ECP Torpedo III [indexed in first post]

I bought a set as well

 

I think my T3 sounds wonderful now even with the HD 800. My DAC and AMP must have burned in. Probably going to pick up the cs board as well.

 

Or the user was burned in Often I think getting used to new gear is the bigger part of the burn in process... Great that it works for you now Jun..!

 

Wow @Riotvan and @MortenB you guys are fast. I just clicked confirm, so I guess I was CCS Output Board order #3.

 

Hahaha, i've been F5'in that motherfucker all day long dude...

or twice a day

 

Yes, indeed. And believe it or not, sometimes it really does help when someone just tells us "this sounds better than that". We sometimes have to relearn that which we thought we knew, and let our brain adapt. Heh.

 

Ordered my set, as well (@MisterRogers.. they're headed your way, sir!). Thanks for getting this out, @TomB & @dsavitsk. Is it safe to assume this is the last board tweak or do you guys have some more tricks up your sleeve for this beast? I get the sense the board's pretty well filled up, right?

 

Very excited to see what you all think of this one.

I think this is probably it. Certainly someone can try FETs instead of BJTs on the output, or different BJTs than the ones supplied, but that is up to individuals to do. Theoretically, one could replace R3 with a small (~1mA perhaps) CCS, but I am doubtful anyone could measure, or hear, the difference. I don't think it is worth the effort. Or rather, I don't think it is worth my effort .

 

Yeah, me too. Things are sounding so good right now as is that I'm really curious to see where the new CCS boards will take it from here.

 

siiiiqqqqq. yeah i have a feeling this is going to be good. i shipped my amp to TomB a while ago and he was teasing/trolling me by telling me how damn good the amp sounded with all the ccs boards in place.

 

I've done this in an unrelated project, and it actually made things worse. The high voltage zeners really aren't the most stable voltage references in the world, and they have a highish impedance. So if your CCS, like mine, has a positive tempco, its current goes up as the supply warms up, and the power supply voltage will rise. My 300V supply rose up to 360V, and eventually pinched off the CCS!

Wtih the resistor, the opposite happens: the current through the zener string goes down if the zener voltage goes up because there is less voltage drop across the resistor.

 

Just a quick note to let everyone know: I am not, never, no how installing or recommending Amtrans resistors for anyone who is using the Output CCS boards.

I just went through one of the scariest mornings I've had in awhile. As brencho mentioned, I've been working to upgrade his amp with all of the tweaks. I finished putting spacers in for his Mundorfs (it was an early version before we got the safety measures in place), installing the Tube CCS boards, and the Output CCS boards. As he mentioned, I was getting 'stats sound from his amp and my HD800's last night - really, really great.

This morning I put in the Amtrans. First of all, I came to the conclusion that these things are not really safe, especially with the Output CCS boards in place. The lead-bending gymnastics are similar to Mundorfs, only the the Mundorfs have a clear pasture between the tubes and the output transformers. Wedging the Amtrans in is like going door-to-door in an urban environment. Nevertheless, I got them in there without touching anything - as best I could tell.

I powered it up and plugged in my HD800's - POP, POW, CRUNCH in the left can! I ripped them off my head and out of the T3. The next couple of hours were spent trying to troubleshoot what the heck was going on. Needless to say, I switched to one of my $5 headphones while this was going on. I normally plug those in after a major change, but I never considered that swapping resistors was going to make that necessary.

Anyway, I tried everything - no offset measured anywhere, but the static and pops were always there in the left channel. I re-flowed all the solder joints, double and triple-checked the Amtrans leads and the Output CCS boards, but couldn't find anything. Finally, I decided to pull them out and put back in the trusty metal-films. All is well and I guess my HD800's are fine, too, because it's back to 'stats sound again.

 

One thing to notice if the Output CCS boards are operating correctly - you will hear a static power "zing" when powering up if you have headphones on. Normally, the output-transformers block any noise from coming through (or DC) when you power up, so it's perfectly safe to have headphones plugged in. The Output CCS boards, however, push a bit of "zing" through when they come online. This happens about 30 seconds after throwing the power switch. I think it's the difference between having active devices in the output where resistors once were. It may also have something to do with the incompatibility of the Amtrans, but I don't know.

Bottom line, it's nothing like a DC surge and is quite subdued, but it's telltale for when the amp is online and ready to go. If and when you hear it, don't be alarmed, unless it's accompanied by some major pops and static (like I had with the Amtrans).

Here's some pics of Brencho's now "fixed" T3:




My Dow Corning 748 applications are far from "nice fillets," but sufficient to provide some additional support. Anyone building from scratch should be able to do a better job, because things are tight in there when it's built.

