Some semi odd things i found out. When listening out of the balanced it seems that output is fully active no matter if the switch is flicked to Balanced or SE, as it makes no difference. Out of the SE output when switched to balanced it just halfs volume. From both outputs, if you switch to speakers or the unused input you can still hear the audio faintly.
While i heard this in some other amps, i find it odd balanced is not affected by the bal/se switch at all, making me wonder why it is there.
Right now i am enjoying my listening sessions. Lows and highs are where i want them to be, and the bendix added great holographic seperation which reminds me of what my plenue S does so well. But i keep feeling i want to see if i can get more out of the mids. I dont want to say they sound thin but i think they need more “meat on the bone” as currently they still feel flat even with WE 300Bs, and rock guitars lack the power and authority i expect.
This is not surprising, the switch will probably be just changing what transformer tap is ground on the output, the DNA does a similar thing, technically you are hearing an SE signal out of the balanced connection when it’s set to SE, I.e. L-/R- are ground, rather than some negative voltage.
SE out will be just ground and the high tap, so it changes volume with the switch.
I should note one undocumented feature of wiring it like this is you can reduce the output impedance by about 1/2 by using the SE headphone out in Balanced mode. Though it’s probably low enough on the EC it makes no difference.
The EC amps generally don’t have a lot of midrange warmth, they tend to be very neutral/dry for SE amps.
But I’d start with 2 or 3 different rectifiers, the difference between the Russian equivalents and some 5U4G’s was pretty dramatic in the amps I’ve tried. My EC doesn’t use compatible tubes, so I can’t comment specifically for Craig’s amps, and I was generally trying to go the other way.
You don’t have a lot of options with pre tubes, and what he ships are considered quite good.
You may actually be better off with cheaper power tubes if you want more midrange weight. The Gold Lions skew that way, at the cost of some control.
Even w/ the Electro-Harmonix tubes in place the EC Studio B never got much midrange warmth. Closest i ever managed to what you are looking for was probably when i had it w/ the Border Patrol SEi DAC as the whole system had a nice midrange hump overall, but then you would be sacrificing technical abilities overall.
I will try this next, right now i have a mullard fat base gz34 as it does wonders for keeping a tight layered textured bass. I have a few others to try, maybe the ole RCA 5u4g does the trick.
VTS had some WE 396a/2c51 with date codes that matched what others reported as early 50s, and for $40 that seemed like a no brainer to try out. I think @Towa would agree there. The holographics and detail are great on the bendix but it is brighter and leaner.
The GLs were the ones Craig recommended, which is what i was going to go for before Nick gave me an offer i could not refuse. I always like to have backup tubes for troubleshooting, so maybe eventually i try those.
In the end i still have the following to navigate:
Break In: Tubes and the amp itself. Both are low hours so lets see how it opens up. Interconnects: Right now they are kimbers, i still have others on hand to try. Headphone cables: The stock zmf doesnt impress, the cables that came with pf Audeze are better but still ground level. I have a chonky copper boy on the way. Warmup: This needs about 15m to get mostly there then another 15-20m for that final touch. Not unusual for tubes obviously but noted.
In the end i still really enjoy the amp and this is a spot where i feel better looking at the minor finishing tweaks. And with headphones like the hd600, it is still exceptional mid wise. I just want to eek that last bit of juice from that section if i can, and i dont think it is exclusively the EC house dryness.
Modern tubes take forever to break in, just leave the amp on for a week or so. It’ll get you most of the way there, but the biggest difference in break-in I’ve noted has been on power tubes.
Caps will also change their character over the first several hundred hours, and technically transformers can take years to sound their best (but you can ignore that).
Though often the pre tubes on my amps are “NOS” and you never know how N they are.
On an unrelated note turning the Studio T’s pot to maximum and using the Lampizators Pre amp exclusively has been pretty much the greatest free upgrade I’ve ever done.
Makes me consider bypassing the pot on the EC properly.
I believe the new WE300Bs are supposed to take at least 100 hours of burn-in. Mine didn’t have that “magical” mid-range when I first got them but they do seem to be opening up as I use them more, it’s just I prefer the Elrogs more so I keep switching them back and forth. I’ve even heard 500 hours being thrown around but I think at least 100 hours is probably reasonable.
