ECP Torpedo III [indexed in first post]

Actually, the R13, R14, R15, R16 resistors form a natural barrier to getting the Mundorfs too close. I added the little wrinkle of putting a "squiggle" in the leads next to the Mundorfs, but unless you over-did it, it would be very difficult to get them close enough to touch the Cinemags. That said, it's assuming you got the Mundorfs as flush to the PCB as possible. If they're up in the air above the PCB, it's a different matter.

Doug to the rescue! Doug has been letting me follow his progress on this, and I'm looking forward to implementing these changes. They should make the Mundorf caps a lot more dependable to install. They should also enhance the longevity of the amp for a decade or more.

 

Tube Impressions:


Hi guys, I’ve spent north of $300 rolling as wide a variety of tubes as possible, partly to learn about the tube world as a relative newbie, and also partly to be able to help prospective Torpedo owners in future, if possible.


As a person who lives in the tropics but has managed to go fishing in Alaska and skiing in the Alps, I feel uniquely qualified to explain the phenomenon of snow to my fellow tropics dwellers. Or in this case, the other way around, to make the metaphor work.


In honor of the Great Valve Guru himself, I will be rating tubes on a scale of 1 Shaff to 5 Shaffs, with 1 Shaff rating representing sound quality comparable to Marv’s banter skills, and 5 Shaffs representing sound quality on par with Marv’s doxxing capabilities.


EH 12AY7 New production (Stock Tubes)

3 Shaffs out of 5


Dynamics: Excellent

Resolution: Good

Clarity: Good

Soundstage: Acceptable

Bass definition: Good

Tone: Poor - Acceptable


Terrific dynamics, probably the best of the bunch here, and fairly resolving. These strong positives are weighed down by several drawbacks, which you guys may or may not be too bothered by. Tonally these are pretty even, but suffer from a rough and grainy upper mid-range which is apparent even on HD650s, especially with vocals. Bass hits hard, but can be a bit one-note. The soundstage is well-defined, but quite narrow. These tubes also seem to be missing a bit of air in the presentation. By no means a bad choice, but the sound from the amp can be raised a notch with some of the other tubes.


RCA 12AU7 Clear Tops:

4 Shaffs out of 5


Dynamics: Good - Very Good

Resolution: Very Good

Clarity: Excellent

Soundstage: Very Good

Bass definition: Good - Very Good

Tone: Good


Slightly bright with upper mid emphasis, best clarity in the lot with well-extended treble, bass is fast and notes are well delineated, but slightly de-emphasised in the range. Bass impact falls a bit short and sounds slightly spitty. Surprising dynamic considering the bass. Very airy. Cuts through the mix most effectively of all the tubes here, with a very forward presentation. My favorite when used with the modded 650s. Low gain means discernible clipping in some situations with Sennheisers.


Philips Miniwatt LRT 12AT7 (1962, Marseille factory, military stock)

4 Shaffs out of 5


Dynamics: Very Good

Resolution: Very Good

Clarity: Very Good

Soundstage: Very Good

Bass definition: Good

Tone: Very Good


Warm, meaty bass and mostly smooth across the board, with just a hint of treble glare. Good air, treble rolls in the last octave. Slams hard, though less tight in the bass than with the RCA tubes or stock EH tubes. Made my HD600s sound a bit too bassy and warm, but spot on tonally with modded HD800s, giving it the body it usually misses.


Mullard ECC81/12AT7s (Blackburn factory, 1965 date matched)


3.5 Shaffs out of 5


Dynamics: Good

Resolution: Very Good

Clarity: Good

Soundstage: Excellent

Bass definition: Acceptable

Tone: Excellent


Bloomy, woolly bass. I can happily overlook the relative shortcoming for all the other good stuff I get out of this tube. Overall presentation is more laid back than with the other tubes here. Most tube “wetness” (possibly a bit much), and a pleasant midrange warmth that makes it seem the most refined. Takes the mild shoutiness out of the HD600 upper midrange. Killer vocals. Exceptional imaging and separation, notably better than the rest. Smooth treble with great air.


RCA 12AV7 Black Plates

3.5 Shaffs out of 5


Dynamics: Very Good

Resolution: Good

Clarity: Good

Soundstage: Good

Bass definition: Very Good

Tone: Good


A fun V-shaped signature that works better with some genres than others. Not that quiet, audible noise. Tight, thunderous bass and a bit of treble sparkle relative to the mids, but not to the point of being offensive. A good performer across the board on other fronts without any major weaknesses. Not the last word in resolution or refinement.


Sylvania 12AT7 Black Plates (Newer production)

2.5 Shaffs out of 5


Dynamics: Acceptable

Resolution: Good

Clarity: Very Good

Soundstage: Good

Bass definition: Good

Tone: Good


Very clean, but a bit bright. Treble is not sharp, but has bit of a rising response. Coherent and accurate through the midrange. Bass is well-defined and tight with good extension, but lacks impact. Stage is not as wide as some of the other tubes mentioned, nor as focussed as the best of them. Reasonably resolving, but the lack of dynamics and bass slam make this tube sound correct but a bit dull.


