[gug42]

At this price, not worth it to test new production ? cv-181 TII and Z ?

 

[Makiah S]

Hey guys I goof'd and bought an un measured un tested tube, I really have no desire to put it into my Amp without knowing how it measures. What tests can I do with my multi meter to ensure that it's... safe to plug in?

 

[attmci]

Not a bargain. You can get a properly matched pair tested for noise, etc., for not a lot more than $176.

It's a bit of a gamble how he's selling them.

Sir, you mean these?

http://www.ebay.com/itm/222531131104?rmvSB=true

 

[winders]

Sir, you mean these?

http://www.ebay.com/itm/222531131104?rmvSB=true

That is a crazy price for those tubes! Sylvania 6SN7W tubes are nice, but not $280 each nice!

 

[Tim Le]

Does anyone have experience with the new PsVane tubes? They look nice, but how do they sound?

 

[Seamaster]

Need some help here. There are few versions of Mullard CV181. Do they sound different? Which version to get? Thanks.

 

[BearMonster]

Does anyone here have experience with the JJ 6Sn7?

 

[Frihed89]

No, but I have an opinion anyway. First of all, if you are using the tube as a driver in some circuits - esp. the cathode follower - the driver doesn't effect the sonic signature, apart from the tube's electrical characteristics. In that case, a $18.00 6SN7 won't sound any different than a $150 one. As an output tube, the story is different, and all I can say is: avoid the expensive Chinese tubes. Buying used (or "NOS") tubes off EBay is a mine field. Avoid it. Talk with a reputable dealer. I recommend Jim McShane (google this) or "Byrd" at electrostatic69@twcny.rr.com. Of course, there are others. Another alternative is to buy a 7N7 GT or GTB and an adapter. It is electrically similar to the corresponding 6SN7 model. They were all made by Sylvania. Great tube. Good luck.

 

[Makiah S]

No, but I have an opinion anyway. First of all, if you are using the tube as a driver in some circuits - esp. the cathode follower - the driver doesn't effect the sonic signature, apart from the tube's electrical characteristics. In that case, a $18.00 6SN7 won't sound any different than a $150 one. As an output tube, the story is different, and all I can say is: avoid the expensive Chinese tubes. Buying used (or "NOS") tubes off EBay is a mine field. Avoid it. Talk with a reputable dealer. I recommend Jim McShane (google this) or "Byrd" at electrostatic69@twcny.rr.com. Of course, there are others. Another alternative is to buy a 7N7 GT or GTB and an adapter. It is electrically similar to the corresponding 6SN7 model. They were all made by Sylvania. Great tube. Good luck.

Not entirely true, but caution is needed as is a very good return policy, I do most of my purchases on eBay for tubes,but I often need to do 1-2 exchanges as I'll get some in MUCH worse condition that what's been measured an or reported,

I do like the dedicated dealers more though, much easier to work with and a lot less hassle. Still if you can work through the disaster of eBay you can get some great sounding Tubes for a bit less some times. Still you need to tread very carefully with eBay sellers

 

[attmci]

No, but I have an opinion anyway. First of all, if you are using the tube as a driver in some circuits - esp. the cathode follower - the driver doesn't effect the sonic signature, apart from the tube's electrical characteristics. In that case, a $18.00 6SN7 won't sound any different than a $150 one. As an output tube, the story is different, and all I can say is: avoid the expensive Chinese tubes. Buying used (or "NOS") tubes off EBay is a mine field. Avoid it. Talk with a reputable dealer. I recommend Jim McShane (google this) or "Byrd" at electrostatic69@twcny.rr.com. Of course, there are others. Another alternative is to buy a 7N7 GT or GTB and an adapter. It is electrically similar to the corresponding 6SN7 model. They were all made by Sylvania. Great tube. Good luck.

Really?