I picked up a '57 (Nish?)old stock metal base Mullard GZ34 which greatly improved tightness and texture on bass. I asked Brent Jessee if he has any other recommendations but he said its hard to improve on the metal base so I haven’t had the urge to switch it out.
I did get a 2C51 NOS Tung Sol from the 40s that Brent claims to be superior to WE396A but I just got past 100 hours on it probably so I’m going to switch back to the stock one that Craig sent and break that one and then do some comparisons.
Blacker background, marginally improved dynamics and staging.
Not really a change in character, more just an increase in “sophistication”.
The Pot in the Studio T like a lot of high end headphone amps isn’t terrible, but it isn’t anything special either, so it doesn’t stun me there was a win, but it was a significantly bigger improvement than I expected.
No to be honest I hadn’t even tried it until there was the discussion of preamps on DAC’s in the Lampizator thread yesterday, and it piqued my curiosity.
I usually treat volume as a convenience Item, the Amp Pot is easier to reach in my system to I set the DAC’s pre, so the range on that is solid and just use it.
As I said impact surprised me.
Nick did me the pleasure of putting about $1k hours on them, though they were light duty in a preamp.
Mine is a '59. Metal bases were a bit much price wise, and the i have an amperex labeled of around the same time. I agree the mullard is where its at, but ill try others to see what else there is.
Tungsol was like a scifi lab with tubes, especially with their Chatham stuff. I know his site says it us better, and i wanted to grab one but i want to try the WE before i go deeper. I do like they are sperry gyroscope tubes. Those were legendary gyroscopes.
I find the bendix to be similar toned to the JAN GE he includes but better in every way. Holographic and detailed, it feels bright but i dont know if i would label it so. I got a 4 pack from that ebay buy so let me know if youre interested in one.
I will try this too. The lumin has the fancy leedh digital volume i can test, and then ill try the volume on something else that im trying to get incorporated soon.
Ah then there’s no more burn-in for them I highly recommend Elrogs (not sure if you already have them or have tried them). I have the Elrog Mos and they are very punchy with tight bass, mid to treble integration is very good, incredible dynamics, layering and stage.
Ooo, I was trying to find a Bendix, let me PM you!
Public Service Announcement, if you are purchasing or selling an Eddie Current Studio B please be aware the amplifier does NOT travel well and can damage easily. The transformers in the power supply unit are mounted well enough to provide years of service but they do NOT ship well. The bolts used to secure them and some other pieces are quick to unscrew and the possibility of minor damage is real. A little bit of blue loctite on some of the internal screws and bolts before shipping the amplifier and power supply are highly recommended.
I sold my EC Studio B recently, the amplifier was basically new with less than 500 hrs on it. I packaged it in a heavy duty Pelican hard sided shipping case because I knew others have had issues and wanted to avoid any headaches w/ my buyer. I used the 4” thick pick & pluck foam ($150) which i had to purchase new for the case, I made sure all was super snug and we STILL had a loose component and a connector that popped off and cracked
A local technician in Chicago, wonderful man, fixed it quickly, cleanly and was kind enough to not bother with charging, it was such an easy repair.
Nonetheless, fair warning, you are best off picking up a unit local and even then giving the bolts and screws a good once over before attempting to power up for the first time.
Consider yourselves warned and informed.
This is how i packed and shipped the amp, it was bomb-proof but not free of g-forces it sustained while on its travels.
Thank you @orrman, there is NO FAULT in this or anyone’s particular situation w/ the EC studio B. This is the 3rd instance-noted in this thread where one of these amplifiers has arrived with slight damage due to shipping. Both @Souldriver and @Towa if i am not mistaken had to deal w/ the same exact issues which is why i decided to overpack and STILL had to deal w/ an unhappy buyer who was worried that he might not be able to get the amp operational.
This is fair warning to all, I love the SQ of the Eddie Current product but 3 similar and separate unrelated instances should be considered a warning to folks to be careful and take extra steps w/ these amplifiers to help avoid loose parts flopping around. The bolts need some loctite for shipping.
I highly recommend Elrogs (not sure if you already have them or have tried them). I have the Elrog Mos and they are very punchy with tight bass, mid to treble integration is very good, incredible dynamics, layering and stage.
