Now that
@4LoveOfSound and I have secured our tubes (and backups). I guess it's time to let the cat out of the bag on this one. I'm sure Steve will post some additional impressions later on as well.
Behold the Telefunken ECC83 Selected Tube "Yellow Tip". This is not a production tube, but rather a specimen manufactured for Grass Instruments in Quincy, MA for use in their polygraph machines. Its was built to specific tolerances and underwent additional screening to ensure optimal performance in medical devices with transconductance tightly controlled internally and from tube to tube.
Brent Jesse has this to say about them. "Watch for the rare Telefunken smoothplates with a cloth label on the glass marked "selected tube". Often these have red painted tips, and watch for blue painted tips, and laboratory grade smoothplates made for Leeds & Northrup as well. These were all screened for critical use in medical equipment, with the "selected tube" or L&N versions being the best.
Grass Instruments also had a yellow tip version which was even lower noise, but they are rare and difficult to find these days. All of the red, yellow, and blue tips are incredibly quiet and very three dimensional in sound. Incredibly accurate, the amazing sound image emerges out of a dead quiet background. (Note this is word for word how he describes the G73-R, he's careful not to make a direct comparison but his description is identical and this is the only other tube I have seen him describe in this manner)
The yellow tips are virtually extinct at this point, last time Brent had them in stock they ran $275 each. They would likely be more today (by his admission) if he could get his hands on any. Even the red or blue tips are going for more than the remaining 4 yellow tips below.
If you take a look at the tube, it has long smooth plates (indicative of early production Tele's) and a thick O getter. Date code puts mine manufactured in Berlin August of 1966. But what about the sound? It's warm, full, highly detailed and resolving. It reaches deep into the music and pulls out detail like you wouldn't believe. Music seems to envelop you out of the blackest of backgrounds. Low end is perfectly articulated and doesn't overpower but it's there when needed. Highs are sparkly without ever being fatiguing and the mids rich and lush. It's the most well rounded tube I have heard and it simply lets you get lost in the music, in fact it demands your attention. It really shines in its staging though. Stage is vast and 3D. Its hauntingly holographic, with perfectly realistic timbre and decay (notes hang in the air with pinpoint precision dance around the stage). Its beautifully realistic in its staging and presentation.
For those who aren't a believer in Selected Tubes versus production tubes, here is a short read from Tube Maze that puts it more eloquently than I can. (Note this is about the red tips, of which the yellow are rarer and generally thought to be of superior quality)
https://tubemaze.info/telefunken-vs-telefunken-a-story-of-two-tubes/
And here is a deeper dive into the ECC83, which these Yellow Tips hail from. Some of the selected tubes for various manufacturers are discussed. One of my favorite quotes from the article is "You will get a highly neutral ultra complex tube sound, a sound, which needs your attention – it is not a sound were you can read a book, while listening to some music. A Telefunken ECC83 sucks you into the music – and it challanges you." (And he's talking about the production ECC83, not even the Selected Tube "Yellow Tip"
https://medialux.blog/2018/04/25/introducing-a-legend/
Yes, I do realize this sounds like a few of you have described the G73-R, I honestly do wish I had one to compare it to but I haven't had the opportunity yet to roll one in my Pendant SE. Pure speculation but I think the yellow tip shares more in common with a G73-R than a production tube. It may not quite reach the same level as a G73-R but it smokes my ECC801S and its not even close. It doesn't even share the same Tele house sound as their production tubes, which is why I think it may be closer in sound to a G73-R. Medical and Avionics tubes would share similarities in their manufacturing processes (minus the black coating of course which to my understanding shielded the tube from radiation which wouldn't be present in a polygraph machine anyway).
Here is the link, they are $225 a piece.
@4LoveOfSound and I each bought a couple so there should be 4 left. Chet is the seller on Reverb, super nice guy. I don't expect these to last long (there are red tips going for more than this on eBay right now and Brent Jesse charges $275 ea for the red/blue tips)
https://reverb.com/item/63902450-ra...3-12ax7-803s-special-labratory-select-medical
Happy Listening!!!
We’ll see how this stacks up to my go to in the Pendant, a good old Brimar 6060.
