ECP Torpedo III [indexed in first post]

Not the 200V kind of boom, right?

 

The kind that makes you flinch during a mini meet. ;-)

 

I'm curious if @dsavitsk has some thoughts on discrete regulators in the T3. The Bellensons are fast (and expensive), but unless you've designed yourself in to a bad place and have ringing on transients or something, I wonder if there would be much benefit realized vs low noise semiconductors?

 

I commissioned @MisterRogers to build my TIII.. it has the Belleson regulators and the rest of it is practically identical to @bazelio's, I think (Mundorf AIO caps, tube & output CCS, Shinkoh tantalum & AMRG carbon resistors).. depending on where he is with the build, @MisterRogers could probably give some impressions with and without the tube CCS.

 

@FlySweep the only potential complication is that bazelio's amp has rike camps instead of mundorfs. my amp may have smaller amtrans resistors along with mundorfs and tube+output ccs, so tomB might be able to provide some impressions of it with vs. without the amtrans resistors (albeit smaller ones that baz has in his).

 

ah, that's right.. good point.. I forgot he & @MortenB went to Rike's. The Rike's seem to be more transparent and less colored than the Amtrans, so we might be able to triangulate impressions.

 

I am doubtful different regs would make much if any difference. I think we had this discussion earlier in the thread and it ultimately led to the small CCS boards.

 

So i installed the CCS board's today and it's a noticeable improvement, FR seems more balanced from top to bottom, tonality and detail have also improved. A worthwhile investment i would say

Also fixed the AMRG resistor's, luckily i had enough lead length left since i mounted resistors a couple mm above the pcb, so putting some teflon tubing on the leads was a breeze.

Great work @dsavitsk and @TomB!! I found my endgame...

Edit: This amp is dangerous.. i'm bopping my head so much i'm afraid i might sprain something, also if you have stuff to do and just want to get in a quick listen well.. big mistake.

 

After having more time with the output CCS update, listening to a variety of tracks, I started to notice that finding the right volume setting was a bit more difficult. It's hard for me to remember exactly what the pre-CCS amp sounded like already, but I'd started to think I was experiencing an increase in overall dyanimcs. It's possible, but what I think is more likely is that because there is a more apparent "plankton" layer, it's become natural to want to turn the thing up a bit louder. But when you do that, any sudden upbeat section of the song that comes along really surprises you. In any event, whatever the reason, I find myself nudging the volume up or down quite a bit more often now than before.

 

Thank you all for your modding efforts and informative posts. I've been following this thread for a while and this week picked up a Beezar-assembled Torpedo 3 ("T3") locally from Todd (skullguise on Head-Fi). Had a great chat with Todd, and he's looking forward to the upgrades on his Black Diamond, @dsavitsk. My amp has the Cinemags, stock tubes, but being a 12/2015 build doesn't (yet) have the upgraded caps or CCS boards. Edit 11/27/16: Epcos caps, not Solen caps.

I spent a few hours this morning with my stock HD650 comparing the T3 to my Valhalla 2 ("V2") with upgraded tubes simultaneously hooked up to my Yggdrasil's RCA outs. I approximately level-matched the amps by using white noise in the Oppo speaker configuration menu and a dB phone app.

My observations:

• Bass: The T3 is noticeably more authoritative, dynamic, punchy, and quick in the bass. This is even with my favorite V2 tubes, including the IR-variant output tubes which I thought gave a slight improvement over the stock 6N6P in bass speed.
• Stage:
  • Width: The V2 stage is wider, maybe 10-20%. I wonder how much of this was due to the stock T3 tubes, as @HitmanFluffy mentioned a narrow stage with them here.
  • Depth: The V2 places you further from the stage than the T3. Depth of the performers/instruments relative to each other seemed close enough that I didn't write notes about it. Wasn't focusing on this.
• Resolution: The T3 is noticeably more resolving. The best example I can give of this was A/Bing a song with acoustic guitar picking. All the picking was audible on the V2, but on the T3 you could hear the pick strike each string in order and the placement of the strings compared to each other, instead of picking/strumming blended together like with the V2. I also found it easier to hear and understand layered vocals on the T3.
• Distortion/Treble: This is the area I have the hardest time describing, but here it goes.
  • Cymbals sound slightly different on these amps. My initial reaction was that the T3 comparatively rolled off the treble. I drew this initial conclusion because there seemed to be air or higher harmonics missing on cymbals above what the T3 reproduced when compared to the V2. After listening further though, I wonder whether I was hearing to some extent what @fjrabon was describing here. I'm not sure which amp's presentation is more "accurate," and it wasn't a negative per se, but I'll be curious to hear what the circuit upgrades and tube rolling do in this respect.
  • The T3 is less fatiguing than the V2 and definitely sounds more delicate and/or refined in the treble.
• Smoothness/Liquidity: The T3 edges out the V2 here as well. The V2 is often described as dry and lean, more of a solid-state sound than a tube sound, and I agree with that assessment to an extent. The T3 is smoother and may slightly round leading-edge transients. Do not infer from this that the V2 is etched or that it emphasizes leading-edge transients.

Conclusion: All in all, I'm very pleased with the T3 and am excited to see where the remaining tweaks take it. This exercise also reaffirmed both that the V2 is an amazing value and that the HD650 scales extremely well.

