ECP Torpedo III [indexed in first post]

Dsavitsk, here are a few pictures so you don't have to smash a bunch of Amtrans resistors to see what's in the tube

Apparently the Amtrans step ladder attenuator uses a naked skeleton version of the Amtrans AMRG resistors. Check this site, where there is also a data sheet: Click ''volume control'' and then click ''Amtrans SAT 23 step ladder attenuator'' http://www.acoustic-dimension.com/

The pictures shows what we would expect: A film type resistor body, end caps of copper plated brass and the gold plated copper legs. It's my understanding that the end cap material and the way the end caps connect with the resistor element and the legs is one of the areas where sound quality can be won or lost in resistors. Maybe who ever makes these resistors for Amtrans got it right...

 

Well, there you go. Interesting.

 

Anyone try this with hd800S? It seems like very interesting next DIY project for me.

 

The 300R secondary is perhaps tailor made for the Senn line? I've found Hd600 and Hd650 to be excellent pairings. The hd800s should be as well, if you are a fan of that phone.

 

My main headphone is still HD650 so i think this will surely on my next DIY target, i picked up HD800S for a very nice price not so long ago so it should be interesting to see how far this project can take it as well!

 

So i installed the Mundorf's, AMRG's and the replacement PT. No more hum so that's good. But i find the sound a bit too forward and bright compared to the Solen's and stock resistors. Clarity and detail has improved, so has smoothness but yeah not really liking how it sounds now. Cymbals are way too present, actually a bit annoying really.

Think i'll let the caps burn in for a while, i've noticed that helping in the past.

 

The Amtrans resistors gives a slightly warmer sound, and a sound that is more natural, dynamic and organic, more transparent also. But certainly not forward and sibilant.

What you hear must be the Mundorfs speaking, and they are brighter and more forward than the Solens... Yes, hopefully some burn in will help

 

Yeah let's hope so but this sounds like something K240 foam for HD650's might fix, think i'll give that a try.

Edit: Yeah the K240 tones things down, seem to lose a bit of air but it's more pleasant and mellow now. If the caps do change after a while i can always put the stock foam back.

 

The cap and, believe it or not, the resistors both change after burnin. After I installed those resistors, my immediate reaction was "These are going to have to come back out." Bass was loose and boomy. But I let her run over night and the next day, things had settled in. So, really, I had two WTF moments with the AMRGs. The first being initial surprise at the significance of the sound delta, and the second being subsequent surprise at the change after a short burnin. I think I shot MortenB a PM at that point to see if I was nuts, and he confirmed having experienced the same.

Regarding cymbals and drums, you might now just be hearing the transient attack through a more transparent cap. Both the Mundorfs and Rikes are a bit forward, IMO, but not offensively so. Maybe the Solens were not? I wouldn't know. But I am pretty confident after our group tubefest and resistor eval that the best sounding T3 through HD650s has your BOM. With Rikes only offering moderately better transparency. The 12AZ7A Amperex tube probably had the best attack of all, and it varied quite a bit from tube to tube.

 

Hum I leaned a new word, transient attack thats how I would describe the T3. The T3 isn't as hard sounding as I thought it was, but the dynamics and transients are so impactful that I called it hard sounding.

 

Listening to @bazelio 's torpedo was probably the first time I've flinched from the intense attack of a drum hit. Granted, I was listening pretty loud, but still... It's a dynamic amp. I like that quality very much.

 

Now it makes sense what you hear Jun..!

Yes, the T3 has very good dynamics and transient attack. These are some of the qualities I really like (as a musician). It makes the T3 sound more natural and more like real live music than many other amps.

 

Yeah i think i will just let the burn in process run it's course, i remember hearing changes in how the T3 sounds up to two weeks after i completed the build. Also installing both the caps and resistors at the same might not have been such a good idea but i wanted to do it all in one go and be done with it so to speak.

Well i hear it more like a change in FR, since other sounds around that frequency range also stand out more. Makes it all sound a bit lean perhaps or spotlighted in a certain area, but i will reserve further judgement after some more burn in. Maybe i'm just sensitive to a forward sound, my ears are a bit weird though and overly sensitive, being young was quite unpleasant growing up with hyperacusis. I still get comments that i listen at a very low volume, i can't for example go to live concerts since that will be torture volume wise.

 

The dynamics and transients may be overkill for my set up, 11/10 on dynamics and transients.

My metrum musette has great transients and dynamics compared with my Bifrost Multibit. When paired with the T3 it is definitely overkill. I need to tone it down a bit.

 

Haha, now that you mention it... I flinched a couple times that evening also!! And, yes, that's a good thing....

 

I don't go to live concerts without these.

 

If this is something you're very sensitive to, then the Solens might be the better choice for you since what you describe in the section I have quoted is the signature of the Mundorfs.

But give it a bit of time to burn in...

 

Yeah but i was under the impression the AMRG's compensated for that. Anyway, like you say, i will let it burn in and see where i go from there

 

Yes, I choose the Amtrans resistors to balance out the slightly lean signature of the Mundorfs and to me the synergy is great.

 

Well it might still happen that i will like this setup, perhaps in a few weeks my last couple of posts can be interpreted as the stages of capacitor burn in, both physically as well as mentally