How are Mullards supposed to sound?


System: Rogers Studio 7, Prima Luna Prologue One, Marantz SA-8003

The stock (Chinese?) tubes in my Prima Luna Prologue One finally wore out after two years. The stock tubes sounded really excellent.

I decided to "upgrade." First to Electro-Harmonix tubes, which sounded decent but not as good as the stock tubes, and now to Mullards.

I know that tubes take a little while to "burn-in" but these Mullards sound awful.

They have a hard, clangy, echoing (microphonic) quality that none of the other tubes ever had. The soundstage seems to have receded backwards by a hundred feet. Everything sounds small and far away.

Is this how Mullards sound? I thought they were supposed to sound romantic. Is this all part of the "burn-in" process?
layman
You have experienced one of the pratfalls of tube rolling.You probably read about the "Mullard sound" and was expecting this with the tubes you installed,which are I suspect,reissues.The warm,lush "Mullard sound" comes from NOS or used old(original)tubes.You also found out you don't like the EH sound.I suggest,if you want to spend the money,trying some used or NOS Mullards.If you don't want to spend that much,and you already know you like the stock tubes,go with them.If you don't watch out,you will find yourself spending tons of money on tubes(I know this from experience).Good luck.
The cost of the NOS Mullards, if you can locate a quad, will set you back significant dollars these days, though possibly worth the investment. In modern production EL34 tubes my expermentation has repeatedly led me back to the SED "Winged C" EL34 tubes. A matched quad will set you back a little more than the reissue Mullards but are reveiwed to be closer to the original (NOS) Mullards than other tubes presently produced. I have tried the new production Mullard Svetlana, Tung-Sol, Gold Lion KT-77, and JJ and in the context of my system the SED tubes have sounded the best. There is also the option of the new Treasure 6CA7 (EL34 equivalent) that you could search the threads about as an additional option that I have no direct experience with.
Drrsutliff's post raises a question. It is logical to assume you are referring to the Power tubes as these usually wear out first. Are you referring to power tubes or the 12AX and 12AU's? Personally I select power tubes first and then fine tube the amp/speaker combo by selecting appropriate matching tubes.

FWIW I use SED EL34's recommended by Drrsutliff and I use EI 12AX7E's and JJ 12AU7's. For me it is the best combo for a warm yet fairly clean sound. A nice compromise using new production or with the EI's recent production. If I wanted to brighten it up a bit I'd try Tesla E34L's (now out of production) or their successors the JJ E34L's. Caveat - they may not be as rugged as the SED's. If you want something more linear with less mid-range warmth typical of EL34's but with better bass and highs you could always consider SED 6L6GC's. Depending on what I'm using for sources I've like these as well as the EL34's.

Hope that helps a bit.

The easiest and cheapest way to solve your problem would be to contact Jim McShane or Kevin Deal. They are tube dealers who are known for their knowledge and integrity. Kevin Deal sells the Prima Luna amps and has access to more NOS tubes (I think).

Either one will discuss with you what kind of sound you would like to hear from your amp and will suggest tubes that should get you there.