ECP Torpedo III [indexed in first post]

In other circuits, the 7062 had been my preferred tube where 12AT7s were called for, but it might not be the case in the T3. Microphonics aside, I also think these come up a bit lean in my amp with Mundorfs.

 

Terrific post, thank you Tom.

 

@TomB are the 12AZ7 also tubey sounding?

 

No. If anything, I would describe them as neutral - but they're not thin/lean. If that makes any sense.

 

Great post Tomb! I did some digging for those 12AZ7's and you're right they seem very rare. But i did find some cheap one for 14 euro's a piece, think i'll give those a try.

Edit: Think this tube might have too much gain for my taste, with 12au7's i get just enough play with the volume to be comfortable. I am a really low volume listener

 

Threw it together during my break and let it warm up while i was eating. I do not have buyers remorse and that's a very good thing. Admittedly i have not spent that much time with it to be critical, but the torpedo sounds very solid state. If I had no experience with any amp in an A/B comp, I would've thought the M3 was the tube amp and the T3 was the SS.

Obvious Strengths:
Neutrality
That bass punch, weight, quality and control
Details

Tbd Weakness:
Mid range focus?
Everything kind of loud or amped/same volume -Dynamics?

Overall, i don't feel i need to make any changes or tweaks to the default personality (Stock tubes, Cinemags, parafeed caps, CCS's).

The base model where i think the T3 has some insane value going. Summit fi like sound and mid fi price - i do agree with that statement.

 

Is there way to soften the sound? The amp is hard sounding. It is probably because of the high dampening factor due to the low output impedence.

 

You can try different output caps like the Solens that are fuller sounding compared to the Mundorfs, and/or you can use carbon resistors such as Allen Bradley for plate loads + grid stoppers. The Allen Bradley carbon are old school resistors that has that slightly softer and warmer sound many want from tube amps. Resistors can't make night and day differences, but you can tweak the sound a bit in a certain direction.

OR you can try to add resistors in series with the output (just before the jack output). don't know what headphones you're using? Some favor a damping factor on approx 6, so if using 300 ohm cans add something like 47 ohm in series. The bigger the resistor the softer the sound might become (because of low damping factor).

 

@Jun I'm curious what you're comparing the T3 to when you call it "hard". Do you mean high frequencies?

 

well i used to have an botlehead crack the sound is mushy in comparison. I don't want the t3 to be as soft as an OTL like the crack but just slightly softer. The t3 is hard as in the drivers are really dampened, its probably a good thing for most people though.

 

I have a set of 6201s that will soften the sound for you in terms of slight HF rolloff... If you want to give them a shot and are in the USA, shoot me a PM.

 

Running mundorfs caps, cinemags opts, tube ccs, 6060 brimars, its probably the high dampening factor.

 

Which headphone? If you replaced the headphone jack with a chassis mount jack and used jumper wires between it and the board, then it'd be easy to insert something like a 10 or 20 ohm series resistor in the path. To put your damping factor theory to the test.

 

Decided to try some 12AZ7 tubes anyway and ordered these: http://www.ebay.com/itm/Matched-pair-Intl-Servicemaster-12AZ7-tubes-Square-getter-excellent-condition-/391383292458?hash=item5b20431a2a:g:e~oAAOSwWTRWvPw1&nma=true&si=SJjC49R2go4UM7f8EABSVyqZBds%3D&orig_cvip=true&rt=nc&_trksid=p2047675.l2557
Have to hear what TomB is raving about

 

Cool, let us know what you think about them

 

Wish I had seen this spacer and dow corning 748 info before I threw in my caps! I don't think ripping them out and putting them back in is an option anymore without buying a new set of caps

 

Well, there's nothing to stop you from putting some other kind of spacer between the caps, now - maybe something like a 1/8 - 3/16 piece of balsa wood. Then squeeze some 748 in there to make the clearance permanent. It should last for a number of years. For that matter, once the 748 has hardened (24 hrs) you can probably take the balsa spacers out.

Yeah, it's not the production spacer that Doug has carefully designed and had produced with a new lead-bending scheme, but it still accomplishes the primary goal: keeping the leads from ever touching each other between the back and front row of caps.

 

Rike Audio S-CAP update...

Some of you has asked me to get the impression on these caps posted, so I better get to it. I have something like 20 hours of burn in on them now, so things might still change with more burn in.

I'm sure you have heard the ideal amp described as ''a wire with gain''..? You know, an amp that simply let the signal pass through without coloring the sound and without any limitations to dynamics, transparency, sound stage or what ever. After installing the S-Caps I got to think about that phrase and in this case it could be rewritten to ''a wire with capacitance'' so to speak. The best way to describe the S-caps is, that they sound like no capacitor at all (I know this is impossible of course, but you know what I mean).

There is nothing forward or laid back with these caps
The tonality sounds spot on
Transparency is high
Dynamics and transient attack is amazing
Etc...

The sound is natural with these and I get this feeling of live music. As explained earlier I'm also a musician and I use live music as my reference. I'm reminded on a daily / weekly basis how voices and instruments actually sounds like live out there in the so called real world, and the Rike caps brings the T3 closer to that sound. For that alone they are worth it to me since I'm very sensitive to tonality being ''off''. That's the down side of having the strong reference to live music, and I found the tonality slightly off with the Mundorfs (a bit forward and a bit lean in the bass). I know that to many others small shifts in tonality means nothing.


Value for money...

Are they worth it? Well I would have to say both yes and no. YES because they do improve the sound and if you want to max out the T3 I feel these are among the best caps we can squeeze in there. NO because the upgrade of the plate load resistors to Amtrans AMRG is so much better value and might even give a bigger improvement in sound, than the change of the caps. The caps are more than USD 200 and discontinued so getting hard to find. The 4 plate load resistors cost less than USD 30, and if you upgrade the entire resistor package like I did the cost is still less than USD 50 and as said eariler: The upgrade of the resistors is a substantial improvement, as big as a tube change from standard tubes to quality NOS tubes. To me the resistor upgrade is a must, and with the resistors upgraded I think most will be happy with the Mundorf caps. I choose the carbon Amtrans AMRG to ''balance out'' the Mundorfs and I feel the synergy is very good. I know that many don't believe me on these resistors, but.....


Rike S-CAP + the resistor upgrade + other upgrades

Combined though these upgrade makes the T3 sound exceptional. I still find it hard to believe that the resistors gives such a big improvement in this design, but that's what I hear. And with the Rike caps in there also the T3 is just amazing. I now use the Telefunken ECC801s that I find neutral tubes. With the ECC801s I hear that live sound described above: Transparent, dynamic, full without being bloated, impressive impact in the bass and a very natural tonality. With the Mullards the sound is almost too powerful in the bass, especially with bass heavy headphones, so there is no longer a need to balance out the tonality of the T3 with the fullest sounding tubes.

It would be so fun to hear this maxed out T3 side by side with a T3 without the silver input wires, TDK pot, e-choke, resistor upgrade and Rike caps. I just don't think there is another T3 here in little old Denmark.