical connections.  So, ensure that the joints on the pins are good and sufficiently soldered.  While soldering from the bottom of the PCB, the solder should be sufficient to wick all the way to the other side and some length up the pin legs.  That said, please refer to the very next pic and description below before soldering the tube sockets into place.
  
*NOTE: Notice that those are 9-pin sockets!*
  
 Similarly, the joints on the Z-switch must be sufficient and secure.  However - in the case of the Z-switch - the body and much of the inside is plastic, so wait between soldering each joint and allow it cool.  Otherwise, you could end up with a plastic puddle on the PCB instead of a nicely installed switch.
  
 As mentioned, here is the reason we do not want to solder the TO-92 regulators (IC1 and IC2) in front of the tube sockets flush to the PCB:

 The real estate on the Torpedo III PCB is very limited.  In this case, IC1 & IC2 were moved forward as far as possible with endangering the traces beneath by having them too close to the output transformer traces.  Even so, they must be bent forward slightly to make room for the tube sockets.  You should be able to bend them far enough forward that no part is touching the tube sockets.  Don't solder the sockets in until you are assured that the regulators are not touching.


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## tomb

Next up are the bridge rectifiers, BR1 and BR2:

 These are easy enough to insert, but beware - they are very large and the leads are very big.  It may take some extra heat to get them soldered.  Also, it's best to solder one lead on each (while the PCB is upside down), then flip over the PCB and make certain that they perpendicular to the PCB.  The leads are so big and tough that when you get all four soldered on each bridge rectifier, it will be impossible to bend them back so that the rectifiers are straight up and down.  The goal is that you do not want them touching the power transformer.
  
 Shoot!  Another one I forgot - the LED:

 That's OK - it's pretty easy to install.  I think the "+" sign didn't make it through it our quality check.  _However, the long lead goes next to the resistor. _Install the LED at the height you desire.
  
 Next is the headphone jack:

 As with the tube sockets and the switch, there is a mechanical connection with the solder joints, but the bulk of the headphone jack is plastic.  So try to get solder wicking up the pins on the top side of the PCB, but give it time to cool between joints, otherwise the plastic will melt.  Do your best to get the headphone jack flush with the PCB, parallel to the PCB surface in the horizontal direction and perpendicular to the front edge of the PCB.


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## tomb

The ALPS Blue Velvet volume pot is next:

 As with the headphone jack, remember there's a lot of plastic there, so go slow on soldering the six pins and try to allow sufficient cooling between joints.  Also as with the headphone jack, do your best to have the pot shaft parallel to the top surface of the PCB and perpendicular to the front edge of the PCB.  This will make aligning the volume knob much easier when you case it up.
  
 I soldered the output transformers in next:

 As with everything else, try to keep these flush to the PCB and oriented orthogonally. Rotate soldering the pins in a sequence to keep things cool.  The PCB pin runners on the transformers are plastic and they will melt.  Solder a pin on one transformer and then solder the same pin on the other.  Go back to the first transformer to solder the next pin, then switch to the other transformer.  Do this taking turns from one transformer to the other and you should be able to keep things cool.
  
 So ... what do I always forget before this step?
  
 The dadgum ground wire for the pot!

 It seems I do this every time I build a Torpedo: forgetting to install the ground wire before soldering in the output transformers.  Luckily, I have a very small screwdriver that I can use, so I can get the pot screw tightened securely down on the ground wire, even though the OT is in the way.  You can probably see a little scrape mark on the laminations in line with the pot screw. 
	

	
	
		
		

		
		
	


	



  
 Another view:

 It may take some effort, but be certain the screw engages the front panel of the pot and that you have some ability to make it tight.  In my case, I always use 22ga SPC teflon hookup wire (Navshipps/John's Wire Shop on ebay).  It's pretty thick compared to the screw, though, but with some effort you can get the wire compressed under the screw and actually have it threaded into the pot's front panel.
  
 Needless to say, this is an awful lot easier if you do it before soldering in the OT's.


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## tomb

Moving right along, we installed C5:

  
 C3:

  
 Next up was C6.  It has a silkscreen for either a large film box cap (as shown here) or an electrolytic.  I asked Dsavitsk which to use and he said the film cap sounds better.  Good enough for me. 
	

	
	
		
		

		
		
	


	




  
 Yes - besides C6, I'm sure you've noticed all of those big box film caps - five of them, counting C6.  To explain some of this, it might be appropriate to show Dsavitsk's schematic of what's going on:

  
 This is what makes this amplifier design unique.  I'm not aware of another amp such as this.  Basically, the tube intputs have been split into their constituent differential signals.  Or, put another way, the outputs from the tubes are balanced leading into the output transformers.  The OT's are still coupled in a parafeed arrangement, but they are accepting balanced/differential signals.  Differential signals mean four signal lines to the output of the amp, or two per output transformer, thus four capacitors to AC-couple the signals to the transformers.
  
 In the case of the Torpedo III, Dsavitsk arrived at 10uf for the parafeed capacitors.  Needless to say, that's pretty big.  The Epcos capacitors shown here are what will be supplied in the kit.  They have a great reputation for sound quality at an inexpensive price.  So, C7, C8, C9, and C10 were installed:

  
 Next up are the heat-sink mounted solid-state devices.  Because of the differential part of the circuit, there are two output transistors for each channel (as shown in the circuit schematic above).

 Note the two heat sinks on the right.  They have transistors mounted on both sides to handle the four signals coming from the two tubes.
  
 Solder all of these into place on the PCB (refer to the silkscreen labels and the BOM for the correct parts):


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## HiGHFLYiN9

Looks great Tom, keep us salivating


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## tomb

The RCA jack comes next - be sure you push the tabs all the way into the holes.

  
 The only capacitors left to install are the two large power caps, C1 and C2:

  
 Next up is the Power Transformer (PT).  It might have been the IEC inlet, but I'll explain that below:

 As with the OT's, try to get the PT flush and alternate soldering pins from one side to the other, so that you don't melt the plastic rails.  When you turn the PCB upside down, try to stabilize the rest of the PCB.  At this point, the PCB is a very long lever arm with big weights on both ends.  The PCB will definitely flex, or worse - if you let it.
  
 The IEC inlet is actually shorter than the PT.  However, after putting together a lot of these, Dsavitsk suggested the best method for installing the IEC inlet and the back plate. The best method requires you to go ahead and mount the IEC inlet to the backplate, first, then mount it to the PCB and solder the IEC pins in place.  The reason this is done is because there a wide tolerance is needed with the back plate fit up with the case.  The reason is with this sort of length of PCB and case (14"), the variances in tolerance - if you solder the IEC inlet to the PCB first - may very well result in your not being able to get the back plate flush with the back of the case.
  
 So, mounting the IEC inlet to the back plate first - solves this problem.  For somewhat similar reasons, the tolerance fit of the IEC inlet and the large rectangular opening is quite small.  Your initial attempts to get the IEC inlet protrusion fit through the rectangular opening may fail.  The tight fit is there for a purpose - safety first.  I have seen a builder take serious unapproved shortcuts and simply press fit the IEC inlet to the back plate without any mounting hardware at all. DO NOT DO THIS - IT IS NOT SAFE.  Instead, work carefully to press fit the IEC into the back plate opening.  When you get all four corners through the opening, then use the mounting hardware to get the IEC inlet flush.  Otherwise, you may bend the back plate.  Usually, all it takes is a small file to round off the corners and the inlet will fit.
  
 The recommended hardware is two sets of 4-40 x 3/8" socket head cap screws with washers on both sides, and lock washer plus nut on the inside.  Obviously, if you are at all interested in looks, please use the black washers on the outside (supplied in the kit).
  
 Here we have the back plate with the IEC inlet mounted in place.  The arrows indicate where you should file if the fit is too difficult:

  
 And a view from the inside:

 As noted, the arrows indicate where the flat washer, lock washer, and nuts are to go.  Please do not neglect this hardware and ensure that everything is flush, snug, and tight before proceeding further.  This is where the mains voltage comes in and ensuring that this is assembled and installed properly is *for your own safety*.


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## tomb

When attaching the back plate assembly to the PCB, line up the IEC inlet pins with the pads on the PCB and line up the RCA jacks with the holes in the back plate.  The RCA jacks have plastic circular bosses that protrude from the RCA jack assembly, ahead of the actual metal jacks themselves.  The holes in the back plate are sized for these bosses, but you must make certain that they line up and that the bosses are poking through the holes.  As it is, there is enough variance that the back plate will actually stick out a bit further from the PCB on the RCA jack side, but it's not enough to affect the final assembly from being flush.

 Use the same hardware mounting that you used on the back plate, except black finish washers are not needed on the inside.  The silver ones are fine. 
	

	
	
		
		

		
		
	


	




  So, socket head cap screw with washer on top of the IEC mounting tab, then washer, lock washer, and nut on the bottom of the PCB.  Do this in two places.
  
 Mounting hardware on the other side in this view:

  
 Once you do this and everything is bolted up tight, then and only then - solder the pins of the IEC inlet on the bottom of the PCB.
  
 You might have noticed in the last couple of pics that I had already soldered the safety ground in place, but here's a look on the back side, along with the IEC inlet pins all soldered up nicely:

 The arrows represent the IEC pins that need to be soldered.
  
 Meanwhile, you can also see the safety ground.  I like to use some extra length so that I can bend it easily.  That makes it easier for me to line up the lug with the hole in the PCB and the mounting hole in the bottom of the case.  If you figure out a better method, use it and then let me know about it. 
	

	
	
		
		

		
		
	


	




  I also both crimp the lug and put some solder in there between the hookup wire end and the metal part of the lug.
  
 In this view, you can see the safety ground, IEC pins, and most importantly - the back plate's position relative to the back edge of the PCB.  As noted previously, you can see that the RCA jack side of the back plate sticks out a bit further than the other side.  Make sure the RCA jack bosses are sticking through the back plate holes.  Even so, there will be the difference in clearance shown here, even with the jacks as flush as you can make them.  Not to worry, though, everything will fit up tight and flush with the case.


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## tomb

The PCB is now complete and ready for assembly into the case!

  
 I would continue, but I need to take some more pics.  I got so excited at this point, that I assembled the whole thing and started using it without taking more photos.


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## tomb

Slide the PCB into the rear of the case (remember the back plate is still attached to the back of the PCB) using the 2nd slot from the bottom.  You should have the two standoffs attached to the PCB at this point.  The standoffs (4-40 x 5/16" tall) should include a single #4 flat washer between the standoff and the bottom of the PCB to get the spacing exactly correct.  Attach on the top of the PCB with a 4-40 x 3/8" long socket head cap screw, a lock washer, and a flat washer against the top surface of the PCB.  The lock washer on the top side (a bit counter-intuitive from conventional practice) ensures that the screw stays locked when you attempt to remove the screws from the bottom of the case that go into the other side of the standoff.

 As noted above, there are two spots available for the standoffs.  The Torpedo I uses three, but we were being especially cautious on that design.  Regardless, one of the standoffs in the Torpedo III goes right between the tubes, which is where the PCB experiences the most stress (from plugging and un-plugging the tubes).  This has worked out fine for the Torpedo III and with three prototypes in the books so far, there are no problems with support.
  
 Here's a look at the bottom of the case -

 Use a 4-40 x 1/4" long socket head cap screw with a single flat washer to screw into the standoffs from the outside.  You probably won't be able to get the screws screwed in all the way flush to the bottom of the case - there simply isn't enough room for threads in the standoffs.  However, the washer + standoff is completely flush with the PCB and the inside of the case so there is no up and down movement.  Overall, the PCB is completely locked from any up and down or sideways movement.  If it worries you that the bottom screws are not completely flush, use another flat washer under the screws on the bottom of the case.  I think that leaves precious little threads in the standoffs to really grip the screws, but I've done it both ways in the past.  There will be plenty of washers included in the kit.
  
 Also note that with a case this long, it just seems a bit better to use bumpers in the middle, besides on both ends.
  
 You can see the third standoff position is simply an open hole with the Torpedo III.  It is, after all, the very same case used for the Torpedo I.
  
 Finally, note the safety ground nut at the rear.  More on that, next -
  
 Here's a view of the safety ground screw underneath the PCB:

_*NOTE: before assembling the PCB, use a knife or file to scrape away the anodizing on the INSIDE of the case around the safety ground hole!*_
 Aluminum anodizing has insulating qualities and you will not get a good safety ground connection if you don't do this!
  
 When assembling, I push the PCB in until I reach the safety ground opening in the PCB that you see here.  Then I check to make sure the safety ground wire and lug assembly is clearing the case and that the lug is lined up with the hole.  Then I push the PCB in the remaining length.  There is usually enough friction on the end of an socket-head ball-driver to hold the cap screw and two flat washers (for spacing) sideways.  So, with the Torpedo III resting sideways on the side of the case, I insert the cap screw/washer collection through the PCB hole and through the hole in the lug underneath.  Before you do all of this, use the socket-head ball-driver to line the lug up with the mounting hole on the bottom of the case, if you can.  Then while the wire/lug is suspended in position, use the ball-driver to push the screw/washer collection through the PCB hole, through the lug, and through the hole in the bottom of the case.
  
 If you mess up, just pull the PCB back out a bit and shake the screw and washers out.  Push the PCB back into the case, line up the lug with the holes, and try again.
  
 Once you get everything pushed through to the bottom of the case, then apply another flat washer against the case, a lock washer and a nut.  Tighten everything up and continue assembling the rest of the case.  Here's a closeup of the safety ground nut and washers on the bottom of the case:

 Note the proximity of the height of the washers/nut assembly to the height of the bumper.  This is close.  It's why I said use two washers under the socket head of the cap screw on the inside.  A 1/4" socket head screw is simply too short to manage poking through those holes, but a 3/8" screw is going to stick out from the bottom of the case further than the bumpers.  This would not be good for your furniture!  So, be sure to use two washers under the screw head before poking the screw through the lug and holes from the topside.
  
 The next step is to screw the 1/4" socket-head cap screws with washers into the two standoffs!


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## tomb

Assembling the rest of the case is pretty easy.  Besides a 4-40-sized socket head ball-driver (or allen wrench), you need the following shown below -

 I've already cheated and attached the front plate and back plate on the bottom.  However, you see the tools in this pic that you can use.  No, you don't really _need_ them, but they will help you from scratching up the case.  Both the Alps volume pot and the Neutrik headphone jack use 7/16" diameter nuts.  A small closed-end 7/16" wrench is a great tool and won't scratch things up.  Remember that you're dealing with plastic, here, so don't go torquing the heck out of those nuts!  They only need to be snug!
  
 The other great tool, especially for the counter-sunk 4-40 socket head screws is the Bondhus 1/16" ball driver.  This tool is so convenient for removing the screws of the top case lid that I provide one with every Torpedo kit sold!  NOTE: You need to remove the case lid to change out the tubes, so this might be done quite a bit and the Bondhus driver is really handy!
  
 Finally, a precision screwdriver is used for the volume knob.  This varies, though.  I purchase the 30mm aluminum knobs from PartsPipe/hongkongsuperseller on ebay.  They seem to have the best, large knobs that don't break a wallet, but consistency is sometimes pretty bad.  I've gotten them with flat-head set screws, allen set screws, and once even got a bunch with two set screws.  Use the tool you find most convenient.  With a flat head screwdriver, though, you need to be certain the blade is not wider than the hole where the set screw is inserted.
	

	
	
		
		

		
		
	


	



  
 Here's a pic using the wrench on the volume pot nut.  You should attach the front plate to the pot and headphone jack, first.  Get the nuts snug, but not overly tight, then screw in the front plate screws to the case extrusion.  Dsavitsk mentioned that he does the front plate in a similar manner as the back plate.  In other words, he attaches the headphone jack and the volume pot to the front plate, then solders them into the PCB.  That's one way to make certain you get the headphone jack and pot straight, so you might try that if you're interested.

 The headphone jack comes with three spacers, a tapered spacer and the ferrule nut.  I use a single spacer on the inside, then one spacer, the tapered spacer, and the ferrule nut.  I just think that looks best, but you might like another spacer in front or only the tapered spacer - it's up to you.
  
  
 There's no pic for this (and I cheated again by already doing it), but you need to cut about 1/4" off of the ALPS shaft to get the knob flush.  I do this with a Dremel cut-off wheel, after I package up the case in a small plastic garbage bag.  I poke a hole in the bottom so the pot shaft can poke through, then I tape all around the shaft and the garbage bag at the hole.  This makes certain that no aluminum dust gets into your Torpedo and makes a fuss with that high voltage! 
	