Anyway, this should give you some good guides until I get the diyforums page posted on Tweak #4: Output CCS Boards.

Thanks for your support! The orders came in fast and furious last night! I think these things are almost another game-changer on the T3.

 

That's definitely scary, Tom. I'm glad none of the equip was harmed. Can you tell us a little about the change/improvement in sound with the output CCS boards in place?

 

I thought I mentioned it before, but sure!

I liken it to turning up the bias from low to high on a Class A amplifier: current goes up, heat goes up, but so does bass and micro-detail resolution. There's a greater sense of authority, all the way down to the bottom end and details up to the highest highs come through (at least what my hearing allows), giving a greater since of "air," too.

A very subjective description for sure, but I found out early on that none of these tweaks are really measurable in the classic sense.

 

Looks good Tom! It sounds like perhaps you had a defective AMRG resistor on the left channel? It's hard to imagine that carbon film resistors by themselves would introduce a "compatibility" issue, don't you think? Interestingly, the description of "more authority" can also be attributed to the resistors without CCS boards in our listening experiments. I think it'll be interesting to compare the effect of AMRG without CCS vs metal film with CCS when @brencho gets his back. I'll hold off on installing my CCS boards to do that.

In any event, bummer that you got caught up on that issue. @TomB - Thanks for all your hard work on these boards and mods for the community!!

 

That's too bad Tom and I'm sorry to hear about your bad experience. Most of all too bad, that you will not get to hear the very positive improvement in sound from the Amtrans compared to the stock resistors. Well, these are doomed now by the design team for sure but thanks a lot for giving it a try.

From your close up picture is seems that you made very tight bends to the legs? My guess is, that the connection between leg and resistor element is damaged on one of the resistors - this can happen with all resistors if we're unlucky with ''tight bending''. Others here in the thread has reported the Dale resistors breaking / falling apart when bending the legs.

Here is how to bend the legs on the Amtrans resistors (or at least how I did it).

With your finger tip bend the leg, this gives a nice round bend, with good clearance to the resistor body. Final step is to make a bend with pliers to get the spacing between the legs right for the holes in the PCB. This takes just a few seconds, and installation is very easy, they drop straight in. Nothing like the lead bending gymnastic with Mundorfs and nothing unsafe.

 

I've emailed a lot with tom through all of the scare and hard work... I've said it before and I'll st may it again - thanks @TomB for all of your amazing work! I'm psyched to get the T3 with all the new boards back.

Also sorry for scaring the sh*** out of you with those amtrans resistors. Hopefully it was a worthwhile experiment. I'm just very grateful you were able to return it back to its former ccs board glory!!

 

Yeah, I suspect that the resistor lead broke/cracked off of that special cap that they use in the Amtrans construction. The problem is, you will never see it in that epoxy tube. IMHO, that's a lot different than V-D resistors "breaking." All you lose from them is the brown epoxy coating. It's pretty much the same with the larger, power metal films. The inside metal and lead attachment is absolutely bullet-proof. I have pushed, pulled, bent, removed, re-used V-D resistors for over 10 years now without a hiccup. This was way different.

Besides, @MortenB, I can't imagine that bending the lead as you show it will give you enough room to keep that bent out lead from touching something. The two resistors on the outside are fine, the ones in the middle, not so much. If you don't have the Output CCS boards in, you can hang them in out in the air, because the resistors are relatively low down on the bottom of the PCB. You can't do that with the Output CCS boards in there. It's either the tube socket pins or the CCS board - it's going to touch one of them unless you squeeze those leads in there tight.

It's possible they would work better on the bottom of the PCB. That might be a solution.

Anyway, brencho can tell you that I tried talking him out of it last night. I didn't want to admit that I would have trouble getting them in there, but I did. Snap, crackle, pop is pretty scary at 200+ Volts.

 

Yes, sometimes we loose the epoxy coating, someone here reported a Dale resistor breaking in two halves. My point is, that all resistors can fail if we bend them ''tight'' close to the body, of course this also goes for the Amtrans. And I get it, that you and Dough seriously dislike these resistors (I'm Danish, but not slow).

I've damaged enough resistors in my time to learn never to do tight bends close to the resistor body, no matter the style / type / manufacturer of the resistor. Trust me, I have also tried the popping sounds you heard My lesson learned is, that it's because the end cap is separated from the resistor element from too much stress when bending the legs. If a tight bend is needed because of space I always do the bending like this, and then bend outside the pliers to minimize the stress on the connection cap between the leg and the resistor element.

With the installation I have now there is plenty of space around the Amtrans resistors with them bent/installed like I just showed, I will evaluate the situation when my output CCS boards arrives after the long trip across the pond (and the Danish customs - scary).