Upgrading my Sovtek 6922 vacuum tubes

Correction to my last post...

The Mullard Mitcham dimpled disc getters were E88CC's (not ECC88's/6dj8's).

I only came across 3 of them when purchasing lots of tubes on Ebay 18-20 years ago, so assume that they are fairly rare.

Two were labeled as Philips SQ (but the etched markings defined them as Mitcham production).

The other (3rd) one was labeled with the standard Mullard (non military) logo of the late 60's (early 70's?).

Think I may still have the single "Mullard" labeled tube somewhere (the SQ pair were quickly destroyed in an AI preamp as I did not know better @ the time).

Just to set the record straight for future Googler's.

PS:  I was never a tube dealer, just and experimenter/roller who purchased gobs of tubes when the prices were reasonable.

The most I ever asked for a matched pair of new testing 7308's (Siemens/Amperex/Telefunken) was $90 and 6922/6dj8's went for considerably less.

Karma paid off as I'm now rich, famous and extremely sexy.

DeKay

I'm on the same quest, the reflektor silvers and vokshods are great and inexpensive, aside of that look for German production Siemens

Small tubes when NOS could be great but noisy (especially when used in phono stages) which is the defacto typical application, using these in high gain stages you need to be sure they are not noisy (I don't say strong because a valve can be strong still noisy)

Hi,
a note for putting an ecc88 where the circuit requires e88cc. They will not last long as their anode voltage is considerably lower compared to the one in e88c/e188cc. Check your amp for this. If your amp is made for running an E88cc then you know why ecc88 is getting noisy after a while, even if some of them sound better in the mids compared to their expensive cousins.
Russian 6n23p and 6n23p-ev have even higher anode voltage figures than a E88CC/E188CC and can take a lot of punishment in a circuit.
Mullards dimple discs appeared in 1969, Mitcham factory only, as E88CC/CV2492, CV2493 (equivalent to Cca) and E188CC.

Petg60:

Mullard Blackburn produced dimpled disc getter ecc88/6dj8's.  

They are more common than the Mitcham (ddg) e88cc/6922, and they have a fuller sound than the Holland (ddg) ecc88 production.

DeKay 

Petgo60:

PS:

Your warning about using ecc88/6dj8's in an e88cc/6922 design is a good one, but it may only apply to a few popular companies (and their designs) which ran the 6922 type especially
 hard (otherwise known as tube eaters).

Off the top of my head this would be ARC, Sonic Frontiers, later CJ's and Audible Illusions*.

The older AI preamps (due to their design from what was explained to - which was over my head) were privy to AC line voltage in this respect in that a higher line voltage feeding the unit the harder on the tubes.

This may explain the wide opinions of what tubes can and/or will not last in the units.

There are also old production ecc88/6dj8's which do survive in some of these supposed tube eater models (Siemens/Tungsram come to mind) that I used in ARC and AI units with success.

However, the problem with both was that I (and the owners) did not care for the sound which was harmonically dry.

Best not to write off the use of vintage 6dj8's (in a 6922 design) on anywhere near a whole as they may very well be fine/long lasting in gobs of gear.

DeKay