	
	
		
		

		
		
	


	




  You may have a different method.  The Dremel cut-off wheel is a hassle sometimes.  The top and bottom surface of the wheels will get loaded up with aluminum, which makes them catch in the cutting throat of the pot shaft and then snap!  The wheel will break.  Some people have mentioned a hack saw before, but I just think that puts a lot more stress on the pot and its internals.  Whichever method you use, go slowly and be sure to protect the rest of the amp from the aluminum dust that results.
  
 When you're ready to mount the volume knob, use a credit card or similar to wedge in under the back of the volume knob.  This will give you the closest spacing without having the knob bind against the front plate.
  
 Here is the amp with both end plates screwed in at the bottom:

 I haven't mentioned this much, because it has little to do with actually building the amp, but note the tubes.  The Torpedo III can use just about every 12A*7 tube made - 12AU7, 12AT7, 12AY7, 12AX7, etc., and all their variants.  I ran the second prototype with 5963's, in fact, and it sounded GREAT.  However, Dsavitsk's design is really optimized on the 12AY7 for the best all-around gain.  So, two modern, new manufacture Electro Harmonix 12AY7's will be supplied in all of the kits.  The rest of the tube rolling will be left up to you. 
	

	
	
		
		

		
		
	


	



  
 Here's a pic of the back plate, since we've seen so much of the front plate.  Yes, I've already attached the lid in this pic.  Regardless, note the socket head screws, black washers, and the IEC inlet with the rectangular section poking out properly.  Oh!  I forgot to mention to screw a 4-40 socket head cap screw + black flat washer into the RCA jack assembly.  This is the screw/washer you see below between the IEC inlet and the RCA jacks themselves.  The plastic is so soft for the RCA jack assembly, that even the 4-40 screw self-threads itself when you screw it in.  Again, this is plastic you're dealing with, so get the screw/washer snug and flush, but don't go torquing crazy!

  
 Finally, a couple of shots of the completely assembled amplifier - Front:

  
 and Back -

  
 DONE!


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## tomb

So, how does it sound?  I will try to run tests this weekend and compare them against the Torpedo I.  Until then, the best way I can state it is:

First, no hum, no noise whatsoever (just confirming this one).
Second, pretty much all the personality of the Torpedo I, but more refined.
Third, about 20% better high-end response, with all the rest being similar to the Torpedo I: bass and midrange.
Lastly, a cleanness of sound that is amazingly non-fatiguing over extended periods of listening.  This can't be over-emphasized.  Detail is extended, yet without tizziness or harshness.  Anyone who ever had an opportunity to listen to ECP Audio's DSHA-1 knows what I'm talking about.  For the rest of you, you are in for a treat.  The amp does nothing spectacularly, so it may not amaze at first listening.  It just keeps on going with a freshness and lack of fatigue that's quite amazing.
  
 How does it sound with Cinemag nickel-core transformers instead of Edcor steel?  Dsavitsk put the Cinemag prototypes on the second prototype Torpedo III we built and has had some very (very!) surprising comments.  I haven't had the opportunity, yet - but will let you know when I do. 
	

	
	
		
		

		
		
	


	



  
 That's it for me - the support website is next and then they should be available.  Enjoy!


----------



## HiGHFLYiN9

tomb said:


> How does it sound with Cinemag nickel-core transformers instead of Edcor steel?  Dsavitsk put the Cinemag prototypes on the second prototype Torpedo III we built and has had some very (very!) surprising comments.


 
 Hey! Way to leave us hanging!


----------



## tomb

highflyin9 said:


> tomb said:
> 
> 
> > How does it sound with Cinemag nickel-core transformers instead of Edcor steel?  Dsavitsk put the Cinemag prototypes on the second prototype Torpedo III we built and has had some very (very!) surprising comments.
> ...


 
 Yeah, I know - but I'm being honest and I also don't want to speak for Doug. 
	

	
	
		
		

		
			





  He thinks the Cinemags will be here this next week, so we'll see.  It's no slouch with the Edcors, though and the Cinemags are not cheap.  Hopefully, the choices will keep everyone happy.


----------



## dsavitsk

My comment to Tom about the Cinemags is that once he's heard them, he will have no interest in hearing the Edcors again.


----------



## tomb

highflyin9 said:


> tomb said:
> 
> 
> > How does it sound with Cinemag nickel-core transformers instead of Edcor steel?  Dsavitsk put the Cinemag prototypes on the second prototype Torpedo III we built and has had some very (very!) surprising comments.
> ...


 
  
  


dsavitsk said:


> My comment to Tom about the Cinemags is that once he's heard them, he will have no interest in hearing the Edcors again.


 
  


dsavitsk said:


> I do have L2 PCBs available and the new Cinemags will fit the boards (as will the Edcors) but frankly I'd build a T3 before an L2 unless one is a glutton for punishment. The L2 build process is non-trivial, and* I like the T3 better anyway.*


  
 OK - he said it: translated, Torpedo III + Cinemags = Summit-Fi.


----------



## dsavitsk

Here's what Spice has to say about the circuit.

[ATTACHMENT=1749]TORPEDO3.pdf (188k. pdf file)[/ATTACHMENT]


----------



## HiGHFLYiN9

Wow! Very low THD for a tube-based amp. Good to hear about the Cinemags. Edcor is a tremendous value, just not the best choice for fussy audiophiles who have a couple extra bucks in their wallet.


----------



## TheEnthusiast

How would the Torpedo III drive some current spec LCD-2's or LCD-X's?


----------



## dsavitsk

These are very efficient headphones and the T3 has plenty of power to make them loud.

Both of the transformer types are designed for either 32 or 300 Ohm loads. Other loads should not be an issue, especially with the T3, but you can always use a resistor either in series or in parallel to make the load more optimal.


----------



## cspirou

For an amp that has a lot of differential parts to it, why is having a balanced output not an option?


----------



## tomb

cspirou said:


> For an amp that has a lot of differential parts to it, why is having a balanced output not an option?


 
  
 I believe dsavitsk will want to weigh in on this, but my perspective is as follows - I suspect that in solid-state, the primary benefit of having differential all the way to the headphone is from the increased voltage swing that's created (slew rate, too, admittedly).  Solid-state doesn't have a lot of voltage to work from.  Tube amps have plenty.  It's kind of pointless to pursue increased voltage swing when you start from a B+ of 200V.
  
 The other factor is in avoiding extreme cost.  Differential inputs - especially a differential volume pot - then differential output connectors, not to mention four output transformers(!), are all very expensive.  The result is very little to no additional common-mode distortion cancellation for a huge cost.


----------



## dsavitsk

The output from a transformer is inherently balanced. But in a high voltage amp, it is necessary for safety reasons to ground the transformer's secondary. Additionally, while a balanced headphone output is useful if you are driving 100m long cables in a noisy environment, in the short run to your head it serves no benefit. 0. None.


----------



## cspirou

dsavitsk said:


> The output from a transformer is inherently balanced. But in a high voltage amp, it is necessary for safety reasons to ground the transformer's secondary. Additionally, while a balanced headphone output is useful if you are driving 100m long cables in a noisy environment, in the short run to your head it serves no benefit. 0. None.


 

 I understand the need to ground it but couldn't that be done with a center tapped secondary and grounding the tap?

 As for the second point, if balanced output doesn't give a benefit for short cable runs then what is your opinion of amps(Schiit Mjolnir1/2, Headamp GS-X, etc) that have a balanced topology and a balanced output? Should the balanced output only be used for long cable runs or in a professional setting?
  
 Personally I just think that having an amp balanced all the way to the end has a sort of aesthetic appeal that you don't have with one that is balanced except for the last part. But that's just my bias.


----------



## cspirou

tomb said:


> I believe dsavitsk will want to weigh in on this, but my perspective is as follows - I suspect that in solid-state, the primary benefit of having differential all the way to the headphone is from the increased voltage swing that's created (slew rate, too, admittedly).  Solid-state doesn't have a lot of voltage to work from.  Tube amps have plenty.  It's kind of pointless to pursue increased voltage swing when you start from a B+ of 200V.
> 
> The other factor is in avoiding extreme cost.  Differential inputs - especially a differential volume pot - then differential output connectors, not to mention four output transformers(!), are all very expensive.  The result is very little to no additional common-mode distortion cancellation for a huge cost.


 
  
 True, a balanced output is a way to double the available power, similar to a bridge tied load used in subwoofers and some Class D amps.
  
 Although I think you are mistaken for the need to double everything to have a balanced output. I actually don't know of any tube amp with balanced output that uses two output transformers to create a differential signal. Even top of the line amps like the Eddie Current Balancing Act(with balance in the name) use only one output transformer per channel. Maybe if you had a stereo amp configured as a monoblock you can have 4 transformers but that's the only case I can think of.


----------



## tomb

That's part of the issue: the Balancing Act is not fully differential - only on the inputs, from what I understand.


----------



## cspirou

tomb said:


> That's part of the issue: the Balancing Act is not fully differential - only on the inputs, from what I understand.




Balancing act has 2 XLR ports and one 4 pin balanced connection. Its pretty clear on the front panel.

 http://www.eddiecurrent.com/BA.html


----------



## OJNeg

Balancing Act -> Balanced (not differential) input via input transformer, single-ended gain stage, single-ended output stage feeding transformer for balanced output
  
 Torp III -> Single-ended input, LTP differential input stage, differential follower feeding transformer for balanced output (that happens to have one leg grounded)
  
 A reminder that differential is not the same as balanced.


----------



## dsavitsk

cspirou said:


> I understand the need to ground it but couldn't that be done with a center tapped secondary and grounding the tap?




I know I have seen that done, but I don't see the benefit. And on the downside it would have made winding these transformers (and switching windings) a lot harder.




cspirou said:


> As for the second point, if balanced output doesn't give a benefit for short cable runs then what is your opinion of amps(Schiit Mjolnir1/2, Headamp GS-X, etc) that have a balanced topology and a balanced output? Should the balanced output only be used for long cable runs or in a professional setting?
> 
> Personally I just think that having an amp balanced all the way to the end has a sort of aesthetic appeal that you don't have with one that is balanced except for the last part. But that's just my bias.




I try not to have public opinions (positive or negative) of other people's amplifiers.

I will say that I use 4-pin connectors on amps all the time. I would prefer the whole headphone world move from TRS to 4-pin XLR,and where necessary simply ground 2 pins. So I agree with you on the aesthetic appeal. But here we are trying to keep costs as low as possible and appeal to as many people as possible, and everyone has a phone with a TRS jack. Maybe the T4 will have an XLR jack 




tomb said:


> I believe dsavitsk will want to weigh in on this, but my perspective is as follows - I suspect that in solid-state, the primary benefit of having differential all the way to the headphone is from the increased voltage swing that's created (slew rate, too, admittedly).




I like differential for the power supply isolation aspect. Phones need so little power that getting extra voltage swing or slew rate it are generally non-issues.




cspirou said:


> Although I think you are mistaken for the need to double everything to have a balanced output. I actually don't know of any tube amp with balanced output that uses two output transformers to create a differential signal.




You would never use 2 transformers.


----------



## tomb

ojneg said:


> Balancing Act -> Balanced (not differential) input via input transformer, single-ended gain stage, single-ended output stage feeding transformer for balanced output
> 
> Torp III -> Single-ended input, LTP differential input stage, differential follower feeding transformer for balanced output (that happens to have one leg grounded)
> 
> A reminder that differential is not the same as balanced.




Yes - and thanks. Although, for all intents and purposes, there is really only one individual who attempts to make that distinction: balanced not equal to differential. For most everyone else, they are the same.


----------



## cspirou

@dsavitsk-Ok so I am still trying to understand this. Even though you said that a balanced connection gives no benefit to a headphone user, if given the choice you would prefer to use 4pin XLR?

Or do XLR connections have a benefit with an ungrounded floating secondary? However you would only consider this for the low voltages in an SS amp and not the high voltages present in a tube amp?

And back to the torpedo III. After looking at the schematics you posted for the L-2 and the DSHA, it looks like the Torpedo III is a mix of both! Would you say that making both amps is what led you to making this design for the Torpedo III?


----------



## dsavitsk

tomb said:


> For most everyone else, they are the same.




Balanced circuit and differential circuit are different, though often very related. The argument you are referencing was about balanced inputs versus balanced circuits and whether saying just "balanced" refers to the former or latter.





cspirou said:


> @dsavitsk-Ok so I am still trying to understand this. Even though you said that a balanced connection gives no benefit to a headphone user, if given the choice you would prefer to use 4pin XLR?




The big benefit of the 4pin is that it does not short the output while plugging and unplugging. And it allows for unreferenced differential outputs (see below.)




cspirou said:


> Or do XLR connections have a benefit with an ungrounded floating secondary? However you would only consider this for the low voltages in an SS amp and not the high voltages present in a tube amp?




This gets a little arcane  With a high voltage circuit with an OPT, the secondaries must be grounded. With a high voltage circuit w/o an OPT, the output must be ground referenced.

In the DSHA2, since it is low voltage, this is not necessary. Using an XLR jack allows the circuit to be fully differential and not ground referenced without using an OPT. 

The benefit here is not so much the balanced output, but the fact that the differential circuit can remain differential. If it needed to be ground referenced, it would either need a slightly different topology, or an OPT (both of which would raise the cost.) 



cspirou said:


> And back to the torpedo III. After looking at the schematics you posted for the L-2 and the DSHA, it looks like the Torpedo III is a mix of both! Would you say that making both amps is what led you to making this design for the Torpedo III?




They are very related  But the "innovation" of the T3 is that the OPT sort of works as a capacitance multiplier. That is, by running the buffer at high voltage we can use a low capacitance low current PS which I find to be quieter and easier to make sound good than a low voltage high current supply. The OPT converts everything down effectively increasing the output current by the turns ratio.


----------



## tomb

dsavitsk said:


> cspirou said:
> 
> 
> > Although I think you are mistaken for the need to double everything to have a balanced output. I actually don't know of any tube amp with balanced output that uses two output transformers to create a differential signal.
> ...


 
  
 It won't be the last time I embarrass myself with an assumption.


----------



## TheEnthusiast

So, how soon 'till you take my money for this kit?!


----------



## HiGHFLYiN9

Perhaps you gents could shed some light on a ballpark price for the kit?


----------



## OJNeg

Anxiety overload in this thread


----------



## dsavitsk

theenthusiast said:


> So, how soon 'till you take my money for this kit?! :atsmile:







highflyin9 said:


> Perhaps you gents could shed some light on a ballpark price for the kit?




I have shipped the nickel transformers to Tom, but he won't have them for a couple more days. I think he is very close to being ready to accept orders, but the number of i's to dot and t's to cross is enormous. So I think it will just be a couple of days, but I know we've said that before. Suffice it to say that we would like to accept your money even more than you'd like to give it to us, but we need to make sure that the process is seamless.

For pricing, I'll let Tom answer that since he is setting up the site, but I will say that the nickel OPTs add a ~$200 premium to the base price.




ojneg said:


> Anxiety overload in this thread :veryevil:




Indeed.


----------



## tomb

OK.  I received Doug's shipment.  The shipment included my first prototype that I sent him with the Edcors, plus a few Cinemag pairs.  I've listened to my prototype where he replaced the Edcors with the Cinemags.  Plus, I spent the last two days building another Torpedo III with the production PCB and a couple of the Cinemags he sent, just to be sure.  (There were some minor differences in the PCBs, plus, we spec'd a new PT from Edcor.)
  
 The results?  I think he _understated_ the sound quality, but maybe that's just me. 
	

	
	
		
		

		
		
	


	






  
  
  
 P.S. One warning in a DIY build with the Cinemags.  They're taller than the Edcors, so: *Do not forget to install the ground wire on the Alps BEFORE installing the Cinemags.  *Guess why I know that.
	

	
	
		
		

		
		
	


	




  I will do my best to get the first few kits on sale this weekend, but the reference website may be a bit sketchy.  Still, this thread is perfectly valid for construction - Edcors or Cinemags.


----------



## Luckbad

How much will the Torpedo III full kit be?


----------



## drfindley

I see the new kit is up, but I don't see how to get cinemag transformers. Did they already sell out?


----------



## FlySweep

drfindley said:


> I see the new kit is up, but I don't see how to get cinemag transformers. Did they already sell out?




My eyes are most likely broke.. But where do you see it available? I checked beezar.com & the Torpedo DIY page and didn't see it.


----------



## tomb

THE NEW KIT IS *NOT* UP.
  
 You are seeing the Torpedo I with a price increase.  That's all there is right now.
  
 I'm working feverishly.  Hopefully, there will be something up tomorrow and it will be perfectly clear which is which.


----------



## drfindley

tomb said:


> THE NEW KIT IS *NOT* UP.


 
  
 Ah, sorry to disturb the peace. Not all change means new


----------



## badf00d

drfindley said:


> Ah, sorry to disturb the peace. Not all change means new


 

 Troublemaker.


