Since you are just starting out with these amps, I would suggest the Svetlana (SED) flying C. They are very reliable and produce a fairly balanced tone. The KT90's may have tighter bass and maybe a bit brighter tone - my biggest reservation is about the reliability of current production KT90's. Sonically, its your choice.
I used Ei KT90s in my Elevens very succesfully. They seem to be loved by many.
Enjoy your Eights; they're fabulous amps
BTW, I think you meant 'retubing'.
I'm sure you meant 8 per side. I also say, use the old tubes to get a fix on what they sound like---then you will notice the dif. when you do retube.
Fernando,the friend of mine using the Premier 8 is a former reviewer for TAS.I had the retubing discussion with him,and,he continues to use the tubes supplied by CJ themselves.He had spoken with Lew Johnson who feels the stock tubes are fine.This is not to say that tube rolling won't be better,but it could save you some money,as well as the possibility that you may actually get best performance from CJ's own stock.
I'd be surprised if c-j is selling their presumed-selected-and-burned-in 6550s for less than the $70 per pair you can buy Ei KT90s for.
Thanks to all for your feedback.
I have a quotation from CJ at about $650 per amp for a full retube set, those are GE if I am correct.
I also have a friend who can get Svets 6550c, which some say have the best sonic behaviour in terms of tonality and dynamics, this route will cost mearound $500 for both amps.
I currently have Sovteks 6550, sounding great to my ears but at the end of their operational life.
Thye prem 8a's sound just fine with the Svetlana 6550's. Lew Johnson strongly recommends them.
I have also used EV KT88's and they sound slightly different. They are a little leaner in the bass so give the impression of slightly more extension.
I would listen to the amps as is , then make a decision on how it integrates into your system.
Downunder -I´ve done that and really liked the sound of the Premier8, I was just wondering tube recommendations for the neccesary re-tubing this unit needs shortly.
Since the Avalons does not go that low, I think I will lean towards a more robust sounding tube, looks like the 6550 is such a ticket.
If you're about to spend a perhaps over a thousand dollars on tubes, spend a few bucks on the recent issue of 'Vacuum Tube Valley' that has MUCH info on new and old 6550s/KT88s/KT90s.
A 2-amp set of Ei KT90s from The Tube Depot would be $560.
Fernando, I don't know where you are getting your price quotes, but I just check the web site of Triode Electronic's. He is selling matched quads of SED (the old Svetlana brand) for 95.90. According to my calculations that would bring the cost of retubing your amps to less than $400. I've used him many times. Very reliable and the product is guaranteed. I'm using these tubes in my amps at this time - I've yet to have a premature failure.
I guess the retube price includes the 12 driver tubes 6fq7 (8)and 5751's(4)----These make a big difference to be sure.
CJ quote came from the company itself (they have been very supportive, kind and informative), again - it would be around 600 US per amp.
The Svet 6550c quote comes from www.sovetk.com, under Svetlana section, my friend has dealer pricing and kindly passing thru.
I am NOT including the driver set, which look OK.
I need to take a decision in the next 48 hours or so (flying to Detroit on Sunday from Mexico) - I have the feeling that I will run the "risk" of re-tubing and keep the Premiers 8 for me.
Believe me the drive tubes matter, more than you think.When you finally get around to getting some cryoed ones;you'll understand.
I would concurr with avguygeorge on the influence of the input and driver tubes. That said: Both the 6fq7's and the 5751's in the amplifiers should give you at least 3000 hours of life before replacement [unless they go noisey or microphonic]. The nos triple mica sylvania 5751's as well as the rca triple mica black plates can have a profound impact on the resolution and bass drive in the CJ amplifiers.
I was placing more focus to the output tubes, thanks for the info.
Do you still own these amps? I am breaking in these amps which I just purchased with new tubes from CJ. I am not very happy yet with the sound as they need to break in! What pre amp and speakers have you chosen with these monos?
When I had my 8's, I used a CAT-3--(10 tubes in that). Just before tuning my estate to my local DWP--- or my tube supplier---I sold the big-8's.--Now use CJ's 350 ss amp and may not have to go under. (I listened way more than some !!)
---Which made it costly.-- I could use up 3000 hrs in a week, and I never exaggerate.
I sold the amp a few years back - I partnered it with many preamos - the best option was a CJ Premier 11 - a little dark sounding - best sound came out from 16 expensive KT88 I got from the UK - (cant remember the make) but are quite famous.
Worked great with my previous Avalon Eclipse speakers.
Hope this helps