 

[wataga123]

Looking to identify this pair of Amperex 6sn7gtb's. I know they are most likely relabeled. Amperex orange world logo. Carton says country of manufacture is stamped on tube, this case it says made in USA. Possible date code 0-40 on both. 1960? 1950? Halo top getter, round mica with 6 spikes, black plates, (t plates at slight angle to each other?) 3 holes but then 2 more holes on outer edge. GE or Sylvania?

http://imgur.com/a/YH3Ak

http://imgur.com/a/h4BSj

 

[Oskari]

Looking to identify this pair of Amperex 6sn7gtb's. I know they are most likely relabeled. Amperex orange world logo. Carton says country of manufacture is stamped on tube, this case it says made in USA. Possible date code 0-40 on both. 1960? 1950? Halo top getter, round mica with 6 spikes, black plates, (t plates at slight angle to each other?) 3 holes but then 2 more holes on outer edge. GE or Sylvania?

Sylvania. 1950 is too early for GTB. The type was introduced in 1954.

 

[JimL11]

Agree, probably Sylvania, date code could be for 1960. Sylvania had plates at an angle, GE were facing each other. Also GE had side getter, Sylvania had top getter.

 

[Blueshound24]

No, but I have an opinion anyway. First of all, if you are using the tube as a driver in some circuits - esp. the cathode follower - the driver doesn't effect the sonic signature, apart from the tube's electrical characteristics. In that case, a $18.00 6SN7 won't sound any different than a $150 one. As an output tube, the story is different, and all I can say is: avoid the expensive Chinese tubes. Buying used (or "NOS") tubes off EBay is a mine field. Avoid it. Talk with a reputable dealer. I recommend Jim McShane (google this) or "Byrd" at electrostatic69@twcny.rr.com. Of course, there are others. Another alternative is to buy a 7N7 GT or GTB and an adapter. It is electrically similar to the corresponding 6SN7 model. They were all made by Sylvania. Great tube. Good luck.

So I have an Icon Audio HP8 MKII but know very little about tube amps/preamps and whether the 6SN7’s are drivers or other. Regarding this amp, would you say the 6SN7 are more important or the ECC83/12AX7 to the quality of the sound? Which tubes should I invest more in, (6SN7 or 12AX7)? Or do they affect the sound equally? Any recommendations for upgrades for either?

It came with 2 - David Shaw CV181 x 2, but right now I’m using 2 - CBS JAN-CHY-5692 brown base, (6sn7), and one Amperex 12ax7 made in Holland (Hammond).



http://www.iconaudio.com/main-products/icon-audio-hp8-mkii/
https://www.innerfidelity.com/content/icon-audio-hp8-mk2-tube-headphone-amplifier
We use two Class A valves with high quality output transformers that provide ideal matching to almost any headphone type 30-600.

The power supply has generous mains transformer two custom output transformers. The HP8 MK II is a heavy 7kg, and very solidly made, giving you an idea of how much iron you get for your money!

Like our other models the HP8 MKII has no printed circuit board and is all hand wired with top quality components. We use silver PTFE audio cable, gold plated terminals and the famous “ALPS” volume pot for sonic purity.

The front valve is the excellent ECC83/12AX7. this has exceptional detail and fluidity. It complements the super 6SN7 (the best hi fi valve ever?). This combination will give you a simply stunning insight into inner detail of your favourite recordings whether analogue or digital.


· All hand wired point to point
· No printed circuit board to ‘colour’ sound
· Japanese Blue ALPS volume pot.
· Class A, all Triode circuit
· Output impedance matching from 6 to 600Ω
· 2 x 6SN7 for output 1x ECC83/12AX7 input valve
· NOS, Treasure and Full Music types available
· Signal to noise level -90db
· Freq response better than 20hz-20kHz +0 –0.2db
· Total harmonic distortion typically less than 0.2% 1khz
· Also Suitable for ≥ 8 ohm high efficiency loudspeakers
· Japanese steel EI transformers with low oxygen copper
· High quality 2W metal film, & wire-wound resistors
· Solen audio capacitors, Jensen upgrade available
· Custom hand wound output transformers
· Ceramic valve holders for minimum leakage
· Silver PTFE audio cable
· Gold plated Input/outputs
· One line input
· Loop through facility
· 350mv input sensitivity.

 

[wataga123]

Thanks for the quick replies. They are marked gtb and so are the boxes. I'm gonna say 1960 era.