----------



## HitmanFluffy

Thats QUITE a jump in price on the original Torpedo kit. I cant imagine the Torpedo III will be cheaper than the Torpedo I.


----------



## tomb

hitmanfluffy said:


> Thats QUITE a jump in price on the original Torpedo kit. I cant imagine the Torpedo III will be cheaper than the Torpedo I.




Perhaps, but please check the BOM on the Torpedo website for reference. As I explain at the top of the listing for the Torpedo on beezar.com, I have been practically losing money on the Torpedo since day one. While the amp had the slight hum issue (it no longer does), we were only trying to re-coup costs. Poor Doug has only received a little more than $10 for every Torpedo sold.

Meanwhile, the specially-extruded long casework ties up $thousands in investment, not to mention stocking transformers with a two-month lead time.

I don't mean to complain and you guys shouldn't have to concern yourselves with anything but the sale price and whether you judge that to be a good value in the marketplace. Nevertheless, the pricing is not arbitrarily set.

With the Cinemags, the Torpedo III is a legitimate Summit-Fi headphone amplifier. Yes, it will be more expensive.


----------



## HitmanFluffy

tomb said:


> Perhaps, but please check the BOM on the Torpedo website for reference. As I explain at the top of the listing for the Torpedo on beezar.com, I have been practically losing money on the Torpedo since day one. While the amp had the slight hum issue (it no longer does), we were only trying to re-coup costs. Poor Doug has only received a little more than $10 for every Torpedo sold.
> 
> Meanwhile, the specially-extruded long casework ties up $thousands in investment, not to mention stocking transformers with a two-month lead time.
> 
> ...



I was just a little surprised with the change and I fully sympathize with you on the difficulties of selling a product. Ears I trust told me that the Torpedo 3 is as good as you say, and rest assured I fully intend to buy it with the Cinemags regardless of the price shift.


----------



## badf00d

tomb said:


> With the Cinemags, the Torpedo III is a legitimate Summit-Fi headphone amplifier. Yes, it will be more expensive.


 
  
 I can't wait to build one. Thanks for putting in all the effort to make these available.


----------



## cspirou

Will the full schematic and PCB be availible like the current Torpedo?


----------



## tomb

badf00d said:


> [CONTENTEMBED=/t/781651/torpedo-iii-build-thread/45#post_12024280 layout=inline]Quote:[/CONTENTEMBED]
> 
> I can't wait to build one. Thanks for putting in all the effort to make these available.




Thanks for the kind comments!




cspirou said:


> Will the full schematic and PCB be availible like the current Torpedo?




Yes, of course - complete BOM as well.


----------



## OJNeg

tomb said:


> Perhaps, but please check the BOM on the Torpedo website for reference. As I explain at the top of the listing for the Torpedo on beezar.com, I have been practically losing money on the Torpedo since day one. While the amp had the slight hum issue (it no longer does), we were only trying to re-coup costs. Poor Doug has only received a little more than $10 for every Torpedo sold.
> 
> Meanwhile, the specially-extruded long casework ties up $thousands in investment, not to mention stocking transformers with a two-month lead time.
> 
> I don't mean to complain and you guys shouldn't have to concern yourselves with anything but the sale price and whether you judge that to be a good value in the marketplace. Nevertheless, the pricing is not arbitrarily set.


 

 I had always suspected that was the case. I remember getting my kit and being amazed that all these parts could come packaged at that price point. The Torpedo I remains an insane value in the world of DIY tube gear, even with the price increase.


----------



## kapanak

I expect the Cinemag versions to be available for order come Wednesday morning for $700 ...


----------



## fierce_freak

Wishful thinking, or in the know?


----------



## dsavitsk

Regardless, it is probably pretty close on both timing and price.


----------



## fierce_freak

Good to see you, Doug. I probably won't be able to resist 


-edit- what's the model on the parafeed caps? Looking to get dimensions to go searching for replacements (though I'll probably build with includes caps first)
http://www.mouser.com/Search/m_ProductDetail.aspx?EPCOS-TDK%2fB32674D3106K%2f&qs=sGAEpiMZZMv1cc3ydrPrF0gALJPP0xBjM%252bvJjWhJfE8%3d maybe?


----------



## FishHead

Will you be mirroring this information on diyforums.org when the systems are ready?


----------



## tomb

dsavitsk said:


> Regardless, it is probably pretty close on both timing and price.


 
 Gosh, I had hoped so, but Wednesday is pushing it, at this point.
  


fishhead said:


> Will you be mirroring this information on diyforums.org when the systems are ready?


 
  
 Yes - working on it right now.  I'm probably 50% finished, so quit bugging me and let me get back to work.
	

	
	
		
		

		
		
	


	




  I only came over here to get Dsavitsk's original schematic.
	

	
	
		
		

		
		
	


	



  
 P.S. The listing will go up on Beezar as soon as I'm finished with the website (enough documentation to support the build).  I guess I'm slipping a week, because that's my estimate right now - sometime this coming weekend, but closer to Friday than Sunday, at this point.


----------



## dsavitsk

fierce_freak said:


> what's the model on the parafeed caps? Looking to get dimensions to go searching for replacements (though I'll probably build with includes caps first)
> http://www.mouser.com/Search/m_ProductDetail.aspx?EPCOS-TDK%2fB32674D3106K%2f&qs=sGAEpiMZZMv1cc3ydrPrF0gALJPP0xBjM%252bvJjWhJfE8%3d maybe?




That looks like the right one. Caps should be at least 300V with min 10uF recommended. Sims with caps as small as 1u show that they transfer bass frequencies, but the phase is distorted which will make it sound like they don't. You might do OK with slightly smaller (8u? possibly 5u?) but I wouldn't really recommend it. You might also be able to parallel 2x 5u caps or something. You can also try a bypass, though I have not tried it.

That said, there are pins for 27.5mm, 32.5mm, 37.5mm, 45mm, and 53mm. Width is the bigger issue 21mm width/diameter being the max. There is actually very little out there that will fit as most things are a little too fat.

And don't use anything with a conductive exterior as it will cause a short.


----------



## fierce_freak

Yep, that's what I'm finding. There are a few alternatives but nothing probably worth it unless you go exotic on the casework. Perhaps radials through the top of the case (keeping leads as short as possible, of course) or even looking into a custom custom case that's double height or close to it to allow mounting two caps on topside of board and two on bottom. If you could make the faceplate a perfect square, that could be cool. Not sure the dimensions work out though.

Thanks.


----------



## Sopp

Doug, would you compare Torpedo III to Black Diamond. HD650, K701, K7XX, SA5000 are used most of time. I will grab the Dharma D1000 or HD800 in the near future and consider to add another amp.


----------



## kapanak

sopp said:


> Doug, would you compare Torpedo III to Black Diamond. HD650, K701, K7XX, SA5000 are used most of time. I will grab the Dhrama D1000 or HD800 in the near future and consider to add another amp.


 

 This is also what I am curious about. Given the very careful selection of parts, many high quality, and especially the cinemag transformers version of the Torpedo III, could you please comment on how the sound and the dynamics compare to the *Black Diamond*? Thank you Doug!


----------



## HiGHFLYiN9

Nevermind, saw that C7, C8, C9, and C10 should be at least 300V. Curious if round caps could be staggered in there. 
  
 If you do some creative mounting and ensure you don't short anything with the metal shells, the obbligatos *may* fit (30mm x 55). Usually Auricaps are pretty small form factor, but they are a bit too large as well. If you do some unusual placement with crisscrossed sleeved leads, the Mcap EVO Oil Series (40mm x 27mm) might be another potential. Would have to do some board measurements to figure any of this out. 
  
 ...then there's always bypassing as a possibility. Plenty of creative possibilities


----------



## fierce_freak

It's 300v. Not really many (or any) options. I thought i had found a good (but stupid expensive) option with vcap oimp, but they're only 150v and a little too fat. I was looking at putting a few soniccaps in parallel, but they're only 200v. Only thing I've really found is a film and foil cap (amtrans) marketed for power supplies. It's stupid expensive, too, and would require mounting through the case.


----------



## fierce_freak

highflyin9 said:


> ...then there's always bypassing as a possibility. Plenty of creative possibilities


 
  
 I'd love to hear impressions on that. Again stupid expensive, but you could bypass with vcap tftf .22uf (if there's enough space between the top of the stock caps and the casing, which there probably isn't.


----------



## dsavitsk

sopp said:


> would you compare Torpedo III to Black Diamond.







kapanak said:


> could you please comment on how the sound and the dynamics compare to the *Black Diamond*?




Oh goodness. T3 is probably a little sweeter sounding. Maybe a little warmer, and punchier, too. BD might be more neutral.


----------



## Rotijon

dsavitsk said:


> Oh goodness. T3 is probably a little sweeter sounding. Maybe a little warmer, and punchier, too. BD might be more neutral.


 
 How does it compared to the ECP L2 on powering a HD800?

 Jon


----------



## dsavitsk

I think I like the T3 better, but keep in mind I've not heard an L2 in a couple of years.


----------



## FlySweep

Doug.. Tom mentioned you've optimized the TIII for use with a wide range of headphones (from low to high impedance as well as various sensitivities).. is there a tweak to optimize the TIII build if one were to use it exclusively with high impedance dynamics (i.e. in my case, the HD650/HD800)?


----------



## dsavitsk

The T3 is basically designed around the HD650s and HD800s because those are what I listen to.


----------



## FlySweep

dsavitsk said:


> The T3 is basically designed around the HD650s and HD800s because those are what I listen to.


 
  
 No way .. ME TOO!


----------



## tomb

dsavitsk said:


> The T3 is basically designed around the HD650s and HD800s because those are what I listen to.


 
 I figured you graduated from your Grados.  I still use the HF-2's and I'm liking them very much with this amp!  I have the HD600's, too, with a great set of Cardas cables, but I still prefer the Grados.
  
 Quote originally from Dsavitsk (not from Head-Fi): 





> *12AT7* - has similar looking gain to the 12AY7. However, the circuit runs it at lower voltage and current than are ideal which will result in slightly higher distortion. Subjectively, we found it to sound more tubey which some people may like.


 
 I just got a pair of matched GE JAN 12AT7's in the mail today.  I have to say they're great.  Maybe I like the "tubey" sound.  As best I can tell - more bass punch, with just as much detail and more presence.  This is an absolutely fantastic amp.
  
 Just a break from the web pages - I'd say I'm at about 90%, so things will go on sale this weekend, for sure! 
	

	
	
		
		

		
		
	


	



  
 P.S. Would've been done by now, but had to go into work today.


----------



## JamieMcC




----------



## tomb

The Torpedo III website is up and running:
  
*Torpedo III*
  







  
 Hopefully, I'll have the sales listings on Beezar complete by sometime today.


----------



## JamieMcC

Great new website
  
 Is the E80cc a tube option for the TIII?


----------



## fierce_freak

What's the height constraint on the parafeed caps? Distance between pcb and case top? 

Forgive the question. I'm sure you've got many more important things to worry about ;D

Site looks good.


----------



## tomb

fierce_freak said:


> What's the height constraint on the parafeed caps? Distance between pcb and case top?
> 
> Forgive the question. I'm sure you've got many more important things to worry about ;D
> 
> Site looks good.


 
  
 The BOM has a note on the top line under the headings - "all parts limited to 48mm high."  The PCB  is placed into the second slot on the custom Context/Beezar case.  It measures closer to 49mm in the CAD file, but I wouldn't push it. 
	

	
	
		
		

		
			




  
  
 Thanks!


----------



## tomb

jamiemcc said:


> Great new website
> 
> Is the E80cc a tube option for the TIII?


 
  
 Thanks!
  
 No.  The E80CC is a 7-pin tube.  The Torpedo III uses the 9-pin 12A*7 tube family.  I believe the E80CC is one of the finest 7-pin tubes ever made, but rest assured, there is equivalent (or superior) quality in the 12A*7 family.  There is probably no other tube family in audio that has as much availability or different equivalents available.


----------



## fierce_freak

Tomb, thanks. Shame on me for not checking the bom! 

Good stuff!


----------



## JamieMcC

tomb said:


> Thanks!
> 
> No.  The E80CC is a 7-pin tube.  The Torpedo III uses the 9-pin 12A*7 tube family.  I believe the E80CC is one of the finest 7-pin tubes ever made, but rest assured, there is equivalent (or superior) quality in the 12A*7 family.  There is probably no other tube family in audio that has as much availability or different equivalents available.


 
  
 E80cc is 9 pin and is often used as a substitute for 12au7 you might have been thinking about a different tube.


----------



## tomb

jamiemcc said:


> tomb said:
> 
> 
> > Thanks!
> ...


 
 Sorry - I got confused with the E90CC, which we have used in the Torpedo I for quite awhile.


----------



## FlySweep

Yep.. I'm interested to know if the t3 can run e80cc optimally, too.. Wonderful tube in the right circuit.


----------



## dsavitsk

The heater current of the E80CC is pretty high, likely too high for the T3. And the mu is pretty low making it less than ideal.


----------



## fierce_freak

in for 1 
  
 Only thing I can find for parafeed caps is the mundorf evo series, and that'll still be fiddly.


----------



## drfindley

Might be a good time to checkout beezar.com: http://www.beezar.com/catalog/product_info.php?products_id=166


----------



## tomb

drfindley said:


> Might be a good time to checkout beezar.com: http://www.beezar.com/catalog/product_info.php?products_id=166


 







  
 Please keep in mind that I only have 5 pairs of Cinemags.  Doug is having more produced, but it may be awhile before they arrive.  Also, as we stated before, the Cinemags are only there for options with Torpedo III kits right now (because of the limited stock).  There is a separate product listing for the Cinemags, but it will show "Out Of Stock" if you try to add it to a shopping cart.
  
 There should be plenty of Edcors.


----------



## fierce_freak

I took a cinemag kit.


----------



## tomb

Whoa!
  
 I guess I should also explain about a limitation with the Beezar store.  It will not deprecate the stock when an item is shown as an option.  I will keep an eye on it, but it may result in someone purchasing a Torpedo III after the Cinemags run out.
  
 There are only two (2) pair left right now.


----------



## dsavitsk

tomb said:


> Please keep in mind that I only have 5 pairs of Cinemags.




I've got plenty more. No worries -- I'll drop them in the mail to Tom on Monday morning


----------



## tomb

dsavitsk said:


> tomb said:
> 
> 
> > Please keep in mind that I only have 5 pairs of Cinemags.
> ...


 
  
 OK - well, there you go.


----------



## OJNeg

Would like to add that it would be very nice if some of us Torpedo I owners could get the Cinemags sooner than later....


----------



## tomb

Down to one pair of Cinemags remaining, for now ...


----------



## tomb

ojneg said:


> Would like to add that it would be very nice if some of us Torpedo I owners could get the Cinemags sooner than later....


 
  
 If Doug sends me a bunch, no problem.  These were just the terms we agreed to for the first half-dozen (I used one pair myself).


----------



## dsavitsk

ojneg said:


> Would like to add that it would be very nice if some of us Torpedo I owners could get the Cinemags sooner than later....h34r:




I will have the individual transformers for sale on my site. I just need to actually put them there. Give me a day.


----------



## tomb

Well, that was quick.  The Cinemag option is gone for now.
  
 I will restore it when I receive more from Doug.


----------



## tomb

OK - Doug is going to send me a bunch that should arrive on Wednesday.  So, I will turn the Cinemag option back on with the understanding that follow-on sales of kits will be delayed in shipping a couple of days.


----------



## tomb

ojneg said:


> Would like to add that it would be very nice if some of us Torpedo I owners could get the Cinemags sooner than later....


 
  
 Since Doug is sending me more, I will show some stock on the Cinemag individual listing.  Understand that I won't be able to ship until Thursday-Friday or so.


----------



## badf00d

@dsavitsk, @tomb - thanks so much for getting this unit together. Ordered mine tonight with Cinemags, and look forward to building it. Are there any other upgrades you would recommend, such as capacitors or tubes?


----------



## fierce_freak

I'm not very knowledgeable on tubes, but everything else is pretty high quality and probably the best it can be. Only potential is probably the parafeed caps, but the dimensions on it are pretty tight.


----------



## tomb

fierce_freak said:


> I'm not very knowledgeable on tubes, but everything else is pretty high quality and probably the best it can be. Only potential is probably the parafeed caps, but the dimensions on it are pretty tight.


 
  
 Yes, I think this is generally correct.  However - tubes are ubiquitous, readily available and the options are almost limitless.
  
