Sirspeedy.. Ediswan did not munfacture tubes. They are an English company that rebrands tubes sourced from many tube manufacturers and suppliers. I have a quad of ecc88's branded ediswan that are actually late 70's seimens. I also have Ediswann branded ecc 82's, ecc802's, ecc83's ecc808's and others. Some are Mullard made,some Brimar made, some eastern block german RFT's,some holland made etc,etc. The good thing here is your Ediswan tubes are non microphonic low noise preamp grade tubes. That said....chances are that any nos PQ labelled Amperex 7308 [white label, orange label, US manufacture or Holland maufactured tube should handily better your Ediswan labelled 6dj8's if they are non microphonic low noise equivalents. The early Holland made white labell ecc88's {both D-getter and O-getter versions} should walk all over your ediswans in every which way. Quiet examples of these tubes tubes are in a whole higher order than most any tube of it's type ever produced. Warm,smooth,great bass resolution with an airy soundstage akin to the hideously expensive siemen and telie CCA's. You haven't mentioned the Phono stage or catridge you are using and most modern phono stages are voiced with currently manufactured tubes so your mileage may vary with your choice of nos tubes. In my experience... Most any brand of pre 70's ecc88 family of tube will step all over any tube manufactured after 1980 regarless of manufacture. Note: Ediswan relabelled and reboxed sovtek 6922's as well as the 6h23ev. These are not the same tubes even though they were manufactured in Russia. The 6h23ev's were manufactured strictly for the Soviet military and were never ever seen until the fall of the BIG RED Machine. Now, I suppose they can be called nos tubes....none the less, they are very good souding valves, very linear with tight triode sections, great bass and the quietest tubes in the 6dj8 family. Not to be confused and no resemblence to the glassy,glarey sounding Sovtek 6dj8/6922.
