Tube advice

I'm thinking about replacing the tubes in my x-10d (Musical Fidelity). Now I know nothing about tubes-I believe the type used is Philips 6922's-I got this from another news group.2 questions. 1.Does it have to be exactly the same serial number or is there a generic form which this number relates to and therefore others I can use? 2.Obviously I'm thinking about changing with more expensive tubes-I'd seen Telefunken mentioned-is it possible to make a major mistake with the more cash is better theory? I appreciate there may be a degree of subjectivity involved in the latter question. Any help appreciatted and thanks in advance, Ben
Try Svetlana's.Have them in my CJ Prem 16LS.They sound great and have gotten good reviews.Maybe someone who has experienced them can second my motion.Thanks.
6922's are also marketed as 6DJ8's. I've had good success with Sovteks, check out Audio Advisor for a selection...
Tou might want to also check with Kevin at for availability.
As to your first question, there are others you can use. I suppose the closest thing to a generic name for this family of tubes is the "6dj8 family" of high transconductance twin triode tubes, which includes the 6dj8, 6922, and 7308 tubes. The European equivalent names (someone correct me if I'm wrong) are the ECC88, E88CC. and E188CC. Also compatible to a certain extent is the Russian 6n1p. The 6922 was marketed as a premium industrial version of the 6dj8, and the 7308 was the top of the line guaranteed low noise version. However, I don't think there is much agreement as to whether 6922 and 7308 designations correspond to actually better sound than a 6dj8. As to your second question, I think it is most definitely possible to make a major mistake with the "more cash, better sound" theory. Certain tubes will sound better in certain applications than others, but that depends both on the component used and the user's preference. I do recommend you avoid the Sovteks if you are looking for better sound - I'd take the Philips tubes you already have. The best thing you can do is talk with a dealer who has experience with the tubes in your particular application. Kevin Deal of Upscale Audio is well respected in these circles as someone to go to, but (again, correct me if I'm wrong) for the time being he is only selling 6dj8 tubes to customers who actually bought their components from him. However, his web site is a good source of information. Another good source of information is the audioasylum tube FAQ ( It contains a list of dealers, and some reviews of the 6dj8 family. From my personal experience, I'm a fan of the Amperex 7308's, but its getting to be tough to find. I also recommend Mullard 6dj8's/6922's. I find the Telefunkens to be a little overpriced for the sound quality offered, but that's based on admitedly limited experience. Best of luck in your tube search!
I agree with the stay away from Sovtek.I replaced a Sovtek 6922 with a Valvo Ecc88/6DJ8.Huge improvment.There are other good replacments.Siemens e188c is great if you can find them>Try the boys the The Parts Conection.Also Kevin at upscale is very helpfull.
Thanks for the advice guys. Only problem I have is I stay in the UK and prefer to buy from there especially with valves. However there are plenty of dealers here. Thanks again. Ben
6922 is an industrial number for 6DJ8 with specific performance requirements to be so designated. 7308 is an even better version of the same tube. Amerex PQ ( premium quality ) 7308's had gold plated pins. These Amperex PQ 7308's are my favorites. A little detective work may yield good results in finding some excellent 6DJ8's. Try to find some New Old Stock (NOS) examples. Best of luck in your quest.
I agree with Rfraudio. I just received my Amperex PQ 7308's for my Melos Maestro preamp. I swapped out the Sovtec 6922's for the 7308's and found a hugh differance in sound quality. Love the Amperex PQ 7308's.
I have just replaced my Valvo ECC88 with a siemens 7308/Ecc188.The improvment was fantastic.I swapped it out and latter that day the wife sat down to listen to some tunes.She looked at me and said,how much cash did you drop.The sytem sounds amazing.She figured i had droped some serious cash into it.When i told her it was 70.00 tube she could not believe the difference it had made.I had a freind recomend it to me.He said he has tried every variation in the 6DJ*/7308/ECC88/Ecc188 family.His advice was save your self time and money the Siemens 7308/ECC188 must have the ECC188 designation its the best one you can get.