 On the Torpedo III website, there is a Tweaks page:
Torpedo III Tweaks
 
 On that page, we describe three tweaks you can do for the Torpedo III, in the order of preference.  Preference, in my mind, would mean also including how much "the juice is worth the squeeze."  Anyway, unless Dsavitsk comes up with something else, we ranked them this way:
 1. Output Transformers
 2. Tubes
 3. Parafeed Capacitors
  
 The Output Transformers are obvious: the Cinemags.  The Parafeed Capacitors, as noted in some of the previous posts, may be problematic due to the high uf needed and the space available (not to mention $cost of high-uf boutique film capacitors).  Note that it is still listed as a possible Tweak, it's just not ranked as high as the other two.
  
 That leaves the tubes.  Even though Doug has stated many times that the Torpedo III is optimized for the 12AY7, neither of us have come close to trying all the brands/makes that are available.  We simply selected the Electro-Harmonix as the most reliably-sourced and quality-controlled option to include with the kits.  That means there's a lot still out there.  Plus, we have already mentioned a number of variants that may have very interesting results when used in the Torpedo III.  As with any other tube amp, then, the idea of rolling tubes is absolutely valid for the Torpedo III _and has yet to be fully explored_.  With the 12A*7 family, the possibilities are almost unlimited.


----------



## fierce_freak

Thanks, looking forward to exploring those possibilities.

Thinking no, but is there enough room to mount ic1 and ic2 under the board rather than on top? Probably just a bit too high.


----------



## tomb

fierce_freak said:


> Thanks, looking forward to exploring those possibilities.
> 
> Thinking no, but is there enough room to mount ic1 and ic2 under the board rather than on top? Probably just a bit too high.


 
  
 IC1 and IC2 were mounted on the bottom in my first prototype, because they simply wouldn't work on the top (I use different sockets than Doug.).  We changed the PCB so that wasn't necessary, but you still have to bend them forward a bit.  We thought that was a much better solution.  Despite the slight bending needed on the top of the PCB, they get in the way a whole lot more on the bottom.


----------



## FishHead

Oh No! I can't decide on the LED color and now there are no more cinimags. Blue.... No Red..... Noo Green. Argh! I should start a thread for this.


----------



## fierce_freak

UV obviously sounds the best ;p


----------



## tomb

fishhead said:


> Oh No! I can't decide on the LED color and now there are no more cinimags. Blue.... No Red..... Noo Green. Argh! I should start a thread for this.


 
  
 You obviously need the Color Change LED.


----------



## kapanak

tomb said:


> You obviously need the Color Change LED.


 

 Future upgrade, yeah!


----------



## TomNC

Could any member build one for a reasonable amount of service fee? Please PM me if you are willing. Thanks.


----------



## OJNeg

tomnc said:


> Could any member build one for a reasonable amount of service fee? Please PM me if you are willing. Thanks.


 

 I would but probably easier if you find someone on the East Coast


----------



## TomNC

I'll keep your message on my mind. Would it be nice if someone in NC can do it? Looking forward to your impressions if you are building one.Thanks.


----------



## dsavitsk

I believe Tom will be offering pre-build T3's once he has time to build some.


----------



## TomNC

That will be great having ready-to-use T3s. Looking forward to impressions. Thanks.


----------



## dsavitsk

ojneg said:


> Would like to add that it would be very nice if some of us Torpedo I owners could get the Cinemags sooner than later....h34r:




Now available: https://squareup.com/market/ecp-consolidated-productions-llc/headphone-amplifier-parafeed-transformers-pair


----------



## OJNeg

dsavitsk said:


> Now available: https://squareup.com/market/ecp-consolidated-productions-llc/headphone-amplifier-parafeed-transformers-pair


 





 
  
 BTW, I noticed the little break-out PCB. I suspect I will have fun with that. Awesome-ballz


----------



## tomb

OK, you guys have really overwhelmed me.  I'm doing my best to get a bunch out at the same time, but it's going to take another day or so.  Please be patient.


----------



## fierce_freak

Understandable, thanks for what you do!

Edit- ok, time's up. Where's our stuff? ;p


----------



## tomb

More Cinemags have arrived! 
	

	
	
		
		

		
		
	


	



  
 Also, I was able to ship the first few orders this morning.  The rest should go out tomorrow.


----------



## fierce_freak

Good stuff, looking forward to it! Of course, i probably won't be able to complete the build till sometime next week ;(


----------



## HitmanFluffy

I just put down my order for the Torpedo III with cinemags. I am really curious about just how impactful rolling the parafeed caps is.


----------



## fierce_freak

I'll try to describe what i hear as changes as best i can, though I'm not expecting much there.

Got my kit today. Really, really good packing job, tomb. Hopefully get started on this tomorrow.


----------



## tomb

OK.  Sorry that took a while, but I'm caught up with all the orders.  Everything has shipped.


----------



## fierce_freak

Mine is built (stock) and running in right now. No time for impressions, but I'm pretty optimistic.
  
 I have another pair of tubes to roll in along with the replacement parafeed caps coming Monday. I'll probably run this stock for a week or two before making any changes to hopefully best detect any changes.


----------



## Misterrogers

Cool. Early impressions are welcome too - we wouldn't hold you to them


----------



## badf00d

fierce_freak said:


> I have another pair of tubes to roll in along with the replacement parafeed caps coming Monday.


 
  
 Would be interested in knowing which caps and tubes you try, along with your impressions. Even if you don't like how it sounds, at least it helps the rest of us skip a combination we wouldn't like.


----------



## fierce_freak

Will do. The caps will be mundorf evo silver gold in oil to replace the parafeed caps. The tubes i picked up are ge 6072a 5 star.
  
 Really haven't had much head time at all, and I won't be with a familiar source until tomorrow, but...excited. Bass detail seems really nice. Fast, clean, natural, open. More later.
  
 -edit- refined but punchy, cymbals sound great


----------



## fierce_freak

Quick update.
  
 Re: vs Valhalla2 (stock tubes). Listened to Valhalla 2 for about an hour this morning and was thoroughly enjoying it. Now listening to the torp3.
 Wow. This is gonna sound kinda gushy and audiophooly (new toy syndrome?), but...veil lifted. Val 2 is kinda soft and round (very slightly on round) compared to torp3. Separation/stage is no contest. Torp3 is highly resolving while still sounding like one cohesive and natural presentation - not pushing itself on you but readily apparent if you "look" for it. Torp3 is punchy but not to the point I'd call it a coloration, also a bit more dynamic in a macro sense. Val 2 sounds a tiny bit fuller (bloomy?) compared to torp3 which still has a solidity to sound that's convincing. I think Val 2 is pretty open sounding, but torp3 is even more so (unrestrained), no hint of congestion.
  
 These aren't huge differences in all cases, and Valhalla 2 is still an incredible value I'd recommend with no hesitation. Torp3 is killer, though.


----------



## tomb

Great! Glad you're liking it.

I haven't heard the Valhalla 2, but the Torpedo 1 easily bested the Valhalla 1, IMHO. I believe there's a fog caused by OTL output electrolytics that is simply not there with either Torpedo.

Just an FYI - I tried a pair of 12AZ7's and did not like them at all. I think higher distortion was readily apparent. Your mileage may vary, but these were a matched pair of GE's that tested pretty well. So, they may not be a good fit for the Torpedo 3.


----------



## fierce_freak

Thanks for the info on the 12AZ7. I think the only other tube I'm interested in is the 12AU7, mostly because I really never need that much gain. I'd love to hear anyone's thoughts on that, and I'd also like to know if there could be any circuit tweaks to put the tube in optimal operating point (probably plate resistors and playing with the ccs).
  
 Do you have FPE files for the panels? I'm thinking of getting some nice thicker ones made up. This amp is a keeper, so I want to spoil it a bit ;D
  
 I'll probably just use the excellent templates on the build site to more-or-less recreate them.


----------



## FlySweep

fierce_freak said:


> Thanks for the info on the 12AZ7. I think the only other tube I'm interested in is the 12AU7, mostly because I really never need that much gain. I'd love to hear anyone's thoughts on that, and I'd also like to know if there could be any circuit tweaks to put the tube in optimal operating point (probably plate resistors and playing with the ccs).
> 
> Do you have FPE files for the panels? I'm thinking of getting some nice thicker ones made up. This amp is a keeper, so I want to spoil it a bit ;D
> 
> I'll probably just use the excellent templates on the build site to more-or-less recreate them.


 
  
 A few of my favorite (non-mega buck) 12AU7's are the Mazda CIFTE, Tungsram 12AU7 (beautiful, liquid midrange), and Raytheon 12AU7 (curved, black plates).


----------



## tomb

fierce_freak said:


> Thanks for the info on the 12AZ7. I think the only other tube I'm interested in is the 12AU7, mostly because I really never need that much gain. I'd love to hear anyone's thoughts on that, and I'd also like to know if there could be any circuit tweaks to put the tube in optimal operating point (probably plate resistors and playing with the ccs).
> 
> Do you have FPE files for the panels? I'm thinking of getting some nice thicker ones made up. This amp is a keeper, so I want to spoil it a bit ;D
> 
> I'll probably just use the excellent templates on the build site to more-or-less recreate them.




No FPE files, but there are plenty of drawings on the website. I will also buy back the original endplates from you if you decide to go that route.

I have run a number of 12AU7's through the Torpedo III, including my personal favorite, the 5963. All have done very well. I would highly recommend that option for Grados and other efficient phones that don't need much gain. The gain is pretty low, though, so keep an eye on it with your particular headphones. If you're cranking it up to 9 or 10 o'clock on the volume all the time, you should probably use another tube.

Sounds like FlySweep has some 12AU7 recommendations, too.


----------



## fierce_freak

With the 12AY7 in I don't get much play on the volume knob. 12AU7 could be good. Man there are some expensive 12AU7s!
 
EVOs are in and cooking. Impressions will have to wait again.
 





 





 
I added some additional spacers and supports here and there to solidify things after these pics were taken.


----------



## dsavitsk

Pick up a thermometer to be sure that you are not overcooking the caps. Tubes can run quite hot.

And wrap the leads in teflon if you didn't already.


----------



## fierce_freak

Good idea. I don't think i actually have a thermometer in my house, oddly enough. I'll have to pick something up and check out the temp between the caps and tubes.

I couldn't find my teflon tape so i used heatshrink anywhere there could be potential for a short. I'd feel better with them teflon wrapped, though.


----------



## kapanak

fierce_freak said:


> Good idea. I don't think i actually have a thermometer in my house, oddly enough. I'll have to pick something up and check out the temp between the caps and tubes.
> 
> I couldn't find my teflon tape so i used heatshrink anywhere there could be potential for a short. I'd feel better with them teflon wrapped, though.


 

 I honestly think if you have them sticking out of the case, like cut four equal disks off the top of the casing, and have the caps sticking out would be a better and safer option. I mean, if I paid $100 a pop for those caps, I'd do that not to risk them being boiled by the tubes. They are pretty too.


----------



## fierce_freak

With them being axial caps, not sure i could get them situated how I'd like and the leads would be short, but I'll explore the option. Maybe cut a large hole over the tubes and caps then finish it with some grating or mesh that'd allow heat to escape.


----------



## fierce_freak

In the interest of keeping temps down on the caps:
 






 





 
I'll have to find some mesh or perforated metal to place there for safety, of course. Probably also going to need to refinish the case - I managed to knick and scratch it up a bit while making the hole.

  
 Also wouldn't recommend all this to anyone. Casework is the devil.


----------



## tomb

Wow!  I guess you felt you had to do this.  Yet, coming from someone who knows the amount of work that went into producing those cases, it's a bit depressing. 
	

	
	
		
		

		
		
	


	



  
 Still, I am amazed at the cut - very straight and true.  What did you use to do that?
  
 P.S. Next time, let me know.  I could swap you a case (with rebated $$) that might already have a questionable finish - good for cutting up and experimenting.


----------



## badf00d

@tomb, I have to say... the packaging you did for the Torpedo III is fantastic. Very professional, and I can't wait to finish the assembly. My soldering station went wonky on me, so as soon as I have that sorted I should be able to finish up and listen to the unit. Thanks so much.


----------



## fierce_freak

Yeah seriously inspired packaging. Excited to see others complete theirs. Really is a killer amp.

I know, tomb, obvious care went into the case. I didn't want to do it, but i got paranoid about boiling the caps. I used a dremel followed by lots of filing. I'm actually not satisfied with it and am exploring options to "fix" it. Maybe use a drill press to set the corners a bit further it out followed by careful filing or maybe a nibbler? I want to get it as close to perfect as i can as I'll be getting it powder coated to cover up my scratches and nicks. I appreciate any suggestions here.

I'm going to use the downtime to wrap the cap leads in teflon and a couple other small things.

Good to know about the b stock cases. I'll keep it in mind, for sure.

Ps- you weren't kidding about the uv led. Not very bright. I don't particularly mind, but I'm curious to try another. Just a standard superbright?


----------



## tomb

fierce_freak said:


> Yeah seriously inspired packaging. Excited to see others complete theirs. Really is a killer amp.
> 
> I know, tomb, obvious care went into the case. I didn't want to do it, but i got paranoid about boiling the caps. I used a dremel followed by lots of filing. I'm actually not satisfied with it and am exploring options to "fix" it. Maybe use a drill press to set the corners a bit further it out followed by careful filing or maybe a nibbler? I want to get it as close to perfect as i can as I'll be getting it powder coated to cover up my scratches and nicks. I appreciate any suggestions here.
> 
> ...


 
  
 A Dremel did that?  Surely you had a jig of some sort.  If not, that's nothing short of amazing.
  
 Yeah, all UV LEDs are that way.  They're down in the 1000 mcd range, while all the rest are at least 4000 (that I have).  They're actually much lower than that, because we all size resistors for about 1/2 max current or less.


----------



## tomb

badf00d said:


> @tomb, I have to say... the packaging you did for the Torpedo III is fantastic. Very professional, and I can't wait to finish the assembly. My soldering station went wonky on me, so as soon as I have that sorted I should be able to finish up and listen to the unit. Thanks so much.


 
  
 Many thanks for your kind comments!! 
	

	
	
		
		

		
		
	


	




  Good luck on the build!


----------



## grendel23

I finished building my Torpedo III with Cinemags last night. Assembly was easy. The kit is superb, great attention to detail.
  
 Compared to my previous amp, a SOHA II, the T3 is a huge step up. The bass is more powerful, with better definition. The treble is smooth and the overall sound is very clean.
  
 I haven't heard any other high end amps to compare it to, but to my humble ears it sounds great. I am listening with a Gamma 1 DAC and HD600s.
  
 I modded my SOHA II to run 12BH7A tubes, twice the heater current of the 12a_7 family, and really liked them. Would the T3 be able to run these? Since the power transformer is custom, I can't look up the ratings. I suspect they would sound worse than the 12AY7s in the T3, but i would like to try and see. If I can do so without damaging the amp.
  
 Now I am going to have to get a better DAC. I am thinking of a Bitfrost MB, or possibly a DAC-19 or maybe a Gamma 3 when AMB finishes it. I would love to hear what pairs up well with this great amp.


----------



## tomb

grendel23 said:


> I finished building my Torpedo III with Cinemags last night. Assembly was easy. The kit is superb, great attention to detail.
> 
> Compared to my previous amp, a SOHA II, the T3 is a huge step up. The bass is more powerful, with better definition. The treble is smooth and the overall sound is very clean.
> 
> ...


 
  
 Many thanks for the kind comments!  Glad you're enjoying the Torpedo III!
  
 As for the 12BH7, we need to hear from Dsavitsk.  The 12AZ7 has 225ma at 12.6V, which Dsavitsk said was OK (even though I did not like the 12AZ7).  Still, as you say, 300ma for the 12BH7 is quite a leap from 150ma with the 12AY7.
  
 I would strongly recommend the 12AT7 or 6201 if you are searching for tubes that may sound just as good, but with a different signature.  I have tried both and like them very much - perhaps better than the 12AY7.  There is even a computer-use upgrade model known as the E180CC or 7062.  There's also the 6414, which is very similar.  Like the E90CC vs. 6J6 in the Torpedo I, the E180CC/7062/6414 are much taller tubes and were designed for 10,000 hr use.  Maybe it's a magic tube for the Torpedo III just as the E90CC is for the Torpedo I.  I have a pair of the 6414's coming in and will let you know.


----------



## dsavitsk

grendel23 said:


> I modded my SOHA II to run 12BH7A tubes, twice the heater current of the 12a_7 family, and really liked them. Would the T3 be able to run these?




I think it is too high, so I would not use them.


----------



## badf00d

Ok, nearing completion of my build. The grounding wire has been a bit tricky, First I had to find suitable wire (not included) which proved to be harder for me than I hoped. Now @tomb mentions in this thread that he soldered it. There doesn't seem to be anything to solder it to. I ran my wire from the screw on the Alps pot through the hole in the board and out the other side.
  
