ECP Torpedo III [indexed in first post]

Nope i went with Solens, i can buy the Mundorf's cheaper here so i figured i'd try the stock first. After some listening i'll see where i want to go sound wise. Am also thinking of a custom case so i can fit a stepped attenuator and huge caps but we'll see. I'll keep your offer in mind

 

I think you are too focused on the carbon -vs- metal film resistor debate. I know we can read online about this until we go totally insane, but IMHO there is no ''perfect resistor'', there is only perfect synergy. Forget what they are made of and use your ears. If you find the sound bright, then add warmth to balance it out. I can't think of any metal film resistors, that can do that, but there might be some. Don't know. Personally I don't think it's possible to add too much warmth with resistors in a T3 with Mundorfs, unless you go with Allen Bradley or similar really old school carbon resistors. And even those can't make such ''night and day differences'' to the sound to make the T3 sound gooey and slow. Don't worry, just have a go at it

Hearing is believing Resistors are cheap so buy some different ones and listen. That's what I did and ended up with a lot of resistors in my small stash

Had this amp been vey warm sounding, we would be talking about metal film resistors, silver caps, bright sounding tubes etc to balance it out in the other direction...

I don't have the stock tubes, so I can't tell...

 

@Riotvan... I also bought my Mundorfs here in Europe, cheaper as you say. Please don't mess with the form factor of the T3 - it's just soon cool as is

 

Hehe well i'm a low volume listener and i have run into problems with pots in the past. Can also mess around with 12au7's though.

 

The TDK pots are very accurate in balance.

Yes, the 12au7 seems to be a good option for lower gain. After they were discussed recently I tried a pair, but I did not have enough gain.

 

Well i listen at really low volume, i get comments about it often. Had hyperacusis when i was younger now it doesn't bother me anymore but i still listen at low volume. That TDK pot looks interesting, i've read about them before. Have you heard of Acoustic dimension? Their 41step is very nice, i used one in a crack build.

 

Yes, I have bought several products from them during the years. Very nice to deal with..!

 

Any rough estimate how long it takes to build one? Just curious since I'm going to be leaving for an internship and trying to gauge if I can squeeze it in before leaving or waiting until I return.

 

A few hours tops, even with mild arthritis and little experience.

 

Yeah, in one sitting, about half a day I would say. Take your time and double check your work as you go.

 

Thanks. One more question and I hope it hasn't been answered yet- which would theoretically offer more performance for ~$70-80 going with Mundorf Evo Aluminum-Oil 10 uf caps, or the stock Solens with 0.1 uf Mundorf Evo Silver-Gold Oil bypasses?

Cost between the two options is pretty similar.

Tried doing reading wrt to the technicalities of bypass caps and it made my head spin a little

 

My $0.02:

Even if you like to tinker, start with a stock build, and listen for a while. Then either leave well enough alone or decide which direction you want to go next.

I have some of the same listening impressions as MortenB, but haven't changed a thing yet. It's a great amp as is. My kit had Mundorf Al Oil caps. I've only tried two different tubes thus far. It's just a very pleasing sound with some relatively minor nits to tweak eventually. And I rarely leave well enough alone, so I am enticed by a couple tweaks, and will inevitably do a couple minor things to mine... but I'm not in a rush. I doubt most people would be after hearing it the first time.

FWIW

 

So just comleted the build a couple of hours ago, worked on the first try, pretty proud of that

First impression's are favorable but i'm gonna let it burn in for a while and form an opinion.

Back to listening i must go, the Torpedo demands it!!!

 

Congrats @Riotvan that's awesome! enjoy and let us know what you think later

 

If the choice is between a better cap straight up or adding bypasses, generally just go for the better cap from the get go. I use the Solens myself for more body.

 

Will do!

 

Did you see this?
http://diy.ecpaudio.com/p/some-notes-on-coupling-capacitors.html

Solen bypassed with 0.1uF Vitamin Q
$2.65 + about $1 on ebay

Notes:
Again, a huge improvement. Most the harshness of the Solen's is more or less gone with an added midrange clarity and richness. Still not as nice as the Auricaps, but the price is about a fifth as much. Indeed, if I were building a system on a tight budget, this is what I would probably use.

 

BTW, speaking of caps, @dsavitsk do you think 250V caps would work in C7,C8,C9,C10 ?

 

250V is a little low. They'll see close to that routinely on startup, and if something were to go wrong in the regulator, considerably more.

Bypasses can be unpredictable. But if it is a good combination, I usually prefer it to a mid quality large cap. You can generally get a better cap for the small size.

 

Yes, bypasses can be unpredictable. I would say, that they are always unpredictable

Reading the entire thread you will see that TomB from the Torpedo design/sales team (maybe also others, can't remember) tried different bypass caps. TomB ended up not using them because the sound always got worse. So yes, unpredictable results.

I must admit, that I have given up trying to find good matches that gives a sound quality I can live with. This is after spending a lot of money on bypass caps over the years, and from being involved with the final voicing of both DIY and commercial designs. To me the sound always get ''artificial'' in some way, and the result has always been to spend the money on the best caps budget/space allows and no bypass caps. These experiences are in high end designs with high end ambitions - like this one. In very cheap gear with basic MKT caps, electrolytics or basic PP caps in the signal path I do hear improvements with bypass caps. In those cases the cap is so bad to begin with that it helps.

My thinking on why bypass caps are so unpredictable (and in my opinion does not work) is that a capacitor is first of all capacitance of course, but it also has resistance and inductance = an L C R resonant circuit (google L C R resonant circuit if you want to read more). By adding a bypass cap we introduce another resonant circuit in parallel with different characteristics and I believe that somehow these resonant circuits clashes and things get unpredictable when it comes to sound (difficult to explain the details in a second language). This is my thinking about why something that seems like an obviously good solution from technical perspective for some reason gives unpredictable results when it comes to the sound.

I don't have any scientific data to back this up, as said it's my thinking about the unpredictable results. I have discussed it with designers through the years after pulling out all the bypass caps they add by default (no listening). To some it make sense, to others it does not...

So my take on this is, that it's cheaper to buy the best caps budget/space allows and no bypass caps because we might end up spending a lot of money on a lot of different expensive caps without getting the sound we hope for. That's why I just spend serious money on the Rike Audio caps, I feel this is a more predictable / cheaper way to go.

I'm not saying it can't work. Actually I'm positive, that it can work and give excellent sonic results. I'm just saying that I have given up trying. If someone takes one for the T3 team and start a quest searching for the perfect cap combination that sounds better, than the best caps we can fit in the T3 box I will be cheering from the side line