Footer "tweak:" I'll be using four Herbie's Audio Lab "Baby Booties" underneath the T3. Corny name, but hear me out. My TV stand shelves are glass, and I noticed that the T3's stock feet were slightly uneven which caused it to rock when touched. The T3 also slid backwards when inserting headphones unless I steadied it with my other hand. With these footers underneath, there is no unevenness/rocking, the T3 is isolated from my cheap glass shelf, and, because the footers are slightly grippy, the T3 doesn't move at all during one-handed headphone insertion/removal. I'm not making any sound quality observations here, but the footers seem effective at vibration control which may help with that. I also use these or similar products under disc-spinners like my Oppo and game consoles because they reduce the annoying spinning/vibration noise.

 

Does this up frontness you describe affect everything you hear or is it contained within a certain range? Dunno how to really describe it but that's kind of how I would describe the black diamond, more upfront for details within a confined range.

 

Terrific impressions, @zonto .. thank you! The consensus is that the stock TIII is a terrific value and offers very high performance, but I'm excited for you to tweak your TIII and see where it can really go.

 

There is a power supply upgrade that replaces the stock regulators.

 

@Mr.Sneis I may not be capable of making that determination, young Jedi. Seriously, I suspect the brain perceives spatial queues differently across the frequency spectrum. I suppose I just feel the amp is detailed top to bottom, perhaps particularly noteworthy at the bottom simply because I normally expect bass detail to be lacking in this price range and even beyond (see: MicroZOTL2). That said, after CCS boards what I noticed most immediately was the mid to treble detail difference vs before and that region being more forward than before. But again, the forwardness may also be an audiological illusion instead! Either way, I do think I'm at the point of having usurped all possible sonic treasures from the T3 ... and I'm very happy with what it has to offer. As I was disassembling it (yet again) this time around I was thinking to myself "here we go again ... is there really anything left to do to this amp!?!?" Hehe. This is all to say, it's just sounding really good IMO.

 

I hear it much the same as you, sounds more forward but in a good suck you into the music kind of way. And yeah i've been messing a bit with volume as well but i suspect after some brain burn in all will be good

 

That's what i was trying to describe about the T3 and it's midrange placement (to me sounded like slightly out of phase) - the headstage and depth is out of proportion particularly in the midrange. I read through the whole thing again and other people have been calling it "weird staging" and that's what i'm going to refer to it as.To me, this attribute sticks out as the T3's main flaw or weakness, but otherwise it does everything else very well or excellent. I was wondering if it was a tube issue or just the hybrid topology causing it.

Well see if the output CCS do anything about it. The package is sitting in my mailbox when i get home i'll install them.

 

The way to think about what the CCSes are doing is that the output stage has to drive the transformer primary in parallel with the 2 emitter resistors. That means that fully half of the output current is driving resistors instead of headphones. The CCSes present an impedance in the several MOhm range, which means that the output goes almost exclusively to the output instead of the CCS.

In other terms, the CCSes each want to have a constant current across them - hence their name. As the tube swings the output transistors up and down, one wants to draw more current while the other wants to draw exactly the same amount less. They solve this by trading the current imbalance across the transformer primary, which is what you are listening to. The stiffer the CCSes, the more perfect that current swap is, and the lower the distortion.

 

The depth on the TIII has been interesting. One thing I've noticed is that it's way more sensitive to how a singer is facing the microphone. At first I thought it was a differential response in harmonics of different frequencies. I.e. Maybe the harmonics of 1kHz are different in level than the harmonics at 2kHz, for example. But I noticed that the same frequency could sound further and closer. Then I noticed that some singers tended to sound like they were moving closer and further towards me. Especially some singers would sound like they started mid distance away, got really close and then backed away a bit at the end of every phrase. A lightbulb clicked when I visualized how a lot of singers approach a mic when on a stand, as they start a little away from the mic and then lean in and then back off as they finish the phrase. What I think I'm hearing is that the TIII is communicating this more than most amps do.

While the TIII with output CCS is more upfront than a lot of amps, it seems to have much more precision of depth. Relatively small differences in mic positioning become much more audible than normal. On some recordings the vocals seem much closer than my other amps, but on other recordings the vocals seem noticeably farther away.

I also noticed this conveyed in B-3 organs. The swirling effect seems more exaggerated on the TIII. Another example is on JD Simo's most recent album, you get a huge sense of space on his guitar tone, which I know from talking to him that none of his amps were close miced for that album. On my other setups it's noticeable, but through the TIII it was blatantly obvious compared to a normal guitar micing setup.

To put this hypothesis to the test a bit more, I put on some live DVDs and listened to the audio through the TIII. On Black Crowes Freak n roll into the fog, it was very pronounced when Chris Robinson would lean in or pull away from the mic. As I visually saw his head movement, it was more than repeated audibly. I can't really tell if the TIII was exaggerating this, or if I was just hearing an effect that has always been there more clearly.

I'm not totally sure how I feel about this aspect of its sound. On the one hand it makes the sound stage seem more three dimensional, on the other it can be a bit disorienting on some recordings. My suspicion is that as I get used to it, other amps will sound depthless in comparison, but for now at least it's a bit of a mixed bag, in this regard. Very interesting, but almost distracting.