 Before I try to button this thing up, is there something different I need to do with the ground wire? Where does it get soldered? I'm confused.


----------



## dsavitsk

The pot grounding wire should be soldered to the small pcb via right next to the pot. It is in the space between the pot, the output transformer, and the edge of the board. It is labeled "PG" for "Pot Ground."


----------



## dsavitsk

The safety ground wire should be soldered to the via right next to the power inlet that is labeled "SG" and then connected to the case. There is a large hole in the PCB through which you can insert a socket wrench or a screw driver to tighten it.

Please note that you *must* scrape away some of the anodize to make a good electrical connection. There are detailed instructions at the beginning of this thread.


----------



## tomb

@badf00d,
  
 As a normal practice, I have never included hookup wire in a Beezar kit - for anything, except the special cabling for the GrubDAC-CableDAC.  I _do_ go as far as supplying heat sink grease in the Starving Student kits, but that's sort of specialized and not really available in a normal hardware store.  I still don't supply wire for the Starving Student.
  
 That said, you probably don't want to wait this long, but if you PM me with your address (Beezar doesn't know Head-Fi usernames), I'll ship some to you.
  
 Or, you can do what I do - order from John at John's Wire Shop on ebay (navships).  Get teflon-coated (PTFE), SPC (silver-plated copper), multi-strand, 22 gauge.  That's about the thickest you can use and still fit it in the holes on the PCB.  This is green (good to represent Ground) and would be a great selection:
http://www.ebay.com/itm/25-feet-22-AWG-Silver-Plated-PTFE-Wire-Green-19-strand-/231675375027?hash=item35f0edadb3
  
 You'll see some people complain about this wire in the headphone cable thread (microphonics, too stiif, etc.), but for hookup wire it's unbeatable.  The teflon will not pull away from the focus of heat while you are soldering.  It's outstanding wire, IMHO.
  
 The other choice is to get normal hookup wire at your local hardware store or Radio Shack, but it's tough to solder wire with PVC coating and keep the insulation in place.  You'll watch the insulation literally move away from the solder joint, leaving your nicely trimmed wire with a 1/4" of bare wire exposed - or worse.


----------



## badf00d

Thanks for the quick reply, guys. I ended up using some telephone wire that appeared to be a reasonable enough gauge to work. Mistake?


----------



## funch

tomb said:


> Or, you can do what I do - order from John at John's Wire Shop on ebay (navships).  Get teflon-coated (PTFE), SPC (silver-plated copper), multi-strand, 22 gauge.  That's about the thickest you can use and still fit it in the holes on the PCB.  This is green (good to represent Ground) and would be a great selection:
> http://www.ebay.com/itm/25-feet-22-AWG-Silver-Plated-PTFE-Wire-Green-19-strand-/231675375027?hash=item35f0edadb3


 
  
 That's the exact wire I used, except mine is orange (had some in my stash). 
  
 I finished mine a couple of days ago and have already been rolling some tubes. Mine has the Cinemags and stock cap's btw.
 My source is a Yggy, and 'phones are HD800's.
  
 Here's my short take.
  
 The stock EH's sound OK, but are bit thin and harsh sounding.  
  
 The RCA 6072/12AY7's I picked up on ebay are a noticeable step up. A much more fleshed out, full sound. Mid's are much sweeter without losing
 the detail.
  
 I also tried a pair of these that I had in my stash; platinum and cryo'ed. http://www.upscaleaudio.com/mullard-cv4003-12au7-vintage-new-old-stock/
 Even better yet than the 6072's above, but I paid less than 60 bucks for the RCA's, and to be honest, I'm not sure that the Mullards
 are enough better to justify the price difference, especially since the Torp III was designed around the 12AY7.  The 4003's had plenty of gain though.
  
 I also had a pair of these on hand; also platinum and cryo'ed. http://www.upscaleaudio.com/mullard-cv4004-12ax7-british-new-old-stock/
 Tomb is correct that the 12AX7 is not the best choice. Even at their much higher price, these sound too aggressive, probably because of some
 distortion. As with the 4003's, plenty of gain.
  
 My main amp is an Eddie Current Balancing Act with PX4 output tubes. After reading the original Torp I thread, I wanted to build one just
 to hear it. Then along comes the Torp III with optional Cinemag OT's, so I couldn't resist ordering one. Besides, I haven't built anything for
 quite a while, and was Jones'ing pretty bad. 
	

	
	
		
		

		
		
	


	




  Of course, I couldn't help but compare the two amps, and while the Torp III can't keep up
 with the BA's 'otherworldly soundstage', it holds its own quite well in all other aspects; detail, dynamics, bass, et al. At around $850 with the
 Cinemags, stock cap's, and a pair of vintage 6072's, it's a steal.
  
 A massive thanks to dsavitsk and tomb for bringing us this marvel and for their continued selfless assistance.
  
 Of course, FWIW and YMMV.


----------



## badf00d

@dsavitsk, @tomb : Wow, I built mine with Cinemags and the sound is fantastic. Been grooving on it all last night and today. It was a lot of fun to build as well. You guys are great.


----------



## tomb

Great!  Glad you're enjoying it.
  
 I think we can add the 12AV7 to the list of quite nice tubes to use in the Torpedo.  I received a pair today and tried them for the first time.  I have more coming in and will report back when I try them, but so far, this pair is outstanding.


----------



## badf00d

tomb said:


> I think we can add the 12AV7 to the list of quite nice tubes to use in the Torpedo.  I received a pair today and tried them for the first time.  I have more coming in and will report back when I try them, but so far, this pair is outstanding.


 
  
 Which manufacturer?


----------



## tomb

RCA

That said, there are a few others that may offer a substantial improvement, perhaps similar to the difference between 6J6 vs 5920 (E90CC) in the Torpedo I. First listens seem to confirm this, but again - I have more coming in and will report for certain soon.


----------



## amtgamt1

Could you explain a bit about how the power supply outputs 225V to the tube and 2mA to the filament as mentioned in your website? I am a newer in diy but i'm kinda interested how this power supply works. Thanks.


----------



## dsavitsk

amtgamt1 said:


> Could you explain a bit about how the power supply outputs 225V to the tube




R3, D3, D4, and D5 form a voltage divider. D3-D5 will always drop a fixed (~225) voltage as they are Zener diodes, and that's what Zeners do. R3 drops the remaining voltage and limits the amount of current flowing through the diodes. That 225V biases the gate of Q1, and the source stays at a fixed voltage from Q1. C5 shunts Zener and residual power supply noise.



amtgamt1 said:


> and 2mA to the filament




There are no filaments here. Directly heated tubes have filaments, these tubes have heaters. At any rate, there is a constant current source connected to the tube's cathodes that is set at 2mA. The CCS connects to the -6.3V power supply which does double duty powering the heaters.


----------



## badf00d

The more I listen to this amp, the more I love it. The bass has some serious attitude, and the highs are very resolving. Can't wait to try some tube rolling... first time for me.


----------



## tomb

badf00d said:


> The more I listen to this amp, the more I love it. The bass has some serious attitude, and the highs are very resolving. Can't wait to try some tube rolling... first time for me.


 
  
 For me personally, I have never had an amp that sounds this good.  It's really something wonderful to think that I can build (and sell) an amp with this kind of quality.  THANKS DOUG!!
  
 I have been busy building several "built" versions of the Torpedo III.  In between time, I have been listening to every different tube I can get my hands on.  Unfortunately, my ears are over-whelmed at this point.  There are a few tubes that are obvious to me as not-so-good-fits, but the rest are completely confused in my mind.  The not-so-good-fits I've already mentioned - the 12AX7 is so-so but acceptable if you need wildly high gain; the 12AZ7 I did not like very much.
  
 The rest have obvious differences, others not so much.  I can say with certainty that the 12AT7's are a great alternative with an obvious difference, but am at a loss to really explain that difference at the moment.  Here are some of the others I've tried, in no particular order:

6072
6201
12AV7
5965
12AT7 (both NOS and NEW EH)
6829
6414
  
 I suspect the 6829 and 6414 may have super-potential, but the pairs that I have are not matched very well and it makes it difficult to tell.  There is also the E180CC/7062, but it seems destined for audiophile-sticker-price-stratosphere.  Similarly, the pair of 5965's I have are not well matched.  There are flashes of greatness, but then my ears get tired and I start questioning whether I've really heard something different or not.
  
 I am going to suspend all listening soon and do some RMAA's, which is a quite good tool (despited NWAVGUY's accusations) if you use it for direct comparisons.  The plan is to come up with some graphs that show a number of these tubes together, assuming all else is held constant.
  
 P.S. Most every 12AU7 tube - including the 5963 - sound great in the amp, but that's with Grados. As Dsavitsk mentioned, they probably don't have enough gain for typical high-impedance phones.


----------



## tomb

tomb said:


> P.S. Most every 12AU7 tube - including the 5963 - sound great in the amp, but that's with Grados. As Dsavitsk mentioned, they probably don't have enough gain for typical high-impedance phones.


 
  
 Dsavistk wanted me to clarify that with transformer output, *power is pretty much the same at low impedance vs. high impedance*.  I understood that, but I'm always talking about Senn HD580's/600's (which I own) vs. HD650's (which he owns).  There's a 6dB improvement in efficiency going from HD600's to HD650's.


----------



## fierce_freak

tomb said:


> P.S. Most every 12AU7 tube - including the 5963 - sound great in the amp, but that's with Grados. As Dsavitsk mentioned, they probably don't have enough gain for typical high-impedance phones.


 
  
 I have some 5963's cooking in mine now. Way more than enough gain for HD650 (for me).
  
Got the case powdercoated. Take a look at the grill and where the tubes protrude from the top - trying to decide whether or not to keep the rings around the tubes. Thoughts?


----------



## AndreYew

That looks pretty good. An easier route might have been drilling a bunch of holes above the caps.


----------



## tomb

Well with the Thanksgiving holidays, I've had a chance to do some fairly thorough tube rolling tests.  I will post all of this sometime this weekend in excruciating detail on the Torpedo III website.  Also,* please note the noise figures may be at the limits of the device used for testing* - see the post below for an explanation.  For now - here are the highlights.*
  
 First, results at 32R:

  
 Second, results at 300R:

  
 In order to make some sense out of this, here are some plots of S/N ratio (same as Noise in RMAA) and %THD vs. tube type.  Again, one for 32R and one for 300R.
  
 32R:

  
 300R:

  
 So what can be gleaned from all of this?  A few conclusions that I've drawn, but again realize that opinion strongly guides my conclusions.  Data can be manipulated, depending on how you display it and how the base settings and assumptions were applied in the beginning.  More on how to manipulate data later.  For now, here are my personal conclusions:
  

*The Torpedo III has an extraordinary frequency response for a tube/tube-hybrid amplifier*, especially with output transformers (all tests were done with Cinemags):
*300R *-.025dB at 20Hz and -0.25dB at 20KHz; ruler-flat inbetween.  The M-Audio Audiophile USB shows the very same drop at 20KHz (so no drop for the Torpedo), and only slightly less at 20Hz.
*32R *-0.25dB at 20Hz and -1 dB at 20KHz; ruler-flat inbetween.  This is still outstanding, but shows that frequency response is a bit better at 300R.
*Bottom line, frequency response was the same with every tube.*  There was no deviation.  The only change in frequency response occurred between 32R vs. 300R.  All other tube differences were in distortion and noise.
*Distortion with the Torpedo III rivals some solid-state amps*.  Distortion of 0.0062% was measured with the 12AY7 EH tubes at 300R.  However, the King of low distortion was the GE 12AZ7 at 0.0031% at 300R!
*We made the right decision in supplying the 12AY7 EH with the kits.*  This tube is consistently superior at both 32R and 300R.
*Dsavitsk was also correct in highlighting the 12AZ7 as a tube with promise for the Torpedo III.*  I don't know what was going on when I personally first listened to a pair, but I missed the boat - big time.  Distortion for the 12AZ7 tube at 300R is simply incredible.  At 32R, the EH 12AY7 bests it quite a bit, but still - lots of potential perhaps with this tube.
*Distortion is consistently higher at 32R, while S/N is ~10dB greater.*  Noise is in the low-to-mid -90dB's all across the board at 32R.  At 300R, noise is in the mid-to-high -80db's.
12AT7 is a viable alternative, although numbers are slightly worse than 12AY7 all around.  The 6829 may be somewhere inbetween, but also shows promise.  Again, the 12AZ7 may be superior at 300R and competitive at 32R.
  
 Other conclusions somewhat related:

Don't believe "matching" for tube pairs on ebay.  I found extremely wide disparities, almost none of which were consistent with my own personal testing and matching.
At least for the Torpedo III, NEW construction tubes (EH anyway) are superior to most NOS tubes in every respect.  They really are better, at least with run-of-the-mill, non-boutique tubes.
I could not even test the 12AU7 at 300R.  The output was not strong enough under any adjustment to meet the levels required to run an RMAA test.  I suspect that may even mean negative gain?
  
 * (Non-brand-specified tubes in the two tables are Electro-Harmonix.)


----------



## tomb

One thing to note about the noise figures is that generally speaking, the noise floor hovers around -130dB.  There are artifacts in using the M-Audio Audiophile USB that contribute to higher noise values, I'm afraid.  Here's a graph of the M-Audio in loopback mode:
  

*This is a noise of -95.1dB because of those peaks.*
  
 Here is a plot of the Torpedo III with EH 12AY7's at 32R:

*This is  a noise of -94.0 for the Torpedo III - because of almost identical peaks.*
  
 So, the Torpedo III measurement is very close to the limits of the M-Audio device, if not THE limits due to variances in measuring.  The M-Audio Audiophile USB actually "looks" worse than my M-Audio Transit, but the straight-line noise floor is in a lower octave.  The M-Audio Audiophile USB is separately powered with an AC walwart.  That makes it overall more quiet than the Transit, but it's obvious that they don't have a power supply good enough to remove the 60 Hz and its harmonics.  In the first plot above, it's easy to see a peak at 60Hz, 120Hz, and unfortunately, another one at 180 Hz and then a few others as well.
  
 So, I would take the noise values with a huge dose of salt when it comes to the Torpedo III.  I think we are way into the limits of the Audiophile USB's performance.


----------



## tomb

I am speechless.  n_maher and Tyll mentioned the Torpedo III on Innerfidelity.com:
http://www.innerfidelity.com/content/2015-innerfidelity-holiday-gift-guide-nate-maher


----------



## dpump

Tomb,
  
 Will you be able to try the Cinemags in the Torpedo II with Telefunken E90CC's and compare to the Torpedo III? Wandering how close the II would then be to the III. Could mean some sales of the Cinemags to those of us with the II who can't afford to upgrade to the III.


----------



## tomb

dpump said:


> Tomb,
> 
> Will you be able to try the Cinemags in the Torpedo II with Telefunken E90CC's and compare to the Torpedo III? Wandering how close the II would then be to the III. Could mean some sales of the Cinemags to those of us with the II who can't afford to upgrade to the III.


 
 Yes, I will plan on doing that, but the Cinemags are in short supply right now.  So, it may be a little while.
  
 That said, I would note that the Torpedo III with Edcors is noticeably superior to the Torpedo I, so you could at least use that as a comparison for now.  Again, Beezar has always tried to have prices proportional with performance.  So, you could price check the two amps and their various options.
  
 I guess the real question is where a Torpedo I with Cinemags would fall compared to a Torpedo III with Edcors.  That might be a battle, perhaps.


----------



## tomb

Several people had asked about "built" Torpedo III's being available.  I'm almost finished constructing four new Torpedo III's.  I'll put these and a couple of others on sale in the next few days.


----------



## Misterrogers

Awesome Tom! This amp is unique (sonically, design), and non-builders should have a chance at it.


----------



## funch

Hey, they all have the pot ground. Nice. 
	

	
	
		
		

		
			





  What are the red and black cap's? 
  
 Actually, the red ones look like Wima's.


----------



## tomb

funch said:


> Hey, they all have the pot ground. Nice. :rolleyes:   What are the red and black cap's?
> 
> Actually, the red ones look like Wima's.




Yep. The red ones are Wima MKP4's. The black ones are Vishay-Roederstein MKP's. I'm testing them while building these. If they're not as good as the Epcos, they'll be swapped out. If they're the same or better - they'll be left in and you all will then know there are some great parafeed cap options.


----------



## raybone0566

Tomb,
Very interested in buying one of the assembled amps.


----------



## tomb

raybone0566 said:


> Tomb,
> Very interested in buying one of the assembled amps.


