Rft Tubes? Any Fans?

[MarshallDog]

When I got my 2204 it had all original Mullards in it. I tested the preamp tubes and removed the best sounding two and put them in my stash of NOS. Put the worst in V1 and then a Sovtek 12AX7WB in V2 and a 12AX7LPS in V3. I have all my best valves sitting in cardboard boxes LOL.
Have to time it right so I get to have them in my amps for the last 15 years of life and die when they do.
Judging by how long the Xf4's have lasted in my 2204 I think maybe they should be in there now
This is the 1981 2204, It sounds OK to me missing the two Mullards in the preamp.

Lol, I have some brand new =C= EL34s, NOS Jan/Ge 12ax7s and 2 NOS Mullard 12ax7s that are in stock and have not used. Maybe some day I guess. For now I really like EH, The Tube Store 7025s and Mullard 12ax7s

 

[MarshallDog]

I'm thinking the builders are getting circuits right that the choice of tubes is less important new vs old.

Buuuuuuutt! I've got old circuits that seem to matter tube wise.

I agree Bro!!!!

 

[thunderstruck507]

Well I got a Ultron labeled RFT 12ax7 on ebay for $30 shipped.

My 800 seems to really like it. I had the stock Marshall JJ in v1 before, the RFT is slightly lower gain but very very smooth and warm. It toned down the highs a LOT. I can now run the highs up at noon or even above, before anything over 10 oclock was very ice picky.

 

[Point 2 Point]

For my SV20
I took you all’s advice and got an Rft for V1 and JJ ECC83MG’s in V2&V3
Also put EL34-B’s in it.
Wow, it sounds great.
Sweetened up the top end, real articulate, midrange growl and punch.
Holds together .
Les Paul and ‘83 1H San Dimas Flat Top.
Into a 2061CX w 2-Purple Haze

Thanks for the great recommendations

 

[yladrd61]

Their EL34s Rock !!!!

 

[Acvox]

I'm a big fan of RFT valves. The Siemens RFT EL34 is one of the most stable, long lasting
and punchy sounding EL34 I've come across. It's a personal favourite of mine in both of my Marshall heads.

The 12ax7 RFT is the toughest 12ax7 I've come across. The abuse this thing can take is unreal.(treble boosted AC30) It's consistently med to high gain, with a very musical midrange, with negligible microphonics. It's not especially bright but imho not as dark as some claim it to be.

If you find a reliable source, I recommend you try some if only to satisfy your curiosity, they just might be what you've been looking for.

 

[David Szabados]

RFT El-34s are really nice, but have gotten pricey. I have a set in my old Super Lead, but with master volume models, those amps are less picky for output tubes as I don’t drive them as hard. So I save money and get EH in my basic 2203/2204.

 

[Acvox]

According to some accounts of Marshall history, Tesla replaced Mullard in the '70's. Did Marshall include Siemens RFT alongside Tesla to meet the demand for Marshall amps ?

When I bought my 1973 Marshall 50 watt head, from the original owner, he declared that all the valves were original, and unchanged from the day he bought it new in '73.
It was really interesting to find that all of the valves were Siemens RFT EL34' s and RFT 12ax7's.

 

[Acvox]

It just hit me that all Marshalls for the US market were 6550 types. Doh!

 

[Sg-ocaster]

Note to you rft 12ax7 guys(me included) they have fragile bases and are known to crack between the pins when handled roughly pulling them in and out of amps. So be extra careful....rock them in/out slowly and easy with little pressure......cracked one befor myself....but it didnt lose vacuum luckily.

 

[yladrd61]

It just hit me that all Marshalls for the US market were 6550 types. Doh!

A lot of them have been converted to EL34s, also quite a few UK spec Amps did make it to the US.

 

[yladrd61]

My

According to some accounts of Marshall history, Tesla replaced Mullard in the '70's. Did Marshall include Siemens RFT alongside Tesla to meet the demand for Marshall amps ?

When I bought my 1973 Marshall 50 watt head, from the original owner, he declared that all the valves were original, and unchanged from the day he bought it new in '73.
It was really interesting to find that all of the valves were Siemens RFT EL34' s and RFT 12ax7's.

My '78 UK Spec 2203 still had the original Mullard's when I got it.

 

[Acvox]

My

My '78 UK Spec 2203 still had the original Mullard's when I got it.

After reading your post, I made some enquiries and your quite right. The very last Mullard el34, were used at this time. This information is accurate, but on the surface contradicts the testimony of those with both Tesla and RFT tubes in their mid 1970s Marshalls.. What are we to make of this? Im really not sure, but dont you find this absolutely fascinating?

 

[yladrd61]

The '70s were a very turbulent decade, the technology was changing, more automation was becoming the norm in manufacturing, many new environmental and workplace safety rules and were being implemented. It was the beginning of the end for vacuum tubes as things were increasingly using transistors and tubes were also still being used in medical and military equipment. Marshall was never known for consistency and neither were many of their suppliers. It was also a time when many guitar amps were being hacked and modified. It is amazing to me that this amp made through that period without being modified in any way. And as another quirk both the chassis and and data plate for this amp say it is a model 1992 Super Bass, it is clearly a U.K. spec 2203 Mk 2 Master Volume Lead Amp with an SL/A serial number, it also still has all of the original electrolytic capacitors. And ironically it currently has a quad of GT labeled Tesla crossed OO getter brown base EL34s in it

 

[Mourguitars]

I got willed these from a friend who passed last year.....he loved these old tubes in a Phaez amp in a HRM 10w in V4 it looks like....i have backups of backups in all the tubes he left me with notes on why each tube goes where and why.....i bought 2 so i think i have 8 in total....i havent tried them in my Ceriatone 800 yet tho....i have the Hot Mod in that position V2.....

Mike

 

[StingRay85]

According to some accounts of Marshall history, Tesla replaced Mullard in the '70's. Did Marshall include Siemens RFT alongside Tesla to meet the demand for Marshall amps ?

When I bought my 1973 Marshall 50 watt head, from the original owner, he declared that all the valves were original, and unchanged from the day he bought it new in '73.
It was really interesting to find that all of the valves were Siemens RFT EL34' s and RFT 12ax7's.

Blackburn produced EL34 up until 1980. Two years ago I flipped a 100% original '81 Marshall 2104 that had Xf4 Blackburns in it

 

[cyberpunk409]

I just purchased these on eBay, they haven't arrived yet...



Are these RFT tubes? I can't find too much on the internet.

 

[Tatzmann]

Yes.

 

[cyberpunk409]

Yes.

Is there a difference between these and ones that are branded RFT?

I got them as NOS from an eBay dealer with thousands of reviews, all 100%

They were pretty "affordable", well I guess that's relative, so I'm not sure if they're exactly the same as RFT branded tubes?

 

[Georgiatec]

Is there a difference between these and ones that are branded RFT?

I got them as NOS from an eBay dealer with thousands of reviews, all 100%

They were pretty "affordable", well I guess that's relative, so I'm not sure if they're exactly the same as RFT branded tubes?

Nope. Lots of companies re-branded RFT tubes. Mazda, Zaerix and Bentley are common, but there are many more.