[MattTCG]

Is it normal for tubes to develop microphonics after a period of use? I've had a pair of Telefunken's that have been dead quiet with only about 70 hours on them and now I'm getting some noise from one channel. 

 

[gmahler2u]

HI>>
 
look at the pinched waist glass.
 
http://www.ebay.com/itm/Amperex-ECC88-6DJ8-Pinched-Waist-D-Getter-Preamp-Tubes-/291131783982?pt=Vintage_Electronics_R2&hash=item43c8ce7b2e

 

[MattTCG]

  HI>>
 
look at the pinched waist glass.
 
http://www.ebay.com/itm/Amperex-ECC88-6DJ8-Pinched-Waist-D-Getter-Preamp-Tubes-/291131783982?pt=Vintage_Electronics_R2&hash=item43c8ce7b2e

 
Who are you recommending these to?

 

[gmahler2u]

anybody, who has lyr?

 

[MattTCG]

^^ Ah, they are kinda pricey. Five days left and already $114

 

[Oskari]

  Is it normal for tubes to develop microphonics after a period of use?

 
http://www.youtube.com/watch?v=tGRZBa4cKWA   

 

[CJs06]

  ^^ Ah, they are kinda pricey. Five days left and already $114

Yeah those D getters tend to be expensive from what I've seen so far; though I'm not really sure why that is...

 

[gmahler2u]

This is Pinched Waist...it is rare item.

 

[satwilson]

I need some help interpreting the production codes at the base of my new tubes, one is: VR1, under that is R2H4. The second one is VR1/R2H1. They are RTC E188CC, Mullard made, backwards Z on bottom inside the gold pins. Bought from Radioman on Ebay. matched pair E188CC from mullard new in box , NOS 

 
 

    

 

[Tuco1965]

Take a look here.  http://www.audiotubes.com/mullcode.htm

 

[satwilson]

  Take a look here.  http://www.audiotubes.com/mullcode.htm

That was the first place I looked...I guess the complexity of what was presented was beyond me. That being said Brents website list VERY simular tubes for 3X the price. Please help I am new to this. I have seen other post's here refer to these tubes.

  Take a look here.  http://www.audiotubes.com/mullcode.htm

 

[gibosi]

> VR1, under that is R2H4. The second one is VR1/R2H1
 
VR = E188CC and 1 is the change code, which isn't all the important in this case.
 
R = Mullard Radio valve Co., Mitcham factory, UK
2 = 1972
H = month (August)
1 and 4 = the week of the month

 

[satwilson]

  > VR1, under that is R2H4. The second one is VR1/R2H1
 
VR = E188CC and 1 is the change code, which isn't all the important in this case.
 
R = Mullard Radio valve Co., Mitcham factory, UK
2 = 1972
H = month (August)
1 and 4 = the week of the month

Thanks for the translation. These are my first set of premium NOS tubes and even as they are just being burnt-in sound fantastic. Both Upscale Audio and Brent Jesse sell the same RTC/Mullard E188CC's for around $300. However on Ebay radioman( in Holland) and radioretail(Lithuania) have matched pairs NOS/NIB for around $100. Radioretail offers a lot of 100 for $3500. Apparently there are quite a few of these available at the moment. For those Lyr owners who enjoy the Mullard sound these are a fantastic buy.

 

[gmahler2u]

I prefer RTC/amperex e188cc year around 1960.  right now, it's my favorite after voskhod 74 gray/SWGP.

 

[Oskari]

  I prefer RTC/amperex e188cc year around 1960.

 
Please try to understand how ambiguous that is when brand names are relatively poor indicators of which factory actually made the tube. RTC and Amperex were both brands of the Philips group, RTC a French brand and Amperex a US brand. We can perhaps guess that you are referring to tubes made by Philips in Heerlen, but you could save us the guesswork by stating this explicitly.