 
  
 ygpm


----------



## tomb

After building these four, I've discovered that some of the kit parts differ slightly from the parts used in the prototype.  The prototype was the basis of the construction sequence page on the web site.  So, I've modified that sequence page to match the parts that you will find in the kits:
http://www.diyforums.org/Torpedo-III/TorpedoIII-construct1.php


----------



## drfindley

Bear with me as it's been a while, but I figured out what was wrong with my T3: I have a transformer buzz that shows up after an hour. Is it best to just order a new one to replace it? Did I likely torch the thing? 
  
 The amp has been a bit fatiguing on my HD650s in the lower highs. I'm betting it's related to my transformer problem though as no one else has had that problem. But if I'm fixing/replacing parts and there's something that'd likely be the cause of that, I'd love any ideas people have


----------



## FallenAngel

This thread was a rude awakening that I've been neglecting the DIY forums for much too long 
  
 This build looks awesome! Super easy build, full PCB, custom panels, custom case, just everything nicely done!
  
 I think I won't be able to resist and within the 15 minutes of reading through the thread before I must pull the trigger and build one myself. 
  
 tomb: I just realized we joined the same month and you're about 200 posts ahead. Definitely I need to up my headfi mojo and try to be as helpful as you've always been!


----------



## HiGHFLYiN9

drfindley said:


> Bear with me as it's been a while, but I figured out what was wrong with my T3: I have a transformer buzz that shows up after an hour. Is it best to just order a new one to replace it? Did I likely torch the thing?
> 
> The amp has been a bit fatiguing on my HD650s in the lower highs. I'm betting it's related to my transformer problem though as no one else has had that problem. But if I'm fixing/replacing parts and there's something that'd likely be the cause of that, I'd love any ideas people have


 
  
 Assuming it's the power transformer? Could *possibly* be DC offset in your mains. You may try a different outlet in your house or at work to see if that makes a difference, if it does Emotiva makes a surge strip that will fix that issue for ~$100. Could also be a bad xformer, in that case you'd have to order another one.
  
 For the fatigue, have you tried rolling in other tubes? It's surprising that the HD650 could be fatiguing as it's such a warm sounding headphone.


----------



## HiGHFLYiN9

A side-note, but if anyone wants to buy my Torpedo I (sans chassis), let me know  You could box it up yourself or purchase a chassis from Beezar.


----------



## tomb

drfindley said:


> Bear with me as it's been a while, but I figured out what was wrong with my T3: I have a transformer buzz that shows up after an hour. Is it best to just order a new one to replace it? Did I likely torch the thing?
> 
> The amp has been a bit fatiguing on my HD650s in the lower highs. I'm betting it's related to my transformer problem though as no one else has had that problem. But if I'm fixing/replacing parts and there's something that'd likely be the cause of that, I'd love any ideas people have




As discussed offline, I'm a bit worried that something else is going on.

That said, if you can return the PT to me, I will send it to Edcor for analysis. Meanwhile, I can send you a new one right away if that sounds like a good solution to you.


----------



## tomb

fallenangel said:


> This thread was a rude awakening that I've been neglecting the DIY forums for much too long
> 
> This build looks awesome! Super easy build, full PCB, custom panels, custom case, just everything nicely done!
> 
> ...




I guess now we're just a couple of old-timers, right?

I thought you were in San Fran!?


----------



## FallenAngel

tomb said:


> I guess now we're just a couple of old-timers, right?
> 
> I thought you were in San Fran!?


 
  
 lol, guess we're the old guys. I spent a couple of years in California but came back to Canada. I like Toronto, there's just no comparison for me. This is home!


----------



## dsavitsk

2006? You guys are a bunch of neophytes.

As for the transformer - It would certainly not be the first noisy Edcor we've seen, but checking for DC offset is a good idea as a first step as replacing these is not trivial.

The buzzing is mechanical? That should not translate into harsh sound. Are you sure the B+ regulator is working properly?


----------



## drfindley

highflyin9 said:


> Assuming it's the power transformer? Could *possibly* be DC offset in your mains. You may try a different outlet in your house or at work to see if that makes a difference, if it does Emotiva makes a surge strip that will fix that issue for ~$100. Could also be a bad xformer, in that case you'd have to order another one.
> 
> For the fatigue, have you tried rolling in other tubes? It's surprising that the HD650 could be fatiguing as it's such a warm sounding headphone.


 

 I tested the mains and there is a 3-10mV noise on the mains. I tried this plugged into a CyberPower Sinewave UPS and had the same problem. The Emotiva strip is probably not a bad idea either.
  
 I've rolled some tubes and I haven't heard a difference. I figured it was due to power issues...


  


tomb said:


> As discussed offline, I'm a bit worried that something else is going on.
> 
> That said, if you can return the PT to me, I will send it to Edcor for analysis. Meanwhile, I can send you a new one right away if that sounds like a good solution to you.


 
 By offline do you mean another discussion on another site? I seem to be missing the discussion, which is why I posted here.
  
 Thanks tomb, I figured it's probably something dumb I did, a replacement seems to be a good way to start. Unless someone in the Bay Area wants to diagnose it first?


----------



## tomb

drfindley said:


> highflyin9 said:
> 
> 
> > Assuming it's the power transformer? Could *possibly* be DC offset in your mains. You may try a different outlet in your house or at work to see if that makes a difference, if it does Emotiva makes a surge strip that will fix that issue for ~$100. Could also be a bad xformer, in that case you'd have to order another one.
> ...


 
  
 Well, shoot.  I thought you were the guy who's been corresponding with me through e-mail already.  If you're not, then that means we have two suspect PT's in the mix.  DANG!  I see what Doug's said, but I thought we only really had one that way in the hundreds of PT's we've sold through the Torpedo I and now, the Torpedo III.  Really, the only time I replaced a PT was when a guy built and shipped one overseas without half the mounting screws attached on the IEC inlet.  When the overseas customer plugged it in, he promptly burned up the PT.  The only other time I can remember was in the Torpedo I prototypes and it was Fitz, if you remember him, and I can't remember what he did - but we never went through a replacement.
  
 If you're not that guy who's e-mailed me, then I guess I should've remembered what "ass-u-me" really means.
  
 It also means I need to have quite a conversation with Edcor if this is really the situation.


----------



## drfindley

tomb said:


> Well, shoot.  I thought you were the guy who's been corresponding with me through e-mail already.  If you're not, then that means we have two suspect PT's in the mix.  DANG!  I see what Doug's said, but I thought we only really had one that way in the hundreds of PT's we've sold through the Torpedo I and now, the Torpedo III.
> 
> If you're not that guy who's e-mailed me, then I guess I should've remembered what "ass-u-me" really means.
> 
> It also means I need to have quite a conversation with Edcor if this is really the situation.


 
  
 I do the same thing when I deal with two similar bugs at work  
  
 I read that for the CyberPower Sinewave to filter your power, you actually have to unplug it from the wall. I'm going give that a shot tonight and see if I'm having a problem with my mains as well.
  
 I'd be happy to send this your way though.


----------



## tomb

dsavitsk said:


> 2006? You guys are a bunch of neophytes.


 
  
 Yeah, that's true, but at least I remember when you were just "drs" and had no avatar.


----------



## tomb

drfindley said:


> tomb said:
> 
> 
> > Well, shoot.  I thought you were the guy who's been corresponding with me through e-mail already.  If you're not, then that means we have two suspect PT's in the mix.  DANG!  I see what Doug's said, but I thought we only really had one that way in the hundreds of PT's we've sold through the Torpedo I and now, the Torpedo III.*
> ...


 
  
  
 Yeah, I edited the above post after you replied.  I can remember two instances of PT issues - 1) A guy built and sold a Torpedo I to an overseas customer.  He had such shoddy workmanship that he left out half of the mounting screws on the IEC inlet.  When it arrived overseas after a tumble in shipping, the overseas customer plugged it in and promptly burned up the PT.  2) During the first set of prototype builds for the Torpedo 1, "Fitz" had a buzzing PT.  I can't remember what he finally did, but he never asked me to replace the PT.
  
 Anyway - yes, I will ship you a new PT if you feel that's the issue.  I only ask that I get the original PT back so that I can hit Edcor over the head with it. (speaking figuratively, of course).


----------



## badf00d

drfindley said:


> Bear with me as it's been a while, but I figured out what was wrong with my T3: I have a transformer buzz that shows up after an hour. Is it best to just order a new one to replace it? Did I likely torch the thing?
> 
> The amp has been a bit fatiguing on my HD650s in the lower highs. I'm betting it's related to my transformer problem though as no one else has had that problem. But if I'm fixing/replacing parts and there's something that'd likely be the cause of that, I'd love any ideas people have


 

 I've been using my HD800 on my T3. After some good burn in with the stock tubes (yes, the EH tubes) the sound has smoothed out quite a bit for me, so hopefully you find the same thing after you sort out your transformer problem. Keep us posted.


----------



## tomb

A few assembled Torpedo III's are now available - very few.


----------



## thinkingoffish

Finished my Torpedo III last week.  This was my first soldering project, and I'm glad I decided to go this route.  The amp is wonderful.  I'm not going to bother going into how it sounds as I hate trying to describe to other people what I hear, but I will say this has an amazingly black background.  No noise even with low impedance / high sensitivity iems plugged in (at usable listening levels).  I haven't gotten to trying out those tubes you sent with mine yet Tom, as I wanted to give myself at least a couple weeks just using the EH 12ay7's first.
  
 Seriously enjoying this though.


----------



## FallenAngel

Really curious how much room is in that case for C7-C10. I just grabbed some Obbligato 10uF/630V caps that are 55mm by 30 mm wide. As the original caps are 31mm tall, I'm really hoping there will be wiggle room in the case to fit these.


----------



## tomb

fallenangel said:


> Really curious how much room is in that case for C7-C10. I just grabbed some Obbligato 10uF/630V caps that are 55mm by 30 mm wide. As the original caps are 31mm tall, I'm really hoping there will be wiggle room in the case to fit these.




Hmm ... I hate to conclude this, but it sounds like they won't fit. There may be 50mm of headroom above the PCB, but I don't know if 55mm is going to make it. What may be worse is the width. The PCB is only 100mm wide, less when counting the case slots. It sounds like you have at least 120mm (4 x 30mm).


----------



## FallenAngel

tomb said:


> Hmm ... I hate to conclude this, but it sounds like they won't fit. There may be 50mm of headroom above the PCB, but I don't know if 55mm is going to make it. What may be worse is the width. The PCB is only 100mm wide, less when counting the case slots. It sounds like you have at least 120mm (4 x 30mm).


 
  
 The caps are 50mm long and 30mm wide.
  
 The documentation says there are pins for 53mm length for C7-C10, so length wise, I'm thinking there should be enough room.
  
 For the width, that's where I'm worried a bit. I need to stagger the caps so that I get a full 20mm extra. A bit of simple math puts me at 5mm overlap per cap, so with a 30mm diameter on the caps, widest in the middle, at 15mm per cap mounted higher, considering that they're cylinder shaped, it should work out that the top of the upper caps are going to be about 45mm above the PCB. LOL, screw those guys that said you never use maths after high school. 
  
 I'll post photos but considering you said that there is 50mm of headroom, I think it should fit.


----------



## tomb

fallenangel said:


> tomb said:
> 
> 
> > Hmm ... I hate to conclude this, but it sounds like they won't fit. There may be 50mm of headroom above the PCB, but I don't know if 55mm is going to make it. What may be worse is the width. The PCB is only 100mm wide, less when counting the case slots. It sounds like you have at least 120mm (4 x 30mm).
> ...




Yeah, I guess I have box caps on the brain. It sounds like you will be able to stagger them.


----------



## dsavitsk

fallenangel said:


> Really curious how much room is in that case for C7-C10. I just grabbed some Obbligato 10uF/630V caps that are 55mm by 30 mm wide.




Do those have metal bodies?



tomb said:


> Hmm ... I hate to conclude this, but it sounds like they won't fit. There may be 50mm of headroom above the PCB.







fallenangel said:


> screw those guys that said you never use maths after high school.
> 
> I'll post photos but considering you said that there is 50mm of headroom, I think it should fit.




Nope.


----------



## FallenAngel

dsavitsk said:


> Do those have metal bodies?
> 
> Nope.


 
  
 Kill my dreams why don't you.
  
 Caps have a plastic exterior.


----------



## dsavitsk

Plastic is good. I think you'll be surprised at how good the box caps are. But if you aren't, the best option is likely a small (0.1u?) bypass across the top of the box cap. Otherwise, you might look for 4.7u/300V caps that will fit and use 8 of them.


----------



## FallenAngel

dsavitsk said:


> Plastic is good. I think you'll be surprised at how good the box caps are. But if you aren't, the best option is likely a small (0.1u?) bypass across the top of the box cap. Otherwise, you might look for 4.7u/300V caps that will fit and use 8 of them.


 
  
 I'm already heartbroken because those were about $160 CAD 
 I'll see if I can return them, hopefully.
  
 I looked around and the Obbligato were some of the smaller caps I found.
  
 I'll keep looking.


----------



## HiGHFLYiN9

dsavitsk said:


>


 
 Doh! 
	

	
	
		
		

		
			





 ...guess you could use two of em


----------



## FallenAngel

highflyin9 said:


> Doh!
> 
> 
> 
> ...


 
  
 https://media.giphy.com/media/pRElAzlflnRYI/giphy.gif


----------



## tomb

dsavitsk said:


> Plastic is good. I think you'll be surprised at how good the box caps are. But if you aren't, the best option is likely a small (0.1u?) bypass across the top of the box cap. Otherwise, you might look for 4.7u/300V caps that will fit and use 8 of them.


 
  
 Nice CAD work, Doug!  (Even though FA is sorely disappointed.)  I was on my smart phone all day, so all I could do was look at the drawings and estimate.


----------



## tomb

fallenangel said:


> highflyin9 said:
> 
> 
> > Doh!
> ...


 
  
 You probably don't want to hear this suggestion, but you could cut out a rectangle in the top of the case.  fierce_freak did that a couple of pages back.  He was concerned about heat, but it might take a very little rectangle to give two center caps more headroom, allowing all of them to squeeze together more closely side-to-side.
  
 This is also drastic, but you might be able to cut two slots in the PCB to allow two of the caps to "sink" lower into the case.


----------



## tomb

Nope - won't work by slotting the PCB.  There's not enough room under the PCB.  The CAD file says the rectangle in the top of the case would have to be 0.9 inches wide per cap, or 2.09 inches all the way across, give or take a few fractions of an inch:


----------



## FallenAngel

tomb said:


> You probably don't want to hear this suggestion, but you could cut out a rectangle in the top of the case.  fierce_freak did that a couple of pages back.  He was concerned about heat, but it might take a very little rectangle to give two center caps more headroom, allowing all of them to squeeze together more closely side-to-side.
> 
> This is also drastic, but you might be able to cut two slots in the PCB to allow two of the caps to "sink" lower into the case.


 
  
 I love the idea, but the board has a signal from R10/R12 moving forward through the middle as well as some signals along the side. I might really have to suck it up, lose some money and return the caps.  I'll mess with it and see where it goes but I don't know how well it would go.


----------



## JamieMcC

Can I ask  if there are any measurements for the actual voltages that C7 and C10 see and what potential consequences would be if one failed would it be terminal for the amp or just a case of replacing the failed capacitor?


----------



## dsavitsk

If the amp is running as expected, they have around 150V across them. At startup, or if the tube is not conducting for some reason, they'll have 225V. And if the regulator fails, they could see close to 300V or so.

If one fails, you still have the transformer between you and the high voltage. The transformer is not rated for high voltage, so it is not to be counted on for any protection. And it could be damaged.

If a cap failed shorted, you could probably expect some transistors to overheat and be damaged. A short to ground should blow the fuse before the power transformer is damaged.

Do not use under specified caps just to get them to fit. The difference in sound is almost insignificant, and if you think it makes a huge difference, build or buy a different amp.


----------



## JamieMcC

dsavitsk said:


> If the amp is running as expected, they have around 150V across them. At startup, or if the tube is not conducting for some reason, they'll have 225V. And if the regulator fails, they could see close to 300V or so.
> 
> If one fails, you still have the transformer between you and the high voltage. The transformer is not rated for high voltage, so it is not to be counted on for any protection. And it could be damaged.
> 
> ...


 

 Understood and thank you.


----------



## drfindley

I put in the new PT and it's now whisper quiet. So much better! The stock tubes still aren't my favorite. A little too shouty in the upper-mid-range. Right around the snare drum level. Playing "Steady as She Goes" by the Raconteurs hits it hard on the first note.
  
 So I did some tube rolling and my favorites are some Amperex E180CC/7062 from a McIntosh solves the problem and sound quite lovely.


----------



## FallenAngel

Finished my build with upgraded transformers and it does sound quite wonderful.
  