GE 6829 5-Star

4 Shaffs out of 5


Dynamics: Good - Very Good

Resolution: Good

Clarity: Good

Soundstage: Very Good

Bass definition: Very Good

Tone: Good - Very Good


Well-behaved, neutral-ish tube, leaning a bit to the warm side. More dry sounding than the RCAs. A bit of treble roughness. Quite dynamic with lovely, rich bass. Not exceptionally good at anything in particular, but sounds good across the board, though it is not the last word in resolution. Doesn’t do much wrong, and great value at the prices on eBay.

Mullard M8162 CV4024

4.5 Shaffs out of 5

Dynamics: Good

Resolution: Very Good

Clarity: Good - Very Good

Soundstage: Excellent

Bass Definition: Good

Tone: Excellent

Very nice, a clear upgrade over the regular ECC81 Mullards. Keeps the good qualities of the civilian tubes, but with much tighter bass and improved clarity. These make the excellent imaging qualities even more apparent. A fair bit more expensive than the other tubes here.

 

Imgur embed is not working for some reason. Also I went full @MisterRogers and bought Brimar Yellow T 6060s to try.

 

Massive thanks, Hitman.. Terrific/useful/hilarious post!

 

Thanks a lot! I need to get some mullards. Seems to be exactly what I am looking for.

 

Be careful about date of production, and if you are shopping on ebay, fakes. Generally pre-70s tubes are better and will be worth more. Brent Jesse's site has a lot of helpful info about this: http://www.audiotubes.com/

You can buy from him too to save yourself the worry, his service and verification is rock-solid, though he does charge more than most.

 

I was wrong, I had Mullard 12AX7s, not 12AZ7s. I have some El (essentially Telefunken) 12AX7s and they are too bright & sharp, though punchy. I bet the ideal tube for this amp is an Amperex of some flavor. I'm going to see if there any 12AZ7s. The 12AX7s would probably also work great, but they are speeeendy. $200ish for the good ones, aka Bugle Boys.

 

Very cool review of tubes for the T3!

I'm especially gratified to see you agree with my impressions of the 6829. If someone is wanting a high quality richness and smoothness (not much distortion for the richness), the 6829's are the way to go. It will be interesting to see what you think of the 12AZ7's. At least from what I'm hearing, I think the dynamics are on par with the EH 12AY7's. They're leaner in bass than the 6829's, but it seems (to me) that there is no tendency toward glare or grain.

My pair of Amperex 7062's seem a bit lean - more than the 12AZ7's, but cleaner, perhaps, if that makes sense. It's pretty cool to have an amp at this level of performance still show fairly distinct differences among different tubes.

I think Doug opted for a pair of those Mullard 12AT7 equivalents from Brent Jesse. That's too rich for my means, but it will be interesting to see what he thinks of them, too.

 

The Tube CCS boards are now available on beezar.com in pairs (separate from a T3 kit) and as options for T3 kits. They are offered as pre-soldered, only.

 

Ok cool. Just ordered the CCS boards for my yet-to-arrive kit... Looks easy enough. I had half a mind to finagle Belleson regs in to place, but will just go this route. Thanks, TomB! The pre-soldered boards here is the preferred choice for sure!

 

Same here! @bazelio wanna help me install mine???

 

This thread is making me want to throw together a Torp. Maybe near the holidays...

 

Cinco de Mayo is a nice holiday ...

 

My birthday is coming up too....

 

I apologize everyone, but the CCS Boards may be delayed by a day. All your orders came in after my bedtime last night. So, I was ready to process them all tonight. Unfortunately, I screwed up and didn't renew my SSL certificate on time - it expires every year around the beginning of May. So, tonight I am unable to access the management portion of beezar.com - it's part of the security features against getting hacked. Anyway, my provider has it all straightened out, but it may be several hours or tomorrow before the certificate is restored and I get full access back.

Again, my apologies. All of the CCS Boards are packaged up and ready to go, but I can't process them through the system until I get this f*-up fixed.

 

It's all good @TomB no worries man!

 

One day! No sweat. LOL we wouldn't have known had you not mentioned it. Shit, my soldering iron is dead so I'm a week away from getting started. You guys like Hakko? Looking at the 888d to replace my dead Weller.

 

Hakko is nice - a great value for the price point. Metcal refurbished if one can be found reasonably - is on a whole other level. If you plan on doing SMD work, Metcal is worth the spend.

http://www.jim-gibson-co.com/memxposufure.html

 

Hello all,

The new guy from Denmark checking in. I'm waiting for my Torpedo to cross the pond (and the Danish customs, ouch...). Thank you Tom for excellent customer service

I have some nice parts sitting on the work table waiting to go into the Torpedo kit:

A TDK volume pot,
The Mundorf para feed caps,
A matched pair of Philips SQ E180CC,
A matched pair of the nice military grade M8162/CV4024 Mullards mentioned above.
And I just scored a matched pair of Telefunken ECC801s that showed up locally. Some say they are the best of the best... Time will tell...

So I'm ready..! There are a few small tweaks that I will make to try squeeze a bit more sound out of the beast, more on that later on.

BTW: How do you upload pictures on this site? Do I need to have them on external site and then link to them? Or can pictures be uploaded here from the computer?