Preamp Valve Test (JJ, Groove Tube, Tung Sol and Mullard )

[PhilKing]

Yesterday gwEm was over to check out his new V90 and I picked up my other Ceriatone (an Overtone Special).  This came with no valves, but Nik had mentioned that he uses the new Tung Sol reissues in the preamp.  I had picked up a set of TAD 6L6WGC-STR's for the power valves as these are supposed to be the best sounding in Dumbles (and clones!).

I also had my JTM45/18 which came with JJ ECC83S's (and an EH EF86).

We used an Ear Candy Sweet tooth 2x10 with Eminence Ramrod & Lil' Buddy and also TO's original Hiwatt 4x12 with Fane's (a monster of a cab!).

After a bit of playing through the Sweet Tooth we swaped the Overtone to the Hiwatt and gave it a blast, but the sound left quite a lot to be desired, it was too bassy.  We switched to the JTM45/18 and the tone was much better.  

After a bit we started to talk about pre-amp valves and I pulled out the collection that I have.  I had some new Mullard reissues along with Goove Tube and originals by Mullard, RCA, GE, Mazda, Sylvania, and others.  We replaced the JJ's in the JTM45/18 with Mullard reissues and fired it up.

WHAT A REVELATION!!!! The amp was just pure early 60's/70's Marshall using the TMB side, while still keeping the Voxy tones of the EF86 side.  With the Hiwatt it was a tone monster - the neighbours must be deaf (though probably they haven't got their hearing back since last year when TO was tracking guitars at my house using his Splawn).

Having heard the difference that the Mullards made to the JTM45/18, we looked at the Overtone.  I only had one Mullard ECC83 left, but had a lot of GT 12AX7-M's, so we decided to go with them (the construction of them seems to match the original Mullards more than the new Mullards do, though I know there have been various versions of the Mullards).

Once again it opened the sound up, but not with as dramatic a change as the Mullards had with the JTM45/18.  Now though the Overtone was working with the Hiwatt and when you switched in the boost and Overdrive, there was great harmonic feedback.  We then tried replacing V1 with the other reissue Mullard, and the sound opened up even more.  It gave a much more musical tone, with better definition and less 'biting' treble.

Having tried the variations, I need to get a few more Mullard reissues, just to see what replacing the V2 & 3 will do to the sound.

So in order of preference we both liked:

Mullard reissues
Groove Tube 12AX7-M's
Tung Sol reissues
JJ's

Just to put it in context though, the JJ's had sounded good until they were changed for the Mullards.

[TwilightOdyssey]

JJ Preamp valves are akin to Starbuck's coffee. Better than the cr@p you get from a street cart, but will not compare when stacked against a really good valve.

Sounds like a fun experiment. Can't wait to hear the Ceriatone.

[hunter]

I put a Mullard RI in V1 of my Bogner Shiva recently and it gave the whole amp a kick forward, dfinitely improved this amp big time.

In the VintageModern though the Mullard was no improvement, took away from the openness of the VM rather ...

[gwEm]

previously i'd considered JJs to be quite decent tubes, in fact it seems like theres alot better out there. those mullard ecc83 RI are amazing indeed - full and gritty sounding. the groove tube mullard copies were less rich, but still very nice, i think they might be good in a dark amp - as phil said they had quite a nice high end.

that dumbell clone is a gain monster :)

[hamfist]

What, no mention of the old tubes !!    Didn't you try the real deal old tubes you had !!

[LazyNinja]

Thanks for the report guys I was thinking of trying some new valves in my Laney and Ceriatone and this review is very useful. I was thinking of getting the Tung Sol RIs but I'll look into the Mullard RIs as well. They are a bit more expensive but if theyre that good I might get a few!

Were all the valves you tried 12AX7s? I heard that putting a 12AT7 in the PI position works very well so I might try that this time too.

ps. what's a JTM45/18?? Does it have the ability to switch between EL84 and EL34s or something??

[PhilKing]

ps. what's a JTM45/18?? Does it have the ability to switch between EL84 and EL34s or something??

See this thread:

http://www.bareknucklepickups.co.uk/forum/viewtopic.php?t=12696

The preamp is from an 18w TMB EF, and the power amp is a JTM45.  The other amp we were using is the Ceriatone Overtone Special (the Dumble clone).

[PhilKing]

I also tried the original valves today, these included Mullard short plates, Tungsram, RCA and and RCA 7025.  The reissue Mullards still have it overall, but the short plate Mullard is smoother in sound, more compressed than the reissues, which are long plates.  I am just bidding on some original long plates, so if I get them I will compare them too.  The Tungsram was good too, but again not as aggressive as the reissues.  The RCA wasn't as good, and in P2 the 7025 didn't push quite as much as the Mullard (or Tung Sol reissues).

[Ratrod]

Too bad the Tung-Sol RI pre-amp tubes aren't living up to their name.

I have tried the Tung-Sol 5881 RI's (power tubes) and those sounded awesome.

[lulusg]

Nice to hear that Phil about the Mullards, the Splawn Competition came with those Mullards, and they sound right on the spot as you said 60s & 70s... We got a 2x12 Eminence Red C. cab, for that awesome British sound... By the way I read that Steve Stevens will be playing a Quick Road on the next tour....lets see. Cheers!!!

[hamfist]

Out of interest I had a surf around to see who stocks the RI Mullards that you liked. Couldn't find anybody with them. Watford - no, Hotrox - no. Ebay - no.  Only dealers in the US.   Who stocks them in the UK ?

[JJretroTONEGOD]

I haven't had good experinces with groove tube valves, especially compared to JJs. It's an interesting experiment though, and I'm thinking of getting some NOS mullards just to see how much it will change the sound, they seem worth the extra money. Are the mullards 'dirtier' in tone?

[Twinfan]

Out of interest I had a surf around to see who stocks the RI Mullards that you liked. Couldn't find anybody with them. Watford - no, Hotrox - no. Ebay - no.  Only dealers in the US.   Who stocks them in the UK ?

Are they not discontinued?  Something at the back of my head says they're not made any more?

[gwEm]

Out of interest I had a surf around to see who stocks the RI Mullards that you liked. Couldn't find anybody with them. Watford - no, Hotrox - no. Ebay - no.  Only dealers in the US.   Who stocks them in the UK ?

Are they not discontinued?  Something at the back of my head says they're not made any more?

I'm not sure about this, just guessing - but I think the Mullard RIs are only officially available in the US. This might be total bullsh!t, but I seem to recall some deal with New Sensor's liscencing of the Mullard name was US only or non-Europe.

Are the mullards 'dirtier' in tone?

The Mullard RIs were pure grit.

[gwEm]

Were all the valves you tried 12AX7s? I heard that putting a 12AT7 in the PI position works very well so I might try that this time too.

Hearing this trick a while ago, I tried a 12AT7 in my 2204 head. I wasn't so convinced about it, but I do agree the PI valve affects tone quite alot.