 Just one thing - at about 50% volume through UE700 IEMs (very efficient, fairly low impedance - http://www.innerfidelity.com/images/UltimateEarUE700.pdf ), there starts to be a slight hum/buzz in the background. At this level, it's already pretty damn loud when music is playing, and it increases as the volume goes up.
 While music plays, it's obviously not noticeable, but with nothing there at ear-splitting levels, you can certainly hear it.
  
 Is this expected at all, or am I unlucky with my build?
  
 I'm seriously not expecting to use this amp for IEMs, that would be overkill, I'm curious how it'll handle the Grados I'm getting soon.


----------



## tomb

fallenangel said:


> Finished my build with upgraded transformers and it does sound quite wonderful.
> 
> Just one thing - at about 50% volume through UE700 IEMs (very efficient, fairly low impedance - http://www.innerfidelity.com/images/UltimateEarUE700.pdf ), there starts to be a slight hum/buzz in the background. At this level, it's already pretty damn loud when music is playing, and it increases as the volume goes up.
> While music plays, it's obviously not noticeable, but with nothing there at ear-splitting levels, you can certainly hear it.
> ...


 

 NO, it is not expected at all.  I've built quite a few of them already and my Ety's are wonderful through the T3.  Needless to say, my Grado HF-2's have been my go-to cans for years.  Everything Doug designs sounds great with Grados.
  
 I suspect you have a bad tube(s).  Is it in both channels?  If you swap the tubes, does anything change?  They may just need a re-seating, too.


----------



## FallenAngel

tomb said:


> NO, it is not expected at all.  I've built quite a few of them already and my Ety's are wonderful through the T3.  Needless to say, my Grado HF-2's have been my go-to cans for years.  Everything Doug designs sounds great with Grados.
> 
> I suspect you have a bad tube(s).  Is it in both channels?  If you swap the tubes, does anything change?  They may just need a re-seating, too.


 
  
 Thanks Tom.
  
 I'll do a little debugging and see how things go.
  
 As you may know, I'm hosting a meet in less than 2 weeks so I'm incredibly busy getting things prepared for it. This was my first listen with the IEMs and I have no idea of details. For all I know, it might be my source because I get intermittent noise anyway. I'll make sure to try it with my "reference testing system" that's darker than black with custom PSUs. It's a little one-box build I made with a DAC, Pre-Amp, Headphone Amp and disconnected POT to make sure nothing enters the signal. I only use it for testing as it's overall a half-decent system I don't want to showcase. 
  
 I'll update in a few days when I have a chance to debug.
  
 Thanks again.


----------



## FallenAngel

Well, that didn't take long!
  
 I hooked up my testing system and checked through everything.
  
 With some sensitive AKG K518 (32 Ohm, 115dB SPL/V), the background is dead black. With the UE700, I get a bit of hiss around 80% volume at which the volume is beyond ear-splitting, it's deafening. I seem to only hear something with those IEMs off this amp.
  
 Look like the DAC I use everyday has enough noise in it that these IEMs can detect. Well, no surprise as it's a balanced DAC with a discrete output stage pushing 4V balanced... Yeah, it's a bit much...With my normal listening setup of Buffalo 3 - Legato - Balaned Dynalo - HD650, there's nothing in the background. Who knew you could connect a pair of IEMs to this system, and slap the man who did it!
  
 No worries guys, the Torpedo 3 is about as silent as my system could ever be. 
  
 Don't mean to make you worry Tom, sorry about that.


----------



## tomb

fallenangel said:


> Well, that didn't take long!
> 
> I hooked up my testing system and checked through everything.
> 
> ...


 
  
 Great!  No worries - good to know things are fine.  I hope people get to enjoy the T3 at your meet and good luck!


----------



## FallenAngel

tomb said:


> Great!  No worries - good to know things are fine.  I hope people get to enjoy the T3 at your meet and good luck!


 
  
 Shhh! Nobody knows that I'm bringing this! I think this will be the first T3 anybody has ever heard in Toronto


----------



## JamieMcC

Hi Tomb any idea when the cinemags for the T3 will be back in stock and what is the availability of the tail CCS?
  
 tia
  
 Cheers
  
 Jamie


----------



## tomb

I believe Dsavitsk is hoping by the end of the month.


----------



## NuClear235

I found the same construction philosophy headphone amp
http://www.6moons.com/audioreviews/yamamoto4/ha02.html
  
 I dont know its sound. I just foud it on web...
 Ilike using C-core power tranformer. Dont it make possible shorter construction ?


----------



## tomb

nuclear235 said:


> I found the same construction philosophy headphone amp
> http://www.6moons.com/audioreviews/yamamoto4/ha02.html
> 
> I dont know its sound. I just foud it on web...
> Ilike using C-core power tranformer. Dont it make possible shorter construction ?




Same construction philosophy? There is nothing similar except for saying that both use tubes. For that matter, there was no reference to DIY, either.


----------



## Misterrogers

Heh. Yea, I was scratching my head on that one too.


----------



## tomb

Torpedo III kits (and a couple assembled) are back in stock at beezar.com with Cinemag output transformers!


----------



## audiojun

How hard is the torpedo III kit to assemble? The only diy experience I have was building the crack and that was about medium difficulty to me.


----------



## tomb

audiojun said:


> How hard is the torpedo III kit to assemble? The only diy experience I have was building the crack and that was about medium difficulty to me.


 
  
 It's ridiculously simple compared to a Bottlehead.  There is no wiring whatsoever except for the small volume pot ground wire and a safety ground wire to the case back at the power transformer.  Everything, literally everything - is all on the PCB.  There are some tricks on the hardware, which many people try to shortcut (not recommended), but if you are good with screws, washers, lock washers and nuts*, there's nothing to worry about.
  
  
 * It's constantly amazing to me how many people have trouble with simple screw-washer-lock-washer-nut assemblies, but there you go.  I've had people send me their amps for repair and more than half the hardware was missing and yet, I supply every bit of it with the kits.  Unbelievable.


----------



## audiojun

Thanks for the info I am probably going to order this soon.
  
 I have a few more questions: What is the output impedance of the amp on low z and on high z? Also is this a push-pull amplifier? (The word differential in the amp name sounds like push-pull).


----------



## tomb

audiojun said:


> Thanks for the info I am probably going to order this soon.
> 
> I have a few more questions: What is the output impedance of the amp on low z and on high z? Also is this a push-pull amplifier? (The word differential in the amp name sounds like push-pull).


 

 You're going to have to ask Dsavitsk about output impedance.  I don't think it has the same meaning that everyone uses when output transformers are involved.  The output transformers can almost be wound to any output impedance desired.  So, the choice is a conscious design decision.  The output transformers themselves are wound for either 300 ohm output matching (high-Z) or 32 ohm output matching (low-Z).  I'm not exactly sure what that means for the overall output impedance for the amp, but the idea is that the separate windings sort of make impedance values of the headphones moot.  The amp produces essentially the same power at 300 ohms that it does at 32 ohms.
  
 As for differential and push-pull, yes - they are similar.  In the T3, the tubes actually perform the phase split/inversion by virtue of a long-tail-pair configuration.  So, the amp is differential from the point of the tubes' output all the way to the output transformers.  Some people call that balanced and ask why there aren't balanced connectors on the input an output.  The reason being is that the T3 was not designed to take advantage of balanced connections.  Rather, it uses the differential internal circuitry to lower common mode distortion/noise.
  
 With a 12AY7 tube, I've measured distortion from 20Hz-20kHz as low as 0.014% THD at 32 ohms and as low as 0.0062% at 300 ohms.  Using 12AZ7 tubes, I've measured distortion in the T3 as low as 0.0031% THD at 300 ohms.  This is simply superlative for a tube ampilifer and pretty d*mn good for solid-state, too.


----------



## dsavitsk

Push-pull is a large catchall that is not very descriptive. Yes, it is push-pull, but this does not mean that it is very closely related to many other designs that can also be described as push-pull. It is a differential circuit, which is a better description here.

The output impedance is very low and is basically just due to the transformers windings. The output portion of the circuit, which is a differential darlington emitter follower, has a Z out of just a few ohms. When transformed by the transformer it is basically 0. The copper just adds some series resistance - under 10 Ohms on low and around 20 Ohms on high IIRC. 

How that relates to the 32 Ohm and 300 Ohm rating of the transformer has to do with the transformer's primary inductance, winding ratio, and the resulting impedance at a particular frequency (20Hz here). In both cases, the rated load reflects a 7K Ohm impedance to the output circuitry.


----------



## audiojun

Thanks for all the info guys! Happy Easter!
  
@tomb
 I just placed my order #2930. I went all out with the Cap upgrade and Cinemag Transformers. Give me some cherry picked and matched parts please!
  
@dsavitsk
 My dad is a little against push-pull topography but this "differential" amp is probably something special. I hope to prove him wrong with the Torpedo III.


----------



## dsavitsk

audiojun said:


> My dad is a little against push-pull topography




There was a time when single ended amps were only used because they was cheaper to build and good enough for low end equipment.


----------



## tomb

We've recently discovered a way to reliably install the new Mundorf EVO caps (Aluminum.Oil may be the best value/performance combination) into the Torpedo III.  This really raises the performance to a new level, perhaps even more than a pair of great tubes.
  
 Anyway, I completed a new how-to on the T3 website for installing these caps:
Torpedo III Mundorf EVO Parafeed Capacitors Installation


----------



## fierce_freak

Awesome tutorial!


----------



## alpha421

^x2. I think this will be my next project.


----------



## tomb

Great!


----------



## Misterrogers

There isn't a better choice out there in this price range.


----------



## drfindley

misterrogers said:


> There isn't a better choice out there in this price range.


 

 Agreed.


----------



## audiojun

I am enjoying my Torpedo III! great dynamics and high resolution with a wide sound stage. A step up from my Bottlehead Crack.
  
 The customer service is amazing! @tomb is really great at helping me and responding to my questions.


----------



## tomb

audiojun said:


> I am enjoying my Torpedo III! great dynamics and high resolution with a wide sound stage. A step up from my Bottlehead Crack.
> 
> The customer service is amazing! @tomb is really great at helping me and responding to my questions.


 

 Well, thank you very much for those kind comments!  Dsavitsk and I both are very happy that you got everything working.  Another LED is on the way to you now.


----------



## audiojun

CCS boards are available now for order. I already picked one up.


----------



## dogears

subscribed


----------



## J-Pak

I ordered a stock kit with the Solen PB. Are the cap dimensions 26 mm (diameter) x 38 mm and if so does this mean they need to be staggered?


----------



## tomb

j-pak said:


> I ordered a stock kit with the Solen PB. Are the cap dimensions 26 mm (diameter) x 38 mm and if so does this mean they need to be staggered?


 

 Staggered, yes - but only in the vertical dimension, not horizontally.  It's entirely possible to install three of them and then have the fourth on top of the open space by about a third of its diameter.  I like symmetry, so I solder the two on the outside flush to the PCB, then have the two in the middle raised up by about 1/2" in the same plane.
  
 Just bend the leads down once - just like a resistor - and pop them in the PCB for a trial fit.  You'll quickly see what I'm talking about - it's very simple.


----------



## J-Pak

tomb said:


> Staggered, yes - but only in the vertical dimension, not horizontally.  It's entirely possible to install three of them and then have the fourth on top of the open space by about a third of its diameter.  I like symmetry, so I solder the two on the outside flush to the PCB, then have the two in the middle raised up by about 1/2" in the same plane.
> 
> Just bend the leads down once - just like a resistor - and pop them in the PCB for a trial fit.  You'll quickly see what I'm talking about - it's very simple.


 
  
 Thank you tomb!
  
 Looking forward to building it, something to do with weather starting to get hot in New England


----------



## bazelio

T3 at home on my desk at work.  So unassuming.  Fantastic sound from this amp, and the form factor is just perfect for tucking it underneath a makeshift monitor stand aside a DAC.


----------



## audiojun

love it when things fit, my monitor stand is just a few mm too short to tuck the torpedo III under.


----------



## bazelio

Yeah, I probably couldn't make this fit with Amperex 7062s installed, but they're not the best tube for me with this amp, so a non-issue.


----------



## J-Pak

tomb that is quite the amazing packaging job! Everything so neat and well labeled.
  

  

  

  
 I did a quick test fit with the Solens if anyone was curious, since I haven't seen pictures with them. There is plenty of room for 26 mm diameter caps. Going by the way these fit I assume 10uf Obbligato films should be ok at 27 mm diameter? (size verified with the shop owner) http://www.store.diyhifisupply.com/Catalog/parts/capacitors/Obbligato-Special-Film-Teflon-Caps/10uf-Obbligato-film-cap-PPE
  
 I've used Obblis in other amp/phono-stages and like the sound of them quite a bit compared to some much more expensive caps (never tried the super caps like V-Cap or Duelund).
 Oh yes and as a recovering transformer junkie the Cinemag OPTs look fantastic in that silver/chrome with blue text


----------



## bazelio

I'd bet you could even stand those Obligatos on end to make them fit...  But the orientation you've found seems to work well also!


----------



## tomb

j-pak said:


> tomb that is quite the amazing packaging job! Everything so neat and well labeled.
> 
> 
> 
> ...


 
  
 Thanks for the kind comments on the kit packaging!
  
 Yes, as mentioned elsewhere - I'm a sucker for symmetry, so I would have the two outside Solens flush to the PCB and raise the two in the middle.  You will find that you can even solder three of them flush and then just have one sticking up, but as I said - I like symmetry. 
	

	
	
		
		

		
		
	


	




  I haven't tried the Obbligatos, but they're among Dsavitsk's favorites.  If you give them a shot, please let us know how they sound in the Torpedo III!


----------



## J-Pak

tomb said:


> Thanks for the kind comments on the kit packaging!
> 
> Yes, as mentioned elsewhere - I'm a sucker for symmetry, so I would have the two outside Solens flush to the PCB and raise the two in the middle.  You will find that you can even solder three of them flush and then just have one sticking up, but as I said - I like symmetry.
> 
> ...


 
  
 I will probably do something like what you describe with the Obbligatos. I'm not going to use the Solens (too lazy to take apart the amp and desolder  ), so I'm not sure if my impressions will mean much; I will offer them once the amp is built.


----------



## J-Pak

tomb I saw the posts at the other forum regarding the new tube CCS, how is it different from the offboard ones that go in IC1 and IC2? Should I hold off in soldering those in? I'm still waiting for the caps to ship from Hong Kong so I'm in no hurry 
  
 Thanks.


----------



## tomb

j-pak said:


> tomb I saw the posts at the other forum regarding the new tube CCS, how is it different from the offboard ones that go in IC1 and IC2? Should I hold off in soldering those in? I'm still waiting for the caps to ship from Hong Kong so I'm in no hurry
> 
> Thanks.


 
  
 Sorry, but there's some confusion.  There is only one tube CCS and that is the one you have.
  
 The _other_ CCS is completely different and new. It has nothing to do with the tubes.  Instead, it replaces the output resistors in the differential buffer.  It has a much more significant effect than other tweaks.  The PCBs are currently in production (parts are in already).  I expect them to be available in a week or two, perhaps.


----------



## jh4db536

Ordered the upgraded Plate Resistors and now there's more stuff to upgrade. You guys are killing my wallet lol


----------



## bazelio

Very nice. Those look like very enjoyable and satisfying builds. Don't look at the Super B.A.F. thread if you're afraid of further upgradeitis though. Enjoy the fruits of your labor!


----------



## J-Pak

tomb said:


> Sorry, but there's some confusion.  There is only one tube CCS and that is the one you have.
> 
> The _other_ CCS is completely different and new. It has nothing to do with the tubes.  Instead, it replaces the output resistors in the differential buffer.  It has a much more significant effect than other tweaks.  The PCBs are currently in production (parts are in already).  I expect them to be available in a week or two, perhaps.


 
  
 Thanks tomb. After having a look at the schematic is the CCS going into R5/7, R6/8?
  
 Oh yes I received the Obbligatos. Looks like it will be a non-issue fitting them into the amp. So time to start building!


----------



## bazelio

R19-R22 for the new CCS boards, I believe.


----------



## MortenB

bazelio said:


> R19-R22 for the new CCS boards, I believe.


 
 Yes, the CCS board replaces those emitter resistors.


----------



## tomb

mortenb said:


> bazelio said:
> 
> 
> > R19-R22 for the new CCS boards, I believe.
> ...


 

 Yep - the Output CCS boards have arrived.  It may take me a week or two to build them up and test each one, but they'll be available after that.


----------



## bazelio

Take your time, Tom. We will be ready when you are.


----------



## tomb

Pics of my personal Torpedo III:


----------



## bazelio

It's a hot rod!!!


----------



## tomb

Yeah - I need some flames on the sides.


----------



## funch

So long as the flames aren't on the inside, you'll be fine. 
	

