ECP Torpedo III [indexed in first post]

Think I'll put the stockresistors back in, don't feel like i need the added warmth of the amrg's now.

Edit: A noticeable improvement to my ears. Seems like a hazzy/slightly grainy veil has been lifted. I think i was trying to mask the effect of using the usb input on Yggdrasil with the amtrans.

 

A question:
On the site, I only see torpedo 1 kits and PCB's.
Is that the same?
What happened to the 3?

 

I believe T3 evolved to the point where they only sold completed units... and now it's gone and they're working on the next one.

 

Would love if he can put a DIY version of DHSA-2, with less expensive parts, something under 1000usd.
I'll buy one in a heartbeat

 

MAXXED T3 AND BRIMAR TUBES
Wanted to update the group after getting my maxxed T3 back from @TomB.

I noticed the sound post-upgrades was a little more clinical, and though I appreciated the increased transparency and resolution, it wasn't as enjoyable overall for me. Seemed to lack some low bass, even using the same stock EH 12AY7s I had before the upgrade. Tom recommended a tube swap and sent me a couple GEs to try: NOS 6414s and 12AZ7As. I could only take a few songs with the 6414s, but left the 12AZ7s in for a while.

BRIMAR 6060 YELLOW TAILS
I really wanted to try a pair of Brimar 6060 yellow tails after conversing with @brencho and @bazelio and reading others' impressions in this thread: one, two, three.

Unfortunately, I couldn't find a yellow tail pair I felt comfortable buying at a good price. I had bookmarked a Tubemonger link to some Brimar 6060 white labels shared earlier in this thread. (one, two) In response to my inquiry about Brent Jesse's claim that the yellow tails were superior, Tubemonger said: "That was the myth started by one of our buyers many years ago on the web to overhype the tubes. We stopped selling to him as soon as we found out. There was another seller who tried to do the same." (In subsequent emails, they confirmed this buyer was not Brent Jesse.)

BRIMAR CV4033
However, Tubemonger recommended another ECC81 tube made by Brimar that in their words was "superior to [the] 6060 or any other variant:" the CV4033. I ordered a pair of NOS 1960 Brimar CV4033 (military-spec, black plate, long-life). With a 10% discount during December, they were $85 shipped. (Tubemonger also has a 12AU7 variant of these from 1970.)

Features

Spoiler: CV4033 features

• Ruggedised construction: Improved design of micas to eliminate electrode movement, with control of mica and internal bulb dimensions to precision limits. This eliminates rattle noise and microphony, At the same time obviating cathode poisoning by gas evolution resulting from frictional movement between mica and glass
• Redesign of grid profiles to control resonances arising from vibration and shock
• Improved metal piece-parts giving greater mechanical rigidity
  
• Redesign of connecting links and stem wires to reduce the possibility of failure
• Specially processed tungsten and advanced methods of heater coating to give a greatly improved heater life
• Long life (10,000+ hours) Deterioration of electrical characteristics over 10,000 hours of operation is less than 30%

(source)

Packaging
Packing was great! The tubes came in their original boxes with the styrofoam toppers inside. They were packed inside a sealed rubber container with packing material, all inside a bubble envelope:




I asked what Tubemonger's matching tolerances were, and they said typically between 5–10%. I asked if they could send me a tightly matched pair, and per the measurements on the boxes above they are within ~3%.

These CV4033s came with all the original factory stickers, including individual tube numbers written on rings on the top. Originally these tubes came only with flying leads and were direct-soldered to the board. Tubemonger developed custom Bakelite bases that allow usage in standard 12AT7 applications.









Sound Quality
Reviews are pretty sparse, but there are two customer reviews on the Tubemonger CV4033 product page (my emphasis added):

I'm not much of a tube roller, but can share my initial impressions. I find the sound of the maxxed T3 much more enjoyable with these than any of the other three tube pairs I have. There is more warmth and realism to the sound. There was always a little harshness using the stock EHs, and I don't hear that at all with these. Using these tubes and my Cardas Golden Reference cables has been the best I've heard the HD600 with my T3. I still use the HD600 most often, even with the Utopia and HD650 (stock and modded). The stock EHs might have more extended treble, but I haven't compared directly so it could also be the comparative lack of bass that I'm remembering.

Either way, I haven't taken these out since I got them, and am really only still curious about hearing a Siemens ECC801S. When I asked Tubemonger about their recommended 12AT7 variants, in addition to the CV4033, they said: "Our other top ECC81 is Siemens E81CC (neutral and a little brighter [zonto: than the CV4033] but also musical)." These appear to be a military-spec, triple mica version of the Siemens ECC801S that a few people have tried and liked here. I'd like to hear them some day, but didn't want to spend that much now. (review 1, review 2 (see Bambi B, last post)) Maybe I'll try a pair in 10,000 hours.

 

@zonto glad you're enjoying these tubes. I don't doubt they're good but it might be worthwhile to get some ears familiar with the yellow 6060s on these because, as far as I can tell, they're at the same price point per pair.

