Tube Rolling w/Crack
- Thread starter Dr. Toobz
- Start date
Lawrence Ho
New member
Hi everyone,
I completed my first build of CRACK recently and have been enjoying the reward very much ever since!
Not so surprisingly, I am already in pursuit of NOS tubes but found myself lacking the knowledge required.
Even though I have done a lot of readings over the past week, there are fundamental questions that hopefully can be answered here.
1.) When buying NOS, what parameters exactly I should check? [Gm, IA?]
2.) Are there any matching of parameters need to be done when buying one single tube [not a pair]?
3.) http://www.ebay.com/itm/RCA-6AS7-G-Vacuum-Tube-Results-2680-3450-/182440130837?hash=item2a7a477915:g:5BwAAOSw2xRYkMxU This tube, the seller says test result = 2680/3450, does it matter these two value aren't close?
4). What else i need to be aware of? Any suggested readings/guideline for beginners like me?
p.s http://www.ebay.com/itm/Tung-Sol-5998-2399-421A-replacement-/272523578533?hash=item3f73abcca5:g:6oEAAOSwNnRYfGrz do you guys think it is a good deal? 5998 is so expensive these day...
Thanks so much in advance!
Lawrence
I completed my first build of CRACK recently and have been enjoying the reward very much ever since!
Not so surprisingly, I am already in pursuit of NOS tubes but found myself lacking the knowledge required.
Even though I have done a lot of readings over the past week, there are fundamental questions that hopefully can be answered here.
1.) When buying NOS, what parameters exactly I should check? [Gm, IA?]
2.) Are there any matching of parameters need to be done when buying one single tube [not a pair]?
3.) http://www.ebay.com/itm/RCA-6AS7-G-Vacuum-Tube-Results-2680-3450-/182440130837?hash=item2a7a477915:g:5BwAAOSw2xRYkMxU This tube, the seller says test result = 2680/3450, does it matter these two value aren't close?
4). What else i need to be aware of? Any suggested readings/guideline for beginners like me?
p.s http://www.ebay.com/itm/Tung-Sol-5998-2399-421A-replacement-/272523578533?hash=item3f73abcca5:g:6oEAAOSwNnRYfGrz do you guys think it is a good deal? 5998 is so expensive these day...
Thanks so much in advance!
Lawrence
Lawrence Ho
New member
Lawrence Ho said:
Appreciation to the member who answered my questions! (also apologizes for not remembering your name as the reply is gone somehow)
I wanted to come back with more questions after doing some study on monophonic problem just like you suggested. But they do not matter anymore,
have given up on that tube already.
Not sure whether you will read this, but I still want to send you my gratitude.
Lawrence
monsterdonkey
New member
I replaced the stock GE 6080 with a Chatham 2399, and the unbranded 12AU7 with an RCA clear top 12AU7A. For a while I preferred the look of the st shaped Chatham tube. It looks impressive sitting there on the cabinet. But I found the sound to be harsh and lacking bass. Maybe a little cold. I have the Crack plugged into the tape monitor output on my NAD C740, which bypasses the eq. Straight signal into HD 600s -what could go wrong? But I wasn't listening as often as I had been in the past.
The other night I plugged the GE back in (left the RCA) and fired up QotSA - Like Clockwork. The richness and warmth and bass I'd been missing was back and the experience was delightful. I've verified my drunken findings in the sober light of day by listening to some other things on the original tube and it still sounds great. If I get a chance maybe I'll do an A/B test with my bias tuned towards the workhorse 6080 rather than the pretty 2399 this time.
My Crack has the Speedball upgrade and some big M-Caps capacitors.
The other night I plugged the GE back in (left the RCA) and fired up QotSA - Like Clockwork. The richness and warmth and bass I'd been missing was back and the experience was delightful. I've verified my drunken findings in the sober light of day by listening to some other things on the original tube and it still sounds great. If I get a chance maybe I'll do an A/B test with my bias tuned towards the workhorse 6080 rather than the pretty 2399 this time.
My Crack has the Speedball upgrade and some big M-Caps capacitors.
monsterdonkey
New member
attmci said:
Yeah. It shows how subjective this stuff can be sometimes. It also may expose the limitations of my gear.
hccuneyt
New member
Noob warning.
Equipment is HD650+Crack(no upgrades)
I was planning to purchase Genalex Gold Lion ECC82, I see 2 versions (regular vs platinum) on eBay, with the following description. I was wondering the difference (hig/low gain), planning to pair with "Svetlana Winged C 6H13C = 6AS7G Vacuum Tubes Black Plates".
Thanks!
GENALEX New PAIR Platinum Matched Gold Lion NIB 12AU7 ECC82 B749 Tubes Gold Pin
From description: It is a high gain, low noise valve with a short plate structure for reduced microphonics. Excellent for use in the highest quality audio amplifiers/pre-amplifiers.
GENALEX New PAIR TWO Gold Lion NIB 12AU7 ECC82 B749 Tubes Gold Pin
From description: It is a medium gain, low noise valve with a short plate structure for reduced microphonics. Excellent for use in the highest quality audio amplifiers/pre-amplifiers.
Equipment is HD650+Crack(no upgrades)
I was planning to purchase Genalex Gold Lion ECC82, I see 2 versions (regular vs platinum) on eBay, with the following description. I was wondering the difference (hig/low gain), planning to pair with "Svetlana Winged C 6H13C = 6AS7G Vacuum Tubes Black Plates".
Thanks!
GENALEX New PAIR Platinum Matched Gold Lion NIB 12AU7 ECC82 B749 Tubes Gold Pin
From description: It is a high gain, low noise valve with a short plate structure for reduced microphonics. Excellent for use in the highest quality audio amplifiers/pre-amplifiers.
GENALEX New PAIR TWO Gold Lion NIB 12AU7 ECC82 B749 Tubes Gold Pin
From description: It is a medium gain, low noise valve with a short plate structure for reduced microphonics. Excellent for use in the highest quality audio amplifiers/pre-amplifiers.
A 12AU7 is a medium gain tube. That high gain comment has to be either a misprint or misrepresentation of the tube as a 12AU7. Most likely it's a misprint, as the platinum thing seems to mean they are somehow "matched" but not any different in spec from the non-platinum version.
fullheadofnothing
Moderator
Since it says USA, it's a re-branding of something (probably GE). Showing those other markings would be helpful .
fullheadofnothing
Moderator
Left is definitely GE.
Right could be a Mullard. Easiest spotting of a a Mullard is if the heater flashes very bright briefly when it's turned on.
Right could be a Mullard. Easiest spotting of a a Mullard is if the heater flashes very bright briefly when it's turned on.
There's a decent amount that can be discerned by looking at the top of the glass. European tubes will usually have 2 or 4 seams in the glass, while American tubes will have none. Some German tubes will also have no seams, but the shape of the top of those tubes will be very straight and well formed, while the American tubes won't look nearly as neat.
teamrushpntball
New member
Quick question for everyone, I picked up a Philips Miniwatt E80CC and think something is faulty. I was under the impression the gain was higher with these than standard EC82 tubes. Mine is incredibly quiet unless my volume is near maxed out. Is this normal?