	
	
		
		

		
		
	


	




  Cool look btw. So, when can we order one in red?


----------



## fjrabon

pretty excited for Tom to deliver (benefits of working literally a quarter mile away from where Tom works) my maxed out TIII (Mundorf caps, tube CCs, cinemags, new output CCS, stock EH 12AY7s, 12Z7s and 6829s) on Monday.  Will pair with my iDAC6.  Can't wait to hear the combo of the tube analog stage of the iDAC6 paired with the TIII on my HD800.


----------



## fjrabon

Well, my maxed out (Mundorfs, cinemags, tube CCS, output CCS) TIII and Cayin iDAC6 just came in today. Finally got them both warmed up. And MY GOD they are singing. I realize ideally I should be A/Bing the TIII with a DAC I'm already familiar with, but I'm enjoying what I'm hearing way too much to worry about that right now. With Sonarworks -> GoodHertz Mid-Side/CanOpener -> iDAC6 -> TIII -> HD800, this is the most similar to a vinyl rig through great speakers I've heard headphones get. But with better bass extension and authority than a vinyl rig can reproduce. later this week I'll be comparing this setup to a Yggy -> KGSSHV -> SR009, and I will be shocked if the SR009 setup wins out. I know this sounds like crazy new toy syndrome, but I've heard that SR009 setup a lot, and I always been blown away, but I think this setup matches it in most regards and beats it in several.  

 Right now I'm using the 6829s mostly because I didn't want to take the case off at work to put the other tubes in. It's crazy to hear this much transparency AND power. Usually I feel like you have to choose one or the other, but not here.  

 Was just listening to the intro of Pink Floyd Hey You, and thought I had accidentally switched output to my nearfield monitors because the sound was so distinctly out of my head. Bass is so crisp. Not elevated, but just so taught. Just feels like I'm listening to a virtually unlimited system.  

 The iDAC6 + TIII put off a LOT of heat though, lol. Like when I sit down in my chair next to the area they're in, it's noticeably 3 degrees warmer than the rest of my office, haha.


----------



## tomb

I've updated the installation documentation for all the Tweaks on the Torpedo III website. Installation for the Output CCS Boards is now "Tweak #5."


----------



## jh4db536

Prepared everything for some surgery. The first impressions (without critical listening), the amp got more open/less congested, clearer, more upfront presentation. Headstage possibly got smaller. Possibly brighter or bass is tighter. I think the amp gets a lot hotter.
 
This thing really punches hard now; it's intense.


----------



## HiGHFLYiN9




----------



## J-Pak

I've been listening to mine for a couple of weeks. I mentioned up thread I went with 10 uf Obbligato caps and it's a non issue fitting them in there, I really like the sound quality of these caps but I did not use the Solens so I have no basis of comparison. I also do not have the latest CCS.
  
 IMHO this is as fine a dynamic amp that I've ever heard. These days I am mostly listening to classical and jazz and this amp is without a question more tonally accurate than the Balancing Act. The BA does throw  a large soundstage which is nice, but it does it on nearly every recording.


----------



## comzee

I'm getting one of these in the next few weeks.
  
 I'm having trouble finding all the supported tube type for this amp, is there a list somewhere?
 I know it takes 12AY7, but I'm not sure what others.
  
 Also, does anybody specifically recommend a tube that would pair well with HD800?


----------



## FlySweep

comzee said:


> I'm getting one of these in the next few weeks.
> 
> I'm having trouble finding all the supported tube type for this amp, is there a list somewhere?
> I know it takes 12AY7, but I'm not sure what others.
> ...


 
  
 http://diyforums.org/Torpedo-III/TorpedoIII-tubes.php


----------



## fjrabon

comzee said:


> I'm getting one of these in the next few weeks.
> 
> I'm having trouble finding all the supported tube type for this amp, is there a list somewhere?
> I know it takes 12AY7, but I'm not sure what others.
> ...


 

 I like the GE 12AY7 5 star


----------



## FallenAngel

jh4db536 said:


> Prepared everything for some surgery. The first impressions (without critical listening), the amp got more open/less congested, clearer, more upfront presentation. Headstage possibly got smaller. Possibly brighter or bass is tighter. I think the amp gets a lot hotter.
> 
> This thing really punches hard now; it's intense.


 
  
 You sexy beast, why do you tease me so?
  
 Great work, it looks very cool.


----------



## fjrabon

fallenangel said:


> You sexy beast, why do you tease me so?
> 
> Great work, it looks very cool.


 

 Yeah, the output CCS are really game changers for this amp.  Before the output CCS I thought it was one of the best values in tube amps.  Afterwards, it's simply one of the best tube amps, period, regardless of price.


----------



## jh4db536

fjrabon said:


> I like the GE 12AY7 5 star


 
 I just bought a pair of these. I heard they're really good though.


----------



## comzee

jh4db536 said:


> I just bought a pair of these. I heard they're really good though.


 
 I coincidentally bought a pair today as well.
 I guess there's two version of the GE 5 star
  
 6072 and 6072A, I guess the "A" signifies low noise, idk....
  
 I bought just the 6072 5 star, couldn't find it nos either, so bought used old stock  ¯\_(ツ)_/¯
  
 Important thing is the design imo, the 3 mica is unique to the 5 star as far as I've seen.
  
 Interesting read on the 5 star brand http://www.tubebooks.org/tubedata/GE_5star.pdf


----------



## FallenAngel

fjrabon said:


> Yeah, the output CCS are really game changers for this amp.  Before the output CCS I thought it was one of the best values in tube amps.  Afterwards, it's simply one of the best tube amps, period, regardless of price.




I have no doubt of that. I've really enjoyed mine and have great respect for both Tom and Doug. I'm not sure it's he remembers it but I was one of the guys testing his initial HPDAC. Cool little project from the old days.


----------



## tomb

fallenangel said:


> fjrabon said:
> 
> 
> > Yeah, the output CCS are really game changers for this amp.  Before the output CCS I thought it was one of the best values in tube amps.  Afterwards, it's simply one of the best tube amps, period, regardless of price.
> ...


 
  
 You've tested and prototyped just about everyone's designs at one time or another!


----------



## FallenAngel

tomb said:


> You've tested and prototyped just about everyone's designs at one time or another!


 
  
 Maybe 
  
 I haven't worked with Ti directly yet. I would if he asked me, but it's not like that kind of thing would happen. I might have to spend time on some other sites for that to happen and troll the amb forum.


----------



## schubert

I've just started looking into the Torpedo III - any idea when the cinemags will be available again?


----------



## badf00d

@tomb - thanks for the heatsinks!


----------



## tomb

schubert said:


> I've just started looking into the Torpedo III - any idea when the cinemags will be available again?


 
  
 There are a few assembled T3's still available, but the last kit was sold.


----------



## tomb

badf00d said:


> @tomb - thanks for the heatsinks!


 

 You're welcome!


----------



## schubert

Since everything else is available separately, I'm only concerned about the cinemags, not the kit.  ECP used to sell them separately but the site says "out of stock".  From what I can gather these are not a stock item for cinemag - or are they?  If they're custom, I assume they could easily make more - are there enough builders out there interested in a group buy?


----------



## tomb

schubert said:


> Since everything else is available separately, I'm only concerned about the cinemags, not the kit.  ECP used to sell them separately but the site says "out of stock".  From what I can gather these are not a stock item for cinemag - or are they?  If they're custom, I assume they could easily make more - are there enough builders out there interested in a group buy?



1. There are no more Group Buys allowed on Head-Fi.

2. You will need to contact ECP Audio. The windings are a proprietary arrangement between ECP Audio and Cinemag. They are not stock, as far as I know.

3. I have no more Cinemags.


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## schubert

tomb said:


> 1. There are no more Group Buys allowed on Head-Fi.
> 
> 2. You will need to contact ECP Audio. The windings are a proprietary arrangement between ECP Audio and Cinemag. They are not stock, as far as I know.
> 
> 3. I have no more Cinemags.


 
 Thanks - no more plans to obtain more then?


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## tomb

schubert said:


> tomb said:
> 
> 
> > 1. There are no more Group Buys allowed on Head-Fi.
> ...



We've been looking at a different mfr because of physical quality (not sound) issues with the Cinemags. Not sure how that's going to work out yet - or whether we will go back to the Cinemags again. Unfortunately, it will take some time and testing.


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## schubert

OK.  I'll stay tuned - thanks


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## tomb

schubert said:


> OK.  I'll stay tuned - thanks


 

 I believe Dsavitsk has one more pair of Cinemags that he may be sending me.  If I can make one last kit out of it, I'll let you know.


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## schubert

Thanks - I'd be happy with just the transformers, though.  I sort of like picking the rest of the parts myself.


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## JWahl

tomb said:


> We've been looking at a different mfr because of physical quality (not sound) issues with the Cinemags. Not sure how that's going to work out yet - or whether we will go back to the Cinemags again. Unfortunately, it will take some time and testing.




That's unfortunate. I've read that Jensen transformers are somewhat similar to Cinemag but maybe more expensive. Knowing Doug's tastes, I'm guessing he'll probably look into Lundahl. Amorphous core could be interesting with parafeed (but I could be assuming incorrectly, some of my fundamentals are a little rusty).

Another interesting thing I've read about is Finemet core material, but it seems rare and extremely expensive. Monolith magnetics (archived) website says they'll make Finemet parafeed transformers (probably intended for speakers). However, I suspect a pair would cost more than the entire maxed Torpedo III kit, which would defeat the purpose to an extent. The high nickel transformers seem to be the best performance value overall.


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## tomb

There are now two remaining _assembled_ T3's up for sale on beezar.com.  Both should be ready to go at the end of the weekend.  There will be no more.
  
 I removed all the options except for the power cord and LED.  All of the upgrades will be included.


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## JWahl

Someone buy these and then sell me one come tax refund season.  Even at the pre-built price, they're a killer deal for the sound quality. I regret having to sell mine, but it was necessary. I know it sounds cliche, but you'd really have to spend a lot more to do better.


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## fjrabon

My old Lyr2 that I sold to a friend came back to me this week (for a short stay for review purposes), and man, it's insane how much the TIII just completely blows it away. Like I'd say that the Lyr2 sounds closer to my HiFiMan EF2C than it does the TIII. I have heard a LOT of HD800 setups, and this is still the best amp I've heard for the HD800, regardless of price. Get it maxed out (especially with the output CCS) and throw some GE 5 stars in there, and man does this thing sing with HD800.


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## Andrew Rieger

Any plans for a Torpedo IV?


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## tomb

andrew rieger said:


> Any plans for a Torpedo IV?




Yes.

I believe all of the following has been mentioned before, just not all in one place. IMHO, the final iteration of the T3 is competitive with any amp in the world for the HD800 (and others). That said, it could still be improved. Besides having become too difficult to build for all but a few, the T3 still has a bit of power supply noise infection from the proximity of the signal traces to the PT. This is below the level of audibility, but it shows up in testing. So, there will no longer be a "torpedo" planform. Also, the T3 still uses capacitors in the signal path to connect the parafeed output transformers. It would be nice to get rid of those entirely (no more giant Mundorfs and Dow Corning cement). We are also looking at changing up the output transformers, but not sure where that will take us, yet. In sum, we are addressing all of these issues with the T4.

Dsavitsk and I also discussed that most of the T4 will be SMD-based. Some parts are simply too difficult to source these days outside of SMD. It also cuts down on the casework costs (but introduces higher investment costs). That will put the difficulty factor up pretty high, so there are no plans to offer kits. They will most likely be mass produced in batches, but a lot of this is unforeseen for the time being.

We are steadily working on all of this now.


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## VERASTARR

Hello Everyone, 
  
 I just finished my Torpedo 3 with all the mods and my final check for chassis ground showed 2.4V AC between the chassis and earth ground at the duplex receptacle. At least it didnt explode so I was thankful for that.. Does anyone know if this is OK, or if I was supposed to check for current rather than voltage, etc ? I'd love to listen..
  
 Thanks !
  
 MP


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## VERASTARR

verastarr said:


> Hello Everyone,
> 
> I just finished my Torpedo 3 with all the mods and my final check for chassis ground showed 2.4V AC between the chassis and earth ground at the duplex receptacle. At least it didnt explode so I was thankful for that.. Does anyone know if this is OK, or if I was supposed to check for current rather than voltage, etc ? I'd love to listen..
> 
> ...


 
 OK, so there was 2.4V without even touching the chassis, so I figured the anodize was insulating. I checked at safety ground nut and we got zero V... all good I guess..


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## tomb

verastarr said:


> verastarr said:
> 
> 
> > Hello Everyone,
> ...


 
  
 Glad you found the 2.4V in a little anodizing.


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## Makiah S

Wow amazing thread! Thank you for a detailed point by point build progression! Bookmarked this one 

Stupid question, what are the power output specs for the Torpedo III


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## tomb

Mshenay said:


> Wow amazing thread! Thank you for a detailed point by point build progression! Bookmarked this one
> 
> Stupid question, what are the power output specs for the Torpedo III


I think it's somewhere between 250-300mW, but Dsavitsk will have to say for sure.  Remember that it's an output transformer-coupled amplifier, so power is roughly equivalent in either the High or Low Z setting.  It will power high-impedance headphones or low-impedance headphones with equal authority.  It will shy away from very-inefficient planars, but not much else, including the original K701s, which were traditionally very difficult to drive with adequate current.  It's a world-class experience with a Senn HD800 - the original, with no harsh peaks, even.


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## Vas19

I wonder why the lack of love for the T3 here. I guess they are relatively rare, but it is an incredibly good amp that can be had used for under $1k now...


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## tomb

Vas19 said:


> I wonder why the lack of love for the T3 here. I guess they are relatively rare, but it is an incredibly good amp that can be had used for under $1k now...



Below $1K would be a great deal, but buyer beware on the used market: not all T3's out there have all the tweaks.  It's a different amp (world-class) with all of those.  As always, just make sure of what you're buying.


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## J-Pak

tomb said:


> Below $1K would be a great deal, but buyer beware on the used market: not all T3's out there have all the tweaks.  It's a different amp (world-class) with all of those.  As always, just make sure of what you're buying.



I am still very happy with mine, it's incredibly transparent without sounding "dead"; just amazing for classical.


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## Dithyrambes

If Anyone has one they are willing to let go, Please send me a PM!


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## HiGHFLYiN9

Someone is selling one on ebay right now (no affiliation). Has the Cinemags but no other upgrades.


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## cspirou

Dithyrambes said:


> If Anyone has one they are willing to let go, Please send me a PM!



There's one in the classifieds

https://www.head-fi.org/threads/fs-ecp-torpedo-3.871369/

I know the seller. Hes a good guy and this is a good build


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## ColtMrFire

Getting ready to join the T3 club soon.  Very excited.  It will be fed by my CD Player/Gumby.  Headphones are Beyerdynamic T90.

At 250ohm (my T90s), I am reading the 12AZ7 tubes are best.  So I am on the hunt for a pair of GE's.


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## tomb

ColtMrFire said:


> Getting ready to join the T3 club soon.  Very excited.  It will be fed by my CD Player/Gumby.  Headphones are Beyerdynamic T90.
> 
> At 250ohm (my T90s), I am reading the 12AZ7 tubes are best.  So I am on the hunt for a pair of GE's.


Actually, the latest info on tubes came to the conclusion that the Mullard 12AT7WA (CV4024) was best:
https://www.ebay.com/itm/12AT7WA-CV...211738?hash=item4836deba9a:g:WQQAAOSwHnFVrhHZ

Their response is as good as the 12AZ7s.  Plus, they have the best sound stage of most tubes that have been tried in the T3.  Downside? They're expensive.  Also, while the ebay seller referenced above seems to have the lowest reliable price, his "matching" is really a manufacture-lot matching, not tube output.  Thankfully, the Mullards are very high quality and seem to be closely matched in output anyway.  You'll probably find a pair that match well if you purchase a quad and your odds are pretty good even by purchasing a pair.

The 12AZ7s are outstanding for the price, but they are hard on the amp.  The heater current runs much higher than the 12AY7 or 12AT7 (including the Mullard 4024 above).  So, the amp will run pretty hot.  I would not recommend leaving it on for extended periods with the 12AZ7s.


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## ColtMrFire

Thanks for the info Tom.


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## Dithyrambes

Have a torpedo III for sale if anyone is interested. Just leaving a note.


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## JImmye00

Can someone please provide a nice concise link to all of the parts i need to order for this and what would be available upgrades? Could a novice build this?


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## cspirou

JImmye00 said:


> Can someone please provide a nice concise link to all of the parts i need to order for this and what would be available upgrades? Could a novice build this?



This has all the information you need, including parts.

http://www.diyforums.org/Torpedo-III/TorpedoIII-overview.php


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