In my chain, the Siemens 801S work out great in the T3. After a bit of time, they've become more extended on the bottom end where initially we'd call them limp dickish. This, with just a touch of euphoria and giving up only a tad to other tubes in resolution and attack, makes them a great all-arounder for me. Oh and they stage better than most I've heard in the T3, too.

 

I actually have those 4033s with the flying leads, only I got them at like $10, but without matching and I had to get my own solution to fit them in the sockets. Unfortunately they arent well matched so I can't really get any useful impressions from them. Should have bought a couple more.

 

How is the gain on those CV4033s? More than EH 12AY7, less, about the same? Do they react well with regards to noise floor on low impedance loads?

 

My understanding is that the CV4033 is a 12AT7-equivalent, but I cannot find a spec sheet to verify. 12AT7 vs. 12AY7 gain is discussed here. Anecdotally, I listen around 9 o'clock or a bit higher on hi Z with Senns and lo Z with Utopia, Yggdrasil RCA as input, with these or the EH 12AY7.

On the latter point, using Utopia today on lo Z I didn't hear anything out of the ordinary while listening, or while paused and with the volume knob maxed. 80-ohm nominal impedance. Don't have anything with a lower impedance to try.

 

This amp is going to kill me one way or another. I've fixed it again (one bias resistor tried to run), but brought it back home and it still does not work on one channel. Weirdness.

The difference in test vs use is only in connectors and case now.

 

That's 4 non-sequiturs in a row, but I don't like the first one. Maybe I missed something from earlier? What's going on? Can you post some pics, and some actual symptoms?

 

I don't think you missed anything. I haven't received any word of issues in months, now. Hopefully, he'll come back and tell us more.

 

So, I recently purchased someone's modded TIII. It arrived packed well and looked to be in good shape; however, during warmup and testing, one channel wouldn't play with the impedance switched to hi. Upon pulling the circuit board I noticed the central housing for the transformers was cracked on both of the CineMags (one pictured below). After pulling the transformer on the offending channel, I found that one of the leads from the central winding to the contacts had broken off flush with the winding.

After being in contact with the seller, builder, and TomB, I contacted CineMag. Good news! CineMag will produce these transformers as model number CM-15615PC. While there's a bit of a wait for them to wind the transformers, I won't be SOL for getting replacements.

Looking at what happened, it appears that the plastic housing stresses from the weight of the core whenever the package is jarred/jostled. I don't think it's out of the question that this would happen to someone else. Also note that even with a cracked housing, one of the transformers still worked perfectly. Barring local pickup or an uncommonly gentle journey with FedEx or UPS, I'm not sure there's really a way to prevent this damage. Perhaps adding some foam within the chassis after pulling the tubes would help prevent this stress. Either way, if anyone else runs into an issue with their transformers, CM-15615PC is the model number and [email protected] is the email.

 

Four new, fully loaded T3s nearing completion - one is already spoken for ...

 

Boom! The T3 thread makes a triumphant return!

Been experimenting with the low gain 12AU7 family lately and like what it does to relax the more-aggressive post output ccs T3. Worth a shot for folks who might want something with a bit more air, stage, and still an otherwise T3 sound sig. I'd say at the expensive of a bit of precise focus especially against something like a GE blackplate 5751. Being a tad more diffuse and open is a tradeoff Im liking for now. Just be prepared to move you normal listening volume past 12 noon with these low gain wonders.

 

@TomB they look good! I'm glad that there will be a few more of these out there in the wild soon.

Also, I forgot to update my earlier post here. CineMag finally finished my OPTs a couple weeks ago, and I had no issues replacing the broken pair that I had. It's a marked improvement over the Edcors I dropped in temporarily.

@bazelio I'm about to start tube rolling. Are there any 12AU7s that stood out? I've got a bunch of those on hand as well as some 12AY7s and 5751s (no GE blackplates though).

 

Westinghouse is good. Mine were microphonic as f**k, and despite liking them, I tossed 'em out. Good enough that I ordered a new pair, though. More to run through still, but Amperex are in for now. They are a little sweeter and a bit less extended up top, but overall quite musical. Better width than 12AT7s, judging by jazz albums not drilling my eardrums so much. A good thing.

 

I have tried conn/Sylvania 12au7 and imo they were not that great. Get some cheap 12az7/12az7a and be amazed for the price performance.

 

Sorry for the silly query, but, looking at those units in the photo above... have you all been replacing individual parts even for the "fully loaded" version to improve the amp? I'm not confident enough to do work like that myself, nor do I want to buy a new unit I would then tinker with anyway. Similarly, are the stock tubes good or would the cost of entry be a new unit + other tubes? Wondering if this unit makes sense for me as a less-DIY user.

 

Those are works-in-process, but will end up being sold as fully assembled "maxxed" T3 builds by @TomB. I'm not a DIY-er either, and purchased a used amp and sent in to @TomB to install the upgrades. @brencho did something similar.

The stock EH 12AY7 tubes are adequate, and the thread has plenty of discussion re: possible replacements with prices ranging from $10 a pair to $100+ a pair if you want to tube roll.