Rickresource Rickenbacker Forum

I have just had my SVT3 re-valved.(for the uninitiated the SVT3 is a 5 valve pre-amp coupled to a 450W transistor power amp...your back will appreciate this amp!)
Thats four 12AX7 Electro Harmonix tubes and one Phillips military spec.NOS 12AU7.
I went on the Ampeg website just to see what they recommend regarding wear and tear.
They reckon on 3 years...mine have been in for 6 so I thought it best to get some new ones!
I have a rehearsal tonight and we will see how it sounds.
The guy that replaced them gets his stuff from Watford Valves (they often advertise in the back of Guitarist Magazine) and the bloke who runs Watford Valves happens to be an Ampeg SVT owner too and he has some NOS 12AU7s that he reckons to be the business. The boxes still have the Army designation on them.
Interestingly seeing how Ampeg recommend Groove Tubes only ONE of the pre-amp valves was in fact a Groove Tube. The rest were Sovtek and the 12AU7 was a Chinese one.
I should be able to get more gain now so I will report back tomorrow.

I saw a thread about replacing tubes in SVTs a while back and its one of those subjects that almost all bass players have opinions on so I would be interested in any thoughts and experiences forumites have to offer.

Happy new Year by the way!....Airports never close so I havent had any time off over the last few weeks...just catching up with everyone.

I have read not to use chinese tubes (valves) in anything . I think your amp will be very happy now .

Pete, I've also got an SVT 3 Pro. It is a LOT lighter and easier on the back over my SVT 2 Pro!

I retubed my early 90's 3 Pro with NOS black plate RCA 12AX7 tubes, because I had some. I also put in a 5963 (heavier duty 12AU7 - more current capability) in the 12AU7 driver position. These replaced the stock tubes - Sovtek 12AX7 tubes and an SLM (Ampeg) branded 12AU7.

Tonal differences - I found the Sovtek tubes dry and brittle sounding. The RCAs bring a deeper, bassier flavor to the sound. I noticed more punch factor with the 5963. I also have these same tubes (RCA and 5963) in the 2 Pro (same front end on that one with tube outputs) and when I got it from an engineer at Ampeg in St. Louis, it had just been factory retubed with Sovteks. Same change in sound when I put in my tubes. Of course the 6 output 6550 tubes have even more punch or jump effect. Hard to put into words, but comparing the 300W tube power against the 450W of MOSFET power in the 3 Pro, the 2 Pro is more tight, responsive, startling, boomier, you pick the word. To me, tube watts sound louder and punchier than solid state watts. Say what you will, I hear and feel it when playing. Comparison is with the same bass, cable, and speaker and cable, just the head change. Settings as same as can be as controls are almost identical between the two.

Hope this helps. I will be interested in reading your report after your practice. Oh, the 3 Pro and my '75 4001 sound really great together. I haven't tried it with the 2 Pro as the 4 ohm cab is at my buddy's house and with winter, it's a ***** to move that 80 lb. tube head!

Thanks for that John.
The sound was way better last night with more grind and the thicker bottom end that you described.
We are starting to put the first rehearsals of Ritual together for the summer( theres tons of harmony work to do ) and its THAT sound coming from the Ampeg now.
I know what you mean about the SVT2 its a great sounding amp and if funds allow I might be getting one second hand eventually.
I used an old Hiwatt all valve power amp when I was in a Who tribute band and theres no replacement for a totally valve driven sound.
We played a real scruffy biker pub one night and I had my Fender Bassman stack linked to the Hiwatt stack. During sound check I thought it didnt sound right and realised the Hiwatt was still on standby so I flicked the switch and we we played Substitute.Next thing the landlord came running into the room from upstairs complaining that his dinner had bounced off the table!
THATS a valve sound for you!
Cheers John,
Pete.

aceonbass wrote:If you can swing $60-$80 bucks a pop, nothing beats NOS or even used Telefunkens.

I would think by now, all REAL NOS Telefunkens are gone. They have been in demand for decades (audiophiles) and I would think all would be gone by now. I personally would be very wary of tubes touted as that brand.

Pete, great story! All tube is a thing to reckon with, but having a roadie to schlep the amp is almost mandatory! How I came upon mine was a quirk of UPS and Guitar Center. I had bought an SVT 2 Pro Special Edition (like the upper one in Chris' amp rack picture that was on his old site) and the idiot in shipping did a terrible job of packing it and when it got here, the 1/4" aluminum faceplate was all bent, the back corner all bent, the frame jogged/bent, and the fuse blew. I looked at it and could not see how it was blowing fuses. I called Ampeg to see if I could get a chassis to rebuild the amp, and the tech I talked to was the guy in charge of the assy. line that built the amp! He said there were no parts to be had, but if I called him on his cell, we could talk. Turns out he had a newer 2 Pro just factory retubed that he was selling. I got it for a very decent price, actually $100 less than the one that was damaged. It has been a great amp.

Best of luck with getting "Ritual" down for live performance. It would be great to see Seyes perform. Let us all know if a USA tour is ever in the works.