Thread: GZ34
View Single Post
  #2   Report Post  
Posted to rec.audio.tubes
martin martin is offline
external usenet poster
 
Posts: 1
Default GZ34

On 2017-04-22, Frank Lucas wrote:
So I've decided to buy two brand new JJ's GZ34 for my two mono 2A3 amps.
JJ's are cheap and I thought that if they were to last a few months
before selling the amps they were good enough.
I replaced the old chinese Golden Dragons (5AR4) and everything worked
flawlessly. The sound was a bit thin but I thought it was just matter of
waiting a few days for the tubes to express themselves better.
Then when I was going to leave everything as it was and replace the amps
with the love of my life the Dynaco ST35 ...

A friend stopped by with a bag of old Mullards GZ34 to put in those amps
and the something really strange happened.

I always prefer double blind testing, I'm an atheist, I don't believe in
cable magic or snake oil or in Bolduc's mystical runes and I trust my
ears more than my eyes.

The difference between the sound with the JJ's and the one with the
Mullards is so clear that even being in another room you could feel the
change. Dynamics, bass response, sweetness ... I was stunned.

The difference when we tried to swap the humble Guiguang monoplate 2A3Bs
with the pricey AVVTs was almost inexistent apart from the latter being
too metallic and so the worst of the two. Great difference was achieved
instead when we tried a couple of Marconis NOS.

Further investigation with the use of a scope and a signal generator
showed that with the Mullards the sag was less and recovery was faster.

Would a couple of solid state rectifiers with a properly calculated
series resistances and maybe a standby switch act better than the mighty
Mullards?

The 35 is still on a shelf waiting ...

Are there any brand of GZ34 or 5AR4 that resemble the sound of the
Mullards or in other words that act electronically like Mullards?

I cant answer that question but I am interested because in the 60's
in fact from 65 to 71 I worked in the Mullard stores in Mitcham
where lorryloads of valves used to come in unmarked, apart from
a datecode round the base, which i dont remember any more, we always
knew they were the best. THe only equivalents in those days were
Russian valves, which were used in some marine equipment.
I has been interesting reading these threads, and i still have a
copy of Radio Valve Data from 1961.

--
Martin